A method for studying microbial corrosion of metals in soil under acid rain

Abstract

The invention discloses a method for studying the corrosion of metal in soil by microorganisms under the action of acid rain. The method comprises the following steps: placing pre-installed soil in a plurality of different discharge barrels of an experimental device, wherein the discharge barrels are installed on a plurality of pillars; conducting experimental soil samples: the soil samples are dried, ground, sieved, sterilized at high temperature, and inoculated with microorganisms such as sulfate-reducing bacteria; pre-embedding: metal test pieces to be studied are respectively buried in soil in different discharge barrels; spraying: a simulated acid rain solution is sprayed from the top of the soil in the discharge barrel through a pipe and a nozzle fixed above the discharge barrel to simulate a natural environment, and the sprayed liquid leaks from a through hole at the bottom of the discharge barrel; data acquisition: the corrosion rate of the metal test piece is monitored by an on-site corrosion measuring instrument; studying the synergistic effect of acid rain and microorganisms such as sulfate-reducing bacteria on buried metal corrosion, providing a scientific theoretical basis for formulating effective protective measures for buried metal materials under the condition of coexistence of acid rain and microbial corrosion, and reducing economic losses caused by material corrosion.

Description

Technical Field

[0001] The invention belongs to the fields of material science, environmental science, etc., and relates to a method for studying the corrosion of metals in soil by microorganisms under the action of acid rain. Background Art

[0002] Acid rain has become an international problem. China is the third largest acid rain area in the world after Europe and North America. Soil is one of the main recipients of acid rain. Under the action of acid rain, a series of complex changes will occur, such as soil acidification, and its physical and chemical properties will also change accordingly, thus affecting the corrosion of buried metals. Microbial corrosion is one of the important types of buried metal corrosion, among which the corrosion caused by sulfate-reducing bacteria is the most serious. Sulfate-reducing bacteria contain a hydrogenase that can use the hydrogen produced in the anode area to reduce sulfate to hydrogen sulfide. In the process of anaerobic electrochemical corrosion, it can act as a cathode depolarizer for metal corrosion. At present, scientific researchers have conducted a series of studies on the corrosion of buried metals under the action of acid rain or microorganisms alone, but there is no systematic research method on the corrosion of metals in soil environments under the synergistic action of acid rain and microorganisms such as sulfate-reducing bacteria, which leads to the corrosion of metal materials such as X80 steel, Q235 steel, aluminum, and copper materials, causing a large amount of economic losses. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a method for studying the corrosion of metals in soil by microorganisms under the action of acid rain.

[0004] The present invention is achieved through the following technical solutions.

[0005] The present invention provides a method for studying the corrosion of metals in soil by microorganisms under the action of acid rain, wherein the following steps are included:

[0006] Sampling: The pre-installed soil is placed in a plurality of different discharge barrels (1) of the experimental device, and the discharge barrels (1) are installed on a plurality of pillars (2);

[0007] Experimental soil samples: The experimental soil samples were dried at 105°C for 6 hours, ground and sieved with a 10-mesh sieve, sterilized at high temperature, inoculated with microorganisms such as sulfate-reducing bacteria (SRB), and then mixed with a certain amount of distilled water until the soil sample was saturated with water; finally, they were placed in a discharge barrel sterilized with alcohol, compacted, sealed, and set aside;

[0008] Pre-embedding: burying metal test pieces made of X80 steel, Q235 steel, aluminum and copper in the soil in different discharge barrels (1);

[0009] Spraying: The simulated acid rain solution is sprayed from the top of the soil in the discharge barrel (1) through the pipe (4) and the nozzle (5) fixed above the discharge barrel (1) to simulate the natural environment, and the sprayed liquid will leak from the through hole (11) at the bottom of the discharge barrel (1);

[0010] Data collection: According to different time periods, the corrosion rate of metal specimens such as X80 steel, Q235 steel, aluminum, and copper is monitored using an on-site corrosion tester.

[0011] Each of the different discharge barrels corresponds to a pipeline and a nozzle.

[0012] The discharge barrel is made of soil required for the experiment.

[0013] The multiple different discharge barrels are placed in the box body, which is separated by partitions. The top of the box body is sealed with a cover plate, so that each discharge barrel is separated into an independent space. The bottom of the box body is provided with through holes corresponding to different discharge barrels for leaking acid rain liquid; the bottom of the box body is supported by multiple legs.

[0014] An exhaust fan is installed in the through hole provided on the box body corresponding to each discharge barrel to simulate the corrosion rate of metal under different air circulation speeds under natural conditions.

[0015] A light heater is installed on the partition of each discharge barrel to simulate the corrosion rate of metal under different temperatures and light under natural conditions.

[0016] The beneficial effects of the present invention are as follows: the pre-installed soil is placed in a plurality of different discharge barrels of the experimental device, and the discharge barrels are installed on a plurality of pillars; experimental soil samples: the experimental soil samples are dried at 105° C. for 6 hours, sieved with a 10-mesh sieve after grinding, sterilized at high temperature, inoculated with microorganisms such as sulfate-reducing bacteria (SRB), and then mixed with a certain amount of distilled water until the water content in the soil samples is saturated; finally, they are respectively loaded into discharge barrels disinfected with alcohol, compacted, sealed, and used for standby; pre-embedded: metal test pieces such as X80 steel, Q235 steel, aluminum, copper, etc. are respectively embedded in the soil in different discharge barrels; Spraying: The simulated acid rain solution is sprayed from the top of the soil in the discharge barrel through the pipe and nozzle fixed above the discharge barrel to simulate the natural environment. The sprayed liquid will leak from the through-holes at the bottom of the discharge barrel; Data collection: According to different time periods, the corrosion rate of metal test pieces such as X80 steel, Q235 steel, aluminum, and copper is monitored with an on-site corrosion tester; The synergistic effect of acid rain and microorganisms such as sulfate-reducing bacteria on buried metal corrosion is studied, providing a scientific theoretical basis for formulating effective protective measures for buried metal materials in the presence of acid rain and microbial corrosion, thereby reducing economic losses caused by material corrosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the explosion structure of the experimental device used in the present invention;

[0018] Figure 2 It is a front view half-section schematic diagram of the experimental device used in the present invention.

[0019] In the figure: 1-discharging barrel; 2-support; 3-support leg; 4-pipeline; 5-nozzle; 6-box body; 7-cover plate; 8-partition plate; 9-exhaust fan; 10-light heater; 11-through hole. DETAILED DESCRIPTION

[0020] The technical solution of the present invention is further described below, but the scope of protection claimed is not limited to the description.

[0021] See also Figure 1 to Figure 2 shown.

[0022] The present invention provides a method for studying the corrosion of metals in soil by microorganisms under the action of acid rain, wherein the following steps are performed:

[0023] Sampling: The pre-installed soil is placed in a plurality of different discharge barrels (1) of the experimental device, and the discharge barrels (1) are installed on a plurality of pillars (2);

[0024] Experimental soil samples: The experimental soil samples were dried at 105°C for 6 hours, ground and sieved with a 10-mesh sieve, sterilized at high temperature, inoculated with microorganisms such as sulfate-reducing bacteria (SRB), and then mixed with a certain amount of distilled water until the soil sample was saturated with water; finally, they were placed in a discharge barrel sterilized with alcohol, compacted, sealed, and set aside;

[0025] Pre-embedding: burying metal test pieces made of X80 steel, Q235 steel, aluminum and copper in the soil in different discharge barrels (1);

[0026] Spraying: The simulated acid rain solution is sprayed from the top of the soil in the discharge barrel (1) through the pipe (4) and the nozzle (5) fixed above the discharge barrel (1) to simulate the natural environment, and the sprayed liquid will leak from the through hole (11) at the bottom of the discharge barrel (1);

[0027] Data collection: According to different time periods, the corrosion rate of metal specimens such as X80 steel, Q235 steel, aluminum, and copper is monitored using an on-site corrosion tester.

[0028] Each of the different discharge barrels 1 corresponds to a pipeline 4 and a nozzle 5 above the barrel.

[0029] The discharge barrel 1 is made of soil required for the experiment.

[0030] The multiple different discharge barrels 1 are placed in the box body 6, which is separated by partitions 8. The top of the box body 6 is sealed with a cover plate 7, so that each discharge barrel 1 is separated into an independent space. The bottom of the box body 6 is provided with through holes corresponding to different discharge barrels 1 for leaking acid rain liquid; the bottom of the box body 6 is supported by multiple legs 3.

[0031] An exhaust fan 9 is installed in the through hole provided on the box body 6 corresponding to each discharge barrel 1 to simulate the corrosion rate of metal under different air circulation speeds under natural conditions.

[0032] A light heater 10 is installed on the partition 8 of each discharge barrel 1 to simulate the corrosion rate of metal under different temperatures and light under natural conditions.

[0033] According to the above steps, the synergistic effect of acid rain and microorganisms such as sulfate-reducing bacteria on buried metal corrosion is studied, which provides a scientific theoretical basis for formulating effective protective measures for buried metal materials in the presence of acid rain and microbial corrosion, and reduces the economic losses caused by material corrosion.

Claims

1. A method for studying microbial corrosion of metals in soil under the action of acid rain, characterized in that: Follow these steps: Sampling: placing the pre-installed soil into a plurality of different discharge barrels (1) of the experimental device, wherein the discharge barrels (1) are installed on a plurality of pillars (2); Experimental soil samples: The experimental soil samples were dried at 105°C for 6 h, ground and sieved with a 10-mesh sieve, sterilized at high temperature, inoculated with sulfate-reducing bacteria, and then mixed evenly with a certain amount of distilled water until the soil sample was saturated with water; finally, they were placed in a discharge barrel sterilized with alcohol, compacted, and sealed for standby use; Pre-embedding: bury metal test pieces made of X80 steel, Q235 steel, aluminum, and copper in the soil in different discharge barrels (1); Spraying liquid: The simulated acid rain solution is sprayed from the top of the soil in the discharge barrel (1) through the pipe (4) and the nozzle (5) fixed above the discharge barrel (1) to simulate the natural environment, and the sprayed liquid will leak from the through hole (11) at the bottom of the discharge barrel (1); Data collection: According to different time periods, the corrosion rate of X80 steel, Q235 steel, aluminum and copper metal specimens was monitored using an on-site corrosion tester; Each of the different discharge barrels (1) has a corresponding pipe (4) and a nozzle (5) above it; The discharge barrel (1) is made of soil required for the experiment; A plurality of different discharge barrels (1) are placed in a box body (6), the box body (6) is separated by partitions (8), the top of the box body (6) is sealed with an upper cover plate (7), so that each discharge barrel (1) is separated into an independent space, and the bottom of the box body (6) is provided with through holes corresponding to different discharge barrels (1) for leaking acid rain liquid; the bottom of the box body (6) is supported by a plurality of legs (3); An exhaust fan (9) is installed in a through hole provided on the box body (6) corresponding to each discharge barrel (1) to simulate the corrosion rate of metal at different air circulation speeds under natural conditions; A light heater (10) is installed on the partition (8) of each discharge barrel (1) to simulate the corrosion rate of metal under different temperatures and light under natural conditions.

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