Microbial dust suppressant based on non-urealysis heterotrophic microorganism induced carbonate precipitation technology and preparation method of microbial dust suppressant
Through the microbial dust inhibitor based on the non-urealysis heterotrophic microorganism-induced carbonate precipitation technology, the problem of traditional dust inhibitors producing ammonia during urea hydrolysis is solved. It achieves high-efficiency, environmentally friendly and low-cost dust suppression effects.
Patent Information
- Application Number
- CN202411626990.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-14
- Publication Date
- 2025-02-18
AI Technical Summary
Existing microbial dust inhibitors produce additional ammonia during urea hydrolysis, which brings environmental risks. Traditional methods rely on urea to activate urease, which has the problem of ammonia production.
Using a microbial dust inhibitor based on non-urealysis heterotrophic microorganism-induced carbonate precipitation (MICP) technology, the organic calcium oxidation process of heterotrophic microorganisms induces the formation of calcium carbonate without adding urea, and the microorganism itself is activated through the enzyme activity of the microorganism itself. Promote calcium carbonate precipitation and provide the required carbon and nitrogen sources through organic calcium sources.
The dust-repressing effect of microorganisms without urea is achieved, the production of ammonia is avoided, environmental pollution is reduced, and the process is green and clean, and the cost is low.
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Figure CN119463809A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of coal mine dust prevention and dust suppression, and relates to a microbial dust suppressant based on non-urea-lysing heterotrophic microorganism-induced carbonate precipitation technology and a preparation method thereof. Background Art
[0002] China is a major coal producer and consumer, with coal consumption accounting for more than half of its total energy consumption. However, large-scale coal mining, processing, storage and transportation lead to the formation of a large amount of dust in the environment. This dust not only pollutes the environment, but also causes irreversible damage to humans. In recent years, microbial dust suppressants based on microbial induced carbonate precipitation (MICP) have attracted widespread attention due to their low cost, environmental friendliness and high efficiency. Among them, the urea hydrolysis pathway is the most widely studied and applied pathway, which uses urease-producing bacteria to hydrolyze urea to produce carbonate precipitation with a bonding effect to achieve dust suppression. However, additional ammonia is produced during the urea hydrolysis process, which will bring environmental risks. Therefore, how to reduce or avoid the production of ammonia is an important research direction in the field of microbial dust suppression. Microbial dust suppressants based on non-urea-lysing heterotrophic microbial induced carbonate precipitation (MICP) technology use the organic calcium oxidation process of heterotrophic microorganisms to induce the formation of calcium carbonate to produce carbonate ions without adding urea, so that the carbonate ions react with the calcium ions in the organic calcium source to form calcium carbonate precipitation, and only CO2 and H2O are produced as by-products in this process. This mineralization process does not require the addition of urea. If this process is applied to the field of dust suppression, it will be conducive to the development of microbial dust suppressants in the field of dust control. Summary of the invention
[0003] In view of the above problems, the present invention provides a microbial dust suppressant based on non-urea-lysing heterotrophic microorganism-induced carbonate precipitation (MICP) technology, which utilizes the metabolic process of heterotrophic microorganisms to induce the formation of calcium carbonate without adding urea. The present invention utilizes the enzyme activity of the microorganisms themselves to promote the precipitation process of calcium carbonate, and at the same time, provides the required carbon source and nitrogen source for microbial growth through the addition of organic calcium sources, promotes mineralization of mineralizing bacteria, and improves the dust suppression effect. In addition, the addition of calcium sources is conducive to the enhancement of enzyme activity, and the organic oxidation process is promoted by microbial formate dehydrogenase (FDH), which is conducive to the growth and reproduction of microorganisms. Carbonic anhydrase (CA) catalyzes the hydration of CO2, creates an alkaline environment for mineralization, and serves as a nucleation site for the attachment and accumulation of calcium carbonate, thereby changing the traditional way of adding urea to activate urease for dust suppression. The catalytic mechanism is shown in Formulas 3.1-3.3.
[0004] NAD(P) + HCOOH NAD(P)H + CO2 + H + (3.1) CO2+ H2O HCO3 - + H + (3.2) HCO3 - + OH - → CO3 2- + H2O (3.3) The technical solution of the present invention is as follows: A microbial dust suppressant based on non-urea-degrading heterotrophic microbial induced carbonate precipitation (MICP) technology, comprising a mineralized bacterial solution and an organic calcium source; The mineralized bacterial solution includes Pasteurella sporosarcina ( Sporosarcina pasteurii ) and culture medium; the organic calcium source is an aqueous solution of calcium formate or calcium acetate.
[0005] When the microbial dust suppressant is not in use, it needs to be stored at low temperature to inhibit the activity of mineralizing bacteria and avoid the mineralizing bacteria solution and the organic calcium source from reacting and causing failure.
[0006] Preferably, the volume ratio of the mineralized bacterial liquid to the organic calcium source is 1:0.75, 1:1.00 or 1:1.25.
[0007] Preferably, the concentration of organic calcium in the organic calcium source is 25 g / L, 30 g / L or 35 g / L.
[0008] Preferably, the culture medium raw materials are peptone, sodium chloride and beef extract powder.
[0009] Further preferably, the culture medium components are: 10 g / L peptone, 5 g / L sodium chloride, 3 g / L beef extract powder, and the pH of the culture medium is adjusted to 7.0 by 1 M NaOH solution.
[0010] Preferably, in the organic calcium source, the concentration of the aqueous solution of calcium formate is 30 g / L, and the concentration of the aqueous solution of calcium acetate is 30 g / L.
[0011] More preferably, when the calcium source is calcium formate, the volume ratio of the mineralized bacteria solution to the organic calcium source is 1:1; when the calcium source is calcium acetate, the volume ratio of the mineralized bacteria solution to the organic calcium source is 1:0.75.
[0012] More preferably, the pH of the aqueous solution of formic acid is 7, and the pH of the aqueous solution of calcium acetate is 8.
[0013] The preparation method of the microbial dust suppressant based on non-urea-degrading heterotrophic microorganism-induced carbonate precipitation (MICP) technology comprises the following steps: (1) Preparation of organic calcium source: dissolving calcium formate or calcium acetate in distilled water, and then filtering with a sterilized filter to obtain an organic calcium source; (2) After the mineralizing bacteria are cultured in a culture medium, a mineralized bacterial solution is obtained, and an organic calcium source is added to the mineralized bacterial solution to obtain a microbial dust suppressant based on non-urea-lytic heterotrophic microbial induced carbonate precipitation (MICP) technology.
[0014] The mineralization method of the microbial dust suppressant comprises the following steps: (1) adding an organic calcium source to a mineralized bacterial solution to prepare a microbial dust suppressant, wherein the pH of the microbial dust suppressant is 7, 8 or 9, the concentration of the organic calcium source is 25 g / L, 30 g / L or 35 g / L, and the volume ratio of the mineralized bacterial solution to the organic calcium source is 1:0.75, 1:1.00 or 1:1.25; (2) Based on step (1), spray microbial dust suppressant on the surface of the coal seam for consolidation.
[0015] The method for using the microbial dust suppressant based on the non-urea-lytic heterotrophic microbial induced carbonate precipitation (MICP) technology is to spray the microbial dust suppressant on the surface of the coal seam.
[0016] Compared with the prior art, the present invention has the following advantages: (1) No urea needs to be added to the microbial dust suppressant of the present invention, thus avoiding the generation of ammonia and reducing environmental pollution, and the entire dust suppression process is green and clean.
[0017] (2) The microbial dust suppressant of the present invention is produced by the formate dehydrogenase and carbonic anhydrase of the bacteria themselves, and produces carbonate ions by adding an external organic calcium source, without causing secondary pollution to the environment.
[0018] (3) The present invention suppresses dust by forming a consolidation layer on the surface of coal dust through the mineralization action of bacteria. The process is simple, the effect is good and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 The calcium carbonate yields of different combinations under the orthogonal test of Example 1.
[0020] Figure 2 It is the wind erosion mass loss rate of different combinations under the orthogonal experimental conditions of Example 2.
[0021] Figure 3 It is the rain erosion mass loss rate of different combinations under the orthogonal experimental conditions of Example 3. DETAILED DESCRIPTION
[0022] The present invention will be further described below in conjunction with specific embodiments, and the advantages and features of the present invention will become clearer as the description proceeds. However, the embodiments are exemplary only and do not constitute any limitation to the scope of the present invention. It should be understood by those skilled in the art that the details and forms of the technical solution of the present invention may be modified or replaced without departing from the spirit and scope of the present invention, but these modifications and replacements all fall within the scope of protection of the present invention.
[0023] Example 1 The following is a microbial dust suppressant based on non-urea-lying heterotrophic microorganisms inducing carbonate precipitation and a preparation method.
[0024] The preparation method comprises the following steps: (1) Preparation of mineralized bacteria: The bacteria used are selected from Pasteurella sporeosarcina ( Sporosarcina pasteurii ); The bacterial culture medium was a broth medium, which contained 10 g / L peptone, 5 g / L sodium chloride, and 3 g / L beef extract powder. The pH of the culture medium was adjusted to 7.0, 8.0, and 9.0 with 1 M NaOH solution. The culture medium was sterilized in an autoclave for 30 min at a temperature of 121°C. After the culture medium was cooled, it was inoculated in an ultra-clean workbench and then cultured in a constant temperature shaking incubator for 24 h to obtain a mineralized bacterial solution.
[0025] (2) Selection of calcium source: Calcium formate or calcium acetate was selected as the organic calcium source, and the concentration was set to 25 g / L, 30 g / L or 35 g / L respectively.
[0026] (3) The volume ratio of the mineralized bacterial solution and the organic calcium source was mixed at 1:0.75, 1:1.00 or 1:1.25, and then an orthogonal test was performed to obtain a series of microbial dust suppressants with different pH, different organic calcium source concentrations and mineralized bacterial solution / organic calcium source volume ratios, which were numbered 1 to 9. After the organic calcium source was dissolved in the culture medium, formate / acetate was generated, which provided free calcium ions and hydroxide ions through oxidation. Ca 2+ With HCO3 - It reacts with CO2 to form CaCO3 precipitation. After adding calcium source, formate dehydrogenase in Sporosarcina pasteurii can better promote the oxidation process of organic matter and help maintain an alkaline environment, so that the continuous production and accumulation of carbonic anhydrase promotes hydration reaction and produces excess H + Ions are used to maintain the stability of the pH value of the culture system. During the consolidation process, calcium carbonate precipitation enhances the interaction between coal powder particles, forming a strong binding force through van der Waals force, electrostatic force, etc. This interaction helps to form a more compact structure, enhance the orientation of coal powder particles, and the particles tend to have a specific orientation, thereby generating calcite and vaterite. These two types of calcium carbonate are conducive to the consolidation effect.
[0027] Experiment: Dry the conical flask and the obtained mineralized product, weigh the conical flask and the mineralized product precipitate, record it as W1; wash it with hydrochloric acid to remove the calcium carbonate precipitate, dry it and weigh it again, record it as W2; the weight of calcium carbonate is W3=W2-W1.
[0028] Table 1. Calcium carbonate production of microbial dust suppressants in different combinations under orthogonal test
[0029] It can be seen from Table 1 that the calcium carbonate content of the microbial dust suppressant prepared under different factors is different. The calcium carbonate content of calcium formate solution as an organic calcium source is higher than that of calcium acetate. When the pH is 7, the concentration of the organic calcium source is 30 g / L, and the ratio of the mineralized bacterial solution to the organic calcium source is 1, the content of calcium carbonate produced is the highest; this is because the formate dehydrogenase in the microorganism can promote the organic oxidation process, help maintain an alkaline environment, and make the continuous production and accumulation of carbonic anhydrase promote the hydration reaction, thereby producing excessive H + , in order to maintain the stability of the pH of the culture system. When calcium ions are added, they react with HCO3 - and Ca 2+ The calcium carbonate production of microbial dust suppressants at different calcium source concentrations is shown in Figure 2. Figure 1 As shown in . In summary, microbial dust suppressants can promote the production of calcium carbonate.
[0030] Example 2 A method for bacterial dust suppression based on microbial dust suppressants that induce carbonate precipitation using non-urea-lytic heterotrophic microorganisms.
[0031] The preparation method of the microbial dust suppressant is the same as that in Example 1.
[0032] Test: Weigh 30 g of coal powder in a petri dish, mix the prepared organic calcium source and mineralized bacterial solution, put them in a spray pot, and spray them evenly on the coal powder.
[0033] Finally, the coal powder sprayed with microbial dust suppressant was placed at room temperature to air dry naturally. After 3 days, it was sprayed again in the above manner. The above operation was repeated 4 times. The treated coal powder was placed at room temperature to air dry naturally. Subsequent operations were carried out after 20 days.
[0034] The treated coal powder was subjected to an anti-wind erosion test with a wind speed of 10 m / s. The results are shown in Table 2.
[0035] Table 2. Wind erosion rates of different combinations of microbial dust suppressants under orthogonal experimental conditions
[0036] Figure 2 is the wind erosion mass loss rate of different combinations under orthogonal experimental conditions; from Figure 2 It can be seen that the wind erosion rate of calcium formate is lower than that of calcium acetate. The wind erosion rate of calcium formate-bacteria solution is the lowest in combination 3, which is only 0.13%, while the wind erosion rate of calcium acetate is the lowest in combination 7, which is 0.35%. The wind erosion rates of calcium formate and calcium acetate in combination 2, combination 4, and combination 8 are very high. In these three combinations, the pH is 9, indicating that high pH is not conducive to the formation of calcium carbonate, thus affecting the consolidation effect.
[0037] Example 3 A method for bacterial dust suppression based on a microbial dust suppressant using non-urea-lytic heterotrophic microorganisms to induce carbonate precipitation.
[0038] The preparation method of the microbial dust suppressant is the same as that in Example 1.
[0039] Test: Weigh 30 g of coal powder in a petri dish, mix the prepared organic calcium source and mineralized bacterial solution, put them in a spray pot, and spray them evenly on the coal powder.
[0040] Finally, the coal powder sprayed with microbial dust suppressant was placed at room temperature to air dry naturally. After 3 days, it was sprayed again in the above manner. The above operation was repeated 4 times. The treated coal powder was placed at room temperature to air dry naturally. Subsequent operations were carried out after 20 days.
[0041] The treated coal powder was subjected to an anti-rain erosion test, with a simulated rainfall of 20 mm per hour, 2 m away from the sample, and a rainfall duration of 5 min. After the rainfall, the sample was placed in an oven at 30 °C to dry, and the results are shown in Table 3.
[0042] Table 3. Rain erosion rate of different combinations of microbial dust suppressants under orthogonal experimental conditions
[0043] As can be seen from Table 3, after rain erosion, calcium formate and calcium acetate both showed good consolidation effects. When calcium source was added, formate dehydrogenase in Bacillus pasteurianus could better promote the organic oxidation process, help maintain an alkaline environment, and make the continuous production and accumulation of carbonic anhydrase promote the hydration reaction, thereby producing excess H + ions to maintain the pH stability of the culture system. When calcium formate is added, Ca 2+ With HCO3 - and CO3 2-Reactions occur, resulting in CaCO3 precipitation. Calcium formate and calcium acetate are both common organic calcium sources, which are low-cost and easily available. They act as both carbon sources and calcium sources during microbial growth and precipitation. Subsequently, we considered looking for calcium sources that rely entirely on environmentally friendly ingredients during bacterial culture and dust suppression, and conducted localized designs based on available resources in specific areas, evaluating the long-term durability of dust suppression effects and the possible environmental impacts of using organic calcium sources.
[0044] This application aims at the dust suppression by the generation of calcium carbonate precipitation by Pasteurella sporosarcina. Urea is often added to this bacterium in the field of dust suppression, and calcium carbonate is generated through the action of urease. This application explores the dust suppression when urease is not activated, reduces the addition of urea, and reduces the subsequent ammonia treatment, which has good economic benefits, environmental benefits and dust suppression effects. Figure 3 is the rain erosion mass loss rate of different combinations under orthogonal experimental conditions.
Claims
1. A microbial dust suppressant based on non-urea-degrading heterotrophic microorganism-induced carbonate precipitation technology, characterized in that: The invention comprises a mineralized bacterial solution and an organic calcium source; the mineralized bacterial solution comprises Sporosarcina pasteurii and a culture medium; and the organic calcium source is an aqueous solution of calcium formate or calcium acetate.
2. The microbial dust suppressant based on non-urea-degrading heterotrophic microorganism-induced carbonate precipitation technology according to claim 1, characterized in that: The volume ratio of the mineralized bacterial liquid to the organic calcium source is 1:0.75, 1:1.00 or 1:1.
25.
3. The microbial dust suppressant based on non-urea-degrading heterotrophic microorganism-induced carbonate precipitation technology according to claim 1, characterized in that: The concentration of organic calcium in the organic calcium source is 25 g / L, 30 g / L or 35 g / L.
4. The microbial dust suppressant based on non-urea-degrading heterotrophic microorganism-induced carbonate precipitation technology according to claim 1, characterized in that: The raw materials of the culture medium are peptone, sodium chloride and beef extract powder.
5. The microbial dust suppressant based on non-urea-degrading heterotrophic microorganism-induced carbonate precipitation technology according to claim 3, characterized in that: In the organic calcium source, the concentration of the aqueous solution of calcium formate is 30 g / L, and the concentration of the aqueous solution of calcium acetate is 30 g / L.
6. A microbial dust suppressant based on non-urea-decomposing heterotrophic microorganism-induced carbonate precipitation technology according to claim 5, characterized in that: When the calcium source is calcium formate, the volume ratio of the mineralized bacterial solution to the organic calcium source is 1:1; when the calcium source is calcium acetate, the volume ratio of the mineralized bacterial solution to the organic calcium source is 1:0.
75.
7. The microbial dust suppressant based on non-urea-degrading heterotrophic microorganism-induced carbonate precipitation technology according to claim 6, characterized in that: The pH of the aqueous solution of calcium formate is 7, and the pH of the aqueous solution of calcium acetate is 8.
8. The microbial dust suppressant based on non-urea-degrading heterotrophic microorganism-induced carbonate precipitation technology according to claim 4, characterized in that: The culture medium components include: 10 g / L peptone, 5 g / L sodium chloride, and 3 g / L beef extract powder. The pH of the culture medium is adjusted to 7.0 by using 1 M NaOH solution.
9. A method for preparing a microbial dust suppressant based on non-urea-degrading heterotrophic microorganism-induced carbonate precipitation technology according to any one of claims 1 to 8, characterized in that: Here are the steps: (1) Preparation of organic calcium source: dissolving calcium formate or calcium acetate in distilled water, and then filtering with a sterilized filter to obtain an organic calcium source; (2) After the mineralizing bacteria are cultured in a culture medium, a mineralized bacterial solution is obtained, and an organic calcium source is added to the mineralized bacterial solution to obtain a microbial dust suppressant based on non-urea-lytic heterotrophic microbial induced carbonate precipitation (MICP) technology.