A device and detection method for collecting soil odor emissions after the tail vegetables are covered with soil and buried

Abstract

The present invention discloses a device and a detection method for collecting soil odor emissions after the tail vegetables are covered with soil and buried, comprising a cylindrical air chamber for collecting ammonia and a static box for collecting hydrogen sulfide, the side of the cylindrical air chamber is provided with a connecting card slot, the side of the static box is provided with a connecting card that is engaged with the connecting card slot, the top of the outer wall of the cylindrical air chamber is fixedly provided with four stainless steel rain shield brackets symmetrical with respect to the center of the cylindrical air chamber, the top of the rain shield bracket is fixedly provided with a rain shield, the cylindrical air chamber is provided with a top sponge and a bottom sponge, and the top sponge and the bottom sponge are injected with a phosphate glycerol mixture. The advantages of the present invention are: the cylindrical air chamber can be used to collect ammonia, the static box is used to collect hydrogen sulfide, the rain shield can prevent rainwater from contaminating the collected samples, the collection effect is good, the sensitivity and accuracy are high, there are few interfering substances, the operation is simple and easy, and it is convenient for field monitoring.

Description

Technical Field

[0001] The invention relates to the technical field of gas collection and detection, and in particular to a device and a method for collecting odor emissions from soil after the tail vegetables are covered with soil and buried. Background Art

[0002] Yuzhong County, Lanzhou City has become the largest main production area and distribution center of "highland summer vegetables" in Gansu. From June to October every year, a large amount of vegetable residues / vegetable waste (tail vegetables) is generated in the vegetable production and circulation links. The tail vegetables are produced in large quantities, have high water content, and are easy to rot. A large number of tail vegetables are piled up in fields, rivers and roadsides, producing a large amount of ammonia and hydrogen sulfide and other foul-smelling gases, polluting the suburban living environment. The semi-arid loess hilly area is adjacent to the tail vegetable production base and vegetable cold storage in Yuzhong County. The loess layer is rich and can reach a depth of 50-80m. The groundwater level is lower than 50m. After the tail vegetables are covered with soil and buried, they are converted into water and nutrients, which will not cause secondary pollution and have a strong absorption capacity. As a low-cost, simple and easy way to use local materials and achieve multiple goals at one stroke, the tail vegetable covering and burying technology can not only handle a large amount of tail vegetables, but also fertilize the soil and improve the quality of loess dryland soil. The burial sites of Lanzhou’s tail vegetable are mainly located in the loess hilly area with gullies and ravines, far away from residential areas and with few power facilities. It is impossible to use a portable automatic air sampler with a working power supply of 220V to collect air samples and detect them in time. It is very necessary to invent an effective device and method to obtain key data such as the emission of soil odorous gases (NH3 and H2S are key components) after the burial of tail vegetable in the loess hilly area. Summary of the invention

[0003] The purpose of the present invention is to solve the problems existing in the background technology and to provide a device and a method for collecting soil odor emissions after the tail vegetables are covered with soil and buried.

[0004] In order to solve the above technical problems, the technical solution provided by the present invention is: a soil odor emission collection device after the tail vegetables are covered with soil and buried, comprising a cylindrical air chamber for collecting ammonia and a static box for collecting hydrogen sulfide, the side of the cylindrical air chamber is provided with a connecting card slot, the side of the static box is provided with a connecting card that cooperates with the connecting card slot, the top of the outer wall of the cylindrical air chamber is fixedly provided with four stainless steel rain shield brackets symmetrical with respect to the center of the cylindrical air chamber, the top of the rain shield bracket is fixedly provided with a rain shield, the inner diameter of the cylindrical air chamber is 15 cm, the height is 20 cm, the bottom of the cylindrical air chamber extends 5 cm into the soil, and the distance between the rain shield and the air shield is 15 cm. The distance from the cylindrical air chamber is 5 cm. A top sponge and a bottom sponge are arranged in the cylindrical air chamber. A phosphate glycerol mixture is injected into the top sponge and the bottom sponge. The diameters of the top sponge and the bottom sponge are both 16 cm and the thicknesses are both 5 cm. The bottom sponge is arranged on the lower side of the top sponge. The distance between the bottom sponge and the soil is 5 cm. A box seat is arranged at the bottom of the static box. A temperature detection hole and an exhaust valve are arranged on the side of the static box. Two fans are arranged inside the static box. The box seat is buried in the soil. The bottom of the box seat is inserted into the soil by 5 cm. A sealed water tank with a depth of 2.5 cm and a width of 2 cm is arranged at the top of the box seat.

[0005] As a preferred solution, the cylindrical air chamber is made of polyvinyl chloride or methyl methacrylate.

[0006] As a preferred solution, the rain shield is made of polyvinyl chloride or methyl methacrylate.

[0007] As a preferred solution, the static box is a 50cm×50cm×50cm cube and is made of 3mm methyl methacrylate.

[0008] As a preferred solution, the box seat is a 50cm×50cm square and is made of stainless steel.

[0009] A detection method for a soil odor emission collection device after tail vegetables are covered with soil and buried, comprising the following steps: taking two 500ml plastic bottles, adding 300ml of 1mol / L potassium chloride solution into the two plastic bottles respectively, taking out the top sponge and the bottom sponge after collecting ammonia, and putting them into two 500ml plastic bottles respectively to make the sponges completely immersed therein, oscillating for 1h respectively, determining the ammonium nitrogen content in the extract, eluting the ammonia absorbed by the sponge, and determining the ammonia content in the soil and the air by indigo spectrophotometry; extracting 3L of gas in a static box by a 500ml syringe, and then evenly injecting the gas into an absorption bottle filled with absorption liquid, and determining the hydrogen sulfide content emitted from the soil by methylene blue spectrophotometry.

[0010] Preferably, the absorption liquid is a cadmium hydroxide-polyvinyl alcohol amine phosphate suspension.

[0011] The present invention has the following advantages: the structure design of the ammonia and hydrogen sulfide emission collection device after covering and burying is reasonable, the cylindrical air chamber can be used to collect ammonia, the static box is used to collect hydrogen sulfide, the rain shield can prevent rainwater from polluting the collected samples, and the top sponge and the bottom sponge are filled with glycerol phosphate mixed liquid, which can collect ammonia in the air and ammonia emitted from the soil respectively, without interfering with each other, and the collection effect is good. Provide a new optional method with high sensitivity and accuracy, less interfering substances, simple and easy operation, and convenient for field monitoring of soil NH3 and H2S emissions, especially suitable for the emission of soil NH3 and H2S after covering and burying the tail vegetables on the Loess Plateau. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The present invention is a schematic structural diagram of a device for collecting soil odor emissions after the tail vegetables are covered with soil and buried.

[0013] Figure 2 It is a curve test chart of ammonia (NH3) detection method.

[0014] Figure 3 It is a curve test chart of hydrogen sulfide (H2S) detection method.

[0015] Figure 4 This is a diagram showing the effect of soil covering pressure on soil hydrogen sulfide (H2S, a) and ammonia (NH3, b) emissions from greenhouse experiments.

[0016] Figure 5 This is a diagram showing the effect of soil covering pressure on soil hydrogen sulfide (H2S, a) and ammonia (NH3, b) emissions in field experiments.

[0017] As shown in the figure: 1. Cylindrical air chamber, 2. Static box, 3. Connecting slot, 4. Connecting card, 5. Rain shield bracket, 6. Rain shield, 7. Soil, 8. Top sponge, 9. Bottom sponge, 10. Box seat, 11. Temperature detection hole, 12. Exhaust valve, 13. Fan, 14. Sealed water tank.

[0018] Figure 2 , Figure 3 The horizontal axis OD represents absorbance, and the vertical axis ρ represents mass concentration.

[0019] Figure 4 , Figure 5 The horizontal axis Day represents the number of days. DETAILED DESCRIPTION

[0020] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0021] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0022] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings.

[0023] The preferred embodiments of the present invention are shown in the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0024] In conjunction with the accompanying drawings, a device for collecting soil odor emissions after the tail vegetables are covered with soil and buried, comprising a cylindrical air chamber 1 for collecting ammonia and a static box 2 for collecting hydrogen sulfide, the side of the cylindrical air chamber 1 is provided with a connecting card slot 3, the side of the static box 2 is provided with a connecting card 4 that cooperates with the connecting card slot 3, four stainless steel rain shield brackets 5 symmetrical with respect to the center of the cylindrical air chamber 1 are fixedly provided on the top of the outer wall of the cylindrical air chamber 1, and a rain shield 6 is fixedly provided on the top of the rain shield bracket 5. The inner diameter of the cylindrical air chamber 1 is 15 cm and the height is 20 cm. The bottom of the cylindrical air chamber 1 extends 5 cm into the soil 7, and the distance between the rain shield 6 and the cylindrical air chamber 1 is 5 cm. A top sponge 8 and a bottom sponge 9 are arranged in the cylindrical air chamber 1, and a glycerol phosphate mixture is injected into the top sponge 8 and the bottom sponge 9. The diameters of the top sponge 8 and the bottom sponge 9 are both 16 cm, and the thicknesses are both 5 cm. The bottom sponge 9 is arranged on the lower side of the top sponge 8, and the distance between the bottom sponge 9 and the soil 7 is 5 cm. A box seat 10 is arranged at the bottom of the static box 2, and a temperature detection hole 11 and an exhaust valve 12 are arranged on the side of the static box 2. Two fans 13 are arranged inside the static box 2. The box seat 10 is buried in the soil 7, and the bottom of the box seat 10 is inserted into the soil 7 by 5 cm. A sealed water tank 14 with a depth of 2.5 cm and a width of 2 cm is arranged at the top of the box seat 10.

[0025] The cylindrical air chamber 1 is made of polyvinyl chloride or methyl methacrylate. The rain shield 6 is made of polyvinyl chloride or methyl methacrylate. The static box 2 is a 50cm×50cm×50cm cube made of 3mm methyl methacrylate. The box seat 10 is a 50cm×50cm square made of stainless steel.

[0026] A detection method for a soil odor collection device after the tail vegetables are covered with soil and buried, comprising the following steps: taking two 500ml plastic bottles, adding 300ml of 1mol / L potassium chloride solution into the two plastic bottles respectively, taking out the top sponge and the bottom sponge after collecting ammonia, and putting them into two 500ml plastic bottles respectively to make the sponges completely immersed therein, shaking for 1h respectively, determining the ammonium nitrogen content in the extract, eluting the ammonia (NH3) absorbed by the sponge, and determining the soil emission and the ammonia content in the air by indigo spectrophotometry; using a 500ml syringe to extract 3L of gas in a static box, and then evenly injecting the gas into an absorption bottle filled with cadmium hydroxide-polyvinyl alcohol phosphate amine suspension, and determining the hydrogen sulfide content emitted from the soil by methylene blue spectrophotometry.

[0027] In the specific implementation of the present invention, the static box is a device that covers the static box on the box seat and seals it so that the air in the box has no exchange with the outside world. The static box (50cm×50cm×50cm cube, made of 3mm methyl methacrylate) is provided with a box seat (50cm×50cm square, made of stainless steel) at the bottom. Two sets of fans are installed inside the box body to mix the gas in the box. At the same time, a temperature sensor and a gas collection pipeline are provided, which are connected to the temperature detection hole and the air extraction valve equipment outside the static box through a wall joint. The box seat is buried in the experimental plot for a long time, the box seat wall is inserted into the soil by 5cm, and there is a sealed water tank with a depth of 2.5cm and a width of 2cm at the top of the box seat. Water is added to seal the box body and cover the soil during sampling. After a certain period of time, 3L of gas in the static box is extracted through the gas collection pipeline with a 500ml syringe, and then the gas is evenly injected into an absorption bottle filled with an absorption liquid (cadmium hydroxide-polyvinyl alcohol phosphate amine suspension), and the methylene blue spectrophotometry is used for determination.

[0028] Ammonia Detection Methods

[0029] Method detection limit test data: According to the technical provisions of method detection limit in Appendix A of "Technical Guidelines for the Formulation and Revision of Environmental Monitoring Analysis Method Standards" (HJ168-2010), when the target substance is detected in the blank test, follow all the steps of sample analysis, repeat n (n≥7) blank experiments, convert each measurement result into the concentration or content in the sample, calculate the standard deviation of n parallel measurements, and calculate the method detection limit according to formula (A.1). The specific data are shown in Table 1.

[0030] Table 1 Method detection limit test data table

[0031]

[0032] Method precision test data: The method precision was verified by actual sample determination. The curve range was 0.0-0.5μg / ml. Three different concentrations of ammonium sulfate solutions were placed in a circular gas chamber for 2h sampling. Each sample was measured 6 times in parallel, and the average value, standard deviation and relative standard deviation were calculated. The laboratory verification data were statistically analyzed according to the statistical method specified in Appendix A of HJ168-2010. The specific data are shown in Table 2.

[0033] Table 2 Precision test data table

[0034]

[0035] Method accuracy test data: The method accuracy was verified by self-prepared known concentration solution. According to the curve range of 0.0-0.5μg / ml, three different concentrations of high, medium and low quality control samples were selected within the curve range. Each quality control sample was measured 6 times in parallel, and the average value and relative error were calculated. The laboratory verification data were statistically analyzed according to the statistical method specified in Appendix A of HJ168-2010, as shown in Table 3.

[0036] Table 3 Method accuracy test data

[0037]

[0038] Hydrogen sulfide detection method

[0039] Method detection limit test data: According to the technical provisions of method detection limit in Appendix A of "Technical Guidelines for the Formulation and Revision of Environmental Monitoring Analysis Method Standards" (HJ168-2010), when the target substance is detected in the blank test, follow all the steps of sample analysis, repeat n (n≥7) blank experiments, convert each measurement result into the concentration or content in the sample, calculate the standard deviation of n parallel measurements, and calculate the method detection limit according to formula (A.1), see Table 4 for details.

[0040] Table 4 Method detection limit test data table

[0041]

[0042] Method precision test data: The method precision was verified by actual sample determination. The curve range was 0.0-0.50μg / ml. The sulfide standard solution was used to prepare high, medium and low solutions for determination. Six parallel determinations were performed for each concentration, and the average value, standard deviation and relative standard deviation were calculated. The laboratory verification data were statistically analyzed according to the statistical method specified in Appendix A of HJ168-2010. The specific data are shown in Table 5.

[0043] Table 5 Precision test data table

[0044]

[0045] Method accuracy test data: The method accuracy was verified by self-prepared known concentration solution. According to the curve range of 0.00-0.50μg / ml, three different concentrations of high, medium and low quality control samples were selected within the curve range. Each quality control sample was measured 6 times in parallel, and the average value and relative error were calculated. The laboratory verification data were statistically analyzed according to the statistical method specified in Appendix A of HJ168-2010, as shown in Table 6.

[0046] Table 6 Method accuracy test data

[0047]

[0048] Comparison of test data: The greenhouse test used the Nessler's reagent spectrophotometric method for the determination of ammonia in ambient air and waste gas (HJ533-2009) and the methylene blue spectrophotometric method for the monitoring and analysis methods of air and waste gas (fourth edition) to monitor the ammonia and hydrogen sulfide emissions after the tail vegetables were covered with soil and buried. Figure 4 ).Depend on Figure 4 (a) The test results show that on the sixth day of the test, the QC treatment had the highest H2S emission, reaching 0.17 mg / m -3 , which was significantly higher than the other treatments. JC1, JC2, JY and QT had similar H2S emissions, with no significant difference. With the extension of treatment time, the H2S emission of QC treatment decreased significantly, but was still significantly higher than the other treatments. Figure 4 (b) It can be seen that the NH3 emission from QC treatment on the sixth day after the start of the experiment was 4.02 mgm -3 , which was significantly higher than that of JC1, JC2, JY and QT treatments. On the 10th day, the NH3 emissions of all treatments increased significantly, but the QC treatment was still higher than that of JC1, JC2, JY and QT treatments. In particular, on the 17th day, the NH3 emissions of JC2 and JY treatments were only 1.98 and 2.38 mgm -3 , which was significantly lower than that of JC1 and QC treatment groups.

[0049] Figure 4 The effect of soil covering pressure of greenhouse vegetable tails on soil hydrogen sulfide (H2S, a) and ammonia (NH3, b) emissions. QC: whole vegetables; JC1: upper 10cm loess + middle layer of vegetable tails 10cm + lower 30cm loess; JC2: upper 20cm loess + middle layer of vegetable tails 10cm + lower 20cm loess; JY: upper 30cm is a uniform mixture of vegetable tails and soil + lower 20cm loess; QT: whole soil 50cm. Capital letters: significance level 0.01; lowercase letters: significance level 0.05.

[0050] In the loess hilly area of ​​Beishan, Yuzhong, we used this patented device and method to carry out a field experiment on the burial of tail vegetables, and monitored the soil ammonia and hydrogen sulfide emissions under different burial thickness and burial treatment combinations ( Figure 5 ).Depend on Figure 5 (a) It can be seen from the test results that on the 7th, 15th and 29th days after the tail vegetables were buried, the H2S emissions of the C1, C2 and C3 soil-covered treatment groups were only 0.01 mg / m -3 However, the peak of H2S emission in the waste vegetable pile treatment group (QC) appeared around the 7th day, reaching 0.11 mg / m -3, which is highly consistent with the greenhouse test data. On the 15th day, the H2S emission of the QC treatment group was still as high as 0.10mgm -3 On the 29th day, the emission decreased to 0.05 mg / m -3 .Depend on Figure 5 (b) It can be seen that the NH3 emission of the tail vegetable covered with soil was higher on the 7th day, and the highest value of all treatment groups was only 4.7 mg / m -3 , much lower than the QC group 19.7mgm -3 On the 15th and 29th days, the NH3 emission of the burial treatment group was much lower than 2.5 mg / m -3 , while the QC treatment group still had high NH3 emissions, up to 5.0 mgm -3 , which is highly consistent with the greenhouse test data.

[0051] Figure 5 The effect of soil pressure on the emission of hydrogen sulfide (H2S, a) and ammonia (NH3, b) in the field experiment was investigated. QC: whole vegetables; C1T1: 20 cm thick vegetables and 10 cm thick soil; C1T2: 20 cm thick vegetables and 20 cm thick soil; C1T3: 20 cm thick vegetables and 30 cm thick soil; C2T1: 40 cm thick vegetables and 10 cm thick soil; C2T2: 40 cm thick vegetables and 20 cm thick soil; C2T3: 40 cm thick vegetables and 30 cm thick soil; C3T1: 60 cm thick vegetables and 10 cm thick soil; C3T2: 60 cm thick vegetables and 20 cm thick soil; C3T3: 60 cm thick vegetables and 30 cm thick soil.

[0052] The technical features of the above-described embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above-described embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. The above-described embodiments only express several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present invention, several variations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A device for collecting soil odor emissions after the tail vegetables are covered with soil and buried, characterized in that: It comprises a cylindrical air chamber for collecting ammonia and a static box for collecting hydrogen sulfide, the side of the cylindrical air chamber is provided with a connecting card slot, the side of the static box is provided with a connecting card member that cooperates with the connecting card slot, the top of the outer wall of the cylindrical air chamber is fixedly provided with four stainless steel rain shield brackets that are symmetrical with respect to the center of the cylindrical air chamber, the top of the rain shield bracket is fixedly provided with a rain shield, the inner diameter of the cylindrical air chamber is 15 cm, the height is 20 cm, the bottom of the cylindrical air chamber extends 5 cm into the soil, the distance between the rain shield and the cylindrical air chamber is 5 cm, the cylindrical air chamber is provided with a top sponge and a bottom sponge, the top sponge and a glycerol phosphate mixture is injected into the bottom sponge, the diameters of the top sponge and the bottom sponge are both 16 cm, and the thicknesses are both 5 cm. The bottom sponge is arranged on the lower side of the top sponge, and the distance between the bottom sponge and the soil is 5 cm. A box seat is arranged at the bottom of the static box, and a temperature detection hole and an exhaust valve are arranged on the side of the static box. Two fans are arranged inside the static box, and the box seat is buried in the soil, and the bottom of the box seat is inserted into the soil by 5 cm. A sealed water tank with a depth of 2.5 cm and a width of 2 cm is arranged on the top of the box seat; the cylindrical air chamber is made of polyvinyl chloride or methyl methacrylate; the rain shield is made of polyvinyl chloride or methyl methacrylate.

2. The device for collecting odor emitted from soil after the tail vegetables are covered with soil and buried according to claim 1, characterized in that: The static box is a 50cm×50cm×50cm cube and is made of 3mm methyl methacrylate.

3. The device for collecting odor emission from soil after the tail vegetables are covered with soil and buried according to claim 1, characterized in that: The box seat is 50cm×50cm square and is made of stainless steel.

4. The detection method of the soil odor emission collection device after the tail vegetable is covered with soil and compressed according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: taking two 500ml plastic bottles, adding 300ml of 1mol / L potassium chloride solution into the two plastic bottles respectively, taking out the top sponge and the bottom sponge after collecting ammonia gas and putting them into the two 500ml plastic bottles respectively, so that the sponges are completely immersed therein, Oscillate for 1 hour respectively, determine the ammonium nitrogen content in the extract, elute the ammonia absorbed by the sponge, and determine the ammonia content in the soil and air by indigo spectrophotometry; use a 500ml syringe to extract 3L of gas in the static box, and then evenly inject the gas into the absorption bottle filled with absorption liquid, and determine the hydrogen sulfide content in the soil by methylene blue spectrophotometry.

5. The detection method of the soil odor emission collection device after the tail vegetables are covered with soil and compressed according to claim 4 is characterized in that: The absorption liquid is cadmium hydroxide-polyvinyl alcohol amine phosphate suspension.

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