Cyclic test system for detecting use effect of bactericide and use method of cyclic test system

Abstract

The invention discloses a circulation test system for detecting the using effect of a bactericide and a using method thereof.The system comprises a test solution pool, a gas injection pipe, a constant flow pump, a flow dividing pipe, one or more test pools and a solution backflow pipe, and the gas injection pipe is installed on a sealing cover of the test solution pool and extends into the lower portion of the test solution pool; one end of the constant-flow pump is communicated with the bottom outlet end of the test solution tank, and the other end is connected with the first end of the shunt pipe; the second end of the shunt pipe is communicated with the test solution tank through a solution return pipe; and the test pool is connected to the middle part of the shunt pipe. The number of the test pools can be increased according to requirements, high-throughput testing of the bactericide is achieved, and the evaluation efficiency is greatly improved. The method can also be used for extracting the biological membrane in a specific environment, and a method is provided for effectively collecting the biological membrane and carrying out fine characterization.

Description

Technical Field

[0001] The present invention relates to the technical field of corrosion and protection in the oil and gas industry, and particularly relates to a circulation test system for detecting the use effect of a bactericide and a method for using the same. Background Art

[0002] With the large-scale application of enhanced oil and gas field injection measures, microbial corrosion has become the main reason threatening the service safety of oil and gas field pipelines. In order to prevent and control microbial corrosion of oil and gas field gathering pipelines, a technical solution of adding a bactericide to the production system is currently commonly used. The evaluation of the use effect of the bactericide is crucial for the control of microbial corrosion in oil and gas fields. However, the existing bactericide evaluation methods focus on detecting the killing effect of the bactericide on planktonic bacteria in aqueous solution, while ignoring the detection of the killing effect on the attached bacteria under the biofilm. For microbial corrosion in oil and gas fields, the attached bacteria under the biofilm are the key to inducing corrosion and causing the ultimate failure of the pipeline. Due to the lack of a test system for detecting the application effect of the bactericide on the bacteria under the biofilm, the use effect of the bactericide cannot be effectively evaluated.

[0003] A method for quantitatively detecting attached sulfate-reducing bacteria and a biofilm sampling device used therefor disclosed in CN101302557A uses the biofilm sampling device to remove the biofilm, and through steps such as bacterial preparation, serial dilution, PCR operation, amplification, electrophoresis detection, and table lookup and recording, detects the attached biofilm on the tank wall and pipe wall, but cannot detect the use effect of the bactericide. A method for measuring the biofilm on the inner wall of an oilfield sewage pipeline and biofilm analysis disclosed in CN102517377B uses a control device installed on the inner wall of the oilfield sewage pipeline to measure the biofilm of the pipeline through a test piece, and after retrieving it, detects it in the laboratory. This technology is installed on-site and cannot directly evaluate the killing effect of the bactericide on the bacteria under the biofilm. A method for rapidly evaluating the biofilm stripping ability of a bactericide disclosed in CN104198543A obtains the impedance value or capacitance value of each bactericide solution through electrochemical measurement, so as to evaluate the stripping ability of the concentration of the bactericide solution on the biofilm. This technology is an indirect measurement method, and there is no direct relationship between the impedance and capacitance characteristics of the biofilm and the number of bacteria below it. Therefore, it cannot evaluate the killing effect of the bactericide on the bacteria under the biofilm.

[0004] Therefore, there are still the following problems in the evaluation of the use effect of the bactericide for oil and gas field gathering pipelines: (1) directly detecting the killing effect of the bactericide on planktonic bacteria in aqueous solution cannot effectively control microbial corrosion; (2) there is a lack of a test system and method for directly detecting the killing effect of the bactericide on the bacteria under the biofilm. Summary of the Invention

[0005] The object of the present invention is to provide a cyclic test system for detecting the use effect of fungicides and its use method, which can directly evaluate the bactericidal effect under biofilms and provide guidance for the effective use of fungicides. To achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides a cyclic test system for detecting the use effect of fungicides, and the system includes,

[0007] a test solution pool, an air injection pipe, a constant flow pump, a shunt pipe, one or more test pools and a solution return pipe, wherein,

[0008] the air injection pipe is installed on the sealing cover of the test solution pool and extends into the lower part of the test solution pool; one end of the constant flow pump is connected to the bottom outlet end of the test solution pool, and the other end is connected to the first end of the shunt pipe;

[0009] the second end of the shunt pipe is connected to the test solution pool through the solution return pipe;

[0010] the test pool is connected to the middle part of the shunt pipe.

[0011] Furthermore, the test solution pool is equipped with a sealing cover;

[0012] the material of the test solution pool includes one of glass, plexiglass or polytetrafluoroethylene.

[0013] Furthermore, the air injection pipe is equipped with a disperser for dispersing gas in the test solution;

[0014] the material of the air injection pipe includes one of glass, plexiglass or polytetrafluoroethylene;

[0015] the inner diameter of the air injection pipe does not exceed 8 mm.

[0016] Furthermore, the disperser includes a porous ceramic disperser or a glass disperser.

[0017] Furthermore, the accuracy of the constant flow pump is greater than or equal to 1 mL / min.

[0018] Furthermore, the volume of the shunt pipe is less than or equal to 1 / 3 of the volume of the test solution pool.

[0019] Furthermore, the test pool includes an upper half test pool with internal threads and scales, a lower half test pool with external threads and scales, and a filter disc;

[0020] wherein, the upper half test pool and the lower half test pool are connected by threads, and the filter disc is fixedly placed at the opening part of the lower half test pool.

[0021] Further, the upper half test pool and the lower half test pool have the same capacity, and the capacity is greater than or equal to 15 mL.

[0022] Further, the filter disc includes a support layer and a filter membrane, and the filter membrane is disposed above the surface of the support layer.

[0023] Further, the system further includes a control valve, and the control valve is disposed between the shunt pipe and the test pool.

[0024] Further, the system further includes a bactericide syringe.

[0025] The bactericide syringe is used to add bactericide into the test pool.

[0026] In another aspect of the present invention, there is also provided a method for using a circulation test system for detecting the use effect of a bactericide as described above. The method includes:

[0027] Adding a bacteria-containing test solution and a bactericide into the test solution pool to form a mixed solution;

[0028] Injecting gas into the mixed solution through an injection pipe for pretreatment, and then pumping the pretreated mixed solution into the shunt pipe at a constant flow rate by a constant flow pump;

[0029] When the amount of the mixed solution in the shunt pipe exceeds 1 / 2 of its capacity, adjusting the control valve to make the mixed solution enter the test pool for sterilization;

[0030] After the sterilization is completed, disassemble the test pool, collect the biofilm sample on the filter membrane in the filter disc to detect the number of bacteria, collect the solution in the lower half test pool to detect the residual concentration of the bactericide and the number of bacteria, and detect the use effect of the bactericide.

[0031] Further, the liquid level height of the solution in the test pool exceeds the height of the filter disc by at least 1 cm.

[0032] In another aspect of the present invention, there is also provided a method for using a circulation test system for detecting the use effect of a bactericide. The method includes:

[0033] Adding a bacteria-containing test solution into the test solution pool;

[0034] Injecting gas into the bacteria-containing test solution through an injection pipe for pretreatment, and then pumping the pretreated test solution into the shunt pipe at a constant flow rate by a constant flow pump;

[0035] When the amount of the solution in the shunt pipe exceeds 1 / 2 of its capacity, adjusting the control valve to make the bacteria-containing test solution enter the test pool;

[0036] At regular intervals, a bactericide injector is used to add bactericide to the bacteria-containing test solution in the test pool for sterilization.

[0037] After the sterilization is completed, the test pool is disassembled. The biofilm sample on the filter membrane of the filter is collected to detect the number of bacteria. The solution in the lower half of the test pool is collected to detect the residual concentration of the bactericide and the number of bacteria, and the use effect of the bactericide is detected.

[0038] Furthermore, the liquid level height of the solution in the test pool exceeds the height of the filter by at least 1 cm.

[0039] The technical effects and advantages of the present invention:

[0040] 1. The present invention can synchronously detect the number of bacteria under the biofilm, the residual concentration of the bactericide, and the number of bacteria in the solution, solving the problem that it is difficult to evaluate the use effect under the biofilm in the current evaluation of oil and gas field bactericides.

[0041] 2. The present invention injects bactericides into the test pool at different intervals, which can synchronously realize the screening and evaluation of different concentrations of the same bactericide and the evaluation of the use effects of different bactericides, avoiding the errors caused by the deviation of the number of bacteria in the bacteria-containing test solution that may exist in different batches of experiments, and realizing the high-throughput evaluation of bactericides.

[0042] 3. The present invention adds the bactericide together with the test solution, which can synchronously realize the use effect of the bactericide at a given concentration at different sterilization times, so as to quickly determine the optimal action time of the bactericide.

[0043] 4. The present invention can also increase the number of test pools according to requirements to realize the high-throughput test of bactericides and greatly improve the evaluation efficiency.

[0044] 5. The present invention can also be used for the extraction of biofilms in specific environments, providing a method for effectively collecting biofilms and carrying out fine characterization.

[0045] Other features and advantages of the present invention will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained by the structures pointed out in the specification and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a schematic diagram of a circulation test system for detecting the use effect of a bactericide in a specific embodiment of the present invention;

[0047] Figure 2 It is a schematic diagram of a test pool in a specific embodiment of the present invention.

[0048] In the figure, 1 is the test solution pool; 2 is the gas injection pipe; 3 is the constant flow pump; 4 is the shunt pipe; 5 is the control valve; 6 is the test pool; 7 is the filter disc; 8 is the bactericide syringe; 9 is the solution return pipe; 6-1-1 is the upper half test pool; 6-1-2 is the lower half test pool. Specific embodiments

[0049] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0050] To solve the deficiencies of the prior art, the present invention discloses a circulating test system for detecting the use effect of bactericides, as Figure 1 , the system includes a test solution pool 1, a gas injection pipe 2, a constant flow pump 3, a shunt pipe 4, one or more test pools 6, a control valve 5, a bactericide syringe 8, and a solution return pipe 9, wherein,

[0051] The gas injection pipe 2 is installed on the sealing cover of the test solution pool 1 and extends into the lower part of the test solution pool 1. The outlet of the gas injection pipe 2 is equipped with a disperser of porous ceramics (or glass) to better disperse the gas in the test solution; one end of the constant flow pump 3 is connected to the bottom outlet end of the test solution pool 1, and the other end is connected to the first end of the shunt pipe 4; the second end of the shunt pipe 4 is connected to the test solution pool 1 through the solution return pipe 9; the control valve 5 is arranged between the shunt pipe 4 and the test pool 6, and the control valve 5 controls the solution flow rate from the shunt pipe 4 to the test pool 6. The test pool 6 is connected to the middle of the shunt pipe 4. The bactericide syringe 8 is used to add bactericides to the test pool 6 as needed to control the concentration of bactericides.

[0052] In a specific embodiment of the present invention, the test solution pool 1 contains a test solution, the purpose of which is to provide a solution for the entire test system. When considering multiple test solutions, multiple parallel test solution pools 1 can be configured. The sample solution pool 1 is made of materials that are not easily corroded, such as glass, plexiglass, and polytetrafluoroethylene, and the capacity range is 1-10L. The sample solution pool 1 should be equipped with a sealing cover.

[0053] In a specific embodiment of the present invention, the material of the gas injection pipe 2 includes one of glass, plexiglass, or polytetrafluoroethylene; the inner diameter of the gas injection pipe 2 does not exceed 8 mm. The gas injection pipe 2 is equipped with a disperser for dispersing the gas in the test solution; the disperser includes a porous ceramic disperser or a glass disperser.

[0054] In a specific embodiment of the present invention, the shunt pipe 4 is made of transparent materials such as glass and plexiglass, and its volume does not exceed 1 / 3 of the volume of the test solution pool 1 to ensure continuous circulation of the overall solution. When the shunt pipe 4 needs to withstand a certain pressure, corrosion-resistant materials such as stainless steel, nickel-based alloy, and titanium alloy can be used to prepare the shunt pipe 4, and an appropriate wall thickness is selected to be sufficient to withstand the required pressure. The volume of the shunt pipe 4 is less than or equal to 1 / 3 of the volume of the test solution pool 1.

[0055] In a specific embodiment of the present invention, as Figure 2 shown, the test pool 6 is composed of an upper half test pool 6-1-1 with internal threads and graduations, a lower half test pool 6-1-2 with external threads and graduations, and a filter disc 7. The upper half test pool 6-1-1 and the lower half test pool 6-1-2 are connected by threads, and the filter disc 7 is fixedly placed at the opening of the lower half test pool 6-1-2. The capacities of the upper half test pool 6-1-1 and the lower half test pool 6-1-2 are similar and should not be less than 15 mL. Four sets of combined test pools, named combined test pool 6-1, combined test pool 6-2, combined test pool 6-3, and combined test pool 6-4, can carry out different test contents in the same batch of tests. Among them, 6-1 is used as a comparison test (i.e., without adding fungicides), and different concentrations of fungicides can be added to the other three test pools 6-2, 6-3, and 6-4 through the fungicide syringe 8 to evaluate the effects of different fungicides. The same concentration of fungicide can also be added through the fungicide syringe 8 as multiple sets of parallel tests to evaluate the relative deviation of the test results.

[0056] In a specific embodiment of the present invention, the filter disc 7 is composed of a support layer and a filter membrane, and its purpose is to support the formation of biofilms but not to hinder the passage of solutions (including fungicides). After the test, the biofilm attached to the surface filter membrane of the filter disc 7 can be used for detecting the number of bacteria under the biofilm, and the solution that enters the lower half test pool 6-1-2 through the filter disc 7 is used for testing the residual concentration of fungicides and detecting the number of bacteria.

[0057] In a specific embodiment of the present invention, the solution return pipe 9 returns the solution at the outlet of the shunt pipe 4 to the test solution pool 1 for recycling.

[0058] In the second aspect of the present invention, the present invention also provides a method for using a circulating test system for detecting the use effect of fungicides. The method includes,

[0059] Add a bacterial test solution and a bactericide to the test solution pool 1 to form a mixed solution; inject gas into the mixed solution through the injection pipe 2 for pretreatment, and then pump the pretreated mixed solution into the shunt pipe 4 at a constant flow rate by the constant flow pump 3; when the amount of the mixed solution in the shunt pipe 4 exceeds 1 / 2 of its capacity, adjust the control valve 5 to make the mixed solution enter the test cell 6, and ensure that the amount of the solution in the combined test cell exceeds the filter disc 7 by at least 1 cm for sterilization; after the sterilization is completed, disassemble the test cell 6, collect the biofilm sample on the filter membrane in the filter disc 7 to detect the number of bacteria, collect the solution in the lower half of the test cell 6-1-2 to detect the residual concentration of the bactericide and the number of bacteria, and detect the use effect of the bactericide. When multiple solutions need to be circulated in the test system, multiple groups of test solution pools 1 can be arranged in parallel to conduct corresponding circulation tests. Using this method, the use effects of a bactericide at a given concentration at different sterilization times can be realized synchronously, so as to quickly determine the optimal action time of the bactericide.

[0060] In the third aspect of the present invention, the present invention also provides a method for using a circulation test system for detecting the use effect of a bactericide, which is characterized in that the method includes,

[0061] Add a bacterial test solution to the test solution pool 1;

[0062] Inject gas into the bacterial test solution through the injection pipe 2 for pretreatment, and then pump the pretreated test solution into the shunt pipe 4 at a constant flow rate by the constant flow pump 3;

[0063] When the amount of the solution in the shunt pipe 4 exceeds 1 / 2 of its capacity, adjust the control valve 5 to make the bacterial test solution enter the test cell 6, and the amount of the solution in the test cell 6 exceeds the height of the filter disc 7 by at least 1 cm;

[0064] At an interval of a predetermined time, for example, after a period of time (such as 3d, 7d, 14d, etc.) after the test solution is added, add the bactericide to the bacterial test solution in the test cell 6 using the bactericide syringe 8 for sterilization;

[0065] After the sterilization is completed, disassemble the test cell 6, collect the biofilm sample on the filter membrane in the filter disc 7 to detect the number of bacteria, collect the solution in the lower half of the test cell 6-1-2 to detect the residual concentration of the bactericide and the number of bacteria, and detect the use effect of the bactericide. Using this method, the screening and evaluation of different concentrations of the same bactericide and the use effect evaluation of different bactericides can be realized synchronously, avoiding the errors caused by the deviation of the control of the number of bacteria in the bacterial test solution in different batches of experiments, and realizing the high-throughput evaluation of the bactericide.

[0066] Using the system of the present invention, it is possible to synchronously detect the number of bacteria under the biofilm, the residual concentration of the bactericide, and the number of bacteria in the solution. This solves the problem that it is difficult to evaluate the use effect under the biofilm in the current evaluation of oil and gas field bactericides.

[0067] The technical solution of the present invention will be further described below in conjunction with specific embodiments.

[0068] Example 1:

[0069] A cyclic test system for detecting the use effect of a bactericide, comprising a test solution pool 1, an injection pipe 2, a constant flow pump 3, a shunt pipe 4, a control valve 5, a combined test pool 6, a filter 7, a bactericide syringe 8, and a solution return pipe 9. The test solution is a simulated oilfield produced water containing 10 6 cells / mL of SRB. An enhanced quaternary ammonium salt is used as the bactericide, and the injection concentrations are 30 ppm, 50 ppm, and 80 ppm respectively. The capacities of the upper test pool 6-1-1 and the lower test pool 6-1-2 in the combined test pool 6 are both 50 mL. Among them, the combined test pool 6-1 is a comparative test pool (without adding bactericide), the combined test pool 6-2 is injected with 30 ppm bactericide, the combined test pool 6-3 is injected with 50 ppm bactericide, and the combined test pool 6-4 is injected with 80 ppm bactericide. The test solution and the bactericide are added to the combined test pool synchronously. After 14 days of the test, the biofilm sample and the solution sample under the biofilm are collected, and the number of SRB is detected by the extinction dilution method. The detection results without adding bactericide are: 10 15 cells / mL (under the biofilm), 10 4 cells / mL (in the solution). The detection results after adding 30 ppm bactericide are: 10 12 cells / mL (under the biofilm), 10 2 cells / mL (in the solution). The detection results after adding 50 ppm bactericide are: 10 10 cells / mL (under the biofilm), 25 cells / mL (in the solution). The detection results after adding 80 ppm bactericide are: 10 9 cells / mL (under the biofilm), 0 cells / mL (in the solution). It can be seen that the enhanced quaternary ammonium salt bactericide has a good killing effect on planktonic bacteria in the solution, and can effectively kill planktonic bacteria at 80 ppm, but the killing effect on bacteria under the biofilm is limited. Thus, a cyclic test system for detecting the use effect of a bactericide disclosed by the present invention can simultaneously detect the number of bacteria under the biofilm, the residual concentration of the bactericide, and the number of bacteria in the solution. This solves the problem that it is difficult to evaluate the use effect under the biofilm in the current evaluation of oil and gas field bactericides.

[0070] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A cyclic test system for detecting the use effect of a bactericide, characterized in that, The system includes a test solution pool (1), an air injection pipe (2), a constant flow pump (3), a shunt pipe (4), one or more test pools (6) and a solution return pipe (9), where the air injection pipe (2) is installed on the sealing cover of the test solution pool (1) and extends into the lower part of the test solution pool (1); one end of the constant flow pump (3) is connected to the bottom outlet end of the test solution pool (1), and the other end is connected to the first end of the shunt pipe (4); the second end of the shunt pipe (4) is connected to the test solution pool (1) through the solution return pipe (9); the test pool (6) is connected to the middle of the shunt pipe (4).

2. The cyclic test system for detecting the use effect of a bactericide according to claim 1, characterized in that, The test solution pool (1) is equipped with a sealing cover; the material of the test solution pool (1) includes one of glass, plexiglass or polytetrafluoroethylene.

3. The cyclic test system for detecting the use effect of a bactericide according to claim 1, characterized in that, The air injection pipe (2) is provided with a disperser for dispersing gas in the test solution; the material of the air injection pipe (2) includes one of glass, plexiglass or polytetrafluoroethylene; the inner diameter of the air injection pipe (2) does not exceed 8 mm.

4. The cyclic test system for detecting the use effect of a bactericide according to claim 3, characterized in that, The disperser includes a porous ceramic disperser or a glass disperser.

5. The cyclic test system for detecting the use effect of a bactericide according to claim 1, characterized in that, The accuracy of the constant flow pump (3) is greater than or equal to 1 mL / min.

6. The cyclic test system for detecting the use effect of a bactericide according to claim 1, characterized in that, The volume of the shunt pipe (4) is less than or equal to 1 / 3 of the volume of the test solution pool (1).

7. The cyclic test system for detecting the use effect of a bactericide according to claim 1, characterized in that, The test pool (6) includes an upper half test pool (6-1-1) with internal threads and scales, a lower half test pool (6-1-2) with external threads and scales, and a filter disc (7); wherein, the upper half test pool (6-1-1) and the lower half test pool (6-1-2) are connected by threads, and the filter disc (7) is fixedly placed at the opening part of the lower half test pool (6-1-2).

8. The cyclic test system for detecting the use effect of a bactericide according to claim 7, characterized in that, The upper half test pool (6-1-1) and the lower half test pool (6-1-2) have the same capacity, and the capacity is greater than or equal to 15 mL.

9. The cyclic test system for detecting the use effect of a bactericide according to claim 7, characterized in that, The filter disc (7) includes a support layer and a filter membrane, and the filter membrane is arranged above the surface of the support layer.

10. The cyclic test system for detecting the use effect of a bactericide according to any one of claims 1-9, characterized in that, The system further includes a control valve (5), and the control valve (5) is arranged between the shunt pipe (4) and the test pool (6).

11. A cyclic test system for detecting the use effect of a fungicide according to any one of claims 1-9, characterized in that, The system further includes a bactericide syringe (8). The bactericide syringe (8) is used to add bactericide into the test pool (6).

12. A method for using a cyclic test system for detecting the use effect of a fungicide according to any one of claims 1-11, characterized in that, The method includes adding a bacteria-containing test solution and a bactericide into the test solution pool (1) to form a mixed solution; injecting gas into the mixed solution through the injection pipe (2) for pretreatment, and then pumping the pretreated mixed solution into the shunt pipe (4) at a constant flow rate by the constant flow pump (3); when the amount of the mixed solution in the shunt pipe (4) exceeds 1 / 2 of its capacity, adjusting the control valve (5) to make the mixed solution enter the test pool (6) for sterilization; after the sterilization is completed, disassembling the test pool (6), collecting the biofilm sample on the filter membrane in the filter disc (7) to detect the number of bacteria, collecting the solution in the test pool (6) to detect the residual concentration of the bactericide and the number of bacteria, and detecting the use effect of the bactericide.

13. According to the use method described in claim 12, characterized in that, The liquid level height of the solution in the test pool (6) exceeds the height of the filter disc (7) by at least 1 cm.

14. A method for using a cyclic test system for detecting the use effect of a fungicide according to any one of claims 1-11, characterized in that, The method includes adding a bacteria-containing test solution into the test solution pool (1); Gas is injected into the bacterial-containing test solution through the injection tube (2) for pretreatment, and then the pretreated test solution is pumped into the shunt tube (4) at a constant flow rate by the constant flow pump (3); When the solution volume in the shunt tube (4) exceeds 1 / 2 of its capacity, the bacterial-containing test solution is made to enter the test cell (6) by adjusting the control valve (5); At intervals of a predetermined time, a bactericide is added to the bacterial-containing test solution in the test cell (6) using the bactericide syringe (8) for sterilization; After the sterilization is completed, the test cell (6) is disassembled, and the biofilm sample on the filter membrane in the filter disc (7) is collected to detect the number of bacteria, and the solution in the lower half of the test cell (6-1-2) is collected to detect the residual concentration of the bactericide and the number of bacteria, so as to detect the use effect of the bactericide.

15. According to the use method described in claim 14, characterized in that, The liquid level height of the solution in the test cell (6) exceeds the height of the filter disc (7) by at least 1 cm.

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