Nanometer biological plugging agent and method for retarding crack leakage pollutants by using nanometer biological plugging agent

Abstract

The invention provides a nano biological plugging agent and a method for retarding crack leakage pollutants by using the nano biological plugging agent, and the method comprises the following steps: adding a biological enzyme catalyst into water to prepare a biological agent, adjusting the hydrolysis rate of the biological agent to organophosphate salt, then adding the organophosphate salt and magnesium acetate into the biological agent, and stirring to obtain the nano biological plugging agent. Phosphate radicals generated by hydrolyzing organophosphate salt through the biological agent react with magnesium acetate, a large number of hydrogen bonds are generated in the reaction through carboxyl groups in the magnesium acetate, nanoscale biological phosphate precipitates are generated, meanwhile, the diffusion potential energy of the generated phosphate radicals is reduced, and the phosphate content is increased. According to the present invention, the biological plugging agent injected into the storage yard crack is subjected to liquid diffusion within 4-6 h, and then rapid condensation is performed so as to achieve the crack plugging, and in addition, the produced nanometer biological phosphate precipitate further has effects of adsorption of ammonia nitrogen, cationic heavy metal and other pollutants produced by the solid waste storage yard so as to achieve green environmental protection sustainable development.

Description

Technical Field

[0001] The invention belongs to the technical field of leakage blocking, and particularly relates to a nano-biological blocking agent and a method for blocking crack leakage of pollutants. Background Art

[0002] The geological defects of the landfill to be built, such as weathered and broken fault zones, as well as the landform evolution or barrier system damage around the existing solid waste landfill may provide advantageous leakage channels for the contaminated leachate generated by the landfill, resulting in frequent interactions between pollutants and surface water and groundwater. The environmental safety issues of the regional landfill are prominent. It is necessary to seal tiny leakage channels such as rock and soil pores and microcracks to prevent further spread of pollutants.

[0003] Traditional plugging materials mostly use hydraulic cementitious slurries mainly composed of cement. For tiny cracks, they are difficult to penetrate, resulting in insufficient plugging, poor compatibility with pollutants, and insufficient long-term effectiveness. In recent years, organic polymer plugging technology has been developed. Polymer plugging agents mainly use polyacrylamide and its copolymers with other monomers as gelling agents, and use their rheological properties to plug formations. They have good plugging effects and can adapt to the size and shape of leakage channels. However, their own strength is insufficient, and the plugging layer formed generally has poor pressure bearing capacity. In addition, polymers are easily degraded or deteriorated, and their durability is insufficient. Researchers have further developed plugging technologies based on biomineralization processes. The most commonly used is bio-induced carbonate precipitation technology, which also has the advantage of adapting to the size and shape of leakage channels. The flowing biological agents can be pumped into filling pores or cracks. The biological agents spontaneously mineralize over time to form carbonate precipitates, which play a role in sealing cracks and supporting structures, with significant durability and mechanical properties. However, the mineralization reaction process of this technology produces a large amount of by-product ammonia nitrogen, which is easy to cause environmental pollution. The biocarbonate produced by mineralization has poor adsorption performance for pollutants. In addition, this technology requires multiple grouting to produce enough mineralization products to achieve leak plugging, and the operation cycle is long.

[0004] Therefore, how to provide a method for using a nano-bioblocking agent to block pollutants from leaking from cracks, and how to use nano-scale bio-phosphates generated by the reaction of phosphate radicals produced by the hydrolysis of organic phosphate salts with magnesium acetate to seal cracks and adsorb pollutants such as ammonia nitrogen in one go, thereby shortening the cycle, is a technical problem that technicians in this field urgently need to solve. Summary of the Invention

[0005] The object of the present invention is to provide a nano-biological plugging agent and a method for blocking the leakage of pollutants from cracks, so as to solve at least one of the above-mentioned technical problems.

[0006] To achieve the above objectives, the first aspect of the present invention provides a method for blocking pollutant leakage from cracks using a nano-bioblocking agent, the method comprising the following steps: S1, adding a bio-enzyme catalyst to water and mixing uniformly to obtain a biological agent; S2, adding an organic phosphate salt and magnesium acetate to the biological agent to obtain a nano-bioblocking agent; S3, injecting the nano-bioblocking agent into the crack damage area of ​​the storage yard, and completing the blocking of the cracks after 4-6 hours.

[0007] In the first aspect, in step S1, the activity of the bio-enzyme catalyst is 10,000-50,000 U, and the volume fraction of the bio-enzyme catalyst is 1%-10%.

[0008] In the first aspect, in step S1, the biological enzyme catalyst includes at least one of phytase, phospholipase and phosphatase.

[0009] In the first aspect, in step S2, the molar concentration of phosphorus in the organic phosphate salt is 0.7-1.5 mol / L.

[0010] In the first aspect, in step S2, the organic phosphate salt includes at least one of sodium glycerophosphate, potassium glycerophosphate, and glycerophosphocholine.

[0011] In the first aspect, in step S2, the molar concentration of the magnesium acetate is 0.7-1.5 mol / L.

[0012] In the first aspect, in step S3, the injection amount of the nano-bioblocking agent is greater than the volume of the fissure, and the nano-bioblocking agent is injected until it fills the fissure area and overflows.

[0013] A second aspect of the present invention provides a nano-bioblocking agent, which comprises: a biological agent, an organic phosphate salt and magnesium acetate; the biological agent is prepared by dissolving a biological enzyme catalyst in water, the activity of the biological enzyme catalyst is 10,000-50,000 U, and the volume fraction of the biological enzyme catalyst is 1%-10%; the molar concentration of phosphorus in the organic phosphate salt is 0.7-1.5 mol / L; and the molar concentration of magnesium acetate is 0.7-1.5 mol / L.

[0014] In the second aspect, the bio-enzyme catalyst comprises at least one of phytase, phospholipase and phosphatase.

[0015] In a second aspect, the organic phosphate salt includes at least one of sodium glycerophosphate, potassium glycerophosphate, and glycerophosphocholine.

[0016] Beneficial effects: The present invention provides a method for blocking the penetration of pollutants through cracks by a nano-biological plugging agent, comprising: adding a bio-enzyme catalyst to water to prepare a biological agent, regulating the hydrolysis rate of the biological agent on an organic phosphate salt, then adding an organic phosphate salt and magnesium acetate to the biological agent, reacting the phosphate radical produced by the biological agent hydrolyzing the organic phosphate salt with magnesium acetate, and generating a large number of hydrogen bonds through the carboxyl group in the magnesium acetate to generate a nano-scale biological phosphate precipitate, while reducing the diffusion potential of the phosphate radical, so that the biological plugging agent injected into the crack of the storage yard is liquid and diffuses within 4-6 hours, and then rapidly condenses, thereby achieving the plugging of the crack. In addition, the generated nano-scale biological phosphate precipitate also has the effect of adsorbing pollutants such as ammonia nitrogen, cationic heavy metals, etc. generated in the solid waste storage yard, thereby achieving green environmental protection and sustainable development. The present invention blocks cracks in the storage yard by injecting a biological plugging agent prepared by a biological agent, an organic phosphate salt, and magnesium acetate, with the advantages of low energy consumption, one-time grouting, simple operation, rapid onset, and environmental compatibility.

[0017] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are specifically listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 This is a flow chart of a method for using a nano-biological plugging agent to block pollutants from leaking from cracks in the present invention; Figure 2 A schematic diagram of a method for using a nano-biological plugging agent to block pollutants from leaking from cracks in the present invention; Figure 3 This is a detection diagram of the blocking structure in an embodiment of the present invention; Figure 4 This is a test diagram of the plugging results of Comparative Example 2 in the present invention. DETAILED DESCRIPTION

[0020] The present invention will be described in detail below in conjunction with specific embodiments and examples, and the advantages and various effects of the present invention will be more clearly presented. It should be understood by those skilled in the art that these specific embodiments and examples are for illustrating the present invention, rather than for limiting the present invention.

[0021] Throughout this specification, unless otherwise specified, the terms used herein should be understood as having the same meaning as commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In the event of any conflict, the present specification shall take precedence.

[0022] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or obtained through existing methods.

[0023] See also Figure 1 The present invention provides a method for blocking the leakage of pollutants from cracks using a nano-bioblocking agent. The method comprises the following steps: S1, adding a bio-enzyme catalyst to water and mixing them evenly to obtain a biological preparation; S2, adding an organic phosphate salt and magnesium acetate to the biological preparation to obtain a nano-bioblocking agent; S3, injecting the nano-bioblocking agent into the crack damage area of ​​the storage yard, and completing the blocking of the cracks after 4-6 hours.

[0024] Specifically, the present invention provides a method for blocking the penetration of pollutants through cracks by a nano-biological plugging agent, comprising: adding a bio-enzyme catalyst to water to prepare a biological agent, regulating the hydrolysis rate of the biological agent on an organic phosphate salt, then adding an organic phosphate salt and magnesium acetate to the biological agent, using the biological agent to hydrolyze the organic phosphate salt to react with the magnesium acetate, and through the carboxyl group in the magnesium acetate, a large number of hydrogen bonds are generated in the reaction to generate a nano-scale biological phosphate precipitate, while reducing the diffusion potential of the phosphate radical, so that the biological plugging agent injected into the cracks of the storage yard is liquid and diffuses within 4-6 hours, and then quickly condenses, thereby achieving the plugging of the cracks. In addition, the generated nano-scale biological phosphate precipitate also has the effect of adsorbing pollutants such as ammonia nitrogen, cationic heavy metals, etc. generated in the solid waste storage yard, thereby achieving green environmental protection and sustainable development. The present invention plugs the cracks in the storage yard by injecting a biological plugging agent prepared by a biological agent, an organic phosphate salt, and magnesium acetate, with the advantages of low energy consumption, one-time grouting, simple operation, rapid onset, and environmental compatibility.

[0025] It should be added that, Figure 2 As shown, the storage yard generally includes the following structures: an aquifer 2 beneath the storage body 1, as well as surrounding ground 3, a fracture zone 4, an underground contamination plume 5, microcracks 6, and damaged areas of the storage body 7. A biological plugging agent 9 is injected into the target cracks along a grouting pipeline 10 through a pump 8 to seal the target cracks.

[0026] In some possible embodiments, in step S1, the activity of the bio-enzyme catalyst is 10,000-50,000 U, and the volume fraction of the bio-enzyme catalyst is 1%-10%.

[0027] In some possible embodiments, in step S1, the biological enzyme catalyst includes at least one of phytase, phospholipase and phosphatase.

[0028] Those skilled in the art will understand that the bio-enzyme catalyst has the ability to catalyze the hydrolysis of phosphate bonds to generate phosphate ions, and in this embodiment, the bio-enzyme catalyst is a phosphate-dissolving microbial suspension or a phosphate-dissolving enzyme liquid, which is concentrated or diluted to an activity of 10,000-50,000 U, and the volume fraction of the bio-enzyme catalyst is 1%-10%, thereby adjusting the hydrolysis efficiency. Among them, the phosphate-dissolving microbial suspension can be purchased from the market, or a single strain or flora of phosphate-dissolving microorganisms that have been domesticated with organic phosphate salts as the required carbon source, such as Aspergillus niger; the phosphate-dissolving enzyme liquid can be purchased from the market, or extracted from phosphate-dissolving microorganisms or plants.

[0029] In some possible embodiments, in step S2, the molar concentration of phosphorus in the organic phosphate salt is 0.7-1.5 mol / L.

[0030] In some possible embodiments, in step S2, the organic phosphate salt includes at least one of sodium glycerophosphate, potassium glycerophosphate, and glycerophosphocholine.

[0031] This is because organic phosphate salts can undergo hydrolysis under the action of biological enzyme catalysts to generate phosphates, and the generated phosphates can react with pollutants such as heavy metal cations and ammonia nitrogen, reducing the migration of heavy metals and forming biological phosphate crystals to provide skeleton support for the cracks.

[0032] In some possible embodiments, in step S2, the molar concentration of the magnesium acetate is 0.7-1.5 mol / L.

[0033] Furthermore, magnesium acetate is added to promote the formation of hydrogen bonds during the reaction, thereby providing potential energy for the generation of phosphate ions, accelerating the reaction, shortening the curing time of the nanobiological plugging agent after injection into the crack, and thus shortening the construction period.

[0034] In some possible embodiments, in step S3, the injection amount of the nano-bioblocking agent is greater than the volume of the fissure, and the nano-bioblocking agent is injected until it fills the fissure area and overflows.

[0035] Those skilled in the art will understand that when sealing a fissure, the injection volume of the nano-bio-blocking agent must be greater than the volume of the fissure in order to fill the fissure and thereby avoid leakage after the nano-bio-blocking agent solidifies.

[0036] Based on a general inventive concept, the second aspect of the present invention provides a nano-bioblocking agent, which includes: a biological agent, an organic phosphate salt and magnesium acetate; the biological agent is made by dissolving a biological enzyme catalyst in water, the activity of the biological enzyme catalyst is 10,000-50,000 U, and the volume fraction of the biological enzyme catalyst is 1%-10%; the molar concentration of phosphorus in the organic phosphate salt is 0.7-1.5 mol / L; the molar concentration of the magnesium acetate is 0.7-1.5 mol / L.

[0037] Specifically, the present invention provides a nano-biological plugging agent including a biological enzyme catalyst, an organic phosphate salt and magnesium acetate, and the above raw materials are placed in water to obtain a crack plugging material with a short initial setting time and excellent permeability coefficient of the soil after solidification.

[0038] In conjunction with the second aspect of the present application, the biological enzyme catalyst includes at least one of phytase, phospholipase and phosphatase.

[0039] In conjunction with the second aspect of the present application, the organic phosphate salt includes at least one of sodium glycerophosphate, potassium glycerophosphate and glycerophosphocholine.

[0040] Those skilled in the art will appreciate that selecting one of phytase, phospholipase or phosphatase as the bio-enzyme catalyst can efficiently and specifically catalyze the hydrolysis of organic phosphate salts, and selecting water-soluble compounds such as sodium glycerophosphate, potassium glycerophosphate or glycerophosphocholine as the organic phosphate salt can reduce the time it takes for the raw materials to dissolve in water, thereby accelerating the reaction time and shortening the construction period.

[0041] The present application will be further described below in conjunction with specific examples. It should be understood that these examples are intended to illustrate the present application only and are not intended to limit the scope of the present application. The experimental methods in the following examples where specific conditions are not specified are usually measured in accordance with national standards. If there are no corresponding national standards, then the methods are carried out in accordance with general international standards, conventional conditions, or according to the conditions recommended by the manufacturer.

[0042] Example This embodiment provides a method for using a nano-biological plugging agent to block the leakage of pollutants from cracks, which is used to plug the fracture zone in a manganese slag storage area of ​​a certain generation of construction, and specifically includes the following steps: (1) Adding 30,000 U of phytase to water at a volume fraction of 1% and mixing well to obtain a biological preparation; (2) adding sodium glycerophosphate and magnesium acetate to the biological agent, wherein the molar concentration of sodium glycerophosphate and magnesium acetate is 1.5 mol / L, and mixing them evenly to obtain a nanobiological plugging agent; (3) Inject nanobiological plugging agent into the fault zone through a zero-pressure pump and test the solidified soil after plugging, such as Figure 3 As shown, the nano-bioblocking agent has a small particle size, and after being injected into the cracks, the nano-bioblocking agent is in close contact with the soil particles, which can fill the cracks and prevent leakage.

[0043] Comparative Example 1 In this comparative example, a phytase with an activity of 2000 U was selected, and the remaining steps were the same as those in the embodiment.

[0044] Comparative Example 2 In this comparative example, 1.5 mol / L magnesium chloride was selected to replace the magnesium acetate in the embodiment, and the remaining steps were the same as those in the embodiment. Figure 4 As shown, the particle size of the biological plugging agent in this comparative example is relatively large, and it builds bridges between soil particles, but does not completely fill the cracks, affecting the plugging effect.

[0045] Comparative Example 3 In this comparative example, the molar concentrations of sodium glycerophosphate and magnesium acetate were both 0.5 mol / L, and the remaining steps were the same as those in the embodiment.

[0046] Comparative Example 4 In this comparative example, the volume fraction of the selected phytase was 15%, and the remaining steps were the same as those in the embodiment.

[0047] The results of testing the solidified soil after plugging in the embodiment and comparative examples 1-4 are shown in Table 1: Table 1 Test results Test items Example Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Initial setting time (h) 5 16 4.3 6.2 1.1 Permeability coefficient (m / s) <![CDATA[0.80×10 -7 ]]> <![CDATA[0.86×10 -7 ]]> <![CDATA[0.54×10 -5 ]]> <![CDATA[0.22×10 -6 ]]> <![CDATA[0.12×10 -6 ]]> It can be seen from the above table that compared with the embodiment, the activity of the phytase selected in Comparative Example 1 is too low, which leads to an extension of the plugging time of the biological plugging agent; the particle crystal size of the biological plugging agent generated by magnesium chloride in Comparative Example 2 is too large, and the permeability coefficient of the solidified soil is too low, affecting the plugging effect; the molar concentration of the organic phosphate salt and magnesium acetate selected in Comparative Example 3 is low, the generated crystal precipitation particle size is large, and the precipitation amount is insufficient, resulting in poor permeability of the solidified soil and poor effect of plugging the cracks; the volume fraction of the phytase selected in Comparative Example 4 is high, and the initial setting time of the nano-biological plugging agent is sharply shortened, resulting in the biological plugging agent condensing in the grouting pipeline or seepage path before reaching the deep crack, thereby causing blockage, and failing to achieve the purpose of plugging the cracks.

[0048] In summary, compared with the prior art, the present invention has the following advantages: (1) The present invention uses a bio-enzyme catalyst to catalyze the hydrolysis of soluble organic phosphate salts, and the generated phosphate radicals react with magnesium acetate to form nano-scale bio-phosphate crystals, which can block the fissure area and provide skeleton support, and simultaneously adsorb and block pollutants such as ammonia nitrogen, cationic heavy metals, etc.; the present invention has the advantages of sufficient perfusion of micro-fissures, flexible regulation of mineralization rate, low energy consumption, simple operation, rapid onset, and environmental compatibility.

[0049] (2) Compared with the traditional biomineralization technology that produces large crystal mineral precipitation, the present invention has developed a nano-precipitation mineralization process that can produce small volume density, good filling performance and excellent adsorption performance after in-depth exploration of the biological phosphate crystal regulation mechanism. That is, when the phospholytic enzyme activity of the biological agent is 10,000-50,000U, the volume fraction is 1-5%, and the molar concentration of magnesium acetate and soluble organic phosphate salt is 1.5M, only one grouting can generate a nano-scale biological phosphate precipitation with excellent blocking performance that fills the crack volume; wherein, the carboxyl group in magnesium acetate is used to make the reaction solution produce a large number of hydrogen bonds, reducing the diffusion potential energy of phosphate generated by biocatalytic hydrolysis. At the same time, the biocatalytic reaction rate is adjusted by regulating the activity and content of the biological agent, thereby controlling the phosphate concentration in the confined area. Under this limiting condition, the growth of phosphate precipitation crystals is hindered, forming nano-scale biological phosphate.

[0050] Finally, it should be noted that the terms "comprises," "includes," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0051] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0052] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A method for blocking the leakage of pollutants from cracks using nano-biological plugging agents, characterized in that: The method comprises the following steps: S1. Add a biological enzyme catalyst to water and mix well to obtain a biological preparation; S2. adding an organic phosphate salt and magnesium acetate to the biological agent to obtain a nanobiological plugging agent; S3. Inject the nanobiological plugging agent into the crack damage area of ​​the storage yard, and complete the plugging of the crack after 4-6 hours.

2. The method for blocking crack leakage of pollutants using nano-biological plugging agents according to claim 1, characterized in that: In step S1, the activity of the bio-enzyme catalyst is 10,000-50,000 U, and the volume fraction of the bio-enzyme catalyst is 1%-10%.

3. The method for blocking crack leakage of pollutants using nano-biological plugging agents according to claim 1, characterized in that: In step S1, the biological enzyme catalyst includes at least one of phytase, phospholipase and phosphatase.

4. The method for blocking crack leakage of pollutants using nano-biological plugging agents according to claim 1, characterized in that: In step S2, the molar concentration of phosphorus in the organic phosphate salt is 0.7-1.5 mol / L.

5. The method for blocking crack leakage of pollutants using nano-biological plugging agents according to claim 1, characterized in that: In step S2, the organic phosphate salt includes at least one of sodium glycerophosphate, potassium glycerophosphate and glycerophosphocholine.

6. The method for blocking crack leakage of pollutants using nano-biological plugging agents according to claim 1, characterized in that: In step S2, the molar concentration of the magnesium acetate is 0.7-1.5 mol / L.

7. The method for blocking crack leakage of pollutants using nano-biological plugging agents according to claim 1, characterized in that: In step S3, the injection amount of the nano-biological plugging agent is greater than the volume of the fissure, and the nano-biological plugging agent is injected until it fills the fissure area and overflows.

8. A nanobiological plugging agent, characterized in that: The nanobiological plugging agent includes: a biological agent, an organic phosphate salt and magnesium acetate; the biological agent is prepared by dissolving a biological enzyme catalyst in water, the activity of the biological enzyme catalyst is 10,000-50,000 U, and the volume fraction of the biological enzyme catalyst is 1%-10%; the molar concentration of phosphorus in the organic phosphate salt is 0.7-1.5 mol / L; and the molar concentration of the magnesium acetate is 0.7-1.5 mol / L.

9. The nanobiological blocking agent according to claim 8, characterized in that: The biological enzyme catalyst includes at least one of phytase, phospholipase and phosphatase.

10. The nanobiological blocking agent according to claim 9, characterized in that: The organic phosphate salt includes at least one of sodium glycerophosphate, potassium glycerophosphate and glycerophosphocholine.

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