Liquid level suspension type gas flux collecting device for low-illumination environment

Abstract

The invention discloses a liquid level suspension type gas flux collecting device for a low-illumination environment. The collecting device comprises a flux chamber, a reflective positioning assembly, a suspension supporting system and a gas sampling passage system, a suspension rope is arranged at the top of the flux chamber, the bottom of the flux chamber is open, a hollow pressure channel and two sampling body channels are arranged in the flux chamber, and one end of the hollow pressure channel and one end of the gas sampling channel penetrate through the top of the flux chamber, are free outside and are respectively provided with a pressure measuring device, a gas sampling inlet and a gas sampling outlet; the reflective positioning assembly comprises a reflective plate arranged on the outer wall of the bottom of the flux chamber; the suspension supporting system comprises a support and an adjusting mechanism. The gas sampling channel system comprises an exhaust pipe, a gas inlet pipe, a gas flowmeter and a sampling device. The device provided by the invention solves the problems of difficult positioning, difficult operation, poor sampling stability and the like, and fills the blank of low-cost and convenient flux sampling deployment technology in a specific scene.

Description

TECHNICAL FIELD

[0001] The application relates to a liquid surface suspension type gas flux collecting device for a low-illumination environment. BACKGROUND

[0002] At present, quantitative monitoring of gas emission characteristics is gradually valued in the field of environmental engineering and sewage treatment. The liquid surface gas flux sampling device is an important tool for evaluating the greenhouse gas emission intensity of places such as biological reaction tanks, septic tanks and the like. Places such as septic tanks, sewage treatment tanks and biogas tanks are often accompanied by low illumination, peculiar smell, heat and other unfavorable conditions, and higher requirements are put forward for the adaptability and convenience of the equipment. However, the existing equipment mostly adopts a floating structure, and it is difficult to realize stable sampling at a specific depth, and the adaptability is poor under conditions such as dim light and narrow liquid surface space, resulting in low sampling efficiency, poor repeatability and large error.

[0003] Therefore, there is an urgent need for a flux sampling device with structural stability, sampling depth control capability and rapid deployment characteristics, and capable of adapting to low light and high humidity environments. SUMMARY

[0004] The purpose of the present application is to provide a liquid surface suspension type gas flux collecting device for a low-illumination environment.

[0005] The device solves the problems of difficult positioning, difficult operation and poor sampling stability, and fills the gap of low-cost, convenient deployment flux sampling technology in specific scenarios.

[0006] The application provides a liquid surface suspension type gas flux collecting device for a low-illumination environment, comprising a flux chamber, a reflective positioning component, a suspension support system and a gas sampling passage system.

[0007] The top of the flux chamber is provided with a suspension rope, and the bottom is provided with an opening, and a hollow pressure channel and two gas sampling channels are arranged inside. The hollow pressure channel and one end of the gas sampling channel both penetrate through the top of the flux chamber and are free from the outside. The two gas sampling channels are respectively provided with a gas sampling inlet and a gas sampling outlet at one end outside the flux chamber. The hollow pressure channel is provided with a pressure measuring device at one end outside the flux chamber.

[0008] The reflective positioning component comprises a reflective plate arranged on the outer wall of the bottom of the flux chamber, which is used to realize accurate positioning and depth tracing in a low-illumination environment in combination with an external light source.

[0009] The suspension support system comprises a support and an adjusting mechanism. The support is used to support and fix the whole device. The adjusting mechanism cooperates with the support and is connected with the suspension rope to control the vertical position of the flux chamber.

[0010] The gas sampling pathway system includes an exhaust pipe, an air inlet pipe, a gas flow meter and a sampling device; one end of the exhaust pipe and the air inlet pipe are respectively connected to the gas inlet and the gas outlet; the other end of the exhaust pipe is connected to the sampling device through the gas flow meter, and the air inlet pipe is also connected to the sampling device.

[0011] In the present invention, the bottom of the flux chamber is open, and when in use, the bottom covers the liquid surface to collect the gas volatilized from the liquid surface;

[0012] The flux chamber collects gas from a container at a certain depth. A soft air pipe (i.e., the air extraction pipe) of appropriate length is selected according to the height of the ground from the liquid level. After the gas passes through the on-site online testing instrument, it is circulated back to the flux chamber through the air intake pipe. The air extraction pipe and the air intake pipe use air pipes that match the corresponding test instrument model and materials, and the inner diameter of the air pipe is not more than 10 mm.

[0013] When using the flux chamber for on-site gas detection, it is not just about extracting gas at a certain time for detection. Generally, it is necessary to monitor the gas concentration at various time points in a closed container (when the lower end opening of the flux chamber is connected to the liquid surface) within 3 hours. This is generally a linear relationship. Through continuous detection within 3 hours (such as monitoring every 20 minutes), a standard curve is established to determine the total amount of gas generated in 24 hours. Therefore, there must be no gas loss during the continuous monitoring, so the gas extracted for monitoring needs to be recycled. Therefore, an exhaust pipe and an air inlet pipe are both connected to the sampling device (and an air pump is used to achieve gas circulation).

[0014] In the above-mentioned liquid surface suspension type gas flux collection device for low-light environment, the suspension rope includes multiple branch suspension ropes and a main rope. The multiple branch suspension ropes are fixed at equal intervals along the circumferential direction along the top surface of the flux chamber and are evenly fixed to the main rope.

[0015] In the above-mentioned liquid-surface suspended gas flux collection device for low-light environments, the flux chamber is cylindrical;

[0016] The top surface of the flux chamber is provided with hanging openings at equal intervals along the circumference for fixing the branch hanging ropes.

[0017] In the above-mentioned liquid surface suspended gas flux collection device for low-light environment, the gas collection channel connected to the gas collection outlet in the flux chamber is shorter than the gas collection channel connected to the gas collection inlet, and a reflective plate is provided at the bottom of the gas collection channel connected to the gas collection inlet near the bottom of the flux chamber.

[0018] In the above-mentioned liquid-surface suspended gas flux collection device for low-light environments, the reflective plate is radially arranged along the outer wall of the bottom of the flux chamber;

[0019] A circular level is also provided on the top of the flux chamber; when the test object is a liquid, the reflector of the flux chamber is the first choice for determining the level; and when the test object is a solid-liquid two-phase with a high solid content resulting in an uneven surface, the circular level can be used as the first choice for observing whether the flux chamber is level.

[0020] In the above-mentioned liquid-surface suspended gas flux collection device for low-light environments, the reflective plate includes a reflective cap and a reflective sticker, and the reflective sticker is adhered to the surface of the reflective cap.

[0021] In the above-mentioned liquid-surface suspended gas flux collection device for low-light environments, the support comprises a retractable tripod, the adjustment mechanism comprises a chain and a chain fixer, and the chain can specifically be a lightweight iron chain;

[0022] The chain passes through the chain holder provided at the intersection of the central axis of the telescopic tripod and is fixed thereto.

[0023] In the above-mentioned liquid-surface suspended gas flux collection device for low-light environments, the pressure measuring device includes a micro-pressure digital barometer for detecting air pressure and adjusting the air pressure in time. Because when using a flux chamber to monitor gas, in addition to continuously detecting gas changes and other data within 3 hours, gas temperature and air pressure data are also required. Only after substituting them into the model can the final gas production result be calculated. For the air pressure in the flux chamber, try to avoid having a long pipe between the flux chamber and the barometer (it is difficult to reflect the true atmospheric pressure of the flux chamber), and consider that the air pressure data can be read at any time in a relatively dark environment. Therefore, a miniature high-sensitivity and low-range barometer with a display screen is configured. The barometer is flat on the top of the flux chamber and is horizontally parallel to the outer top, which is convenient for reading data from above.

[0024] In the above-mentioned liquid-surface suspended gas flux collection device for low-light environments, the sampling device includes a gas dryer and a portable gas detector;

[0025] The portable gas detector is connected to the gas extraction pipe through the gas dryer and the gas flow meter which are connected in sequence, and is used for online detection of collected gas samples.

[0026] In the above-mentioned liquid-surface suspended gas flux collection device for low-light environments, the sampling device includes an air pump and a sampling bag;

[0027] The sampling bag is connected to the air pump, the gas flow meter and the air extraction pipe through the sequentially connected ones, and is used for collecting gas samples.

[0028] In the present invention, in typical scenarios such as septic tanks and anaerobic tanks where the liquid level is low and the light is weak, the user can use the tripod support structure and the iron chain adjustment mechanism to stably suspend the flux chamber to a specified depth of 5 cm below the liquid surface. Combined with lighting, the operator uses a reflective cap to achieve accurate positioning and height control. During the sampling process, the exhaust pipe is connected in series with the gas flow meter, dryer, and portable gas detector for on-site online monitoring; or the sample is collected in a closed manner through the sampling bag (driven by an air pump) for subsequent laboratory analysis.

[0029] The flux chamber body and vent interface utilize a standard 1 / 4-1 / 8" external thread design, allowing for flexible docking with various commercial sensors and sampling devices. All components are constructed from corrosion-resistant engineering plastics or anodized aluminum, offering excellent corrosion resistance, pressure resistance, and high-temperature stability.

[0030] The present invention has the following beneficial effects:

[0031] 1. Through the facilities of the suspension support system, a controllable sampling depth can be achieved, and highly repeatable flux sampling at a specified height below the liquid surface (such as 5 cm) can be achieved. Two major problems will be encountered in actual sampling. First, the liquid surface (solid feces surface) of the gas sampling objects such as septic tanks is inconsistent, but it is necessary to ensure that the flux chamber penetrates 5 cm below the liquid surface. Therefore, the height of the flux chamber can be controlled up and down through the suspension rope (iron chain) of the suspension support system. The second problem is that the surrounding surface environment of the sampling objects such as septic tanks is often not horizontal or complete and continuous. It is difficult for a general support system to be placed horizontally and stably. Therefore, the support system selects 3 retractable support legs to solve the above problems. At the same time, the support system can be shortened after the sampling is introduced to facilitate carrying and rapid deployment during on-site sampling.

[0032] 2. The setting of the reflective positioning component has visual positioning capability and is suitable for complex sampling environments such as dim light and limited space. When the flux chamber is sampling and calculating, it is necessary to clarify the volume of the flux cavity, and at the same time ensure that the lower end of the flux chamber is immersed below the liquid surface to ensure airtightness. So taking this device as an example, the flux chamber is fixedly immersed 5cm below the liquid surface to ensure that the air cavity is a constant 5 liters. However, it is difficult to see the immersion height from a vertical perspective in a low-light environment. Therefore, a circle of rings is set at this position with a ring width of 2-5cm. Some reflective strips are attached to the upper part of the ring. When the liquid surface is observed from the top, it is the measurement height. At this moment, the fixed height can be used to start the test. At the same time, the ring is also conducive to the horizontal arrangement of the device on the liquid surface.

[0033] 3. Modular structure, standardized interfaces, and detachable connections facilitate rapid deployment and maintenance.

[0034] 4. It can realize dual modes of in-situ online detection or offline collection of sample bags. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 Schematic diagram of the structure of the liquid surface suspended gas flux collection device for low-light environment of the present invention;

[0036] invention Figure 2 This is a schematic structural diagram of the liquid surface suspended gas flux collection device for low-light environments of the present invention.

[0037] The marks in the figure are as follows:

[0038] 100 flux chamber; 101 hanging port; 102 gas sampling inlet; 103 branch hanging rope; 104 micro-pressure digital display barometer; 105 gas sampling outlet; 106 conical gas collecting cap; 107 hollow pressure channel; 108 hollow gas channel; 109 adapter, 110 reflector; 200 retractable tripod; 201 lightweight iron chain; 202 iron chain fastener; 203 bracket expansion joint; 301 exhaust pipe; 302 air inlet pipe; 303 gas flow meter; 304 gas dryer; 305 portable gas detector; 306 air pump; 307 sampling bag.

[0039] Figure 3 This is the linear fitting result of CO2 emissions from Shuangweng, a monitoring point in Shuidongtun Village.

[0040] Figure 4 Linear fitting of CO2 and CH4 emissions at the Wuzhuang Village monitoring point.

[0041] Figure 5 This is a graph showing the relationship between CO2 and CH4 emission concentrations.

[0042] Figure 6 Linear fitting of CO2, CH4 and N2O emissions from the gas chromatograph in Wuzhuang Village.

[0043] Figure 7 This is a graph showing the relationship between CO2 and CH4 emission concentrations. DETAILED DESCRIPTION

[0044] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0045] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0046] To facilitate understanding of the present technical solution by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings in the embodiments. The contents of the embodiments are not intended to limit the present invention. All other embodiments obtained by those skilled in the art without creative work based on the present invention shall fall within the scope of protection of the present invention.

[0047] The present invention provides a liquid surface suspended gas flux collection device for low light environment, such as Figure 1 As shown, it includes a flux chamber 100, a reflective positioning assembly, a suspension support system and a gas sampling passage system;

[0048] The flux chamber 100 (in a cylindrical shape) is provided with a suspension rope at the top and an opening at the bottom. A hollow pressure channel 107 and two gas sampling channels 108 are provided inside the flux chamber 100. One end of the hollow pressure channel 107 and the gas sampling channel 108 passes through the top of the flux chamber 100 and is free to the outside. The two gas sampling channels 108 are provided with a gas inlet 102 and a gas outlet 105 at one end outside the flux chamber 100 (specifically, the gas sampling channel 108 connected to the gas outlet 105 in the flux chamber 100 is longer than the other gas sampling channel 108 connected to the gas inlet 102). 8 is short, and a reflective plate 110 is provided at the bottom of the gas collection channel 108 connected to the gas collection inlet 102 near the bottom of the flux chamber 100); a pressure measuring device (specifically, a micro-pressure digital display barometer 104) is provided at one end of the hollow pressure channel 107 outside the flux chamber 100; wherein, the suspension rope includes multiple branch suspension ropes 103 and a main rope, and the multiple branch suspension ropes 103 are fixed at equal intervals along the circumferential direction along the top surface of the flux chamber 100 and are evenly fixed to the main rope; the top surface of the flux chamber 100 is provided with suspension ports 101 at equal intervals along the circumferential direction for fixing the branch suspension ropes 103.

[0049] The reflective positioning assembly includes a reflective plate 110 (specifically composed of a reflective cap and a reflective tape, with the reflective tape adhered to the surface of the reflective cap). The reflective plate 110 is arranged on the outer wall of the bottom of the flux chamber 100 (specifically, it is radially arranged along the outer wall of the bottom of the flux chamber 100) and is used to achieve precise positioning and depth tracking in low-light environments in combination with an external light source;

[0050] The suspension support system includes a bracket and an adjustment mechanism; the bracket is used to support and fix the entire device; the adjustment mechanism cooperates with the bracket and is connected to the suspension rope to control the vertical position of the flux chamber 100;

[0051] The gas sampling passage system includes an exhaust pipe 301, an air inlet pipe 302, a gas flow meter 303 and a sampling device; one end of the exhaust pipe 301 and the air inlet pipe 302 are respectively connected to the gas inlet 102 and the gas outlet 105; the other end of the exhaust pipe 301 is connected to the sampling device through the gas flow meter 303, and the air inlet pipe 302 is also connected to the sampling device. The gas extracted for monitoring must be circulated back to the flux chamber 100 to realize gas circulation.

[0052] like Figure 1 As shown in , the sampling device includes a gas dryer 304 and a portable gas detector 305;

[0053] The portable gas detector 305 is connected to the gas extraction pipe 301 through the gas dryer 304 and the gas flow meter 303 which are connected in sequence, and is used for online detection of the collected gas samples.

[0054] like Figure 2 As shown in , the sampling device includes an air pump 306 and a sampling bag 307;

[0055] The sampling bag 307 is connected to the air extraction pipe 301 through the air pump 306 and the gas flow meter 303 which are connected in sequence, and is used for collecting gas samples.

[0056] Furthermore, a circular level (not shown) is provided on the top of the flux chamber 100 to ensure that the instrument is placed horizontally.

[0057] Furthermore, the bracket includes a retractable tripod 200, and the adjustment mechanism includes a chain (specifically, a lightweight iron chain 201) and a chain fixer 202;

[0058] The chain (light iron chain 201 ) passes through a chain holder 202 provided at the central axis intersection of the telescopic tripod 200 .

[0059] Example 1

[0060] During gas extraction, a retractable tripod 200 is used to suspend the flux chamber 5 cm below the liquid level. Three hanging ports 101 are equidistantly arranged on the top of the flux chamber. The three branch hanging ropes 103 are suspended and converge into a main rope. The main rope is buckled on a hook 205 and is retracted up and down by a lightweight iron chain 201 to control the height of the flux chamber 100. A circular level (not shown) is provided on the top cover of the flux chamber 100 to ensure that the instrument is placed horizontally. Since the liquid level inside a general septic tank is relatively low, in order to locate the 5 cm intrusion height from a bird's-eye view, a circular ring with a width of 2-5 cm is fixed 5 cm above the bottom of the flux chamber. A high-gloss reflective sheet is coated on the circular ring and assembled into a reflective cap (i.e., a reflective board). If the indoor light is weak, light can be used to directly illuminate the reflective cap for tracing. The flux chamber is equipped with three 20mm diameter rigid ventilation tubes. The exhaust tube 301 and the circulating gas inlet tube 302 are connected to the 1 / 4-1 / 8 male threaded air pipe interface at the top of the 100 flux chamber. During extraction, a gas flow meter 303, a dryer 304, and a portable gas sampler 305 can be connected in between for on-site monitoring. Alternatively, a flow meter 303, an air pump 306, and a gas sampling bag 307 can be connected for bag sampling.

[0061] When using the liquid-surface-suspended gas flux collection device for low-light environments of the present invention to perform on-site gas detection, the specific operations are as follows:

[0062] 1. In typical scenarios with low liquid levels and weak lighting, such as septic tanks and anaerobic tanks, users can use the tripod support structure and iron chain adjustment mechanism to stably suspend the flux chamber, with the bottom of the flux chamber open and above the liquid surface, to a specified depth of 5 cm below the liquid surface. Combined with lighting, the operator uses a reflective cap to achieve accurate positioning and height control. When the test object is a liquid, the reflector of the flux chamber is the preferred method for determining levelness. When the test object is a solid-liquid two-phase with a high solid content, resulting in an uneven surface, a circular level can be used to observe whether the flux chamber is level.

[0063] 2. During the sampling process, the extraction tube is connected in series with the gas flow meter, dryer, and portable gas detector for on-site online monitoring; or the sample is collected in a closed manner through the sampling bag (driven by the air pump) for subsequent laboratory analysis;

[0064] Among them, when using a flux chamber for on-site gas detection, it is generally necessary to monitor the gas concentration at each time point in a closed container (when the lower end opening of the flux chamber is connected to the liquid surface) within 3 hours. It is generally a linear relationship. Through continuous detection within 3 hours (such as monitoring once every 20 minutes), a standard curve is established to determine the total amount of gas generated in 24 hours. During the detection process, the air pressure in the flux chamber 100 is detected by a micro-pressure digital pressure gauge 104, and the air pressure is adjusted in time; the gas extracted by the exhaust pipe 301 and monitored by the portable gas detector 305 is circulated back to the container through the air inlet pipe 302.

[0065] Example 2

[0066] The liquid-surface suspended gas flux collection device for low-light environments of the present invention was used to conduct a sampling experiment. The specific experiments and results are as follows:

[0067] 1. Basic information of monitoring sampling points

[0068] In order to carry out the analysis and research work of the China Rural Toilet Operation Effectiveness Monitoring Project, a pilot project survey was conducted in Gucheng County, Hebei Province in May 2025. A total of 6 villages were surveyed, and fecal and sewage samples were collected from 2 public toilets and 9 household toilets, including 6 double-urn toilets, 2 three-compartment toilets, and 3 traditional dry toilets. The relevant information of the points was collected, and the monitoring records are shown in Table 1. The permanent population is 2 to 7 people, and the septic tank volume is 0.76 to 10m 3 .

[0069] Table 1 Record contents of monitoring sampling points

[0070]

[0071] 2. Carbon Emissions Accounting

[0072] The Biogass 5000 was used to measure the concentrations of CO2, CH4, O2 and H2S at the monitoring sites, and the gas was collected in a bag. The concentrations of CO2, CH4 and N2O were measured in the laboratory using a gas chromatograph. The emission rates of greenhouse gases were further analyzed, and the annual greenhouse gas emissions of villages were estimated based on the population and the type of toilets.

[0073] 1. Biogas analysis method

[0074] The monitoring results of the Biogass 5000 are shown in Table 2. The Shuidongtun village was selected as a typical water closet site, and the Wuzhuang village was selected as a typical dry toilet site. The flux chamber gas circulation method was used for continuous multi-time point monitoring.

[0075] Table 2 Monitoring results of the Biogass 5000

[0076]

[0077] Table 2 (continued) Monitoring results of the Biogass 5000

[0078]

[0079] The CO2 emission concentrations of the double-pot fecal pollution in the Shuidongtun village were linearly fitted with time (Fig. 1). Figure 3 The CO2 emission slope of the double-pot 1 fecal pollution was 0.18653 mg / L / min (R 2 = 0.96), and the CO2 emission slope of the double-pot 2 fecal pollution was 0.1181 mg / L / min (R 2 = 0.94).

[0080] The CO2 and CH4 emission concentrations of the dry toilet fecal pollution in the Wuzhuang village were linearly fitted with time (Fig. 2). Figure 4 The CO2 emission slope of the fecal pollution in the storage tank was 0.32428 mg / L / min (R 2 = 0.99), and the CH4 emission slope was 0.03349 mg / L / min (R 2 = 0.96).

[0081] The CO2 and CH4 emission concentrations of each monitoring site were linearly fitted (Fig. 3). Figure 5 The slope was 0.08582 (R 2 = 0.95), indicating a strong correlation between CO2 and CH4.

[0082] Table 3 CO2 and CH4 emission rates of typical monitoring sites

[0083]

[0084] Table 3 shows the CO2 and CH4 emission rates at typical monitoring sites. The average CO2 emission rate for a typical double-urn flush toilet is 2.05 g / person / day, and the CH4 emission rate is 0.51 g / person / day. The CO2 emission rate for a typical dry toilet is 15.81 g / person / day, and the CH4 emission rate is 3.67 g / person / day. Shuidongtun Village has a total permanent population of 1,023, and Wuzhuang Village has a total permanent population of 1,360. The ratio of double-urn toilets to traditional dry toilets is 2:1. Shuidongtun Village's estimated annual CO2 emissions are 2,572.96 kg and 534.38 kg, respectively. Wuzhuang Village's estimated annual CO2 emissions are 4,882.92 kg and 777.48 kg, respectively.

[0085] 2. Gas chromatography

[0086] The monitoring results of the gas chromatograph are shown in Table 4. Shuidongtun Village was selected as a typical water toilet site and Wuzhuang Village was selected as a typical dry toilet site. The liquid surface hanging type gas flux collection device for low light environment of the present invention was used (wherein the sampling device is set as shown in the figure). Figure 2 Continuous multi-time point monitoring was performed using a flux chamber gas circulation method (as shown). Because three air bag samples were collected from both urns in Shuidongtun Village, the linear fit was not strong. Therefore, the greenhouse gas emission rate at the Shuidongtun Village site was based on the data from Wuzhuang Village.

[0087] Table 4 Greenhouse gas concentration monitoring results

[0088]

[0089] Table 4 (Continued) Greenhouse gas concentration monitoring results

[0090]

[0091] The CO2, CH4 and N2O emission concentrations of Wuzhuang Village dry toilet sewage were linearly fitted with time changes ( Figure 6 ), it can be seen that the CO2 emission slope of manure in the manure storage tank is 0.18544 mg / L / min (R 2 =0.96), CH4 emission slope was 0.04375 mg / L / min (R 2 =0.94), and the N2O emission slope was 0.0598 μg / L / min (R 2 =0.97).

[0092] Linear fitting was performed on the CO2 and CH4 emission concentrations at each monitoring point ( Figure 7 ), we can see that the slope is 0.15725(R 2 =0.77), which also shows that there is a certain correlation between CO2 and CH4.

[0093] The CO2, CH4 and N2O emission rates of the typical monitoring points are shown in Table 5. It can be seen that the average CO2 emission rate of the typical double-pot water closet is 2.25 g / person / d, the CH4 emission rate is 0.53 g / person / d, and the average N2O emission rate is 0.001 g / person / d. The CO2 emission rate of the typical dry toilet point is 14.75 g / person / d, the CH4 emission rate is 3.49 g / person / d, and the average N2O emission rate is 0.005 g / person / d. The permanent population of Shuidongtun Village is 1023, and the permanent population of Wuzhuang Village is 1360. The proportion of double-pot toilets and traditional dry toilets is 2:1. The annual CO2 emission of Shuidongtun Village is estimated to be 2395.95 kg, the annual CH4 emission is 566.32 kg, and the annual N2O emission is 0.871 kg. The annual CO2 emission of Wuzhuang Village is 3185.23 kg, the annual CH4 emission is 752.87 kg, and the annual N2O emission is 1.158 kg.

[0094] Table 5 CO2, CH4 and N2O emission rates of typical monitoring points

[0095]

[0096] 3. Comparison of two methods

[0097] The greenhouse gas emission concentrations obtained by the biogas analyzer method and the gas chromatograph method used by the sampling device of the present application are compared, and the outliers are removed. The CO2 and CH4 obtained by the two methods are in linear fitting relationship (R 2 > 0.90). The CO2 and CH4 emission rates of the double-pot water closet obtained by the gas chromatograph method are close. The Biogass5000 biogas analyzer used in this monitoring can be replaced by a portable device for on-site determination, and the GeoTech GA5000 landfill gas analyzer is also recommended.

[0098] In summary, the sampling device of the present application has the advantages of compact structure, accurate sampling and simple operation, and is particularly suitable for in-situ measurement of gas emission flux in closed and low-illumination environments such as septic tanks and sewage tanks. Its high adaptability and modular design provide an efficient and reliable technical path for on-site gas sampling and environmental monitoring, and have wide practical application and promotion prospects.

Claims

1. A liquid-surface suspended gas flux collection device for low-light environments, characterized in that: It includes a flux chamber, a reflective positioning assembly, a suspension support system and a gas sampling passage system; The flux chamber is provided with a suspension rope at the top and an opening at the bottom, wherein a hollow pressure channel and two gas collection channels are provided inside. One end of each of the hollow pressure channel and the gas collection channel passes through the top of the flux chamber and is free to the outside. The two gas collection channels are provided with a gas inlet and a gas outlet at one end outside the flux chamber, respectively; a pressure measuring device is provided at one end outside the flux chamber of the hollow pressure channel; The reflective positioning assembly includes a reflective plate, and the reflective plate is arranged on the outer wall of the bottom of the flux chamber; The suspension support system includes a bracket and an adjustment mechanism; the bracket is used to support and fix the entire device; the adjustment mechanism cooperates with the bracket and is connected to the suspension rope to control the vertical position of the flux chamber; The gas sampling pathway system includes an exhaust pipe, an air inlet pipe, a gas flow meter and a sampling device; one end of the exhaust pipe and the air inlet pipe are respectively connected to the gas inlet and the gas outlet; the other end of the exhaust pipe is connected to the sampling device through the gas flow meter, and the air inlet pipe is also connected to the sampling device.

2. The liquid surface suspended gas flux collection device for low light environment according to claim 1, characterized in that: The suspension ropes include a plurality of branch suspension ropes and a main rope. The plurality of branch suspension ropes are fixed at equal intervals along the circumferential direction along the top surface of the flux chamber and are fixed to the main rope with uniform force.

3. The liquid-surface-suspended gas flux collection device for low-light environments according to claim 2, characterized in that: The flux chamber is cylindrical; The top surface of the flux chamber is provided with hanging openings at equal intervals along the circumference for fixing the branch hanging ropes.

4. The liquid surface suspended gas flux collection device for low light environment according to claim 1 or 2, characterized in that: The gas collection channel connected to the gas collection outlet in the flux chamber is shorter than the gas collection channel connected to the gas collection inlet, and a reflector is provided at the bottom of the gas collection channel connected to the gas collection inlet near the bottom of the flux chamber.

5. The liquid surface suspended gas flux collection device for low light environment according to claim 1 or 2, characterized in that: The reflective plate is radially arranged along the outer wall of the bottom of the flux chamber; A circular level is also provided on the top of the flux chamber.

6. The liquid surface suspended gas flux collection device for low light environment according to claim 1 or 2, characterized in that: The reflective plate comprises a reflective cap and a reflective sticker, and the reflective sticker is adhered to the surface of the reflective cap.

7. The liquid-surface-suspended gas flux collection device for low-light environments according to claim 1 or 2, characterized in that: The support comprises a retractable tripod, and the adjustment mechanism comprises a chain and a chain retainer; The chain passes through the chain holder provided at the intersection of the central axis of the telescopic tripod and is fixed thereto.

8. The liquid surface suspended gas flux collection device for low light environment according to claim 1 or 2, characterized in that: The pressure measuring device includes a micro-pressure digital display barometer.

9. The liquid surface suspended gas flux collection device for low light environment according to claim 1 or 2, characterized in that: The sampling device includes a gas dryer and a portable gas detector; The portable gas detector is connected to the gas extraction pipe through the gas dryer and the gas flow meter which are connected in sequence, and is used for online detection of collected gas samples.

10. The liquid surface suspended gas flux collection device for low light environment according to claim 1 or 2, characterized in that: The sampling device includes an air pump and a sampling bag; The sampling bag is connected to the air pump, the gas flow meter and the air extraction pipe through the sequentially connected ones, and is used for collecting gas samples.

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