Pretreatment method for measuring soil exchangeable base composition

Abstract

The invention provides a pretreatment method for determining soil exchangeable salt composition, and relates to the technical field of soil detection, and the pretreatment method comprises the following steps: placing a weighed sample in a conical flask, adding ammonium acetate, shaking uniformly, and standing for one night; performing suction filtration by using suction filtration equipment, connecting a suction filtration flask to a suction filtration main pipeline, putting a Buchner funnel with a rubber plug on the suction filtration flask, and then putting filter paper into the Buchner funnel; pouring supernatant on the upper layer in the conical flask into a Buchner funnel with filter paper through conveying equipment; the interior of the conical flask is washed with ammonium acetate, so that all soil in the conical flask is transferred into the Buchner funnel; washing the soil sample in the Buchner funnel by using a washing bottle filled with ammonium acetate; according to the invention, the reaction of the sample is more complete, and the exchange is more thorough; the pretreatment efficiency is greatly improved, the loss of the glass rod with the rubber head is avoided, the blockage probability of an instrument is reduced, and the suction filtration speed in the early stage is higher.

Description

Technical Field

[0001] This invention relates to the field of soil testing technology, specifically to a pretreatment method for determining the composition of exchangeable bases in soil. Background Technology

[0002] Determining the exchangeable base composition of soil can assess the content and proportion of exchangeable cations (such as calcium, magnesium, potassium, and sodium) in the soil, reflecting soil fertility, acid-base buffering capacity, and salinization risk. Its significance lies in: guiding scientific fertilization and improving crop nutrient supply by adjusting base balance; determining soil acidification or alkalization trends, providing a basis for soil improvement; and in saline soil research, base composition data is crucial for salt type identification and remediation.

[0003] Furthermore, the determination of soil exchangeable base composition is a necessary item in soil survey. The instrument used for pretreatment of exchangeable base composition is mainly an electric centrifuge. Generally, the centrifuges used in laboratories can only hold a maximum of 8 samples. The processing steps require multiple centrifugations and multiple stirring with a glass rod with a rubber tip. This process has low efficiency, and each stirring with the glass rod with a rubber tip also results in the loss of the tested substances, making it inconvenient for large-scale testing. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a pretreatment method for determining the exchangeable base composition of soil, thereby solving the problems mentioned in the background art. The present invention enables more complete sample reaction and more thorough exchange; it greatly improves pretreatment efficiency, avoids wear and tear on glass rods with rubber tips, reduces the probability of instrument clogging, and allows for faster initial filtration.

[0005] To achieve the above objectives, the present invention provides a pretreatment method for determining the composition of exchangeable bases in soil, comprising the following steps:

[0006] S1. Place the weighed sample in an Erlenmeyer flask, add ammonium acetate, shake well, place the ammonium acetate on a shaker and shake, and let stand overnight.

[0007] S2. Use a vacuum filtration device to filter the filter. Connect the vacuum filtration flask to the main vacuum filtration pipe. Place the Buchner funnel with a rubber stopper on the vacuum filtration flask. Then put two filter papers into the Buchner funnel. The bottom is a microporous filter membrane, and a qualitative filter paper is placed on the microporous filter membrane.

[0008] S3. Install the settled conical flask on the conveying equipment, and pour the supernatant from the upper layer inside the conical flask into the Buchner funnel containing filter paper through the conveying equipment;

[0009] S4. Rinse the inside of the conical flask with ammonium acetate to transfer all the soil in the conical flask into the Buchner funnel installed on the suction flask;

[0010] S5. Rinse the soil sample in the Buchner funnel with a wash bottle containing ammonium acetate;

[0011] S6. When the clear liquid in the filtration flask reaches 200 ml, pour it into a volumetric flask and make up to volume. Then, determine the composition of exchangeable bases in the soil.

[0012] Furthermore, the ammonium acetate in step S1 is 50-80 ml of 1 mol·L⁻¹. -1 Ammonium acetate with a pH of 7.0 was used. The shaking time on the shaker was 2 hours, and the shaking speed was 180 rpm. -1 .

[0013] Furthermore, the filtration device includes an engine, a filtration bottle, and a Buchner funnel; the conveying device in step S3 includes a base, a rotating mechanism, and a conveying mechanism, and the installation of the conical bottle includes the following process: placing the conical bottle on the rotating mechanism, placing a collar on the surface of the conveying assembly at the top of the rotating mechanism, and pressing the collar down until the collar is pressed against the surface of the rotating mechanism.

[0014] Furthermore, the rotating mechanism includes a flip plate, a tray, and a turntable. The surface of the turntable is provided with a locking hole. After the collar is pressed onto the rotating mechanism, the locking rod at the bottom of the collar is inserted into the locking hole, and the locking rod part protruding to the outside of the tray is fixed with a nut. The collar is pressed against the surface of the conical bottle by the pressing ring at the top, and the entire conical bottle is pressed and fixed on the surface of the tray.

[0015] Furthermore, the conveying assembly is fitted onto the top of the conical flask, and the inside of the conveying assembly is connected to the external pressure pump via an injection pipe. The sealing plug in the conveying assembly is placed at the mouth of the conical flask, and the guide pipe in the conveying mechanism is pulled to press the end of the guide pipe into the inside of the conical flask.

[0016] Furthermore, an external air is pumped into the conical flask using a pressure pump. The end of the guide tube is pressed against the surface of the precipitate by a pressure pad. The pumped air draws the supernatant from the inside of the conical flask into the guide tube through the inlet and into the Buchner funnel.

[0017] Furthermore, step S4 also includes a rinsing process for the soil sample portion inside the conical flask: manually control the entire rotating mechanism to rotate until the flip plate is rotated to the top and rests against the limit stop, controlling the entire conical flask to reach a state where the flask mouth faces downwards and aligning the flask mouth with the top of the Buchner funnel.

[0018] Furthermore, before controlling the rotation mechanism to rotate, the cover plate of the conveying component is pulled up in advance, and the sealing plug is pulled out from the inside of the bottle mouth. At this time, the guide rod slides along the top of the conical bottle. After controlling the rotation mechanism to tilt the conical bottle, the soil inside the conical bottle is poured directly into the Buchner funnel.

[0019] Furthermore, an external pressure pump sprays ammonium acetate into the interior along the injection pipe, and a handwheel is turned to rotate the turntable in the middle of the tray, causing the entire conical flask to rotate, while the injection pipe remains in a fixed position. The ammonium acetate inside is sprayed into the inner wall of the rotating conical flask through the injection pipe to rinse the soil sample remaining on the inner wall.

[0020] Furthermore, in step S5, ammonium acetate is used to rinse the inside of the Buchner funnel until the leachate is completely free of Ca. 2+ Stop the reaction after it has started.

[0021] The beneficial effects of this invention are:

[0022] 1. This pretreatment method for determining the exchangeable base composition of soil allows for more complete sample reaction. Shaking the sample on a shaker for two hours followed by overnight standing results in more complete exchange compared to direct centrifugation, significantly improving pretreatment efficiency.

[0023] 2. This pretreatment method for determining the exchangeable base composition of soil has virtually no loss. Traditional methods require thorough mixing of the sample with a glass rod with a rubber tip after each centrifuge cycle, repeating this process 3-4 times. This process inevitably results in some sample loss. Furthermore, some soil samples contain leaf-like material, which floats on top of the clear liquid after centrifugation, easily causing instrument clogging. The improved method avoids these issues with the resulting clear liquid.

[0024] 3. The pretreatment method for determining the exchangeable base composition of soil uses a conveying device to transport the sample in the conical flask. The conveying component first squeezes out the supernatant on the inside, which can greatly reduce the impact on the bottom sediment, making the initial filtration speed faster. In the later stage, the bottom rotating mechanism and base can evenly and efficiently rinse the inside of the conical flask. Attached Figure Description

[0025] Figure 1 This is a flowchart of the pretreatment method for determining the composition of exchangeable bases in soil according to the present invention;

[0026] Figure 2 This is a structural diagram of the conveying equipment used in the processing method of the present invention;

[0027] Figure 3This is an exploded view of the rotating mechanism in the conveying device of the present invention;

[0028] Figure 4 This is a bottom structural diagram of the rotating mechanism of the present invention;

[0029] Figure 5 This is a schematic diagram of the installation of the conveying component and the conical bottle of the present invention;

[0030] Figure 6 This is an exploded view of the delivery component of the present invention;

[0031] Figure 7 This is a graph of the first set of measurement data after processing in an embodiment of the present invention;

[0032] Figure 8 This is a second set of measurement data graphs after processing in an embodiment of the present invention;

[0033] Figure 9 This is a graph of the third set of measurement data after processing in this embodiment of the invention;

[0034] In the diagram: 1. Base; 2. Rotating mechanism; 3. Conical flask; 4. Conveying assembly; 5. Column; 6. Base plate; 7. Limiting stop; 8. Rotating seat; 9. Tilting plate; 10. Support plate; 11. Turntable; 12. Locking hole; 13. Collar; 14. Pressing ring; 15. Notch; 16. Locking rod; 17. Handwheel; 18. Cover plate; 19. Sealing plug; 20. Connecting rod; 21. Guide ring; 22. Injection pipe; 23. Guide pipe; 24. Pressing pad; 25. Pressing hole; 26. Spray hole. Detailed Implementation

[0035] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0036] Please see Figures 1 to 9 The present invention provides the following technical solution: a pretreatment method for determining the composition of exchangeable bases in soil, comprising the following steps:

[0037] S1. Place the weighed sample in conical flask 3, add ammonium acetate, shake well, place the ammonium acetate on a shaker, and let it stand overnight. The ammonium acetate is 50-80 ml of 1 mol / L solution. -1 Ammonium acetate with a pH of 7.0 was used. The shaking time on the shaker was 2 hours, and the shaking speed was 180 rpm. -1 ;

[0038] S2. Use a vacuum filtration device to perform vacuum filtration. Connect the vacuum filtration flask to the main vacuum filtration pipeline. Place the Buchner funnel with a rubber stopper on the vacuum filtration flask. Then, put two filter papers in the Buchner funnel. The bottom is a microporous filter membrane. Place a qualitative filter paper on the microporous filter membrane. The vacuum filtration device includes an engine, a vacuum filtration flask, and a Buchner funnel.

[0039] S3. Install the conical flask 3 after it has been settling on the conveying equipment, and pour the supernatant from the upper layer inside the conical flask 3 into the Buchner funnel containing filter paper through the conveying equipment.

[0040] In this embodiment, a conveying device is used, which includes a base 1, a rotating mechanism 2, and a conveying assembly 4. The base 1 includes a column 5, a base plate 6, and a rotating seat 8. The rotating mechanism 2 includes a support plate 10, a tilting plate 9, and a turntable 11. The base plate 6 is welded to the top of the column 5. A limit stop bar 7 is welded to one side of the base plate 6. The rotating seat 8 is screwed to the edge of the surface of the base plate 6. The turntable 11 is embedded in the inner side of the support plate 10. A locking hole 12 is opened on the surface of the turntable 11. A handwheel 17 is welded to the bottom of the turntable 11. The tilting plate 9 is welded to the side of the support plate 10. The end of the tilting plate 9 is sleeved on the surface of the rotating seat 8.

[0041] A locking rod 16 is inserted into the locking hole 12. A collar 13 is welded to the top of the locking rod 16. A pressing ring 14 is integrally formed on the top of the collar 13. A notch 15 is provided on the side of the collar 13.

[0042] The conveying equipment includes a base 1, a rotating mechanism 2, and a conveying mechanism. The installation of the conical flask 3 includes the following process: placing the conical flask 3 on the rotating mechanism 2, fitting a collar 13 onto the surface of the conveying assembly 4 at the top of the rotating mechanism 2, pressing the collar 13 downwards until it is pressed against the surface of the rotating mechanism 2, fitting the conveying assembly 4 onto the top of the conical flask 3, and connecting the inner side of the conveying assembly 4 to the external pressure pump via an injection pipe 22, sealing the mouth of the conical flask 3 with a sealing plug 19 in the conveying assembly 4, pulling the guide pipe 23 in the conveying mechanism, pressing the end of the guide pipe 23 into the inner side of the conical flask 3, using the pressure pump to pump external air into the interior of the conical flask 3, pressing the end of the guide pipe 23 against the surface of the precipitate via a pressing pad 24, and using the pumped air to pump the supernatant inside the conical flask 3 into the guide pipe 23 from the inlet hole 25 and then into the Buchner funnel.

[0043] The rotating mechanism 2 includes a flip plate 9, a support plate 10 and a turntable 11. The surface of the turntable 11 is provided with a locking hole 12. After the collar 13 is pressed onto the rotating mechanism 2, the locking rod 16 at the bottom of the collar 13 is inserted into the locking hole 12, and the locking rod 16 that protrudes to the outside of the support plate 10 is fixed with a nut. The collar 13 is pressed against the surface of the conical bottle 3 by the pressing ring 14 at the top, and the entire conical bottle 3 is pressed and fixed on the surface of the support plate 10.

[0044] A conveying device is used to transport the sample in the conical flask 3, and the supernatant on the inner side is squeezed out first by the conveying component 4. This process can greatly reduce the impact on the bottom sediment, making the initial filtration speed faster. In the later stage, with the bottom rotating mechanism 2 and the base 1, the inside of the conical flask 3 can be rinsed evenly and efficiently.

[0045] S4. Rinse the inside of conical flask 3 with ammonium acetate to transfer all the soil in conical flask 3 into the Buchner funnel installed on the suction filtration flask.

[0046] In this embodiment, a conveying assembly 4 is used. The conveying assembly 4 includes a cover plate 18, a guide ring 21, a flow guiding pipe 23, and an injection pipe 22. A connecting rod 20 is integrally formed on the side of the cover plate 18, and a guide ring 21 is integrally formed at the end of the connecting rod 20. A sealing plug 19 is attached to the bottom of the cover plate 18. The flow guiding pipe 23 and the injection pipe 22 are inserted into the inner side of the cover plate 18. The guide ring 21 is sleeved on the outside of the mouth of the conical flask 3. The sealing plug 19 is used to insert into the inside of the mouth of the conical flask 3. The flow guiding pipe 23 is partially movably connected to the cover plate 18, and the injection pipe 22 is partially bonded and fixed to the cover plate 18. Spray holes 26 are provided at the end and side of the injection pipe 22. A pressing pad 24 is provided at the end of the flow guiding pipe 23, and a pressing hole 25 is provided on the side of the end of the flow guiding pipe 23.

[0047] Manually control the entire rotating mechanism 2 to rotate until the flip plate 9 is rotated to the top and rests against the limit stop 7, controlling the entire conical flask 3 to reach a state where the flask mouth faces downwards and aligns with the top of the Buchner funnel. Before controlling the rotation of the rotating mechanism 2, pull up the cover plate 18 of the conveying assembly 4 and pull out the sealing plug 19 from the inside of the flask mouth. At this time, the guide rod slides along the top of the conical flask 3. After controlling the rotating mechanism 2 to tilt the conical flask 3, directly pour the soil inside the conical flask 3 towards the inside of the Buchner funnel. The ammonium acetate is sprayed into the inside through the injection pipe 22 by the external pressure pump, and the turntable 11 in the middle of the tray 10 is rotated by rotating the handwheel 17, which drives the entire conical flask 3 to rotate, while the injection pipe 22 remains in a fixed position. The ammonium acetate inside is sprayed into the inner wall of the rotating conical flask 3 through the injection pipe 22 to rinse the soil sample remaining on the inner wall.

[0048] S5. Rinse the soil sample in the Buchner funnel with a wash bottle containing ammonium acetate, and continue rinsing the inside of the Buchner funnel with ammonium acetate until the leachate is completely free of Ca. 2+ Stop the reaction after it has started;

[0049] S6. When the clear liquid in the filtration flask reaches 200 ml, pour it into a volumetric flask and make up to volume. Then, determine the composition of exchangeable bases in the soil.

[0050] This pretreatment method for determining the exchangeable base composition of soil allows for more complete sample reaction. Shaking the sample on a shaker for two hours and then allowing it to stand overnight results in more complete exchange compared to direct centrifugation, significantly improving pretreatment efficiency. This method is virtually loss-free. Traditional methods require thorough mixing with a glass rod with a rubber tip after each centrifuge cycle, repeating this process 3-4 times, which causes some sample loss. Furthermore, some soil samples contain leaf-like material that floats to the top of the supernatant after centrifugation, easily causing instrument clogging. The improved method avoids this problem in the resulting supernatant.

[0051] This embodiment also provides the result data applied to the soil testing process using the above-described improved post-processing method, as detailed below:

[0052] Table 1: Results of the first set of measurement data

[0053]

[0054] The first set of measurement results data corresponding to the above is shown in the figure below. Figure 7 As shown.

[0055] Table 2: Results of the Second Set of Measurement Data

[0056]

[0057] The corresponding second set of measurement results data is shown in the figure above. Figure 8 As shown.

[0058] Table 3: Results of the third set of measurement data

[0059]

[0060] The corresponding third set of measurement results data is shown in the figure above. Figure 9 As shown.

[0061] The foregoing has shown and described the basic principles and main features of the present invention and its advantages. It will be apparent to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention.

[0062] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A pretreatment method for determining the composition of exchangeable bases in soil, characterized in that, Includes the following steps: S1. Place the weighed sample in an Erlenmeyer flask, add ammonium acetate, shake well, place the ammonium acetate on a shaker and shake, and let stand overnight. S2. Use a vacuum filtration device to filter the filter. Connect the vacuum filtration flask to the main vacuum filtration pipe. Place the Buchner funnel with a rubber stopper on the vacuum filtration flask. Then put two filter papers into the Buchner funnel. The bottom is a microporous filter membrane, and a qualitative filter paper is placed on the microporous filter membrane. S3. Install the settled conical flask on the conveying equipment, and pour the supernatant from the upper layer inside the conical flask into the Buchner funnel containing filter paper through the conveying equipment; S4. Rinse the inside of the conical flask with ammonium acetate to transfer all the soil in the conical flask into the Buchner funnel installed on the suction flask; S5. Rinse the soil sample in the Buchner funnel with a wash bottle containing ammonium acetate; S6. When the clear liquid in the filtration flask reaches 200 ml, pour it into a volumetric flask and make up to volume. Then, determine the composition of exchangeable bases in the soil.

2. The pretreatment method for determining the composition of exchangeable bases in soil according to claim 1, characterized in that: In step S1, the ammonium acetate is 50-80 ml of 1 mol·L⁻¹. -1 Ammonium acetate with a pH of 7.0 was used. The shaking time on the shaker was 2 hours, and the shaking speed was 180 rpm. -1 .

3. The pretreatment method for determining the composition of exchangeable bases in soil according to claim 1, characterized in that: The filtration equipment includes an engine, a filtration bottle, and a Buchner funnel; the conveying equipment in step S3 includes a base, a rotating mechanism, and a conveying mechanism. The installation of the conical bottle includes the following process: placing the conical bottle on the rotating mechanism, placing a collar on the surface of the conveying assembly at the top of the rotating mechanism, and pressing the collar down until the collar is pressed against the surface of the rotating mechanism.

4. The pretreatment method for determining the composition of exchangeable bases in soil according to claim 3, characterized in that: The rotating mechanism includes a flip plate, a tray, and a turntable. The surface of the turntable has a locking hole. After pressing the collar onto the rotating mechanism, the locking rod at the bottom of the collar is inserted into the locking hole, and the locking rod part that protrudes to the outside of the tray is fixed with a nut. The collar is pressed against the surface of the conical bottle by the pressing ring at the top, and the entire conical bottle is pressed and fixed on the surface of the tray.

5. The pretreatment method for determining the composition of exchangeable bases in soil according to claim 3, characterized in that: The conveying assembly is fitted onto the top of the conical flask, and the inside of the conveying assembly is connected to the external pressure pump via an injection pipe. The sealing plug in the conveying assembly is placed at the mouth of the conical flask. The guide pipe in the conveying mechanism is pulled, and the end of the guide pipe is pressed into the inside of the conical flask.

6. The pretreatment method for determining the composition of exchangeable bases in soil according to claim 5, characterized in that: External air is pumped into the conical flask using a pressure pump. The end of the flow channel is pressed against the surface of the precipitate by a pressure pad. The pumped air draws the supernatant from the inside of the conical flask into the flow channel through the inlet and into the Buchner funnel.

7. The pretreatment method for determining the composition of exchangeable bases in soil according to claim 4, characterized in that, Step S4 also includes the rinsing process of the soil sample portion inside the conical flask: manually control the entire rotating mechanism to rotate until the flip plate is rotated to the top and rests against the limit stop, control the entire conical flask to reach a state where the mouth of the flask is tilted downwards, and align the mouth of the flask with the top of the Buchner funnel.

8. The pretreatment method for determining the composition of exchangeable bases in soil according to claim 7, characterized in that: Before controlling the rotation mechanism to rotate, pull up the cover plate of the conveying component and pull the sealing plug out from the inside of the bottle mouth. At this time, the guide rod slides along the top of the conical bottle. After controlling the rotation mechanism to tilt the conical bottle, pour the soil inside the conical bottle directly into the Buchner funnel.

9. The pretreatment method for determining the composition of exchangeable bases in soil according to claim 8, characterized in that: Ammonium acetate is injected into the flask through an external pressure pump. The turntable in the middle of the tray is rotated by turning the handwheel, which rotates the entire conical flask. The flask remains in a fixed position in the injection pipe. Ammonium acetate is then injected into the inner wall of the rotating conical flask through the injection pipe to rinse the soil sample remaining on the inner wall.

10. The pretreatment method for determining the composition of exchangeable bases in soil according to claim 1, characterized in that: In step S5, ammonium acetate is used to rinse the inside of the Buchner funnel until the leachate is completely free of Ca. 2+ Stop the reaction after it has started.

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