Microbial material for mineralization and sand fixation of seabed substrate and application method of microbial material

Abstract

The invention provides a microbial material for mineralization and sand fixation of a seabed substrate and an application method of the microbial material, and particularly relates to the technical field of seabed substrate solidification. According to the application method, a microbial material is adopted, and the microbial material comprises a hollow microbial immobilization sealing body, a calcium source urea capsule, spherical aquatic plant mud particles and sea sand; the calcium source urea capsule is placed in an inner cavity of the microorganism immobilization sealing body; the spherical aquatic plant mud particles comprise aquatic plant mud containing nutrient substances and aquatic plant seeds wrapped in the aquatic plant mud. Calcium carbonate minerals are induced under the action of seawater to form a mineralized film on the surface of the seabed, so that spherical aquatic plant mud particles containing aquatic plant seeds are stabilized in a microorganism immobilization sealing body and sea sand, conditions are created for breeding of the aquatic plant seeds, seabed underflow scouring can be effectively resisted, the surface of the seabed is solidified, and the survival rate of the aquatic plant seeds is increased. And the seabed substrate is further improved.

Description

Technical Field

[0001] The patent of this invention relates to the technical field of seabed substrate solidification, and specifically to a microbial material used for seabed substrate mineralization and sand fixation and its application method. Background Art

[0002] In the field of marine engineering, the stability of offshore wind power and offshore photovoltaic pile foundations is seriously threatened by seabed scouring, especially under the influence of complex marine environments such as wind, waves, and currents, the problem of local scouring is particularly prominent. Scouring not only leads to a decrease in the stability of the pile foundation, but also may cause resonance of the overall structure of the wind turbine, increase structural fatigue stress, and affect the life of the wind turbine. Therefore, pile foundation scouring protection for offshore wind farms and offshore photovoltaic farms is one of the key technologies to ensure their safe operation.

[0003] Traditional scour protection methods include dumping (such as sand belts, riprap), solidified soil protection, geotextile covering, etc., but these methods are easy to be lost in sea areas with high current velocity, resulting in secondary scour, and their effectiveness is limited in sea areas with large sediment content and turbid water. Therefore, the development of new seabed improvement technology is of great significance to improving the stability and safety of offshore wind farms. Summary of the invention

[0004] In order to overcome the above-mentioned deficiencies of the prior art, the present invention provides a microbial material for seabed mineralization and sand fixation and an application method thereof. The specific technical scheme is as follows:

[0005] A microbial material for seabed substrate mineralization and sand fixation, comprising a hollow microbial solid carrier and sealing body, a calcium source urea capsule, spherical water grass mud particles and sea sand; the inner cavity of the calcium source urea capsule wraps a mixed solution of urea solution and calcium chloride solution; the calcium source urea capsule is placed in the inner cavity of the microbial solid carrier and sealing body; the spherical water grass mud particles include water grass mud containing nutrients and water grass seeds wrapped inside; wherein the microbial solid carrier and sealing body, the spherical water grass mud particles and sea sand are mixed in a volume ratio of 1:1:2.

[0006] Preferably, the microorganism-immobilized and sealed body is prepared by immersing porous nano-culture balls in a suspension of active urease-producing bacteria extracted from marine sediments for 6 hours, and then placing the balls in a vacuum dryer and evacuating the mixture with a vacuum pump for 8 to 10 hours.

[0007] Preferably, the active urease-producing bacterial suspension comprises a nutrient solution and bacteria cultured in the nutrient solution; the bacteria are selected from the group consisting of Bacillus lysinicus, Bacillus pasteurianus, and Ochrobacterium; the number of colonies in the active urease-producing bacterial suspension is 3.0×10 7 CFU / mL~5.0×10 7 CFU / mL.

[0008] Preferably, the ingredients of the nutrient solution include fish peptone, yeast extract powder and sodium chloride; wherein the concentration of fish peptone is 5-10 g / L, the concentration of yeast extract powder is 3-7 g / L, the concentration of sodium chloride is 5-10 g / L, and the pH value of the nutrient solution is equal to 7.

[0009] Preferably, the particle size of the porous nano-bacteria culture ball is 20 mm.

[0010] Also preferably, the capsule coating of the calcium source urea capsule comprises a capsule shell body, and both the inner and outer surfaces of the capsule shell body are sprayed with a cellulose triacetate coating.

[0011] Also preferably, the capsule shell body is made of a mixture of cold-soluble gelatin, glycerin and water; wherein the cold-soluble gelatin: glycerin: water are mixed in a volume ratio of 1: 0.4-0.6: 0.8-1.2.

[0012] Further preferably, the pH value of the mixed solution in the calcium source urea capsule is neutral; wherein the concentration of the urea solution is 1.0-1.5 mol / L; and the concentration of the calcium chloride solution is 0.8-1.2 mol / L.

[0013] Still further preferably, the clay, activated carbon, mineral powder, calcium oxalate, calcium silicate and silica sol in the water grass mud are mixed in a volume ratio of 12:4:2:2:1:1.

[0014] More preferably, a method for applying seabed sediment mineralization and sand fixation, using the above-mentioned microbial material, specifically comprises the following steps:

[0015] S1. Prepare microbial immobilization and sealing bodies, calcium source urea capsules and spherical water grass mud particles, and select sea sand with uniform particle size for standby;

[0016] S2. Mix the microorganism solidified sealing body, spherical water grass mud particles and sea sand in a volume ratio of 1:1:2, transport them to the seabed area to be solidified and improved by ship, and evenly spray them on the seabed surface through a pumping pipeline to form a covering layer;

[0017] S3. The cellulose triacetate coating on the outer surface of the calcium source urea capsule in the cavity of the microorganism immobilization and sealing body undergoes a deacetylation reaction under weakly alkaline seawater conditions and exposes the capsule shell body, and the cold-soluble gelatin in the capsule shell body gradually melts in water until the cellulose triacetate coating on the inner surface is exposed, and then continues to undergo a deacetylation reaction, causing the capsule coat to disintegrate and release the mixed liquid in the capsule coat cavity;

[0018] S4. The mixed solution is decomposed into ammonia and carbon dioxide under the catalytic action of bacteria in the active urease-producing bacterial suspension. Then, in the alkaline environment of seawater, ammonia is converted into ammonium ions and hydroxide ions, and carbon dioxide is converted into carbonate ions and bicarbonate ions, and reacts with calcium ions in seawater to form calcium carbonate, which wraps around the microbial immobilization and sealing body, the spherical water grass mud particles and the sea sand;

[0019] S5. After 14 to 28 days, calcium carbonate will fill the gaps between the microbial solid sealing body, spherical water grass mud particles and sea sand and connect them to form a mineralized film. The spherical water grass mud particles will be stabilized in the microbial solid sealing body and sea sand. The water grass seeds will begin to grow relying on the nutrients in the water grass mud and their roots will penetrate into the lower mud and sand, and together with the mineralized layer, they will complete the solidification and improvement of the seabed bottom.

[0020] The beneficial effects of the present invention are:

[0021] 1. The present invention induces the production of calcium carbonate minerals under the action of seawater and then forms a mineralized film on the seabed surface, so that the spherical water grass mud particles containing water grass seeds are stabilized in the microbial solidification and sealing body and sea sand, creating conditions for the reproduction of water grass seeds while effectively resisting the scouring of the seabed low flow, solidifying the seabed surface, and realizing the improvement of the seabed bottom quality;

[0022] 2. The preparation method of the present invention is simple and easy to implement. Mixing the microbial material into sea sand can also effectively reduce the cost of improving the seabed substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings constituting the specification of this application are used to provide further understanding of this application and do not constitute improper limitations on this application.

[0024] Figure 1 A process diagram of forming a mineralized film using the microbial material of the present invention;

[0025] Figure 2 To finally form a mineralized film. DETAILED DESCRIPTION

[0026] The specific implementation manner of a microbial material for seabed sediment mineralization and sand fixation and an application method thereof provided by the present invention is further described in conjunction with the accompanying drawings and examples.

[0027] A microbial material for seabed bottom mineralization and sand fixation, comprising a hollow microbial solidification and sealing body, a calcium source urea capsule, spherical water grass mud particles and sea sand;

[0028] The preparation method of the microorganism solid-carrying and sealed body is to immerse the porous nano-cultured bacteria ball in a suspension of active urease-producing bacteria extracted from marine sediments for 6 hours, and then place the porous nano-cultured bacteria ball in a vacuum dryer and use a vacuum pump to evacuate for 8 to 10 hours to dry and remove foreign bacteria; preferably, the particle size of the porous nano-cultured bacteria ball is 20 mm.

[0029] Preferably, the active urease-producing bacterial suspension comprises a nutrient solution and bacteria cultured in the nutrient solution; the bacteria are selected from the group consisting of Bacillus lysinicus, Bacillus pasteurianus, and Ochrobacterium. The number of colonies in the active urease-producing bacterial suspension is 3.0×10 7 CFU / mL~5.0×10 7 CFU / mL; the ingredients of the nutrient solution include fish peptone, yeast extract powder and sodium chloride; wherein the concentration of fish peptone is 5-10g / L, the concentration of yeast extract powder is 3-7g / L, the concentration of sodium chloride is 5-10g / L, and the pH value of the nutrient solution is equal to 7.

[0030] Preferably, the calcium source urea capsule is placed in the inner cavity of the microorganism solid support and sealing body, and the inner cavity of the calcium source urea capsule encapsulates the mixture of urea solution and calcium chloride solution and keeps the pH value of the mixture neutral; wherein, the concentration of urea solution is 1.0-1.5 mol / L; the concentration of calcium chloride solution is 0.8-1.2 mol / L.

[0031] It is worth noting that, in order to ensure that the calcium source urea capsule will not be dissolved by the solution in the inner cavity before it enters the seawater, the capsule coating of the calcium source urea capsule is prepared in the following manner: comprising a capsule shell body, the inner and outer surfaces of which are sprayed with a cellulose triacetate (CTA) coating. The capsule shell body is made of a mixture of cold-soluble gelatin, glycerin and water; and the cold-soluble gelatin: glycerin: water are mixed in a volume ratio of 1: 0.4-0.6: 0.8-1.2. The basic principle is that the calcium-source urea mixed solution inside the capsule coating is neutral and does not react chemically with the cellulose triacetate (CTA) coating on the inner surface, and has good anti-melting properties. In dry environments such as capsule preparation, storage, and transportation, the inside and outside of the capsule are in a stable state and will not melt spontaneously. However, when exposed to seawater, the cellulose triacetate (CTA) coating on the outer surface of the capsule coating will undergo a deacetylation reaction under weakly alkaline seawater conditions, exposing the capsule shell body, and the cold-soluble gelatin contained therein will gradually melt in water, exposing the cellulose triacetate (CTA) coating on the inner surface and continuing to undergo a deacetylation reaction, ultimately causing the capsule coating to disintegrate and release the calcium-source urea mixed solution in the capsule cavity.

[0032] Also preferably, the spherical water grass mud particles include water grass mud containing nutrients and water grass seeds wrapped inside thereof; wherein the clay, activated carbon, mineral powder, calcium oxalate, calcium silicate and silica sol in the water grass mud are mixed in a volume ratio of 12:4:2:2:1:1.

[0033] Further preferably, the microorganism solid sealing body, spherical water grass mud particles and sea sand are mixed in a volume ratio of 1:1:2.

[0034] When implementing the application, first, prepare the microbial solid-carrying sealing body, calcium source urea capsule and spherical water grass mud particles, and select sea sand with uniform particle size for use; then, mix the microbial solid-carrying sealing body, spherical water grass mud particles and sea sand in a volume ratio of 1:1:2, transport them to the seabed area to be solidified and improved by ship, and use a pumping pipeline to evenly spray them on the seabed surface to form a covering layer; then, the triacetate cellulose coating on the outer surface of the calcium source urea capsule in the cavity of the microbial solid-carrying sealing body undergoes a deacetylation reaction under weakly alkaline seawater conditions and exposes the capsule shell body, and the cold-soluble gelatin in the capsule shell body gradually melts in water until the triacetate cellulose coating on the inner surface is exposed and then the deacetylation reaction continues to occur, so that the capsule coat disintegrates and releases the mixed liquid in the capsule coat cavity; then Afterwards, the mixed liquid decomposes into ammonia and carbon dioxide under the catalytic action of bacteria in the active urease-producing bacteria suspension, and then in the alkaline environment of seawater, ammonia is converted into ammonia ions and hydroxide ions, and carbon dioxide is converted into carbonate ions and bicarbonate ions, and reacts with calcium ions in seawater to form calcium carbonate, which wraps the microbial solid sealing body, spherical water grass mud particles and sea sand; finally, after 14 to 28 days, calcium carbonate fills the gaps between the microbial solid sealing body, spherical water grass mud particles and sea sand and connects them to form a mineralized film, the spherical water grass mud particles are stabilized in the microbial solid sealing body and sea sand, and the water grass seeds begin to grow relying on the nutrients in the water grass mud, and the roots penetrate into the lower mud and sand, and together with the mineralized layer, complete the solidification and improvement of the seabed substrate.

[0035] Example:

[0036] S1. Preparation of microbial immobilization and sealing body and calcium source urea capsule:

[0037] The nutrient solution with the concentration of fish peptone 10g / L, yeast extract powder 5g / L, and sodium chloride 10g / L was used to prepare a bacterial concentration of 5.0×10 7 CFU / mL of Bacillus lysininus suspension, immerse a porous nano-culture ball (hollow inside) with a diameter of 20 mm in the suspension and soak it for 6 hours, then take it out; then put the soaked porous nano-culture ball into a vacuum dryer and evacuate it with a vacuum pump for 8 hours to obtain a microorganism immobilization and sealing body and store it in a dry environment at room temperature;

[0038] A solution with a urea concentration of 1.0 mol / L and a solution with a calcium chloride concentration of 0.8 mol / L were used to prepare a calcium source urea mixed solution (the pH value of the mixed solution was adjusted to 7 by hydrochloric acid); a capsule shell body was made by using cold-soluble gelatin: glycerol: water in a volume ratio of 1:0.4:0.8, and a cellulose triacetate coating was sprayed on the inner and outer surfaces of the capsule shell body to prepare a capsule coating; the mixed solution and the capsule coating were encapsulated and the prepared calcium source urea capsule was placed in the inner cavity of a microbial solid sealing body and stored in a dry environment at room temperature.

[0039] S2. Preparation of spherical water grass mud particles:

[0040] The cement grass and water grass seeds containing nutrients are rolled into small particles in a material making machine. During the forming process, water is sprayed to ensure the formation of particles. The spherical water grass mud particles obtained must be used within 24 hours after preparation.

[0041] The ingredients of cement grass include the following components as shown in Table 1:

[0042] Table 1: Cement grass ingredients

[0043] clay Activated carbon Ore powder Calcium Oxalate Calcium silicate Silica Sol 70 20 10 10 5 5

[0044] S3. Preparation of microbial materials:

[0045] The microorganism solid-sealed body, spherical water grass mud particles and sea sand obtained above are mixed in a volume ratio of 1:1:2 to obtain a microbial material for use.

[0046] S4. Seabed solidification and improvement method:

[0047] S4.1 Prepare microorganism immobilization and sealing bodies, calcium source urea capsules and spherical water grass mud particles, and select sea sand with uniform particle size for later use;

[0048] S4.2 The microbial material obtained in S3 is transported by ship to the seabed area to be solidified and improved, and is evenly sprayed on the seabed surface through a pumping pipeline to form a covering layer;

[0049] S4.3 The cellulose triacetate (CTA) coating on the outer surface of the calcium source urea capsule in the cavity of the microbial immobilization and sealing body undergoes a deacetylation reaction under weakly alkaline seawater conditions (see reaction formula 1), exposing the capsule shell body, and the cold-soluble gelatin contained therein gradually melts in water, exposing the cellulose triacetate (CTA) coating on the inner surface and continuing to undergo a deacetylation reaction, eventually causing the capsule coat to disintegrate and release the calcium source urea mixed solution in the capsule cavity;

[0050] S4.4 High concentration of calcium source urea is decomposed into ammonia (NH3) and carbon dioxide (CO2) under the catalytic action of lysine Bacillus (see reaction formula 2). Then, in the alkaline environment of seawater, ammonia (NH3) is hydrated to form ammonium ions (NH4 - ) and hydroxide ions (OH - ), CO2 is converted into carbonate ions (CO3 2- ) and bicarbonate ions (HCO3 - ), (see reaction formula 3-5), and react with calcium ions (Ca 2+ ) reacts to form calcium carbonate (CaCO3) (see reaction formula 6), which gradually wraps the microbial solidification and sealing body, the spherical water grass mud particles and the sea sand. Figure 1 As shown;

[0051] S4.5 After 14 to 28 days, calcium carbonate will fill the gaps between the microbial solidification and sealing body, the spherical water grass mud particles and the sea sand and connect them to form a mineralized membrane. The spherical water grass mud particles will be stabilized in the microbial solidification and sealing body and the sea sand. The water grass seeds will begin to grow based on the nutrients in the water grass mud and their roots will penetrate into the lower mud and sand, and together with the mineralized layer, they will complete the solidification and improvement of the seabed bottom. Figure 2 shown.

[0052] Among them, under weakly alkaline seawater conditions, the main chemical reaction of the deacetylation reaction of cellulose triacetate (CTA) coating can be expressed as:

[0053] CTA+OH - →CA+AcO-CTA+OH - →CA+AcO - (1);

[0054] In the formula, CTA is cellulose triacetate, OH - is hydroxide ion, CA is cellulose, AcO - Acetate ions; the acetyl group in CTA is hydrolyzed under alkaline conditions to produce cellulose and acetate ions.

[0055]

[0056] The present invention provides an efficient and environmentally friendly method for improving seabed substrate, which solidifies the seabed surface through microbial mineralization, creates conditions for the reproduction of aquatic grass seeds, and effectively enhances the seabed's ability to resist scour, thereby promoting the recovery of marine habitats.

[0057] In the present invention, the orientation or position relationship indicated by terms such as "upper", "lower", "bottom", "top", etc. is based on the orientation or position relationship shown in the accompanying drawings. They are relational words determined only for the convenience of describing the structural relationship of the various parts or elements of the present invention. They do not specifically refer to any part or element in the present invention and cannot be understood as limitations on the present invention. Terms such as "connected" and "connected" should be understood in a broad sense, indicating that it can be fixedly connected, integrally connected or detachably connected; it can be directly connected or indirectly connected through an intermediate medium. For relevant scientific research or technical personnel in this field, the specific meanings of the above terms in the present invention can be determined according to specific circumstances, and they cannot be understood as limitations on the present invention.

[0058] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A microbial material for seabed mineralization and sand fixation, characterized in that: It includes a hollow microorganism solid-carrying and sealing body, a calcium source urea capsule, spherical water grass mud particles and sea sand; The inner cavity of the calcium source urea capsule contains a mixture of urea solution and calcium chloride solution; The calcium source urea capsule is placed in the inner cavity of the microorganism immobilization and sealing body; The spherical water grass mud particles include water grass mud containing nutrients and water grass seeds wrapped inside; Among them, the microbial solid sealing body, spherical water grass mud particles and sea sand are mixed in a volume ratio of 1:1:

2.

2. The microbial material for seabed mineralization and sand fixation according to claim 1, characterized in that: The microorganism solid-carrying and sealed body is prepared by immersing a porous nano-culture ball in an active urease-producing bacterial suspension extracted from marine sediments for 6 hours, and then placing the ball in a vacuum dryer and using a vacuum pump to evacuate the ball for 8 to 10 hours.

3. The microbial material for seabed mineralization and sand fixation according to claim 2, characterized in that: The active urease-producing bacterial suspension comprises a nutrient solution and bacteria cultured in the nutrient solution; The bacteria is one of Bacillus lysinicus, Bacillus pasteurianus or Ochrobacterium; The colony count of the active urease-producing bacteria suspension was 3.0×10 7 CFU / mL~5.0×10 7 CFU / mL.

4. The microbial material for seabed mineralization and sand fixation according to claim 3, characterized in that: The ingredients of the nutrient solution include fish peptone, yeast extract powder and sodium chloride; Among them, the concentration of fish peptone is 5-10 g / L, the concentration of yeast extract powder is 3-7 g / L, the concentration of sodium chloride is 5-10 g / L, and the pH value of the nutrient solution is equal to 7.

5. The microbial material for seabed mineralization and sand fixation according to claim 2, characterized in that: The particle size of the porous nano bacterial culture ball is 20 mm.

6. The microbial material for seabed mineralization and sand fixation according to claim 1, characterized in that: The capsule coating of the calcium source urea capsule comprises a capsule shell body, and the inner and outer surfaces of the capsule shell body are sprayed with a cellulose triacetate coating.

7. The microbial material for seabed mineralization and sand fixation according to claim 6, characterized in that: The capsule shell body is made of a mixture of cold-soluble gelatin, glycerin and water; Among them, cold-soluble gelatin: glycerol: water are mixed in a volume ratio of 1:0.4-0.6:0.8-1.

2.

8. The microbial material for seabed mineralization and sand fixation according to claim 7, characterized in that: The pH value of the mixed solution in the calcium source urea capsule is neutral; Wherein, the concentration of urea solution is 1.0-1.5 mol / L; the concentration of calcium chloride solution is 0.8-1.2 mol / L.

9. The microbial material for seabed mineralization and sand fixation according to claim 1, characterized in that: The clay, activated carbon, mineral powder, calcium oxalate, calcium silicate and silica sol in the water grass mud are mixed in a volume ratio of 12:4:2:2:1:

1.

10. An application method for seabed mineralization and sand fixation, using the microbial material according to any one of claims 1 to 9, characterized in that: The specific steps include: S1. Prepare microbial immobilization and sealing bodies, calcium source urea capsules and spherical water grass mud particles, and select sea sand with uniform particle size for standby; S2. Mix the microorganism solidified sealing body, spherical water grass mud particles and sea sand in a volume ratio of 1:1:2, transport them to the seabed area to be solidified and improved by ship, and evenly spray them on the seabed surface through a pumping pipeline to form a covering layer; S3. The cellulose triacetate coating on the outer surface of the calcium source urea capsule in the cavity of the microorganism immobilization and sealing body undergoes a deacetylation reaction under weakly alkaline seawater conditions and exposes the capsule shell body, and the cold-soluble gelatin in the capsule shell body gradually melts in water until the cellulose triacetate coating on the inner surface is exposed, and then continues to undergo a deacetylation reaction, causing the capsule coat to disintegrate and release the mixed liquid in the capsule coat cavity; S4. The mixed solution is decomposed into ammonia and carbon dioxide under the catalytic action of bacteria in the active urease-producing bacterial suspension. Then, in the alkaline environment of seawater, ammonia is converted into ammonium ions and hydroxide ions, and carbon dioxide is converted into carbonate ions and bicarbonate ions, and reacts with calcium ions in seawater to form calcium carbonate, which wraps around the microbial immobilization and sealing body, the spherical water grass mud particles and the sea sand; S5. After 14 to 28 days, calcium carbonate will fill the gaps between the microbial solid sealing body, spherical water grass mud particles and sea sand and connect them to form a mineralized film. The spherical water grass mud particles will be stabilized in the microbial solid sealing body and sea sand. The water grass seeds will begin to grow relying on the nutrients in the water grass mud and their roots will penetrate into the lower mud and sand, and together with the mineralized layer, they will complete the solidification and improvement of the seabed bottom.

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