Composite nutrient slow-release filler and preparation method thereof

Abstract

The invention provides a composite nutrition slow-release filler, which comprises a nutrition slow-release filler and volcanic rock particles, the nutrition slow-release filler accounts for 5-10% of the total mass of the composite nutrition slow-release filler, and the nutrition slow-release filler is prepared by taking a plant fiber skeleton as a support and loading an adhesive and mineral powder water slurry. According to the method, the functional material with the nutrition slow-release function is combined with the volcanic rock with the excellent micro-ecological environment, so that the treatment efficiency of a biological purification technology can be improved, and the method plays an important role in improving the operation convenience of the system and reducing the operation and maintenance cost. The research, development and application of the novel composite filler are beneficial to realizing an environment-friendly waste gas treatment technology and bring a new development opportunity to the field of biological purification.

Description

Technical Field

[0001] The present invention relates to the technical field of waste gas biological purification in one or more embodiments, and in particular to a composite nutrient slow-release filler and a preparation method thereof. Background Art

[0002] Biological Filter Purification (BFP) is essentially a process in which microorganisms use pollutants in waste gas as energy and carbon sources for their life activities, converting pollutants into simple inorganic substances (CO2, water, minerals, etc.) and microbial cells.

[0003] In biological purification technology, the selection and optimization of fillers are key. As a growth medium for microorganisms, fillers not only provide a place for microorganisms to attach, but also affect the distribution and growth conditions of microorganisms through their special physical structure, thereby affecting the treatment efficiency and treatment effect of the entire system. How to provide a filler that has both good microbial adhesion and can provide nutrient supply is a technical problem that needs to be solved urgently. Summary of the invention

[0004] The present invention describes a composite nutritional sustained-release filler and a preparation method thereof, which can solve the above technical problems.

[0005] According to a first aspect, a composite nutritional slow-release filler is provided, the composite nutritional slow-release filler comprising a nutritional slow-release filler and volcanic rock particles, wherein the nutritional slow-release filler accounts for 5%-10% of the total mass of the composite nutritional slow-release filler;

[0006] The nutrient slow-release filler is made of a plant fiber skeleton as a support and loaded with an adhesive and mineral powder slurry.

[0007] Furthermore, the mineral powder water slurry includes mineral powder and calcium carbonate powder, and the mass ratio of the mineral powder to the calcium carbonate powder is 10-15:1.

[0008] Furthermore, the mineral powder is prepared according to the following method: the humic acid-rich lignite is mechanically crushed and then sieved to a fineness of 150 meshes to obtain the mineral powder.

[0009] Furthermore, calcium carbonate powder is prepared according to the following method: the shells and / or oyster shells are cleaned, calcined at high temperature and ground to obtain a powdery material, which is then sieved to a fineness of 100 mesh to obtain calcium carbonate powder.

[0010] Furthermore, the adhesive comprises water-based polyurethane adhesive, acrylic emulsion and pectin, wherein the mass ratio of the water-based polyurethane adhesive, acrylic emulsion and pectin is 8:3:1.

[0011] Furthermore, the adhesive also includes a functional group cross-linking agent.

[0012] Furthermore, the nutritional sustained-release filler is prepared according to the following method:

[0013] The nutrient sustained-release filler is prepared according to the following method:

[0014] The plant fiber skeleton is immersed in the adhesive, and then the plant fiber skeleton is taken out. After removing the excess adhesive in the plant fiber skeleton, the skeleton is placed in a container containing mineral powder water slurry. When the surface of the plant fiber skeleton is covered with the mineral powder water slurry, the skeleton is taken out and dried at 80°C for 5 minutes. The loosely adhered mineral powder water slurry is removed, and the plant fiber skeleton is immersed in the adhesive again so that a layer of adhesive is evenly adhered to the surface of the plant fiber skeleton. The skeleton is taken out and dried at 80°C to obtain a nutrient slow-release filler.

[0015] According to a second aspect, a method for preparing a composite nutritional sustained-release filler is provided, comprising:

[0016] Weigh mineral powder and calcium carbonate in a mass ratio of 10-15:1, add an appropriate amount of water, stir and mix evenly, and then place for aging to obtain mineral powder water slurry;

[0017] Weigh water-based polyurethane adhesive, acrylic emulsion and pectin according to proportion, put them into a container, stir and mix them evenly to obtain an adhesive;

[0018] The plant fiber skeleton is immersed in the adhesive, and then the plant fiber skeleton is taken out. After removing the excess adhesive in the plant fiber skeleton, the skeleton is placed in a container containing mineral powder water slurry. When the surface of the plant fiber skeleton is fully adhered to the mineral powder water slurry, the skeleton is taken out, and dried at 80° C. for 5 minutes. The loosely adhered mineral powder water slurry is removed, and the plant fiber skeleton is immersed in the adhesive again, so that a layer of adhesive is evenly adhered to the surface of the plant fiber skeleton, and then the skeleton is taken out and dried at 80° C. to obtain a nutrient slow-release filler;

[0019] The volcanic rock and the nutrient slow-release filler are uniformly mixed to obtain the composite nutrient slow-release filler, wherein the nutrient slow-release filler accounts for 5%-10% of the total mass.

[0020] According to the third aspect, there is provided a use of the nutrient slow-release filler in the first aspect in treating waste gas.

[0021] The composite nutrient slow-release filler provided in the embodiment of the present invention can not only improve the treatment efficiency of biological purification technology by combining functional materials with nutrient slow-release function with volcanic rocks with excellent microecological environment, but also play an important role in improving the operational convenience of the system and reducing operation and maintenance costs. The development and application of this new composite filler will help to realize environmentally friendly waste gas treatment technology while bringing new development opportunities to the field of biological purification. DETAILED DESCRIPTION

[0022] The solution provided by the present invention is described below in conjunction with the diagrams.

[0023] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be described below with reference to the diagrams.

[0024] In the description of the embodiments of the present invention, words such as "exemplary", "for example" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary", "for example" or "for example" in the embodiments of the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary", "for example" or "for example" is intended to present related concepts in a concrete way.

[0025] In the description of the embodiments of the present invention, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, B exists alone, and A and B exist at the same time. In addition, unless otherwise specified, the term "plurality" means two or more.

[0026] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. The terms "include", "comprises", "has" and their variations all mean "including but not limited to", unless otherwise specifically emphasized.

[0027] Biological Filter Purification (BFP) is essentially a process in which microorganisms use pollutants in waste gas as energy and carbon sources for their life activities, converting pollutants into simple inorganic substances (CO2, water, minerals, etc.) and microbial cells.

[0028] In biological purification technology, the selection and optimization of fillers are key. As a growth medium for microorganisms, fillers not only provide a place for microorganisms to attach, but also affect the distribution and growth conditions of microorganisms through their special physical structure, thereby affecting the treatment efficiency and treatment effect of the entire system. Therefore, developing a filler that has good microbial attachment and can provide nutrient supply is of great significance to improving the performance of biological purification technology.

[0029] Although traditional biological fillers can provide a place for microorganisms to attach and grow, there are problems in their application: the supply of nutrients is discontinuous, and traditional filler systems require regular addition of nutrient solution during operation to maintain the activity and proliferation of microorganisms. This not only increases the complexity of operation, but may also lead to increased costs and uncertainties in the operation process due to frequent addition of nutrient solution.

[0030] Among the many fillers, volcanic rock has become a hot topic of research due to its unique physical and chemical properties. Volcanic rock has a good porous structure, high specific surface area and a large specific surface area / volume ratio. These characteristics make it have good adsorption properties for microorganisms and also provide abundant growth space for microorganisms. In addition, volcanic rock itself is a natural and environmentally friendly material, which is more environmentally friendly when used.

[0031] In view of the traditional volcanic rock filler, the purpose of the present invention is to develop a new type of composite filler, aiming to improve the treatment effect of biological purification technology, especially to increase the nutrient slow release function. This nutrient slow release function is achieved by adding specific functional materials to the volcanic rock, which can gradually release various nutrients required by microorganisms during the use of the filler, such as nitrogen, phosphorus, etc. Such a design can effectively solve the problem of frequent nutrient supplementation of traditional fillers, and also provide a stable nutrient source for the long-term growth and reproduction of microorganisms.

[0032] In this way, the composite filler can not only improve the biological activity and treatment efficiency of the biofilm, but also extend the life cycle of the biofilm and reduce maintenance costs. In addition, the application of this technology can also reduce the operating errors and operating costs caused by frequent addition of nutrient solution, while reducing the risk of secondary pollution caused by nutrient solution leakage.

[0033] By combining functional materials with slow-release nutrition with volcanic rocks with excellent microecological environment, it is not only possible to improve the treatment efficiency of biological purification technology, but also play an important role in improving the operational convenience of the system and reducing operation and maintenance costs. The development and application of this new composite filler will help to achieve environmentally friendly waste gas treatment technology while bringing new development opportunities to the field of biological purification.

[0034] Humic acid is a natural substance rich in organic matter and highly active groups. It is mainly distributed in lignite and also in peat. Researchers have conducted in-depth physical and chemical analysis on the properties of humic acid, but its structure is complex and the specific structure and molecular weight of the molecule have not yet been determined. Elemental analysis shows that it mainly contains C, H, O, N, and S elements. The content of each element varies with the degree of humification. In the commonly used molecular unit model, there are many functional groups around the center of the molecule, such as phenolic hydroxyl, carboxyl, hydroxyl, etc. These active groups enable it to perform a variety of physical and chemical effects. Practical applications have proved that by adding biologically and chemically active humic acid to agricultural fertilizers, the buffering capacity of the soil is improved through a series of complex biochemical reactions. At the same time, due to the increase in constant and trace elements, the number of microorganisms also increases.

[0035] The humic acid-rich lignite is mechanically crushed and then sieved to obtain lignite powder with a fineness of 150 meshes.

[0036] Shells are composed of 95% calcium carbonate and a small amount of 5% protein, glycoprotein, polysaccharide and other organic matter. Shell powder is a powdery material made of shells and oyster shells as the main raw materials. The main components are calcium carbonate, calcium oxide and other calcified substances. Then it is sieved to a fineness of 100 mesh. An appropriate amount of calcium carbonate CaCO3 is used as a buffer to adjust the acidity and alkali.

[0037] Water-based polyurethane adhesives, i.e. water-based PU adhesives, have the characteristics of wear resistance, corrosion resistance, water resistance, good film-forming properties, good weather resistance, etc., and are safe, environmentally friendly, and easy to use and operate. PEVA emulsion, i.e. acrylic emulsion, pectin and other adhesives are added to water-based polyurethane adhesives and mechanically blended in a certain proportion to give full play to the advantages of each component and improve the performance of the adhesive. And these components can be biodegraded. In the process of exhaust gas purification, these adhesives are gradually degraded by microorganisms, thereby releasing the nutrients embedded in them.

[0038] Among them, the mass ratio of water-based polyurethane adhesive: acrylic emulsion: pectin is 8:3:1.

[0039] Choose plant fiber as the skeleton of the filler with slow-release function. You can choose bamboo fiber, which has good surface hydrophilicity. It needs to be pre-treated and softened, and choose plant fiber with a length of 2-6mm.

[0040] The preparation method of the filler with sustained-release function comprises:

[0041] Weigh appropriate amount of mineral powder and calcium carbonate in a mass ratio of 10-15:1, add appropriate amount of water, stir thoroughly and mix evenly, then place for aging for a period of time for use. Stir again for more than 5 minutes before mixing with the adhesive to make the slurry fully mixed and evenly mixed. The amount of water added is enough to form mineral powder water slurry.

[0042] Accurately weigh water-based polyurethane adhesive, acrylic emulsion and pectin according to the proportion, put them into a container and stir to mix them evenly. During the operation, an appropriate amount of functional group cross-linking agent can be added to the mixed adhesive. The cross-linking agent can cross-link with water-based polyurethane or acrylic ester at low temperature. After adding, it can significantly improve the water resistance, solvent resistance, high temperature resistance, adhesion and wear resistance of the coating. Generally speaking, when the adhesive has a high consistency, it can be diluted with water, but if the viscosity is low, a small amount of thickener can also be added to improve the viscosity and rheological properties of the adhesive.

[0043] Use a container of a certain volume to hold the adhesive prepared in proportion. You can add a certain amount of water or cross-linking agent to adjust the viscosity of the adhesive and stir it to make it uniform. Select a certain number n of plant fiber skeletons, weigh the mass m1, and then immerse the filler skeleton in the adhesive. After it is fully soaked, remove the excess adhesive and put it into a container filled with nutrient water slurry. Shake it gently and take it out when the surface of the plant fiber is full of adhesion. Dry it at 80℃ for 5 minutes, remove the nutrients that are not firmly adhered, weigh it, record the filler mass m2, immerse it in the adhesive again, make a layer of adhesive adhere to the surface evenly, dry it at 80℃ to constant weight, and form a film on the surface.

[0044] Preparation of volcanic rock particles: acid wash in weak acid solution, then wash with water, and air dry naturally; then alkaline wash in weak alkaline solution, then wash with water, and air dry naturally; finally, fumigate the volcanic rock with high-pressure steam to remove the salt substances remaining on the surface of the volcanic rock, and screen the volcanic rock particles with a particle size of 30-50 mm. The weak acid is a nitric acid or sulfuric acid solution with a pH of 4-5, and the acid wash time is 3-5 minutes; the weak base is a sodium hydroxide or potassium hydroxide solution with a pH of 8-10, and the alkaline wash time is 3-5 minutes; the high-pressure steam fumigation refers to fumigating the volcanic rock in 5M-10M Pa steam for 2-3 minutes.

[0045] The volcanic rock and the functional filler with the nutrient slow-release function are mixed evenly, and the weight ratio of the functional filler is about 5%-10% of the total mass.

[0046] In another embodiment of the present invention, a nutrient slow-release filler is provided, wherein the composite nutrient slow-release filler comprises a nutrient slow-release filler and volcanic rock particles, wherein the nutrient slow-release filler accounts for 5%-10% of the total mass of the composite nutrient slow-release filler;

[0047] The nutrient slow-release filler is made of a plant fiber skeleton as a support and loaded with an adhesive and mineral powder slurry.

[0048] Furthermore, the mineral powder water slurry includes mineral powder and calcium carbonate powder, and the mass ratio of the mineral powder to the calcium carbonate powder is 10-15:1.

[0049] Furthermore, the mineral powder is prepared according to the following method: the humic acid-rich lignite is mechanically crushed and then sieved to a fineness of 150 meshes to obtain the mineral powder.

[0050] Furthermore, calcium carbonate powder is prepared according to the following method: the shells and / or oyster shells are cleaned, calcined at high temperature and ground to obtain a powdery material, which is then sieved to a fineness of 100 mesh to obtain calcium carbonate powder.

[0051] Furthermore, the adhesive comprises water-based polyurethane adhesive, acrylic emulsion and pectin, wherein the mass ratio of the water-based polyurethane adhesive, acrylic emulsion and pectin is 8:3:1.

[0052] Furthermore, the adhesive also includes a functional group cross-linking agent.

[0053] Furthermore, the nutritional sustained-release filler is prepared according to the following method:

[0054] The nutrient sustained-release filler is prepared according to the following method:

[0055] The plant fiber skeleton is immersed in the adhesive, and then the plant fiber skeleton is taken out. After removing the excess adhesive in the plant fiber skeleton, the skeleton is placed in a container containing mineral powder water slurry. When the surface of the plant fiber skeleton is covered with the mineral powder water slurry, the skeleton is taken out and dried at 80°C for 5 minutes. The loosely adhered mineral powder water slurry is removed, and the plant fiber skeleton is immersed in the adhesive again so that a layer of adhesive is evenly adhered to the surface of the plant fiber skeleton. The skeleton is taken out and dried at 80°C to obtain a nutrient slow-release filler.

[0056] Another embodiment of the present invention provides a method for preparing a nutrient sustained-release filler, comprising:

[0057] Weigh mineral powder and calcium carbonate in a mass ratio of 10-15:1, add an appropriate amount of water, stir and mix evenly, and then place for aging to obtain mineral powder water slurry;

[0058] Weigh water-based polyurethane adhesive, acrylic emulsion and pectin according to proportion, put them into a container, stir and mix them evenly to obtain an adhesive;

[0059] The plant fiber skeleton is immersed in the adhesive, and then the plant fiber skeleton is taken out. After removing the excess adhesive in the plant fiber skeleton, the skeleton is placed in a container containing mineral powder water slurry. When the surface of the plant fiber skeleton is fully adhered to the mineral powder water slurry, the skeleton is taken out, and dried at 80° C. for 5 minutes. The loosely adhered mineral powder water slurry is removed, and the plant fiber skeleton is immersed in the adhesive again, so that a layer of adhesive is evenly adhered to the surface of the plant fiber skeleton, and then the skeleton is taken out and dried at 80° C. to obtain a nutrient slow-release filler;

[0060] The volcanic rock and the nutrient slow-release filler are uniformly mixed to obtain the composite nutrient slow-release filler, wherein the nutrient slow-release filler accounts for 5%-10% of the total mass.

[0061] Furthermore, a functional group cross-linking agent is added to the adhesive.

[0062] The embodiment of the present invention also provides an application of the nutrient slow-release filler in treating waste gas.

[0063] In another embodiment of the present invention, the preparation of the adhesive comprises the following steps:

[0064] Film production:

[0065] Weigh the required adhesive accurately according to the proportion and stir thoroughly, then place on a 10cm×10cm polytetrafluoroethylene plate. Next, place in a constant temperature oven to dry until constant weight. Evaluate the appearance and properties of the film by observation and touch, and compare and describe.

[0066] Selection of drying temperature: Combined with the activation temperature and heat deformation temperature of several adhesives, the experiment examined three temperatures of 70°C, 80°C, and 90°C. Among these three temperatures, 80°C was found to be more suitable, and the drying time was about 1 hour.

[0067] Regarding the investigation of the water absorption of the film, a certain amount of film was cut and placed in sufficient distilled water, and then left to soak for 24 hours. The water absorption rate formula (2-1) and weight loss rate formula (2-2) of the film were determined. Then, the appearance and properties of the film were observed again.

[0068] Water absorption

[0069] Weight loss rate

[0070] In the formula: S is the water absorption rate, L is the weight loss rate, m0 is the original weight, m1 is the weight after soaking for 24 hours, and m2 is the weight after drying again.

[0071] The experimental data are shown in Table 1. Taking into account the film-forming properties, water absorption rate and weight loss rate, adhesive No. 4 was selected.

[0072]

[0073] Table 1 Experimental data of several adhesives

[0074] The humic acid-rich lignite is mechanically crushed and then sieved to a fineness of 150 mesh.

[0075] Shells are composed of 95% calcium carbonate and a small amount (5%) of protein, glycoprotein, polysaccharide and other organic matter. Shell powder is a powdery material made of shells and oyster shells as the main raw materials. The main components are calcium carbonate, calcium oxide and other calcified substances after washing, high temperature calcination and grinding. Then it is sieved to a fineness of 100 mesh. An appropriate amount of calcium carbonate (CaCO3) is used as a buffer to adjust the acid-base.

[0076] The mineral powder was mixed with calcium carbonate in different proportions as shown in Table 2 below.

[0077] Serial number Mineral powder Calcium carbonate 1 5 1 2 10 1 3 15 1 4 20 1 5 25 1

[0078] Table 2 Proportion of mineral powder and calcium carbonate

[0079] Weigh an appropriate amount of composite filler sample, immerse it in a flask filled with 500ml distilled water, place the flask in a 30℃ constant temperature shaker, take out the filler after leaching for 24 hours, rinse the filler surface with distilled water, replace the leaching solution, and continue the leaching test. The total organic carbon and total nitrogen in the leaching solution are determined according to the national standard method. The data of 5 extractions are as follows:

[0080]

[0081] Table 3 Experimental data of 5 extractions

[0082] Select nutrient No. 3 with better initial release and slower later release. Excessive release of nutrients will cause excessive biomass, resulting in a decrease in the actual porosity and specific surface area of ​​the filter tower packing layer, and a decrease in the actual contact time between the gas and the biofilm, which in turn affects the removal performance of the system.

[0083] The waste gas containing hydrogen sulfide is filtered by a biological filter bed. The composite filler is prepared according to the proportions in the following table, and the treatment rate is as follows:

[0084]

[0085] Table 4 Removal efficiency of composite fillers prepared in proportion

[0086] Based on Table 4 above, composite filler No. 4 was finally selected.

[0087] The composite nutrient slow-release filler provided in the embodiment of the present invention can not only improve the treatment efficiency of biological purification technology by combining functional materials with nutrient slow-release function with volcanic rocks with excellent microecological environment, but also play an important role in improving the operational convenience of the system and reducing operation and maintenance costs. The development and application of this new composite filler will help to realize environmentally friendly waste gas treatment technology while bringing new development opportunities to the field of biological purification.

[0088] Those skilled in the art should be aware that in one or more of the above examples, the functions described in the present invention can be implemented by hardware, software, firmware or any combination thereof. When implemented by software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium.

[0089] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made on the basis of the technical solution of the present invention should be included in the scope of protection of the present invention.

Claims

1. A composite nutritional sustained-release filler, characterized in that: The composite nutrition slow-release filler comprises nutrition slow-release filler and volcanic rock particles, wherein the nutrition slow-release filler accounts for 5%-10% of the total weight of the composite nutrition slow-release filler; The nutrient slow-release filler is made of a plant fiber skeleton as a support and loaded with an adhesive and mineral powder slurry.

2. The composite nutritional sustained-release filler according to claim 1, characterized in that: The mineral powder water slurry includes mineral powder and calcium carbonate powder, and the mass ratio of the mineral powder to the calcium carbonate powder is 10-15:

1.

3. The composite nutritional sustained-release filler according to claim 2, characterized in that: The mineral powder is prepared according to the following method: the humic acid-rich lignite is mechanically crushed and then sieved to a fineness of 150 meshes to obtain the mineral powder.

4. The composite nutritional sustained-release filler according to claim 2, characterized in that: The calcium carbonate powder is prepared according to the following method: the shells and / or oyster shells are cleaned, calcined at high temperature and ground to obtain a powdery material, which is then sieved to a fineness of 100 meshes to obtain the calcium carbonate powder.

5. The composite nutritional sustained-release filler according to claim 1, characterized in that: The adhesive comprises water-based polyurethane adhesive, acrylic emulsion and pectin, wherein the mass ratio of the water-based polyurethane adhesive, acrylic emulsion and pectin is 8:3:

1.

6. The composite nutritional sustained-release filler according to claim 5, characterized in that: The adhesive also includes a functional group cross-linking agent.

7. The composite nutritional sustained-release filler according to claim 1, characterized in that: The nutrient sustained-release filler is prepared according to the following method: The plant fiber skeleton is immersed in the adhesive, and then the plant fiber skeleton is taken out. After removing the excess adhesive in the plant fiber skeleton, the skeleton is placed in a container containing mineral powder water slurry. When the surface of the plant fiber skeleton is covered with the mineral powder water slurry, the skeleton is taken out and dried at 80°C for 5 minutes. The loosely adhered mineral powder water slurry is removed, and the plant fiber skeleton is immersed in the adhesive again so that a layer of adhesive is evenly adhered to the surface of the plant fiber skeleton. The skeleton is taken out and dried at 80°C to obtain a nutrient slow-release filler.

8. A method for preparing a composite nutritional sustained-release filler, characterized in that: include: Weigh mineral powder and calcium carbonate in a mass ratio of 10-15:1, add an appropriate amount of water, stir and mix evenly, and then place for aging to obtain mineral powder water slurry; Weigh water-based polyurethane adhesive, acrylic emulsion and pectin according to proportion, put them into a container, stir and mix them evenly to obtain an adhesive; The plant fiber skeleton is immersed in the adhesive, and then the plant fiber skeleton is taken out. After removing the excess adhesive in the plant fiber skeleton, the skeleton is placed in a container containing mineral powder water slurry. When the surface of the plant fiber skeleton is fully adhered to the mineral powder water slurry, the skeleton is taken out, and dried at 80° C. for 5 minutes. The loosely adhered mineral powder water slurry is removed, and the plant fiber skeleton is immersed in the adhesive again, so that a layer of adhesive is evenly adhered to the surface of the plant fiber skeleton, and then the skeleton is taken out and dried at 80° C. to obtain a nutrient slow-release filler; The volcanic rock and the nutrient slow-release filler are uniformly mixed to obtain the composite nutrient slow-release filler, wherein the nutrient slow-release filler accounts for 5%-10% of the total mass.

9. The preparation method according to claim 8, characterized in that: Also includes: Add a functional group cross-linking agent to the adhesive.

10. Use of the composite nutrient slow-release filler according to any one of claims 1 to 7 in treating waste gas.

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