An apparatus and method for ex situ sampling of deep soil fugitive gases

Abstract

The application provides a kind of deep soil fugitive gas's ex situ sampling device and method, and the ex situ sampling device includes static box, and soil sample barrel is arranged in static box, and the top of static box has first exhaust valve, second exhaust valve, third exhaust valve and fourth exhaust valve;First exhaust valve is connected to first high barrier sampling bag;Second exhaust valve is connected to activated carbon tube;Third exhaust valve is connected to porous glass plate absorption tube;Fourth exhaust valve is connected to second high barrier sampling bag.The application provides a kind of deep soil fugitive gas's ex situ sampling device and method, solves the problem that groundwater level is relatively shallow in some areas at present, and it is difficult to collect soil emission gas in situ;Soil samples can be heated at a set temperature, shorten the gas emission time, and improve work efficiency;A variety of malodorous substance samples can be collected simultaneously, meet the needs of simultaneous investigation of a variety of odor indicators such as sulfide, benzene series, amine, etc.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of gas sampling, and particularly relates to an ex-situ sampling device and method for deep soil escaping gas. BACKGROUND

[0002] In recent years, the problem of malodor (also known as odor) pollution frequently occurs in pesticide, petroleum, and chemical contaminated sites, which seriously affects the daily life and health of the surrounding residents. In the past, site investigation mainly focused on toxic and harmful substances in the site, and less attention was paid to malodor or odor substances in the contaminated site. If the odor substances in the soil are not treated, the odor substances in the soil will enter the air through volatilization in the later site construction and use process, which will affect the surrounding residents. Therefore, in recent years, soil odor investigation has been gradually required in the process of contaminated site investigation to determine the odor pollution degree and pollution range.

[0003] The existing odor investigation method mainly adopts an in-situ sampling method, which generally collects samples through the construction of soil gas monitoring wells or directly collects samples through a special soil gas drilling machine. However, due to the shallow groundwater level in some areas of China, the odor pollution mainly exists in the saturated layer soil below the groundwater level and is greatly affected by the groundwater, which cannot meet the requirements of in-situ soil gas sampling.

[0004] Therefore, in view of the problem that the groundwater level is low, the soil pollution depth is large, and it is difficult to collect the soil escaping gas in-situ in some sites, there is an urgent need to develop a new collection device and method. SUMMARY

[0005] The technical problem to be solved by the application is to provide an ex-situ sampling device and method for deep soil escaping gas, which has the advantages of simple structure, convenient use, easy installation and recovery, and good use effect, and can be widely applied.

[0006] To solve the above technical problems, the technical scheme adopted by the application is as follows: an ex-situ sampling device for deep soil escaping gas, characterized by comprising a static box, a soil sample barrel is arranged in the static box, a box cover is fixedly installed at the top end of the static box, and a first exhaust valve, a second exhaust valve, a third exhaust valve, and a fourth exhaust valve are arranged on the box cover.

[0007] The first exhaust valve is connected to a first high-barrier sampling bag through a first silica gel pipe, the first high-barrier sampling bag is arranged in a first vacuum sampling barrel, the first vacuum sampling barrel is vacuumized, and the gas in the static box enters the first high-barrier sampling bag from the first exhaust valve along the first silica gel pipe under the action of atmospheric pressure, and the gas collected in the first high-barrier sampling bag is used for analyzing sulfide malodor substances.

[0008] The second exhaust valve is connected to an activated carbon tube through a second silica gel tube, an output end of the activated carbon tube is connected to a first vacuum pump, the first vacuum pump is further connected with a first flow meter, the first vacuum pump draws the gas in the static tank along the second silica gel tube, when the gas flows through the activated carbon tube, the activated carbon tube absorbs benzene series odor substances, and the first flow meter is used for monitoring the gas flow rate, so as to adjust the power of the first vacuum pump.

[0009] The third exhaust valve is connected to a porous glass plate absorption tube through a third silica gel tube, the porous glass plate absorption tube is filled with sulfuric acid absorption solution, a filter membrane clamp is arranged on the third silica gel tube, and a 0.45 μm filter membrane is arranged in the filter membrane clamp, an output end of the porous glass plate absorption tube is connected to a second vacuum pump, the second vacuum pump is further connected with a second flow meter, the second vacuum pump draws the gas in the static tank along the third silica gel tube, when the filtered gas flows through the porous glass plate absorption tube, the porous glass plate absorption tube collects amine odor substances, and the second flow meter is used for monitoring the gas flow rate, so as to adjust the power of the second vacuum pump.

[0010] The fourth exhaust valve is connected to a second high-barrier sampling bag through a fourth silica gel tube, and the second high-barrier sampling bag is arranged in a second vacuum sampling barrel. The gas in the static tank enters the second high-barrier sampling bag from the fourth exhaust valve along the fourth silica gel tube under the action of atmospheric pressure, and the gas collected in the second high-barrier sampling bag is used for analyzing odor concentration.

[0011] Preferably, a base is arranged below the static tank, a sealing groove is arranged outside the top surface of the base, the bottom end of the static tank is arranged in the sealing groove, the static tank can be sealed by adding sufficient water into the sealing groove, a gas guide cover is movably arranged outside the soil sample barrel, the inner diameter of the gas guide cover is greater than the outer diameter of the soil sample barrel, the height of the gas guide cover is greater than the height of the soil sample barrel, the bottom end of the gas guide cover is close to the bottom surface of the static tank, an exhaust hole is arranged on the side wall of the lower part of the gas guide cover, an air inlet valve is arranged on the tank cover, and a porous air distribution pipe is movably arranged in the soil sample barrel.

[0012] External air enters the porous air distribution pipe through the air inlet valve, the air is dispersed and flows through the porous air distribution pipe, and after contacting the soil sample barrel, the air is mixed with the gas emitted by the soil sample to be detected to form a mixed gas flow, the mixed gas flow rises to the top end of the gas guide cover along the inner wall of the soil sample barrel, then flows downward from the gap between the soil sample barrel and the gas guide cover, and finally enters the static tank from the exhaust hole in the side wall of the gas guide cover.

[0013] Preferably, a heater is fixedly installed on the base, the bottom surface of the soil sample barrel is in close contact with the top surface of the heater, the heater heats the bottom end of the soil sample barrel, the soil sample in the soil sample barrel is warmed, and the gas in the soil sample can be quickly released to improve efficiency, a fan is fixedly installed on the bottom surface of the box cover, and the fan blows the gas in the static box to make the gas components uniformly distributed.

[0014] Preferably, a fan switch for controlling the fan is arranged on the top surface of the box cover, a heater switch and a heater temperature switch for controlling the heater are arranged on the top surface of the box cover, and a temperature display screen is further arranged on the top surface of the box cover, the temperature display screen is connected with a thermometer, and a thermometer probe of the thermometer is installed on the bottom surface of the box cover and used for detecting the temperature in the static box.

[0015] A method for ex-situ sampling of deep soil released gas, characterized in that the method comprises the following steps:

[0016] S1: 2 kg of deep soil is collected through drilling, the deep soil is added into a soil sample barrel, the soil sample barrel is placed on the heater of the base, a gas guide cover is covered on the soil sample barrel, the static box is covered, the lower end of the static box is located in a sealing groove, and the sealing groove is sealed by using water.

[0017] S2: The deep soil is left to stand or the heater is started to heat the deep soil, the heating temperature is 50 DEG C, and the volatilization of the gas in the deep soil is accelerated.

[0018] S3: After heating for 1 h, the fan is started, the fan is turned off after running for 30 s, and the gas in the static box is uniformly distributed.

[0019] S4: After the fan is turned off, the air inlet valve, the first air outlet valve, the second air outlet valve, the third air outlet valve and the fourth air outlet valve are opened.

[0020] S401: The first vacuum sampling barrel is started, 10 L of gas is extracted into the first high-barrier sampling bag, and the gas collected by the first high-barrier sampling bag is used for analyzing sulfide substances, the sulfide substances including one or any of hydrogen sulfide, methyl mercaptan, dimethyl sulfide and dimethyl disulfide.

[0021] S402: The first vacuum pump is started, 5 min of gas is extracted at a speed of 0.5 L / min, and benzene series is collected in an activated carbon tube, the benzene series including one or any of benzene, toluene, o-xylene, m-xylene, p-xylene and ethylbenzene.

[0022] S403: The second vacuum pump is started, 5 min of gas is extracted at a speed of 0.5 L / min, and amine substances are collected in a porous glass plate absorption tube after being filtered through a filter membrane, the amine substances including one or any of ammonia, monomethylamine, dimethylamine and trimethylamine.

[0023] S404: Start the second vacuum sampling barrel, and extract 3L of gas to the second high-barrier sampling bag; the gas sample collected by the second high-barrier sampling bag is used for analyzing the odor concentration.

[0024] S401, S402, S403 and S404 are synchronously performed.

[0025] S5: Send the four samples collected in S4 to a laboratory for corresponding determination.

[0026] Collect 1 parallel sample and 1 blank sample for each batch of samples or every 10 samples.

[0027] Compared with the prior art, the present application has the following advantages:

[0028] The present application provides an ex situ sampling device and method for deep soil fugitive gas, solves the problem that it is difficult to collect soil fugitive gas in situ in some areas where the groundwater level is relatively shallow, optimizes the gas flow path, strengthens the mixing of odor substances and air, ensures the uniformity and stability of the collected gas samples, can heat the soil samples at a set temperature, shortens the gas fugitive time, improves the work efficiency, and can collect samples of multiple malodorous substances at the same time, meeting the needs of simultaneously investigating multiple odor indicators such as sulfide, benzene series, amine, etc.

[0029] The present application will be further described in detail below in combination with the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a structural schematic diagram of the ex situ sampling device of the present application.

[0031] Figure 2 is a structural schematic diagram of the static box of the present application.

[0032] Figure 3 is a gas flow diagram of the static box of the present application.

[0033] Figure 4 is a top view of the box cover of the present application.

[0034] Figure 5 is a bottom view of the box cover of the present application.

[0035] Figure 6 is Figure 2 A-A sectional view of

[0036] Explanation of reference signs:

[0037] DETAILED DESCRIPTION

[0038] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0039] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0040] Example 1

[0041] like Figures 1-6 As shown, the present invention provides an ex-situ sampling device for gas escaping from deep soil, including a static box 1, a soil sample container 7 inside the static box 1, a box cover 2 fixedly installed on the top of the static box 1, and a first exhaust valve 18, a second exhaust valve 19, a third exhaust valve 20 and a fourth exhaust valve 21 provided on the box cover 2.

[0042] The first exhaust valve 18 is connected to the first high-barrier sampling bag 23 through the first silicone tube 22. The first high-barrier sampling bag 23 is placed inside the first vacuum sampling barrel 24. The first vacuum sampling barrel 24 is evacuated. Under atmospheric pressure, the gas in the static chamber 1 enters the first high-barrier sampling bag 23 from the first exhaust valve 18 along the first silicone tube 22. The gas collected in the first high-barrier sampling bag 23 is used to analyze sulfide-based malodorous substances.

[0043] The second exhaust valve 19 is connected to the activated carbon tube 26 via the second silicone tube 25. The output end of the activated carbon tube 26 is connected to the first vacuum pump 27. The first vacuum pump 27 is also connected to the first flow meter 28. The first vacuum pump 27 draws the gas in the static chamber 1 out along the second silicone tube 25. When the gas flows through the activated carbon tube 26, the activated carbon tube 26 absorbs benzene-based malodorous substances. The first flow meter 28 is used to monitor the gas flow rate, thereby adjusting the power of the first vacuum pump 27.

[0044] The third exhaust valve 20 is connected to a porous glass absorption tube 31 through a third silica gel tube 29, the porous glass absorption tube 31 is filled with sulfuric acid absorption solution, a filter membrane clamp 30 is arranged on the third silica gel tube 29, and a 0.45 μm filter membrane is arranged in the filter membrane clamp 30, an output end of the porous glass absorption tube 31 is connected to a second vacuum pump 32, and the second vacuum pump 32 is further connected with a second flow meter 33, the second vacuum pump 32 draws the gas in the static box 1 out along the third silica gel tube 29, the filtered gas flows through the porous glass absorption tube 31, the porous glass absorption tube 31 collects amine odor substances, and the second flow meter 33 is used for monitoring the gas flow rate, so as to adjust the power of the second vacuum pump 32.

[0045] The fourth exhaust valve 21 is connected to a second high-barrier sampling bag 35 through a fourth silica gel tube 34, and the second high-barrier sampling bag 35 is arranged in a second vacuum sampling barrel 36. The gas in the static box 1 enters the second high-barrier sampling bag 35 from the fourth exhaust valve 21 along the fourth silica gel tube 34 under the action of atmospheric pressure, and the collected gas in the second high-barrier sampling bag 35 is used for analyzing odor concentration.

[0046] In the embodiment, the static box 1 is arranged below a base 4, a sealing groove 5 is arranged on the top surface of the base 4, and the bottom end of the static box 1 is arranged in the sealing groove 5, water is added into the sealing groove 5 to seal the static box 1, a gas guide cover 9 is movably arranged on the soil sample barrel 7, the inner diameter of the gas guide cover 9 is greater than the outer diameter of the soil sample barrel 7, the height of the gas guide cover 9 is greater than the height of the soil sample barrel 7, the bottom end of the gas guide cover 9 is close to the bottom surface of the static box 1, a plurality of exhaust holes 10 are uniformly arranged on the side wall of the lower part of the gas guide cover 9, an air inlet valve 17 is arranged on the box cover 2, a porous air distribution pipe 8 is movably arranged in the soil sample barrel 7, and the air inlet valve 17 is connected with the porous air distribution pipe 8.

[0047] As shown in Figure 3 , external air enters the porous air distribution pipe 8 from the air inlet valve 17, the air is dispersed and flows through the porous air distribution pipe 8, and after contacting the soil sample barrel 7, the air is mixed with the gas emitted by the soil sample to be detected to form a mixed gas flow, the mixed gas flow rises to the top end of the gas guide cover 9 along the inner wall of the soil sample barrel 7, then flows downward from the gap between the soil sample barrel 7 and the gas guide cover 9, and finally enters the static box 1 from the exhaust holes 10 in the side wall of the gas guide cover 9.

[0048] In the embodiment, a heater 6 is fixedly arranged on the base 4, the bottom surface of the soil sample barrel 7 is close to the top surface of the heater 6, the heater 6 heats the bottom end of the soil sample barrel 7, the soil sample in the soil sample barrel 7 is warmed, the gas in the soil sample can be emitted faster, and the efficiency is improved, and a fan 11 is fixedly arranged on the bottom surface of the box cover 2, the fan 11 blows the gas in the static box 1 to make the gas components uniformly distributed.

[0049] In this embodiment, the top surface of the box cover 2 is provided with a fan switch 12 for controlling the fan 11, the top surface of the box cover 2 is provided with a heater switch 13 and a heater temperature switch 14 for controlling the heater 6, and the top surface of the box cover 2 is further provided with a temperature display screen 15 connected with a thermometer, and the thermometer probe 16 of the thermometer is installed on the bottom surface of the box cover 2 for detecting the temperature in the static box 1.

[0050] A method for ex-situ sampling of deep soil fugitive gases, comprising the following steps:

[0051] S1: Collect 2 kg of deep soil through drilling, and put the deep soil into a soil sample barrel 7, and place the soil sample barrel 7 on the heater 6 of the base 4, cover the soil sample barrel 7 with the air guide cover 9, cover the static box 1, and make the lower end of the static box 1 located in the sealing groove 5, and seal the sealing groove 5 with water.

[0052] S2: Stand at room temperature, and the gases in the deep soil are naturally volatilized.

[0053] S3: After standing for 8 hours, start the fan 11, and after the fan 11 runs for 30 seconds, turn off the fan 11, so that the gases in the static box 1 are uniformly distributed.

[0054] S4: After turning off the fan 11, open the air inlet valve 17, the first air outlet valve 18, the second air outlet valve 19, the third air outlet valve 20 and the fourth air outlet valve 21.

[0055] S401: Start the first vacuum sampling barrel 24, and extract 10 L of gas into the first high-barrier sampling bag 23, and the gas collected in the first high-barrier sampling bag 23 is used for analyzing sulfide substances, and the sulfide substances include one or any of hydrogen sulfide, methyl mercaptan, methyl mercaptan and dimethyl disulfide.

[0056] S402: Start the first vacuum pump 27, and extract 5 min of gas at a speed of 0.5 L / min, and collect benzene series in the activated carbon tube 26, and the benzene series includes one or any of benzene, toluene, o-xylene, m-xylene, p-xylene and ethylbenzene.

[0057] S403: Start the second vacuum pump 32, and extract 5 min of gas at a speed of 0.5 L / min, and after the gas is filtered through the filter membrane clamp 30, collect amine substances in the porous glass plate absorption tube 31, and the amine substances include one or any of ammonia, monomethylamine, dimethylamine and trimethylamine.

[0058] S404: Start the second vacuum sampling barrel 36, and extract 3 L of gas into the second high-barrier sampling bag 35, and the gas sample collected in the second high-barrier sampling bag 35 is used for analyzing odor concentration.

[0059] S401, S402, S403 and S404 are synchronously performed.

[0060] S5: The four samples collected in S4 are sent to a laboratory for corresponding determination.

[0061] 1 parallel sample and 1 blank sample are collected for each batch of samples or every 10 samples.

[0062] Laboratory detection and analysis method:

[0063] (1) Analysis of sulfur ether and other malodorous components

[0064] 1 μL of gas in the gas bag is sucked by a syringe and directly injected into a gas chromatograph, and the quantitative analysis is performed by using "Air Quality Determination of Hydrogen Sulfide, Methyl Mercaptan, Methyl Mercaptan and Dimethyl Disulfide Gas Chromatography" (GB / T 14678-1993).

[0065] (2) Benzene series analysis method

[0066] After solvent desorption by activated carbon, the components such as benzene, toluene, o-xylene, m-xylene, p-xylene and ethylbenzene are quantitatively analyzed by gas chromatograph according to "Air and Waste Gas Monitoring and Analysis Method" (Fourth Edition Supplement) "Activated Carbon Adsorption Carbon Disulfide Desorption Gas Chromatography (B) 6.2.1 (1)".

[0067] (3) Amine analysis method

[0068] The sample absorption liquid after collection is quantitatively analyzed according to the method of "Determination of Ammonia, Methylamine, Dimethylamine and Trimethylamine in Ambient Air by Ion Chromatography" (HJ 1076-2019).

[0069] (4) Odor concentration analysis method

[0070] The collected sample is analyzed according to the method of "Air Quality Determination of Odor Three-point Comparison Odor Bag Method" (GB / T 14675-1993).

[0071] The application is applied to soil pollution investigation of a pesticide factory plot, 4 deep soil samples with heavy odor are collected and put into the ex situ sampling device, soil emission gas samples (G1-G4) are collected respectively, and sent to a laboratory for analysis of sulfur ether, benzene series, amine and other malodorous substances and odor concentration, and the results are shown in Tables 1-3.

[0072] Table 1 Sulfur ether detection results (unit: mg / m 3 )

[0073]

[0074] Table 2 Benzene series detection results (unit: mg / m 3 )

[0075]

[0076] Table 3 Odor and amine detection results (unit: mg / m 3 , except odor concentration)

[0077]

[0078] It can be seen that the sulfide odor substances are not detected; the detection rate of benzene series substances is very high, and there are over-standard phenomena, among which G1 is seriously over-standard; among the amine substances, only ammonia has 2 samples detected and appears to be over-standard; the odor concentration as a comprehensive index is over-standard.

[0079] In order to further identify the characteristic index and distribution range of soil odor pollution, the second investigation was carried out on the basis of the first investigation. A total of 6 samples were collected and sent to the laboratory for analysis, and the results are shown in Tables 4-5.

[0080] Example Two

[0081] In order to further identify the characteristic index and distribution range of soil odor pollution, the second investigation was carried out on the basis of the first investigation.

[0082] As Figures 1-6 shown, the present application provides a kind of deep soil off-gas ectopic sampling device, including static box 1, soil sample barrel 7 is arranged in the static box 1, the top of the static box 1 is fixedly installed with box cover 2, first exhaust valve 18, second exhaust valve 19, third exhaust valve 20 and fourth exhaust valve 21 are arranged on the box cover 2.

[0083] First exhaust valve 18 is connected to first high barrier sampling bag 23 by first silica gel pipe 22, first high barrier sampling bag 23 is placed in first vacuum sampling barrel 24, first vacuum sampling barrel 24 is vacuumized, gas in static box 1 under the action of atmospheric pressure enters first high barrier sampling bag 23 along first silica gel pipe 22 from first exhaust valve 18, and the gas collected in first high barrier sampling bag 23 is used to analyze sulfide odor substances.

[0084] Second exhaust valve 19 is connected to activated carbon tube 26 by second silica gel pipe 25, the output end of activated carbon tube 26 is connected to first vacuum pump 27, and first vacuum pump 27 is also connected with first flow meter 28, first vacuum pump 27 draws gas in static box 1 along second silica gel pipe 25, when gas flows through activated carbon tube 26, activated carbon tube 26 absorbs benzene series odor substances, and first flow meter 28 is used to monitor gas flow rate, so as to adjust the power of first vacuum pump 27.

[0085] The third exhaust valve 20 is connected to a porous glass absorption tube 31 containing sulfuric acid absorption solution through a third silica gel tube 29, a filter membrane clamp 30 is arranged on the third silica gel tube 29, and a 0.45 μm filter membrane is arranged in the filter membrane clamp 30. An output end of the porous glass absorption tube 31 is connected to a second vacuum pump 32, and the second vacuum pump 32 is further connected with a second flow meter 33. The second vacuum pump 32 draws the gas in the static box 1 along the third silica gel tube 29. When the filtered gas flows through the porous glass absorption tube 31, the porous glass absorption tube 31 collects amine odor substances. The second flow meter 33 is used to monitor the gas flow rate, so as to adjust the power of the second vacuum pump 32.

[0086] The fourth exhaust valve 21 is connected to a second high-barrier sampling bag 35 through a fourth silica gel tube 34, and the second high-barrier sampling bag 35 is arranged in a second vacuum sampling barrel 36. The gas in the static box 1 enters the second high-barrier sampling bag 35 from the fourth exhaust valve 21 along the fourth silica gel tube 34 under the action of atmospheric pressure, and the collected gas in the second high-barrier sampling bag 35 is used to analyze the odor concentration.

[0087] In the embodiment, a base 4 is arranged below the static box 1, a sealing groove 5 is arranged on the top surface of the base 4, and the bottom end of the static box 1 is arranged in the sealing groove 5. A sufficient amount of water is added into the sealing groove 5 to seal the static box 1. An air guide cover 9 is movably arranged on the soil sample barrel 7. The inner diameter of the air guide cover 9 is greater than the outer diameter of the soil sample barrel 7, and the height of the air guide cover 9 is greater than the height of the soil sample barrel 7. The bottom end of the air guide cover 9 is tightly attached to the bottom surface of the static box 1. A plurality of air exhaust holes 10 are uniformly arranged on the side wall of the lower part of the air guide cover 9. An air inlet valve 17 is arranged on the box cover 2. A porous air distribution pipe 8 is movably arranged in the soil sample barrel 7, and the air inlet valve 17 is connected to the porous air distribution pipe 8.

[0088] As shown in Figure 3 The external air enters the porous air distribution pipe 8 through the air inlet valve 17. The air is dispersed and flows through the porous air distribution pipe 8, and then mixes with the gas emitted by the soil sample to be detected after contacting the soil sample barrel 7 to form a mixed gas flow. The mixed gas flow rises to the top end of the air guide cover 9 along the inner wall of the soil sample barrel 7, and then flows downward from the gap between the soil sample barrel 7 and the air guide cover 9, and finally enters the static box 1 through the air exhaust holes 10 on the side wall of the air guide cover 9.

[0089] In this embodiment, the base 4 is fixedly installed with a heater 6, the bottom surface of the soil sample barrel 7 is in close contact with the top surface of the heater 6, the heater 6 heats the bottom end of the soil sample barrel 7, the soil sample in the soil sample barrel 7 is warmed, the gas in the soil sample can be quickly released, the efficiency is improved, the bottom surface of the box cover 2 is fixedly installed with a fan 11, and the fan 11 blows the gas in the static box 1 to make the gas components uniformly distributed.

[0090] In this embodiment, the top surface of the box cover 2 is provided with a fan switch 12 for controlling the fan 11, the top surface of the box cover 2 is provided with a heater switch 13 and a heater temperature switch 14 for controlling the heater 6, and the top surface of the box cover 2 is further provided with a temperature display screen 15, the temperature display screen 15 is connected with a thermometer, and a thermometer probe 16 of the thermometer is installed on the bottom surface of the box cover 2 and used for detecting the temperature in the static box 1.

[0091] An ex situ sampling method of deep soil released gas, comprising the following steps:

[0092] S1: 2 kg of deep soil is collected by drilling, the deep soil is added into the soil sample barrel 7, the soil sample barrel 7 is placed on the heater 6 of the base 4, the gas guide cover 9 is covered on the soil sample barrel 7, the static box 1 is covered, the lower end of the static box 1 is located in the sealing groove 5, and the sealing groove 5 is sealed by using water.

[0093] S2: In order to save time, the heater 6 is started to heat the deep soil sample, the heating time is 1 h, the heating temperature is 50℃, and the volatilization of the gas in the deep soil is accelerated.

[0094] S3: After the heating is completed, the fan 11 is started, the fan 11 is turned off after running for 30 seconds, and the gas in the static box 1 is uniformly distributed.

[0095] S4: After the fan 11 is turned off, the air inlet valve 17, the first air outlet valve 18, the second air outlet valve 19, the third air outlet valve 20 and the fourth air outlet valve 21 are opened.

[0096] S401: The first vacuum sampling barrel 24 is started, 10 L of gas is extracted into the first high-barrier sampling bag 23, and the gas collected by the first high-barrier sampling bag 23 is used for analyzing sulfide substances, the sulfide substances including one or any of hydrogen sulfide, methyl mercaptan, methyl mercaptan and dimethyl disulfide.

[0097] S402: The first vacuum pump 27 is started, 5 min of gas is extracted at a speed of 0.5 L / min, and benzene series is collected in the activated carbon tube 26, the benzene series including one or any of benzene, toluene, o-xylene, m-xylene, p-xylene and ethylbenzene.

[0098] S403: Start the second vacuum pump 32 to extract gas at a speed of 0.5 L / min for 5 min, and collect the amine substances including one or any combination of ammonia, monomethylamine, dimethylamine and trimethylamine in the multi-well glass absorption tube 31 after filtering the gas through the filter membrane clamp 30.

[0099] S404: Start the second vacuum sampling barrel 36 to extract 3 L of gas into the second high-barrier sampling bag 35, and the gas sample collected in the second high-barrier sampling bag 35 is used for analyzing the odor concentration.

[0100] S401, S402, S403 and S404 are performed synchronously.

[0101] S5: Send the four samples collected in S4 to the laboratory for corresponding determination.

[0102] Collect one parallel sample and one blank sample for every batch of samples or every 10 samples.

[0103] Laboratory detection and analysis method:

[0104] (1) Analysis of malodorous components such as sulfides

[0105] Take 1 μL of gas from the gas bag by syringe and inject it directly into the gas chromatograph for quantitative analysis according to the "Air Quality Determination of Hydrogen Sulfide, Methyl Mercaptan, Methyl Mercaptan and Dimethyl Disulfide Gas Chromatography" (GB / T 14678-1993).

[0106] (2) Benzene series analysis method

[0107] After desorption by activated carbon solvent, the components such as benzene, toluene, o-xylene, m-xylene, p-xylene and ethylbenzene are quantitatively analyzed by gas chromatograph according to "Air and Waste Gas Monitoring and Analysis Method" (Fourth Edition Supplement) "Activated Carbon Adsorption Carbon Disulfide Desorption Gas Chromatography (B) 6.2.1 (1)".

[0108] (3) Amine analysis method

[0109] The collected sample absorption liquid is quantitatively analyzed according to the "Determination of Ammonia, Methylamine, Dimethylamine, Trimethylamine in Ambient Air by Ion Chromatography" (HJ 1076-2019) method.

[0110] (4) Odor concentration analysis method

[0111] The collected sample is analyzed according to the "Air Quality Determination of Odor Three-point Comparison Odor Bag Method" (GB / T 14675-1993) method.

[0112] The application is applied to the soil pollution investigation of a pesticide factory plot, 6 deep soil samples with heavy odor are collected, put into the ex-situ sampling device, soil gas samples (G1-G4) are collected respectively, sent to the laboratory, and analyzed for sulfide, benzene series, amine and other malodorous substances and odor concentration, and the results are shown in Tables 4-5.

[0113] Table 4: Detection results of benzene series in the second investigation (unit: mg / m 3 )

[0114]

[0115] Table 5: Detection results of other indicators in the second investigation (unit: mg / m 3 , except odor concentration)

[0116]

[0117] Different from the first result, in the sulfide malodorous substances, methyl mercaptan and dimethyl disulfide also exceed the standard, which is mainly related to the different sampling points.

[0118] Therefore, the malodorous substances in the local plot soil include benzene series, sulfides and ammonia, which should be focused on in soil pollution remediation.

[0119] The above is only a preferred embodiment of the application, and does not limit the application. Any simple modification, change and equivalent change of the above embodiment according to the technical essence of the application still belongs to the protection scope of the technical solution of the application.

Claims

1. An apparatus for the ex situ sampling of deep soil fugitive gases, characterized in that, Including static box (1), soil sample barrel (7) is arranged in static box (1), box cover (2) is fixedly installed at the top of static box (1), first exhaust valve (18), second exhaust valve (19), third exhaust valve (20) and fourth exhaust valve (21) are arranged on the box cover (2); The first exhaust valve (18) is connected to the first high barrier sampling bag (23) through the first silica gel pipe (22); The second exhaust valve (19) is connected to the activated carbon pipe (26) through the second silica gel pipe (25); The third exhaust valve (20) is connected to the porous glass plate absorption pipe (31) through the third silica gel pipe (29); The fourth exhaust valve (21) is connected to the second high barrier sampling bag (35) through the fourth silica gel pipe (34); The bottom of the static box (1) is provided with a base (4), the top surface of the base (4) is provided with a sealing groove (5), the bottom of the static box (1) is installed in the sealing groove (5), the soil sample barrel (7) is movably sleeved with a gas guide cover (9), the bottom of the gas guide cover (9) is tightly attached to the bottom surface of the static box (1), and the exhaust hole (10) is arranged on the side wall of the lower part of the gas guide cover (9); The base (4) is fixedly installed with a heater (6), the bottom surface of the soil sample barrel (7) is tightly attached to the top surface of the heater (6), and the fan (11) is fixedly installed on the bottom surface of the box cover (2); The box cover (2) is provided with an air inlet valve (17), and the soil sample barrel (7) is movably provided with a porous air distribution pipe (8), and the air inlet valve (17) is communicated with the porous air distribution pipe (8).

2. The apparatus of claim 1, wherein, The first high barrier sampling bag (23) is placed in the first vacuum sampling barrel (24).

3. The apparatus of claim 1, wherein, The output end of the activated carbon pipe (26) is connected to the first vacuum pump (27), and the first vacuum pump (27) is further connected with the first flow meter (28).

4. The apparatus of claim 1, wherein, The third silica gel pipe (29) is provided with a filter membrane clamp (30), and the output end of the porous glass plate absorption pipe (31) is connected to the second vacuum pump (32), and the second vacuum pump (32) is further connected with the second flow meter (33).

5. The apparatus of claim 1, wherein, The second high barrier sampling bag (35) is placed in the second vacuum sampling barrel (36).

6. A method for ex situ sampling of deep soil fugitive gases, characterized in that, The following steps are included: S1: a certain amount of deep soil is collected by drilling, the deep soil is added into the soil sample barrel (7), and the sealing groove (5) is sealed with water; S2: start the heater (6) to heat the deep soil, and accelerate the volatilization of the gas in the deep soil; S3: after a certain time of heating, start the fan (11) to make the gas in the static box (1) uniformly distributed, and the fan (11) is closed after running for 30 seconds; S4: after closing the fan (11), open the air inlet valve (17), the first exhaust valve (18), the second exhaust valve (19), the third exhaust valve (20) and the fourth exhaust valve (21). S401: Start the first vacuum sampling barrel (24) to extract 10L of gas to the first high barrier sampling bag (23), and the gas collected by the first high barrier sampling bag (23) is used to analyze sulfide substances, including one or any of hydrogen sulfide, methyl mercaptan, methyl mercaptan and dimethyl disulfide; S402: Start the first vacuum pump (27) to extract gas at a speed of 0.5L / min for 5min, and collect benzene series in the activated carbon tube (26), including one or any of benzene, toluene, o-xylene, m-xylene, p-xylene and ethylbenzene; S403: Start the second vacuum pump (32) to extract gas at a speed of 0.5L / min for 5min, and collect amine substances in the porous glass plate absorption tube (31) after filtering through the filter membrane clamp (30), including one or any of ammonia, monomethylamine, dimethylamine and trimethylamine; S404: Start the second vacuum sampling barrel (36) to extract 3L of gas to the second high barrier sampling bag (35), and the gas sample collected by the second high barrier sampling bag (35) is used to analyze odor concentration; S5: Send the four samples collected in S4 to the laboratory for corresponding determination.

7. The method of claim 6, wherein the method further comprises, In S2, the heating temperature is 50℃, and the heating time is 1h.

8. The method of claim 7, wherein the method further comprises, In S4, S401, S402, S403 and S404 are carried out synchronously.

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