Microbial nutrient carrier based on porous chemical material and preparation method thereof

Abstract

The application provides a kind of microbial nutrient carrier based on porous chemical material and its preparation method, belongs to sludge treatment technical field.The preparation method includes (1) after mixing glucose, fish meal, yeast powder uniformly, nutrient substance mixed powder is obtained, and after mixing with natural substance again, nutrient substance is obtained;(2) microbial bacteria liquid and nutrient substance mixed powder are fully stirred uniformly, mixture is obtained, then mixed with porous carrier, and after being fully oscillated, the microbial nutrient carrier is obtained after drying and solidification.The carrier has high porosity, good mechanical strength and excellent strain loading capacity, when applied to sludge aerobic fermentation, can quickly start fermentation, significantly improve organic matter degradation efficiency and strengthen dewatering effect, has good industrial application prospect.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment, specifically to a microbial nutrient carrier based on porous chemical materials and its preparation method. Background Technology

[0002] In the field of microbial treatment and environmental remediation, especially in sludge stabilization and wastewater biological purification, microbial carriers serve as key functional components for maintaining the efficient and stable operation of the system. Their core role is to provide functional microorganisms with a stable attachment interface, a suitable growth microenvironment, and a continuous supply of metabolic substrates, thereby significantly improving the biodegradation efficiency of pollutants. Currently, widely used microbial carriers in the industry mainly include physical adsorption or composite materials such as activated carbon, bentonite, and polymer particles. These carriers typically load nutrients such as carbon, nitrogen, and phosphorus sources through physical adsorption, ion exchange, or surface coating to support the energy metabolism and proliferation needs of microorganisms.

[0003] However, existing carriers generally suffer from problems such as dense pore structure, limited mass transfer, weak microenvironment regulation ability, uncontrollable nutrient release, rapid efficiency decay, high cost, and poor sustainability. Patent CN118812011A discloses a microbial carrier made of polypropylene, diatomaceous earth, lithium tourmaline micropowder, and graphene oxide powder. While it can increase the oxygen content in water, its low porosity (9-18%) makes it prone to compaction in sludge piles, restricting oxygen and nutrient diffusion and making it difficult to maintain microbial activity. Chinese patent CN108018280A discloses a slow-release microbial carrier using a mixture of activated carbon, chitosan, and sodium alginate to immobilize microorganisms. This method is low-cost and simple, achieving 85% microbial release within 30 days with a bacterial survival rate of 6.5%; however, the carrier prepared by this method has low mechanical strength (6.67-10.41 N / cm²). 2 The high loss rate of the carrier material under water flow impact leads to the loss of microbial strains with the water flow. Patent CN118289944A discloses a microbial carrier packing material suitable for low-temperature environments; however, this carrier is designed for low-temperature environments and does not address the uncontrollable nutrient release problem under normal conditions. This results in rapid nutrient release in the initial stage of use in conventional wastewater treatment systems, followed by insufficient supply and metabolic imbalance of microorganisms. The root cause of these problems lies in the deficiencies of existing carriers in material structure design and surface chemical functionalization, making it difficult to synergistically achieve the three core functions of high-stability nutrient loading, efficient mass transfer channel construction, and independent microenvironment creation.

[0004] In view of this, the present invention provides a microbial nutrient carrier based on controllable porous chemical materials. This carrier, through precise control of pore size distribution, specific surface area, and surface chemical properties at the nanoscale, possesses high porosity, excellent adsorption performance, and interfacial functionalization capabilities. It can effectively promote the mass transfer and diffusion of oxygen and substrates, achieve multi-stage slow release of nutrients, and construct a stable and isolated microecological reaction zone for microorganisms, thereby significantly improving their activity, community stability, and overall system operational efficiency. Summary of the Invention

[0005] This invention aims to provide a microbial nutrient carrier based on porous chemical materials and its preparation method, solving the technical problems of existing technologies such as dense pore structure, limited mass transfer, weak microenvironment regulation ability, uncontrollable nutrient release, and poor sustainability. The microbial nutrient carrier of this invention uses a porous chemical matrix as the structural framework, nutrient components as a slow-release source, and a microbial community as the active unit. These three components combine through physical adsorption to form a functionally integrated carrier. This carrier possesses four functions: nutrient storage, slow-release supply, microenvironment construction, and mechanical support.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] A method for preparing a microbial nutrient carrier based on porous chemical materials includes the following steps: (1) After mixing glucose, fish meal and yeast powder evenly, a nutrient mixture powder is obtained, and then mixed with natural substances again to obtain nutrients. (2) The microbial liquid and nutrient powder are thoroughly mixed to obtain a mixture, which is then mixed with a porous carrier and shaken thoroughly before being dried and solidified to obtain the microbial nutrient carrier.

[0008] The proposed solution uses industrial-grade glucose as the main carbon source to provide energy and metabolic substrates for heterotrophic microorganisms. Fish meal and yeast powder together provide organic nitrogen sources, phosphorus sources, amino acids, B vitamins and trace elements, etc., to construct a carbon-nitrogen-phosphorus balanced compound nutrition system rich in growth factors, which is suitable for the colonization and continuous metabolism of a variety of heterotrophic microorganisms.

[0009] Preferably, the mass ratio of glucose, fish meal, yeast powder and natural substances is 80-90:5-10:5-10:20.

[0010] Preferably, the mass ratio of the microbial inoculum to the nutrient mixture is 15-25:1; and the mass ratio of the mixture to the porous oxygen carrier is 0.5-1.5:1.

[0011] Preferably, the microbial culture solution is obtained after fermentation and culture of microbial strains, and the initial viable cell concentration in the microbial culture solution is 10.9 CFU / mL, the microbial species is Bacillus licheniformis.

[0012] Preferably, the porous carrier is selected from porous alumina or composite oxide, with a pore size of 2-50 nm and a specific surface area ≥100 m². 2 / g, with a uniform pore structure, which is conducive to the efficient adsorption and stable loading of nutrient molecules.

[0013] Preferably, the natural substance is selected from at least one of natural cellulose or chitosan fiber; used to improve the mechanical strength, structural stability and air permeability of the carrier.

[0014] Preferably, the strain loading in the microbial nutrient carrier is 1×10⁻⁶. 10 CFU / g.

[0015] The microbial nutrient carrier has a porosity of 70-90%, a pore size of 15-30 nm, and a specific surface area of ​​80-120 m². 2 / g.

[0016] The second aspect of this invention provides a microbial nutrient carrier based on porous chemical materials obtained by the aforementioned preparation method, comprising porous chemical materials, a nutrient system, and structural reinforcing components; wherein the porous chemical materials are selected from porous alumina or Al2O3-SiO2 composite oxides, with a pore size of 2-50 nm and a specific surface area ≥100 m². 2 / g; the nutrient system includes glucose, fish meal and yeast powder; the structural reinforcing components include natural cellulose or chitosan fiber, used to improve mechanical strength, structural stability and system permeability.

[0017] The microbial nutrient carrier of the present invention achieves efficient storage and controllable release of nutrients through the synergistic effect of porous inorganic framework, multi-nutrient slow release and natural polymer reinforcement, avoiding nutrient excess in a short period of time or nutrient deficiency in a later period; the microenvironment for microbial colonization is optimized by isolating external adverse factors through the pore structure, improving the survival stability of microorganisms and the structural durability and functional stability in complex engineering environments, and extending the service life of the carrier.

[0018] The third aspect of this invention provides the application of the aforementioned microbial nutrient carrier based on porous chemical materials in sludge treatment.

[0019] The present invention also provides a sludge treatment method, comprising the following steps: Simply mix the microbial nutrient carrier based on porous chemical materials and the sludge to be treated evenly, and then carry out aerobic fermentation.

[0020] Compared with the prior art, the present invention has the following beneficial effects: 1. This formula utilizes a porous framework with a high specific surface area (≥100m²). 2 The uniform mesoporous structure (2-50nm) allows carbon, nitrogen, phosphorus and growth factors to be evenly distributed in the pores and to achieve stable and continuous release of nutrients through adsorption-slow release mechanism. This effectively avoids local nutrient overload or deficiency caused by traditional one-time addition methods, significantly prolongs the metabolic active period of microorganisms and ensures their long-term stability in complex environments.

[0021] 2. The carrier particles of the present invention form a stable porous network structure in the sludge system, acting as "micro-air channels", reducing the compaction density of the pile and improving the looseness of the sludge; at the same time, the pores inside the carrier provide a physically isolated microenvironment for the microbial community, effectively buffering external pH fluctuations, temperature changes and toxic substance impacts, reducing physiological stress, and improving the colonization capacity and ecological stability of functional bacteria.

[0022] 3. The raw materials used in this invention are widely available and inexpensive; the slow-release nutrient characteristics greatly reduce the frequency of external supplementation and significantly reduce long-term operating costs; at the same time, the structural enhancement components are biodegradable natural polymers, the carrier has good overall environmental compatibility, no risk of secondary pollution, and some components can be recycled, thus improving resource utilization.

[0023] 4. The carrier of this invention has strong versatility and a wide range of applications, such as aerobic composting of municipal and industrial sludge, biological treatment of high-concentration organic wastewater, in-situ remediation of polluted water bodies, and microbial inoculation of agricultural soil, demonstrating good technical universality and industrial application potential. Detailed Implementation

[0024] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1: A method for preparing a microbial nutrient carrier based on porous chemical materials includes the following steps: (1) By mass fraction, 85% glucose, 7.5% fish meal and 7.5% yeast powder are mixed evenly to obtain a nutrient mixture powder, and then mixed again with chitosan fiber accounting for 20% of the mass of the mixture powder to obtain nutrients. (2) Load with live bacteria (concentration of 10) 9Microbial culture (CFU / mL) and nutrients were thoroughly mixed at a mass ratio of 20:1 to obtain a mixture. This mixture was then combined with a porous Al₂O₃-SiO₂ carrier at a mass ratio of 1:1, thoroughly shaken, and dried and solidified at 35°C to obtain the microbial nutrient carrier. The porous Al₂O₃-SiO₂ carrier had a specific surface area of ​​100 m² / mL. 2 / g, pore size is 20nm; (3) After storing the microbial nutrient carrier in the dark for 7 days, take 10g of the carrier and dissolve it in 90mL of LB medium, then dilute it by 10. -7 After doubling, 100 μL of liquid was spread onto solid LB medium and incubated at 35°C for 12 h. Plate counts were performed, and the viable cell concentration (CFU / mL) was calculated. The viable cell concentration (CFU / mL) was compared with the initial viable cell concentration (CFU / mL) of the bacterial solution to calculate the survival rate. The porosity and mechanical strength of the microbial nutrient carrier were also tested.

[0026] The strain loading rate was tested to be 80%; the porosity of the microbial nutrient carrier was 80%, and the specific surface area was 120 m². 2 / g, with a particle size of 0.5mm and a mechanical strength of 1.4MPa.

[0027] Comparative Example 1: A method for preparing a microbial nutrient carrier based on porous chemical materials includes the following steps: (1) By mass fraction, 85% glucose, 7.5% fish meal and 7.5% yeast powder are mixed evenly to obtain a nutrient mixture powder; (2) Load with live bacteria (concentration of 10) 9 Microbial culture (CFU / mL) and nutrient powder were thoroughly mixed at a mass ratio of 20:1 to obtain a mixture. This mixture was then combined with a porous Al₂O₃-SiO₂ carrier at a mass ratio of 1:1, thoroughly shaken, and dried and solidified at 35°C to obtain the microbial nutrient carrier. The porous Al₂O₃-SiO₂ carrier had a specific surface area of ​​100 m² / mL. 2 / g, pore size is 20nm; (3) After storing the microbial nutrient carrier in the dark for 7 days, take 10g of the carrier and dissolve it in 90mL of LB medium, then dilute it by 10. -7 After doubling, 100 μL of liquid was spread onto solid LB medium and incubated at 35°C for 12 h. Plate counts were performed, and the viable cell concentration (CFU / mL) was calculated. The viable cell concentration (CFU / mL) was compared with the initial viable cell concentration (CFU / mL) of the bacterial solution to calculate the survival rate. The porosity and mechanical strength of the microbial nutrient carrier were also tested.

[0028] The strain loading rate was tested to be 75%; the porosity of the microbial nutrient carrier was 70%, and the specific surface area was 80 m².2 / g, with a particle size of 5mm and a mechanical strength of 1.3MPa.

[0029] Comparative Example 2: A method for preparing a microbial nutrient carrier based on porous chemical materials includes the following steps: (1) By mass fraction, 85% glucose, 7.5% fish meal and 7.5% yeast powder are mixed evenly to obtain a nutrient mixture powder, and then mixed again with chitosan fiber accounting for 20% of the mass of the mixture powder to obtain nutrients. (2) Load with live bacteria (concentration of 10) 9 Microbial culture (CFU / mL) and nutrients were thoroughly mixed at a mass ratio of 20:1 to obtain a mixture. This mixture was then combined with a porous Al₂O₃-SiO₂ carrier at a mass ratio of 1:1, thoroughly shaken, and dried and solidified at 35°C to obtain the microbial nutrient carrier. The porous Al₂O₃-SiO₂ carrier had a specific surface area of ​​75 m² / mL. 2 / g, pore size is 7mm; (3) After storing the microbial nutrient carrier in the dark for 7 days, take 10g of the carrier and dissolve it in 90mL of LB medium, then dilute it by 10. -7 After doubling, 100 μL of liquid was spread onto solid LB medium and incubated at 35°C for 12 h. Plate counts were performed, and the viable cell concentration (CFU / mL) was calculated. The viable cell concentration (CFU / mL) was compared with the initial viable cell concentration (CFU / mL) of the bacterial solution to calculate the survival rate. The porosity and mechanical strength of the microbial nutrient carrier were also tested.

[0030] The test showed that the bacterial load was 70%; the porosity of the microbial nutrient carrier was 65%, and the specific surface area was 80 m². 2 / g, with a particle size of 7mm and a mechanical strength of 1.4MPa.

[0031] Comparative Example 3: A method for preparing a microbial nutrient carrier based on porous chemical materials includes the following steps: (1) By mass fraction, 85% glucose, 7.5% fish meal and 7.5% yeast powder are mixed evenly to obtain a nutrient mixture powder, and then mixed again with polypropylene fiber accounting for 20% of the mass of the mixture powder to obtain nutrients. (2) Load with live bacteria (concentration of 10) 9 Microbial culture (CFU / mL) and nutrients were thoroughly mixed at a mass ratio of 20:1 to obtain a mixture. This mixture was then combined with a porous Al₂O₃-SiO₂ carrier at a mass ratio of 1:1, thoroughly shaken, and dried and solidified at 35°C to obtain the microbial nutrient carrier. The porous Al₂O₃-SiO₂ carrier had a specific surface area of ​​100 m² / mL. 2 / g, pore size is 20nm; (3) After storing the microbial nutrient carrier in the dark for 7 days, take 10g of the carrier and dissolve it in 90mL of LB medium, then dilute it by 10. -7 After doubling, 100 μL of liquid was spread onto solid LB medium and incubated at 35°C for 12 h. Plate counts were performed, and the viable cell concentration (CFU / mL) was calculated. The viable cell concentration (CFU / mL) was compared with the initial viable cell concentration (CFU / mL) of the bacterial solution to calculate the survival rate. The porosity and mechanical strength of the microbial nutrient carrier were also tested.

[0032] The strain loading rate was tested to be 80%; the porosity of the microbial nutrient carrier was 80%, and the specific surface area was 90 m². 2 / g, with a particle size of 5.5mm and a compressive strength of 1.5MPa.

[0033] Application examples The microbial nutrient carriers prepared in the above examples and comparative examples were mixed with the sludge to be treated at a dosage of 0.5%, and then 10% straw additive was added. The organic matter content, moisture content, and time to reach the maximum temperature were measured after 30 days of fermentation. The results are shown in Table 1.

[0034] Table 1 (Unit: ppm)

[0035] As shown in Table 1, Example 1, which constructed a microbial nutrient carrier by combining chitosan fibers with high specific surface area porous Al2O3-SiO2, achieved efficient loading (80%) and long-term activity maintenance of Bacillus licheniformis. In sludge fermentation applications, this carrier significantly accelerated the fermentation start-up speed (reaching high temperature in 1.5 days), improved the organic matter degradation efficiency (degradation of 11.3%), and effectively reduced the water content (40%). Compared with Comparative Examples 1-3, which did not contain chitosan, had excessively small pore sizes, or used non-biological fibers, its overall performance was superior.

[0036] In summary, the microbial nutrient carrier of the present invention significantly enhances the aerobic fermentation process of sludge by efficiently loading and slow-release functional bacteria, not only greatly shortening the heating cycle, but also effectively promoting the deep mineralization of organic matter, and has good potential for industrial application.

[0037] The above embodiments are merely preferred technical solutions of the present invention and should not be considered as limitations on the present invention. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A method for preparing a microbial nutrient carrier based on porous chemical materials, characterized in that: Includes the following steps: (1) After mixing glucose, fish meal and yeast powder evenly, a nutrient mixture powder is obtained, and then mixed with natural substances again to obtain nutrients. (2) The microbial liquid and nutrient powder are thoroughly mixed to obtain a mixture, which is then mixed with a porous carrier and shaken thoroughly before being dried and solidified to obtain the microbial nutrient carrier.

2. The method for preparing a microbial nutrient carrier based on porous chemical materials according to claim 1, characterized in that: The mass ratio of glucose, fish meal, yeast powder and natural substances is 80-90:5-10:5-10:

20.

3. The method for preparing a microbial nutrient carrier based on porous chemical materials according to claim 1, characterized in that: The mass ratio of the microbial inoculum to the nutrient mixture is 15-25:1; the mass ratio of the mixture to the porous oxygen carrier is 0.5-1.5:

1.

4. The method for preparing a microbial nutrient carrier based on porous chemical materials according to claim 1, characterized in that: The microbial culture solution is obtained after fermentation and culture of microbial strains, and the initial viable cell concentration in the microbial culture solution is 1×10⁻⁶. 9 CFU / mL, the microbial species is Bacillus licheniformis.

5. The method for preparing a microbial nutrient carrier based on porous chemical materials according to claim 1, characterized in that: The porous carrier is selected from porous alumina or composite oxides, with a pore size of 2-50 nm and a specific surface area ≥100 m². 2 / g.

6. The method for preparing a microbial nutrient carrier based on porous chemical materials according to claim 1, characterized in that: The microbial nutrient carrier has a strain loading of 1×10⁻⁶. 10 CFU / g.

7. The method for preparing a microbial nutrient carrier based on porous chemical materials according to claim 1, characterized in that: The microbial nutrient carrier has a porosity of 70-90%, a pore size of 15-30 nm, and a specific surface area of ​​80-120 m². 2 / g.

8. The microbial nutrient carrier based on porous chemical materials obtained by the preparation method according to any one of claims 1-7.

9. The application of the microbial nutrient carrier based on porous chemical materials as described in claim 8 in wastewater treatment.

10. A sludge treatment method, characterized in that: The process includes the following steps: mixing the microbial nutrient carrier based on porous chemical materials as described in claim 8 with the sludge to be treated and then carrying out aerobic fermentation.

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