Method and system for in-situ treatment of fluorine-containing mine water in cooperation with coal mine underground reservoir

Abstract

The invention relates to a method and system for in-situ treatment of fluorine-containing mine water in cooperation with a coal mine underground reservoir. The method comprises the following steps: S1, screening coal gangue of which the coal content is 5-20% and the particle size is less than or equal to 5mm; s2, fluorine-containing mine water or sediment collected near the site to be treated is used as a sample, the sample is subjected to screening, enrichment and domestication of mixed anaerobic flora, and efficient defluorination mixed bacteria are obtained; s3, the bacterial liquid of the efficient defluorination mixed bacteria and the coal gangue are subjected to mixed culture, and microbial biofilm culturing coal gangue is obtained; and S4, adding the microbial biofilm formation coal gangue into a material adding mechanism, and adding the microbial biofilm formation coal gangue into mine water of a coal mine underground reservoir through the material adding mechanism for defluorination treatment. According to the invention, in-situ defluorination can be carried out on the mine water of the coal mine underground reservoir, and the purification treatment effect of the coal mine underground reservoir on the mine water is greatly improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of defluorination of mine water, and in particular, to a method and a system for synergistically treating fluorine-containing mine water in-situ in a coal mine underground reservoir. Background Art

[0002] Fluoride pollution has become an important factor restricting the utilization of mine water resources. Currently, common defluorination methods include chemical precipitation method, coagulation precipitation method, ion exchange-adsorption method, electrochemistry method, etc. These methods need to introduce additional chemical reagents, which not only increase the cost but also may cause secondary pollution to the environment.

[0003] Patent document CN115072827A discloses a mine water purification system. When treating mine water, this system needs to apply a specific adsorption composition containing fly ash, cement and aggregate on the surface of fractured rock mass in a coal mine underground reservoir, and solidify to form an adsorption material covering film on the surface of the fractured rock mass. Once the underground reservoir is completed, the adsorption material covering film cannot be repaired anymore. The adsorption capacity of the adsorption material covering film is limited, and after a period of time, the defluorination effect decreases. Patent document CN110015781A discloses an efficient defluorination method for mine water. This method has a complex process and needs to use an electrolytic cell, activated alumina defluorination agent, etc., and can only perform off-site defluorination outside the coal mine underground reservoir.

[0004] In summary, the method for defluorinating mine water in a coal mine underground reservoir needs to be further improved. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the purpose of the present disclosure is to provide a method and a system for synergistically treating fluorine-containing mine water in-situ in a coal mine underground reservoir.

[0006] To achieve the above purpose, the first aspect of the present disclosure provides a method for synergistically treating fluorine-containing mine water in-situ in a coal mine underground reservoir, the method comprising the following steps: S1. Screening coal gangue with a coal content of 5-20% and a particle size ≤ 5 mm; S2. Using the fluorine-containing mine water or sediment collected near the site to be treated as a sample, and subjecting the sample to screening, enrichment and domestication of mixed anaerobic bacteria to obtain highly efficient defluorinating mixed bacteria; S3. Mixing and culturing the bacterial liquid of the highly efficient defluorinating mixed bacteria with the coal gangue to obtain microbial film-coated coal gangue; S4. Adding the microbial film-coated coal gangue to a feeding mechanism, and feeding the microbial film-coated coal gangue into the mine water of the coal mine underground reservoir through the feeding mechanism for defluorination treatment.

[0007] Optionally, step S2 further includes: S2-1. Mix the sample with normal saline for leaching treatment to obtain a leaching solution. S2-2. Add the leaching solution to an enrichment medium for enrichment culture to obtain an enrichment solution. S2-3. Add the enrichment solution to a domestication medium for domestication culture, transfer to a new generation every 5 - 10 days, and continuously transfer and domesticate for 15 - 30 generations to obtain the high-efficiency fluoride-removing mixed bacteria. Wherein, the fluoride content in the fluorine-containing mine water is greater than 1 mg / L.

[0008] Optionally, the viable count of the high-efficiency fluoride-removing mixed bacteria in the microbial biofilm-coated coal gangue is ≥ 10 6 CFU / g. Wherein, the dominant bacteria in the high-efficiency fluoride-removing mixed bacteria are anaerobic bacteria.

[0009] Optionally, step S4 further includes: Add the microbial biofilm-coated coal gangue to a feeding mechanism. When feeding into the underground coal mine reservoir, make the microbial biofilm-coated coal gangue in the feeding mechanism enter the inlet pipeline of the underground coal mine reservoir. Turn on the mine water control pump to make the mine water enter the inlet pipeline of the underground coal mine reservoir and carry the microbial biofilm-coated coal gangue into the mine water of the underground coal mine reservoir for fluoride removal treatment.

[0010] Optionally, after the fluoride removal treatment, the fluoride content in the treated mine water obtained is lower than 1 mg / L.

[0011] The second aspect of the present disclosure provides a system applicable to the method described in the first aspect. The system includes an underground coal mine reservoir, a feeding mechanism, a mine water control pump, and an automatic control device. The inlet of the underground coal mine reservoir is connected to the mine water control pump through an inlet pipeline of the underground coal mine reservoir. A feeding branch is provided at a position on the inlet pipeline of the underground coal mine reservoir close to the underground coal mine reservoir, and the inlet of the feeding branch is connected to the outlet of the feeding mechanism. The automatic control device is respectively signal-connected to the feeding mechanism and the mine water control pump, and is used to control the addition of the microbial biofilm-coated coal gangue and the power of the mine water control pump.

[0012] Optionally, the part of the inlet pipeline of the underground coal mine reservoir extending into the underground coal mine reservoir is set as a telescopic pipeline.

[0013] Optionally, the system further includes a detection device, and the detection device is signal-connected to the automatic control device; it is used to control the addition amount of the microbial biofilm-coated coal gangue according to the fluoride content of the mine water in the underground coal mine reservoir detected by the detection device in real time.

[0014] Optionally, the detection device includes a sampling tube and a detector. The sampling tube is arranged at intervals at the artificial dam of the underground coal mine reservoir and is connected to the detector, so that the detector can detect the fluorine content of the sample in the sample tube.

[0015] Optionally, the system further includes a pneumatic unit. The pneumatic unit includes an air pipe laid at the bottom of the underground coal mine reservoir. The inlet of the air pipe is connected to a blowing pump, and a blowing nozzle is arranged on the air pipe.

[0016] Through the above technical solutions, the present disclosure provides a method and a system for synergistically treating fluorine-containing mine water in situ in an underground coal mine reservoir. By utilizing the self-purification effect of the underground coal mine reservoir and simultaneously synergistically using the treatment means of microbial purification, the fluoride ions in the mine water are adsorbed, fixed or precipitated to achieve the purpose of removing fluoride ions. Through the method and system of the present disclosure, in-situ defluorination of the mine water in the underground coal mine reservoir can be realized, greatly improving the purification effect of the underground coal mine reservoir on the mine water. At the same time, using microorganisms to remove fluorine can reduce the use of defluorination agents and avoid environmental pollution caused by the use of agents.

[0017] Other features and advantages of the present disclosure will be described in detail in the subsequent specific implementation part. Brief Description of the Drawings

[0018] The drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific implementation manners, they are used to explain the present disclosure, but do not constitute a limitation to the present disclosure. In the drawings: Figure 1 is a structural diagram of the system of the present disclosure.

[0019] Figure 2 is a flowchart of a method for synergistically treating fluorine-containing mine water in situ in an underground coal mine reservoir provided by an exemplary embodiment of the present disclosure. Specific Embodiments

[0020] The following will describe the specific embodiments of the present disclosure in detail with reference to the drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure and are not used to limit the present disclosure.

[0021] The first aspect of the present disclosure provides a method for synergistically treating fluorine-containing mine water in situ in an underground coal mine reservoir. The method includes the following steps: S1. Screen coal gangue with a coal content of 5-20% and a particle size ≤ 5 mm; S2. Take the fluorine-containing mine water or sediment collected near the site to be treated as a sample, and subject the sample to screening, enrichment and domestication of mixed anaerobic bacteria to obtain highly efficient fluorine-removing mixed bacteria; S3. Mix the bacterial solution of the high-efficiency fluoride-removing mixed bacteria with the coal gangue for mixed culture to obtain microbial film-coated coal gangue; S4. Add the microbial film-coated coal gangue to the feeding mechanism, and input the microbial film-coated coal gangue into the mine water of the underground coal mine reservoir through the feeding mechanism for fluoride removal treatment.

[0022] The present disclosure uses coal gangue as a carrier, and uses the coal in the coal gangue to provide nutrients required for the growth of high-efficiency fluoride-removing mixed bacteria, forming a microbial film on the surface of the coal gangue. Without the need to additionally provide a carbon source, etc., the operation is simple, and the resource utilization of coal gangue (a large amount of coal-based solid waste) is realized. The microbial film-coated coal gangue is used to remove fluoride from the wastewater of the underground coal mine reservoir. By means of the self-purification effect of the underground coal mine reservoir and the collaborative purification of microorganisms, the fluoride ions in the mine water are adsorbed, fixed or precipitated to achieve the purpose of removing fluoride ions. Through the method of the present disclosure, in-situ fluoride removal of the mine water in the underground coal mine reservoir can also be realized, greatly improving the purification effect of the underground coal mine reservoir on the mine water. At the same time, the use of microorganisms to remove fluoride can reduce the use of fluoride-removing agents and avoid environmental pollution caused by the use of agents.

[0023] Furthermore, the underground coal mine reservoir is filled with a large amount of caving rock mass and coal gangue. The coal gangue after microbial treatment is left in the reservoir, which will not change the original performance and physical and chemical properties of the reservoir and will not cause secondary pollution.

[0024] In the present disclosure, in order to enable microorganisms to better form a film on the coal gangue, coal gangue with a particle size ≤ 5 mm is selected; this kind of coal gangue has a small particle size, a large specific surface area, and a large contact area with microorganisms, and can better form a microbial film. Further, the present disclosure also limits the coal content of the coal gangue to 5-20%. This kind of coal gangue can provide sufficient nutrients for the high-efficiency fluoride-removing mixed bacteria, promoting the growth of the high-efficiency fluoride-removing mixed bacteria and the formation of the film. In addition, when the microbial film-coated coal gangue is put into the mine water, it can still use the nutrients in the coal gangue to continue growing and reproducing, so that the microbial film-coated coal gangue can have the ability to remove fluoride for a long time.

[0025] In an embodiment of the present disclosure, step S2 further includes: S2-1. Mix the sample with normal saline for leaching treatment to obtain a leaching solution; S2-2. Add the leaching solution to an enrichment medium for enrichment culture to obtain an enrichment solution; S2-3. Add the enrichment solution to a domestication medium for domestication culture, transfer once every 5-10 days, and continuously transfer and domesticate for 15-30 generations to obtain the high-efficiency fluoride-removing mixed bacteria.

[0026] In the present disclosure, taking the fluorine-containing mine water or sediment collected near the site to be treated as a sample means the fluorine-containing mine water collected from the fluorine-containing mine water with a relatively high fluorine content near the site to be treated and the sediment in the fluorine-containing mine water; wherein, the sediment in the fluorine-containing mine water is preferably bottom mud; further, the fluorine content in the fluorine-containing mine water is greater than 1 mg / L; In an embodiment of the present disclosure, the viable count of the high-efficiency fluorine-removing mixed bacteria in the microbial film-coated coal gangue ≥ 10 6 CFU / g; further, considering that the coal mine underground reservoir is an anaerobic environment, the dominant bacteria in the high-efficiency fluorine-removing mixed bacteria are anaerobic bacteria. In the present disclosure, the high-efficiency fluorine-removing mixed bacteria refer to a mixed bacterial community system that can maintain the relative stability of the community in the fluorine-removing microbial system and has anaerobic bacteria as the dominant bacterial species.

[0027] In an embodiment of the present disclosure, step S4 further includes: Adding the microbial film-coated coal gangue to the feeding mechanism. When feeding into the coal mine underground reservoir, the microbial film-coated coal gangue in the feeding mechanism enters the coal mine underground reservoir inlet pipeline. Turn on the mine water control pump, so that the mine water enters the coal mine underground reservoir inlet pipeline and brings the microbial film-coated coal gangue into the mine water of the coal mine underground reservoir for fluorine removal treatment; According to the present disclosure, after the fluorine removal treatment, the fluorine content in the treated mine water obtained is lower than 1 mg / L.

[0028] As Figure 1 shown, the second aspect of the present disclosure provides a system applicable to the method described in the first aspect. The system includes a coal mine underground reservoir, a feeding mechanism, a mine water control pump, and an automatic control device; The inlet of the coal mine underground reservoir is connected to the mine water control pump through the coal mine underground reservoir inlet pipeline. A feeding branch is provided on the coal mine underground reservoir inlet pipeline and near the coal mine underground reservoir. The inlet of the feeding branch is connected to the outlet of the feeding mechanism; The automatic control device is respectively signal-connected to the feeding mechanism and the mine water control pump, and is used to control the addition of the microbial film-coated coal gangue and the power of the mine water control pump.

[0029] The system of the present disclosure can realize in-situ fluorine removal of the mine water in the coal mine underground reservoir, and greatly improve the purification treatment effect of the coal mine underground reservoir on the mine water. At the same time, the system can realize full-automatic control, reducing the input of manpower and cost.

[0030] In the present disclosure, the diameters of the inlet pipe of the underground coal mine reservoir and the feeding branch are both larger than the particle size of the microbial biofilm - attached coal gangue, which can effectively ensure that the microbial biofilm - attached coal gangue enters the inlet pipe of the underground coal mine reservoir from the feeding mechanism through the feeding branch, and then enters the underground coal mine reservoir through the inlet pipe of the underground coal mine reservoir. The outlet of the feeding branch is connected to the inlet pipe of the underground coal mine reservoir, and the connection is far away from the mine water control pump. Such a setting can effectively avoid the phenomenon that the microbial biofilm - attached coal gangue is scattered, broken, or the microbial biofilm ruptures due to the excessive impact force of the outflow of mine water when the mine water control pump is turned on.

[0031] In order to further avoid the accumulation of microbial biofilm - attached coal gangue at a certain place, in an embodiment of the present disclosure, the part of the inlet pipe of the underground coal mine reservoir extending into the underground coal mine reservoir is set as a telescopic pipe. By extending or shortening the pipe, the input position of the microbial biofilm - attached coal gangue is adjusted, further improving the treatment efficiency.

[0032] In an embodiment of the present disclosure, the system further includes a detection device, and the detection device is in signal connection with the automatic control device; it is used to control the addition amount of the microbial biofilm - attached coal gangue according to the fluoride content of the mine water in the underground coal mine reservoir detected by the detection device in real - time.

[0033] Specifically, the detection device includes a sampling pipe and a detector. The sampling pipe is arranged at intervals at the artificial dam of the underground coal mine reservoir and is connected to the detector so that the detector can detect the fluoride content of the sample in the sample pipe.

[0034] In the present disclosure, the automatic control device can control the feeding mechanism to feed, and can also control the opening and closing of the mine water control pump; at the same time, when the fluoride content of the mine water in the underground coal mine reservoir detected by the detection device is relatively high, the automatic control system controls the feeding device to increase the input of the microbial biofilm - attached coal gangue according to the fluoride content signal, and vice versa, it reduces or stops the input of the microbial biofilm - attached coal gangue.

[0035] In the present disclosure, by adjusting the power of the mine water control pump, the flow rate of the mine water can be controlled, effectively avoiding the accumulation of microbial biofilm - attached coal gangue at a certain place in the underground coal mine reservoir and improving the treatment efficiency.

[0036] In an embodiment of the present disclosure, the system further includes a pneumatic unit. The pneumatic unit includes an air pipe laid at the bottom of the underground coal mine reservoir. The inlet of the air pipe is connected to a blowing pump, and blowing nozzles are arranged on the air pipe. The pneumatic unit of this embodiment can blow up the deposited microbial biofilm - attached coal gangue to avoid long - term accumulation and affect the treatment efficiency of microorganisms. In addition, waterproof design can be carried out at the blowing nozzles, such as setting waterproof caps, etc.

[0037] In a specific embodiment according to the present disclosure, a system for synergistically treating fluorine-containing mine water in-situ in a coal mine underground reservoir includes: a coal mine underground reservoir, a feeding mechanism, a mine water control pump, and an automatic control device; The inlet of the coal mine underground reservoir is connected to the mine water control pump through a coal mine underground reservoir water inlet pipe. A feeding branch is provided on the coal mine underground reservoir water inlet pipe near the coal mine underground reservoir, and the inlet of the feeding branch is connected to the outlet of the feeding mechanism; The automatic control device is respectively signal-connected to the feeding mechanism and the mine water control pump, and is used to control the addition of microbe-coated coal gangue and the power of the mine water control pump.

[0038] The part of the coal mine underground reservoir water inlet pipe extending into the coal mine underground reservoir is set as a telescopic pipe.

[0039] The system further includes a detection device, and the detection device is signal-connected to the automatic control device; it is used to control the addition amount of microbe-coated coal gangue according to the fluorine content of the mine water in the coal mine underground reservoir detected by the detection device in real time.

[0040] The detection device includes a sampling pipe and a detector. The sampling pipe is arranged at intervals at the artificial dam of the coal mine underground reservoir and is connected to the detector, so that the detector detects the fluorine content of the sample in the sample pipe.

[0041] The method for synergistically treating fluorine-containing mine water in-situ in a coal mine underground reservoir using the above system includes: S1. Screen coal gangue with a coal content of 5-20% and a particle size ≤ 5 mm; S2. Take the fluorine-containing mine water or sediment collected near the site to be treated as a sample, and subject the sample to screening, enrichment, and domestication of mixed anaerobic flora to obtain a highly efficient fluorine-removing mixed bacteria; Specifically, take 10 g of fresh sludge from the sediment of the fluorine-containing mine water, mix it with 1 L of physiological saline at 25 °C for leaching treatment, and take the supernatant to obtain a leaching solution; take 10 mL of the leaching solution and add it to a butyl nitrile stoppered culture flask containing 1000 mL of inorganic salt medium, and add 1 g of sodium succinate and 0.1 g of sodium fluoride. Use high-purity nitrogen to displace the headspace gas in the flask, and place it in a shaker at 37 °C and 150 r / min for 5 d; take 10 mL of the obtained bacterial solution and add it to a butyl nitrile stoppered culture flask containing 1000 mL of inorganic salt medium and add 0.1 g of sodium fluoride, and place it in a shaker at 37 °C and 150 r / min for 5 d. 5 d is taken as one generation, and domesticate 30 generations according to this operation to obtain a highly efficient fluorine-removing mixed bacteria.

[0042] S3. Anaerobically mix and culture the bacterial solution of the highly efficient fluorine-removing mixed bacteria with coal gangue at room temperature for 10 d to obtain microbe-coated coal gangue, and the viable bacteria count is 10 6 CFU / g; S4. Add the microbial biofilm - attached coal gangue to the feeding mechanism. When feeding into the underground coal mine reservoir, make the microbial biofilm - attached coal gangue in the feeding mechanism enter the intake pipeline of the underground coal mine reservoir. Turn on the mine water control pump to make the mine water enter the intake pipeline of the underground coal mine reservoir and carry the microbial biofilm - attached coal gangue into the mine water of the underground coal mine reservoir for defluorination treatment.

[0043] The preferred embodiments of the present disclosure have been described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details in the above - mentioned embodiments. Within the scope of the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0044] In addition, it should be noted that for each of the specific technical features described in the above - mentioned specific embodiments, they can be combined in any appropriate manner without contradiction. To avoid unnecessary repetition, the present disclosure will not separately describe various possible combination methods.

[0045] Furthermore, any combination can be made among various different embodiments of the present disclosure as long as it does not violate the idea of the present disclosure, and it should also be regarded as the content disclosed by the present disclosure.

Claims

1. A method for in-situ treatment of fluoride-containing mine water in cooperation with underground reservoirs in coal mines, characterized in that: The method comprises the following steps: S1. Screening coal gangue with coal content of 5-20% and particle size ≤5mm; S2. Using fluorine-containing mine water or sediment collected near the site to be treated as a sample, screening, enriching and taming a mixed anaerobic bacterial community on the sample to obtain a highly efficient fluorine-removing mixed bacteria; S3, mixing and culturing the bacterial liquid of the high-efficiency fluoride removal mixed bacteria with the coal gangue to obtain microbial biofilm-bearing coal gangue; S4, adding the microorganism-filmed coal gangue to a feeding mechanism, and injecting the microorganism-filmed coal gangue into the mine water of the underground reservoir of the coal mine through the feeding mechanism to perform fluorine removal treatment.

2. The method according to claim 1, wherein: Step S2 also includes: S2-1, mixing the sample with physiological saline for extraction to obtain an extract; S2-2, adding the extract to an enrichment medium for enrichment culture to obtain an enrichment solution; S2-3, adding the enriched solution to an acclimation medium for acclimation culture, transferring one generation every 5-10 days, and continuously transferring and acclimating for 15-30 generations to obtain the highly efficient fluoride removal mixed bacteria; Wherein, the fluoride content in the fluoride-containing mine water is greater than 1 mg / L.

3. The method according to claim 2, wherein: The number of viable bacteria of the highly efficient fluoride removal mixed bacteria in the microbial biofilm-forming coal gangue is ≥ 10 6 CFU / g; Wherein, the dominant bacteria in the highly efficient fluoride removal mixed bacteria are anaerobic bacteria.

4. The method according to claim 1, wherein: Step S4 also includes: The microbial biofilm-coated coal gangue is added to a feeding mechanism. When feeding into a coal mine underground reservoir, the microbial biofilm-coated coal gangue in the feeding mechanism enters into a water inlet pipe of the coal mine underground reservoir. The mine water control pump is turned on to allow the mine water to enter into the water inlet pipe of the coal mine underground reservoir and bring the microbial biofilm-coated coal gangue into the mine water of the coal mine underground reservoir for defluorination treatment.

5. The method according to any one of claims 4, wherein: After the defluorination treatment, the fluoride content in the treated mine water obtained is less than 1 mg / L.

6. A system suitable for the method according to any one of claims 1 to 5, characterized in that: The system includes a coal mine underground water reservoir, a feeding mechanism, a mine water control pump and an automatic control device; The inlet of the coal mine underground water reservoir is connected to the mine water control pump through a coal mine underground water reservoir water inlet pipeline, and a feeding branch is arranged on the coal mine underground water reservoir water inlet pipeline and near the coal mine underground water reservoir, and the inlet of the feeding branch is connected to the outlet of the feeding mechanism; The automatic control device is respectively connected to the feeding mechanism and the mine water control pump signal, and is used to control the addition of microbial biofilm-forming coal gangue and the power of the mine water control pump.

7. The system according to claim 6, wherein: The portion of the coal mine underground water reservoir water inlet pipe extending into the coal mine underground water reservoir is configured as a retractable pipe.

8. The system according to claim 6, wherein: The system also includes a detection device, which is connected to the automatic control device by signal; and is used to control the amount of microbial biofilm added to coal gangue according to the fluorine content of mine water in the coal mine underground reservoir detected in real time by the detection device.

9. The system according to claim 8, wherein: The detection device comprises a sampling tube and a detector. The sampling tube is arranged at intervals at the artificial dam body of the underground water reservoir of the coal mine and is connected to the detector so that the detector detects the fluorine content of the sample in the sample tube.

10. The system according to claim 8, wherein: The system also includes a pneumatic unit, which includes an air pipe laid at the bottom of the underground water reservoir of the coal mine, the inlet of the air pipe is connected to an air pump, and an air nozzle is arranged on the air pipe.

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