A biological pore-enlarging and wetting agent and its preparation method and application

Abstract

The present invention belongs to the technical field of coal seam water injection and dust suppression, and in particular, relates to a biological pore expansion and wetting agent, a preparation method thereof, and an application thereof. The biological pore expansion and wetting agent of the present invention comprises the following components: an acid-producing bacterial group, a nutrient substance, a biological surfactant, and ethanol wastewater. The present invention enriches acetic acid bacteria from the vinegar mash discarded from the vinegar brewing industry under non-sterile conditions, mixes it with a culture solution containing ethanol wastewater to prepare a biological pore expansion and wetting agent, and injects it into the coal seam water injection hole, so that the acetic acid bacteria group adheres to the surface of the coal seam to oxidize ethanol to produce acetic acid, a corrosive substance, to expand the pores of the coal seam. The present invention uses an acetic acid bacteria culture solution containing ethanol wastewater for treatment, which can effectively solve the problem that the coal seam is not easily wetted by water and difficult to penetrate, improves the water injection efficiency of the coal seam, expands the wetting radius of the coal seam, and effectively reduces the dust production of the coal seam working face.

Description

Technical Field

[0001] The invention belongs to the technical field of coal seam water injection and dust suppression, and in particular relates to a biological pore enlarging and wetting agent and a preparation method and application thereof. Background Art

[0002] Coal plays a very important role in my country's energy. With the increasing shortage of oil and natural gas resources and the further development of clean coal technology, the importance and status of coal will gradually increase. If necessary dust prevention measures are not taken during coal mining, a large amount of dust will be generated. Dust is the most harmful pollutant in the process of coal mining: workers staying in a high-concentration dust environment for a long time are prone to lung lesions and pneumoconiosis; when the dust concentration is too high, it is easy to explode and cause safety accidents; secondly, long-term dust influence will also accelerate the wear of mechanical equipment, resulting in a short service life of mechanical equipment.

[0003] At present, coal seam water injection technology is the most effective dust prevention measure for mining working faces. By injecting water to moisten the coal body, the mechanical properties of the coal body can be changed, the elasticity and strength of the coal can be reduced, and the plasticity can be increased. In addition, water will significantly hinder the movement of gas in the coal seam. Therefore, coal seam water injection can not only prevent dust but also eliminate the harm of gas. However, for coal seams with low permeability and small porosity, it is difficult to achieve the expected wetting effect by water injection. At present, surfactants and wetting agents are being developed in China to solve the problem of difficulty in wetting coal seams, but these reagents often contain substances that are difficult to degrade in the environment. Large-scale use often has an adverse effect on the environment and causes secondary pollution. Summary of the invention

[0004] In view of the shortcomings of the current water injection technology in the above-mentioned prior art, the present invention uses microbial means to wet the coal seam, and uses industrial ethanol wastewater mixed with non-sterile enriched acetic acid bacteria culture fluid to replace traditional water and inject it into the coal seam water injection hole, so that acetic acid-producing bacteria can penetrate and attach to the coal body, expand the pores of the coal body, and produce corrosive substances to corrode the coal body, thereby improving the permeability of the coal seam, improving the water injection efficiency, and expanding the wetting radius.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] One of the purposes of the present invention is to disclose a biological pore-enlarging and wetting agent, which comprises the following components: acid-producing bacteria, nutrients, biological surfactants and ethanol wastewater.

[0007] Preferably, the acid-producing bacteria are acetic acid bacteria, which are enriched from waste mash from the vinegar brewing industry under a non-sterile state. The conditions for enriching the acetic acid bacteria are: 7% ethanol wastewater, pH=3.5-4.5, 10-20g / L yeast extract, 1-5g / L NaH2PO4, 0.8-1.2g / L MgSO4, 0.65-1g / L KCl, and 0.01%-1% surfactant.

[0008] Preferably, the ethanol wastewater is 7% supersaturated oxygen ethanol wastewater, which is obtained by filtering and oxygenating industrial ethanol production wastewater, and the mass fraction of ethanol in the 7% supersaturated oxygen ethanol wastewater is 7%.

[0009] Preferably, the surfactant is one or more of alkyl glycoside, fatty acid glyceride, fatty acid sorbitan, polysorbate and other applicable surfactants, and the mass fraction of the surfactant is 0.01%-1%.

[0010] Preferably, different nutrients are selected according to different acid-producing bacteria. The nutrients of the acetic acid bacteria group include 10-20 g / L yeast extract powder, 1-5 g / L NaH2PO4, 0.8-1.2 g / L MgSO4, and 0.65-1 g / L KCl.

[0011] Preferably, the biological pore-expanding and wetting agent comprises the following components in parts by weight: 1-2 parts of acetic acid bacteria, 5-10 parts of nutrients, 0.01-1 parts of biological surfactants, and 70-90 parts of supersaturated oxygen 7% ethanol wastewater.

[0012] The present invention discloses a biological pore enlarger and moisturizer, which mainly utilizes the acid-producing characteristics of acid-producing bacteria to expand the pores of coal seams. With ethanol as the substrate of the culture medium, acetic acid bacteria can oxidize ethanol to produce acetic acid through oxidation in an oxygen-containing environment. After the biological pore enlarger and moisturizer is injected into the coal seam, the bacteria can adhere to the surface of the coal seam and corrode the coal seam by producing acidic substances to expand the pores of the coal body. The utilization of ethanol wastewater not only reduces the discharge of pollutants, but also provides a carbon source and acetic acid production substrate for the growth of bacteria, thereby realizing the recycling of waste and saving costs.

[0013] The second object of the present invention is to disclose a method for preparing a biological pore-enlarging and wetting agent, comprising the following steps:

[0014] (1) Preparation of acetic acid bacteria: crushing, dissolving and filtering industrial waste vinegar mash to obtain a vinegar mash solution, aspirating the vinegar mash solution into an enrichment medium, culturing to the logarithmic phase, obtaining a non-sterile acetic acid bacteria group, centrifuging and refrigerating to obtain an acetic acid bacteria group for later use;

[0015] (2) Treatment of ethanol wastewater: The collected industrial ethanol wastewater is filtered, diluted, concentrated, and oxygenated to make the ethanol content reach 7% and the dissolved oxygen content reach supersaturation;

[0016] (3) Preparation of the wetting agent: The acetic acid bacteria obtained in step (1) and the ethanol wastewater treated in step (2) are mixed evenly, and then a biological surfactant is added to obtain the biological pore-enlarging wetting agent.

[0017] Preferably, in step (1), the enrichment medium comprises: 10-20 g / L yeast extract, 1-5 g / L NaH2PO4, 0.8-1.2 g / L MgSO4, 0.65-1 g / L KCl, and the remainder is ethanol wastewater with an ethanol content of 7%, pH = 3.5-5.5.

[0018] By adding MgSO4, KCl, and NaH2PO4, the necessary trace elements Mg, K, and P are provided for the growth and metabolism of acetic acid bacteria.

[0019] By adjusting the pH to 3.5-5.5, the growth of other bacteria can be inhibited, providing an acid-base environment suitable for the growth of acetic acid bacteria, thereby enhancing the survival advantage of acetic acid bacteria. Figure 3 , Figure 4 As shown, under environmental conditions of pH=7, the growth of most bacteria is suitable for the growth of acetic acid bacteria, and the growth of acetic acid bacteria is restricted, resulting in a decrease in acid production capacity; under environmental conditions of pH=2, the overacidic environment restricts the growth and metabolism of most bacteria, including acetic acid bacteria, resulting in a decrease in the acid production capacity of acetic acid bacteria.

[0020] The addition of 7% ethanol can stimulate the activity of acetic acid bacteria in the mixed bacteria and provide a carbon source for the growth and metabolism of acetic acid bacteria.

[0021] Preferably, in step (1), the volume ratio of the vinegar mash solution to the enrichment culture medium is 1:19; and the culture conditions are culture in a constant temperature shaker at 30°C and 150 r / min.

[0022] The ratio of the target bacterial community to the nutrient solution-containing ethanol wastewater is 1:100.

[0023] The third object of the present invention is to disclose an application of a biological pore enlargement and wetting agent, which is applied to coal seam water injection. The specific application method includes the following steps:

[0024] (1) Before mining operations, water injection holes are drilled at the coal seam working face;

[0025] (2) The water injection hole is sealed with a sealer, and then the biological pore enlargement and wetting agent described in any one of claims 1 to 5 is mixed and injected into the coal seam through a high-pressure water injection pump.

[0026] Preferably, in step (1), the water injection hole is arranged on the vertical coal wall along the working face directly in front of the excavation working face, at the center position of 2 / 3 of the height from the bottom surface; in step (2), in order to maintain the acetic acid bacteria group in a highly active state, after the first water injection is completed, a biological pore expansion and wetting agent is injected every 36 hours, and this is repeated three times until the acidity value of the acetic acid bacteria reaches a maximum.

[0027] Beneficial Effects

[0028] The present invention discloses a biological pore-enlarging and wetting agent. The present invention enriches acetic acid bacteria from vinegar mash discarded from the vinegar brewing industry under non-sterile conditions, and the enriched and cultured bacteria are combined with treated industrial ethanol wastewater to form a pore-enlarging and wetting agent, which is injected into the water injection hole. Under the coordinated action of a surfactant and high pressure, the acetic acid-producing bacteria penetrate and adhere to the coal body, and the acetic acid produced by oxidizing ethanol corrodes the coal body, thereby expanding the pores of the coal body, enhancing the wetting effect, expanding the wetting radius, and improving the wetting effect of the coal seam. The present invention has the following technical effects:

[0029] The biological pore-enlarging and wetting agent provided by the present invention realizes the recycling of waste resources, reduces the discharge of pollutants, and is green, environmentally friendly and pollution-free.

[0030] The acetic acid bacteria group utilized in the present invention is enriched under a non-sterile environment, which reduces the cost, reduces the complexity of the operation, and greatly improves the practicability of the method.

[0031] The acidic substances produced by acid-producing microorganisms will corrode the coal seam to create more pores or expand the pore size, making it easier for the aqueous solution to flow into the coal seam and wet the coal body. This can effectively solve the problem that the coal seam is not easily wetted and penetrated by water, improve the efficiency of coal seam water injection, and increase the coal seam water injection volume and wetting radius to varying degrees. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The process flow chart for preparing biological pore-enlarging and wetting agent;

[0033] Figure 2 This is the principle diagram of acidification of coal seam by acetic acid bacteria;

[0034] Figure 3 This is a comparison chart of the acid production of acetic acid bacteria under different pH conditions;

[0035] Figure 4 This is the growth curve of acetic acid bacteria under different pH conditions;

[0036] Figure 5 It is the growth curve of acetic acid bacteria under different ethanol concentrations;

[0037] Figure 6 This is a comparison chart of the acid production of acetic acid bacteria under different ethanol concentration conditions;

[0038] Figure 7 On-site process diagram for water injection into coal seams;

[0039] In the figure: 1: valve; 2: flow meter; 3: hole sealer; 4: water injection pipe; 5: pressure gauge; 6: high-pressure water pump; 7: water storage tank. DETAILED DESCRIPTION

[0040] Hereinafter, the present invention will be described in detail. Before describing, it should be understood that the terms used in this specification and the appended claims should not be interpreted as being limited to the general meaning and dictionary meaning, but should be interpreted according to the meaning and concept corresponding to the technical aspects of the present invention on the basis of the principle that the inventor is allowed to appropriately define the terms for the best interpretation. Therefore, the descriptions presented here are only preferred examples for illustrative purposes and are not intended to limit the scope of the present invention, so that it should be understood that other equivalents or improvements can be obtained therefrom without departing from the spirit and scope of the present invention.

[0041] The following examples are only listed as examples of embodiments of the present invention and do not constitute any limitation to the present invention. It can be understood by those skilled in the art that modifications within the scope of the essence and concept of the present invention fall within the scope of protection of the present invention. Unless otherwise specified, the reagents and instruments used in the following examples are all commercially available products.

[0042] Example 1

[0043] A biological pore-enlarging and wetting agent comprises the following components in parts by weight: 1 part of acetic acid bacteria, 5 parts of nutrients, 0.4 parts of biological surfactants, and 90 parts of supersaturated oxygen 7% ethanol wastewater.

[0044] The preparation method of the biological pore-enlarging and wetting agent specifically comprises the following steps:

[0045] (1) Preliminary treatment of vinegar mash: The vinegar mash discarded from the vinegar brewing industry is collected, ground, dissolved in water, and then filtered through a filter grid to obtain the bacterial source liquid.

[0046] (2) Ethanol wastewater treatment: The collected industrial ethanol wastewater is filtered, diluted, concentrated, and oxygenated to make the ethanol content reach 7% and the dissolved oxygen content reach a supersaturated state.

[0047] (3) Add 10-20 g / L yeast extract, 1-5 g / L NaH2PO4, 0.8-1.2 g / L MgSO4, and 0.65-1 g / L KCl to 7% ethanol wastewater, adjust the pH to 2, 4, and 7 with sodium hydroxide solution, and prepare a non-sterile enrichment medium suitable for the growth of acetic acid bacteria. Divide 570 mL into three conical flasks and perform parallel experiments.

[0048] (4) Take 10 mL of the bacterial source liquid and inoculate it into the culture medium described in step 3, and culture it in a constant temperature shaker (30°C, 150 r / min) for 5 days. Use an ELISA reader to measure the absorbance at 600 nm every four hours during the first 48 hours. Use an acid-base titration method to determine the acidity in the culture medium every day. The initial sample is used as a blank sample.

[0049] The measured results are as follows Figure 3 , Figure 4 As shown, Figure 3 is the acidity production of acetic acid bacteria under different pH conditions, Figure 4 The growth conditions of acetic acid bacteria under different pH conditions are shown in Table 1. The optimal enrichment pH conditions in this example are applied to Examples 2-4.

[0050] Example 2

[0051] A biological pore-enlarging and wetting agent comprises the following components in parts by weight: 1.5 parts of acetic acid bacteria, 8 parts of nutrients, 0.01 parts of biological surfactants, and 80 parts of supersaturated oxygen 3% ethanol wastewater.

[0052] The preparation method of the biological pore-enlarging and wetting agent comprises the following steps:

[0053] (1) Preliminary treatment of vinegar mash: The vinegar mash discarded from the vinegar brewing industry is collected, ground, dissolved in water, and then filtered through a filter grid to obtain the bacterial source liquid.

[0054] (2) Ethanol wastewater treatment: The collected industrial ethanol wastewater is filtered, diluted, concentrated, and oxygenated to make the ethanol content reach 3% and the dissolved oxygen content reach a supersaturated state.

[0055] (3) Cultivation of acetic acid bacteria: 10 mL of the bacterial source liquid described in step (1) was inoculated into a 3% ethanol wastewater culture medium and cultured in a constant temperature shaker (30° C., 150 r / min) for 5 days. During the first 48 hours, the absorbance at 600 nm was measured every four hours using an ELISA reader to find the logarithmic growth phase of the bacteria. The acidity of the culture medium was determined every day using an acid-base titration method, and the initial sample was used as a blank sample.

[0056] (4) Figure 5 As shown, the logarithmic phase bacterial solution with OD=1.5 was centrifuged at 8000r / min for five minutes to obtain acetic acid bacteria, which were refrigerated and stored for later use.

[0057] (5) Add 10-20 g / L yeast extract, 1-5 g / L NaH2PO4, 0.8-1.2 g / L MgSO4, and 0.65-1 g / L KCl to the 3% ethanol wastewater in step (3), adjust the pH to 4, and prepare a non-sterile enrichment medium suitable for the growth of acetic acid bacteria. Divide 570 mL of the medium into three conical flasks for parallel experiments.

[0058] (6) The acetic acid bacteria described in steps (3) and (4) and the treated ethanol wastewater are mixed at a ratio of 1:100, and then a biosurfactant with a concentration of 0.4% is added to obtain a biological pore enlargement and wetting agent.

[0059] The method for using the biological pore-enlarging and wetting agent prepared in this embodiment comprises the following steps:

[0060] (1) Before mining operations, water injection holes are drilled at appropriate locations on the coal seam working face using a water injection drill. The water injection holes are located on the vertical coal wall directly in front of the excavation working face, at the center of the 2 / 3 height from the bottom surface. A high-pressure pump is used to provide power, and high-pressure water is injected through a water pipe.

[0061] (2) In order to make acetic acid bacteria play a better role in the coal seam, after the first water injection, biological pore expansion and wetting agent is injected again every 36 hours to maintain the growth and metabolic conditions of the acetic acid bacteria group, and the injection is repeated three times. The water injection volume of the water injection hole is measured by the flow meter installed on the water injection pipeline, and the wetting radius is obtained by drilling holes to observe the wetting degree of the coal body.

[0062] The wetting properties of the biological pore-expanding and wetting agent prepared in this embodiment are shown in Table 1 below.

[0063] Table 1. Wetting of biological pore-enlarging and wetting agents in wastewater containing 3% ethanol

[0064]

[0065] It can be seen from Table 1 above that in the non-sterile culture medium containing 3% ethanol wastewater, the water injection volume increased by 43.8%, the wetting radius increased by 35.5%, and the dust concentration decreased by 22.6%.

[0066] from Figure 5 , Figure 6 It can be seen that the 3% ethanol concentration does not restrict other organisms except acetic acid bacteria, which affects the growth of acetic acid bacteria. In addition, the lower ethanol concentration also reduces the acid production capacity of acetic acid bacteria, resulting in unsatisfactory coal seam wetting effect.

[0067] Example 3

[0068] A biological pore-enlarging and wetting agent comprises the following components in parts by weight: 2 parts of acetic acid bacteria, 10 parts of nutrients, 1 part of biological surfactant, and 70 parts of supersaturated oxygen 7% ethanol wastewater.

[0069] The preparation method of the biological pore-enlarging and wetting agent comprises the following steps:

[0070] (1) The treatment of vinegar mash is the same as in Example 2.

[0071] (2) Ethanol wastewater treatment: The collected industrial ethanol wastewater is filtered, diluted, concentrated, and oxygenated to make the ethanol content reach 7% and the dissolved oxygen content reach a supersaturated state.

[0072] (3) Cultivation of acetic acid bacteria: 10 mL of the bacterial source solution described in step (1) was inoculated into a 7% ethanol wastewater culture medium and cultured in a constant temperature shaker (30°C, 150 r / min) for 5 days. During the first 48 hours, the absorbance at 600 nm was measured every four hours using an ELISA reader to find the logarithmic growth phase of the bacteria. The acidity of the culture medium was determined every day using an acid-base titration method, and the initial sample was used as a blank sample.

[0073] (4) Figure 5 As shown, the logarithmic phase bacterial solution with OD=1.5 was centrifuged at 8000r / min for five minutes to obtain acetic acid bacteria, which were refrigerated and stored for later use.

[0074] (5) Add 10-20 g / L yeast extract, 1-5 g / L NaH2PO4, 0.8-1.2 g / L MgSO4, and 0.65-1 g / L KCl to the 7% ethanol wastewater in step (3), adjust the pH to 4, and prepare a non-sterile enrichment medium suitable for the growth of acetic acid bacteria. Divide 570 mL of the medium into three conical flasks for parallel experiments.

[0075] (6) The acetic acid bacteria described in steps (3) and (4) and the treated ethanol wastewater are mixed and then a biosurfactant with a concentration of 0.4% is added to obtain a biological pore-enlarging and wetting agent for standby use.

[0076] The use method, water injection process and method of the biological pore-enlarging and wetting agent prepared in this embodiment are the same as those in Embodiment 2. The wetting conditions of the biological pore-enlarging and wetting agent prepared in this embodiment are shown in Table 2 below.

[0077] Table 2. Wetting of biological pore-enlarging and wetting agents in wastewater containing 7% ethanol

[0078]

[0079] It can be seen from Table 2 above that in the non-sterile culture medium containing 7% ethanol wastewater, the water injection volume increased by 100.3%, the wetting radius increased by 102.6%, and the dust concentration decreased by 58.2%.

[0080] from Figure 5 , Figure 6 It can be seen that the 7% ethanol concentration restricts other organisms except acetic acid bacteria, improves the growth advantage of acetic acid bacteria, and the higher ethanol concentration also promotes the acid production ability of acetic acid bacteria, and the coal seam wetting effect is more ideal.

[0081] Example 4

[0082] A biological pore-enlarging and wetting agent comprises the following components in parts by weight: 1 part of acetic acid bacteria, 5 parts of nutrients, 0.4 parts of biological surfactants, and 90 parts of supersaturated oxygen 10% ethanol wastewater.

[0083] The preparation method of the biological pore-enlarging and wetting agent comprises the following steps:

[0084] (1) The treatment of vinegar mash is the same as in Example 2.

[0085] (2) Ethanol wastewater treatment: The collected industrial ethanol wastewater is filtered, diluted, concentrated, and oxygenated to make the ethanol content reach 10% and the dissolved oxygen content reach a supersaturated state.

[0086] (3) Acetic acid bacteria culture: 10 mL of the bacterial source solution described in step (1) was inoculated into a 10% ethanol wastewater culture medium and cultured in a constant temperature shaker (30°C, 150 r / min) for 5 days. During the first 48 hours, the absorbance at 600 nm was measured every four hours using an ELISA reader to find the logarithmic growth phase of the bacteria. The acidity of the culture medium was measured every day using an acid-base titration method, and the initial sample was used as a blank sample.

[0087] (4) Figure 5 As shown, the logarithmic phase bacterial solution with OD=1 was centrifuged at 8000r / min for five minutes to obtain acetic acid bacteria, which were refrigerated and stored for later use.

[0088] (5) Add 10-20 g / L yeast extract, 1-5 g / L NaH2PO4, 0.8-1.2 g / L MgSO4, and 0.65-1 g / L KCl to the 10% ethanol wastewater described in step (3), adjust the pH to 4, and prepare a non-sterile enrichment medium suitable for the growth of acetic acid bacteria. Divide 570 mL into three conical flasks and perform parallel experiments.

[0089] (6) The acetic acid bacteria described in steps (3) and (4) and the treated ethanol wastewater are mixed and then a biosurfactant with a concentration of 0.4% is added to obtain a biological pore-enlarging and wetting agent for standby use.

[0090] The method of using the biological pore-enlarging and wetting agent prepared in this embodiment, and the water injection process and method are the same as those in Example 2.

[0091] The wetting properties of the biological pore-expanding and wetting agent prepared in this embodiment are shown in Table 3 below.

[0092] Table 3. Wetting of biological pore-enlarging and wetting agents in wastewater containing 10% ethanol

[0093]

[0094] It can be seen from Table 3 above that in the non-sterile culture medium containing 10% ethanol wastewater, the water injection volume increased by 23.3%, the wetting radius increased by 20.1%, and the dust concentration decreased by 17.8%.

[0095] from Figure 5 , Figure 6 It can be seen that the 10% ethanol concentration restricts the growth of most microorganisms, including acetic acid bacteria, thereby reducing the acid production capacity of acetic acid bacteria and resulting in unsatisfactory coal seam wetting effect.

[0096] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for a person skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to replace some of the technical features therein by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions claimed to be protected by the present invention.

Claims

1. A biological pore-enlarging and wetting agent, characterized in that: The method comprises the following components: acid-producing bacteria, nutrients, biosurfactants and ethanol wastewater; the acid-producing bacteria are acetic acid bacteria, which are acetic acid bacteria enriched from vinegar mash discarded from the vinegar brewing industry under a non-sterile state; the ethanol wastewater is 7% supersaturated oxygen ethanol wastewater, which is obtained by filtering and oxygenating industrial ethanol production wastewater, and the mass fraction of ethanol in the 7% supersaturated oxygen ethanol wastewater is 7%; The method comprises the following components in parts by weight: 1-2 parts of acetic acid bacteria, 5-10 parts of nutrients, 0.01-1 parts of biosurfactant, and 70-90 parts of supersaturated oxygen 7% ethanol wastewater; Preparation of acetic acid bacteria: crush, dissolve and filter the industrial waste acetic acid mash to obtain acetic acid mash solution, absorb the acetic acid mash solution into an enrichment medium, culture to the logarithmic phase, obtain acetic acid bacteria in a non-sterile state, centrifuge and refrigerate to obtain acetic acid bacteria for later use; The enrichment culture medium comprises: 10-20 g / L yeast extract, 1-5 g / L NaH2PO4, 0.8-1.2 g / L MgSO4, 0.65-1 g / L KCl, and the remainder is ethanol wastewater with an ethanol content of 7%, and the pH value is 3.5-5.

5.

2. The biological pore-enlarging and wetting agent according to claim 1, characterized in that: The surfactant is one or more of alkyl glycoside, fatty acid glyceride, fatty acid sorbitan, and polysorbate.

3. A method for preparing the biological pore-enlarging and wetting agent according to claim 1, characterized in that: The following steps are involved: (1) Preparation of acetic acid bacteria: crushing, dissolving and filtering industrial waste vinegar mash to obtain a vinegar mash solution, aspirating the vinegar mash solution into an enrichment medium, culturing to the logarithmic phase, obtaining a non-sterile acetic acid bacteria group, centrifuging and refrigerating to obtain an acetic acid bacteria group for later use; (2) Treatment of ethanol wastewater: The collected industrial ethanol wastewater is filtered, diluted, concentrated, and oxygenated to make the ethanol content reach 7% and the dissolved oxygen content reach supersaturation; (3) Preparation of the wetting agent: The acetic acid bacteria obtained in step (1) and the ethanol wastewater treated in step (2) are mixed evenly, and then a biological surfactant is added to obtain the biological pore-enlarging wetting agent.

4. The method for preparing the biological pore-enlarging and wetting agent according to claim 3, characterized in that: In step (1), the volume ratio of the vinegar mash solution to the enrichment culture medium is 1:19; and the culture conditions are culture in a constant temperature shaker at 30°C and 150 r / min.

5. An application of a biological pore-enlarging and wetting agent, characterized in that: Applied to coal seam water injection, the specific application method includes the following steps: (1) Before mining operations, water injection holes are drilled at the coal seam working face; (2) The water injection hole is sealed with a sealer, and then the biological pore expander and lubricant described in any one of claims 1 to 2 or the biological pore expander and lubricant prepared by the preparation method described in any one of claims 3 to 4 is mixed and injected into the coal seam through a high-pressure water injection pump.

6. The use of the biological pore-enlarging and wetting agent according to claim 5, characterized in that: In step (1), the water injection hole is arranged on the vertical coal wall along the working face directly in front of the excavation working face, at the center position of 2 / 3 of the height from the bottom surface; in step (2), after the first injection is completed, the biological pore expansion and wetting agent is injected again every 36 hours, and the injection is repeated three times.

Images