Coupling fermentation production method of refined cotton

Abstract

The invention relates to the technical field of refined cotton processing, in particular to a refined cotton coupling fermentation production method which comprises the following fermentation production steps: S1, selecting microbial strains which are active ligninase, irpex lacteus and betula platyphylla, and promoting the irpex lacteus and the betula platyphylla to form high-yield ligninase by taking lignin as induction, the method comprises the following steps: selecting main components of a culture medium, preparing microbial strains into fermentation liquor in proportion, filtering to remove solid residues in the fermentation liquor, and naturally storing the fermentation liquor in a container. The method subverts the traditional chemical cooking and bleaching process, adopts a microbial coupling fermentation technology, improves the fiber reaction uniformity, realizes the technical index that the polymerization degree fluctuation range of products of the same specification is less than 80, realizes high-efficiency impurity removal and refining, improves the impurity removal efficiency, reduces the impurity content, the ash content and the metal ion content, and is suitable for industrial production. And the quality requirements of special paper and cellulose acetate markets are met.

Description

Technical Field

[0001] The invention belongs to the technical field of refined cotton processing, and in particular relates to a refined cotton coupled fermentation production method. Background Art

[0002] Refined cotton is a specially processed cotton fiber product with the characteristics of uniform looseness and no impurities. Refined cotton is a white flocculent fiber without impurities such as sawdust, sand, oil, mineral ions, etc. It is widely used in food processing, papermaking industry, petrochemical industry, metallurgical industry, aerospace industry and other industries, and is called "industrial MSG". With people's increasing admiration for green, healthy and environmentally friendly consumption concepts, and the cellulose market gradually entering the traditional peak season, the market demand for refined cotton continues to grow. At present, the overall operation of domestic refined cotton manufacturers is still good, and the supply of raw cotton linters in the market is tightened, and the quotation may still have room for upward movement. At the same time, the improvement of cellulose market has also boosted the demand for refined cotton market, which is good for the refined cotton spot market. Therefore, it is expected that the upward momentum of the refined cotton market in the future will remain strong.

[0003] In the prior art, an alkaline pulping process is used to process refined cotton. The alkaline pulping process includes preparing materials, configuring a cooking liquid, cooking the materials, washing and screening the materials after cooking, and then bleaching the materials. After completion, the materials are dried and sorted to complete the traditional refined cotton processing. In the traditional chemical cooking and bleaching process, the directional control effect of the degree of polymerization is low, the range of the degree of polymerization is large, the fiber reaction is not consistent, and the processing steps are complicated. In this regard, we propose a refined cotton coupled fermentation production method. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a refined cotton coupled fermentation production method to solve the above technical problems.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for producing refined cotton by coupled fermentation, wherein the fermentation production steps are:

[0006] S1, selecting microbial strains, the strains are active ligninase, white capsule rake tooth fungus and birch fold inoculum, using lignin as an induction to promote the formation of high-yield ligninase by white capsule rake tooth fungus and birch fold inoculum, and selecting the main components of the culture medium, preparing the microbial strains into a fermentation liquid according to a proportion, filtering and removing solid residues in the fermentation liquid, and placing the fermentation liquid in a container for natural storage;

[0007] S2, preparing cotton linters, steaming and bleaching the cotton linters, and dehydrating and loosening the cotton linters;

[0008] S3, adding organic acid and surfactant to the fermentation liquid, stirring, standing, and optimizing fermentation efficiency;

[0009] S4, sampling the fermentation broth and verifying the degree of polymerization of the prepared fermentation broth;

[0010] S5. Fermentation is performed under an environment with an ambient temperature of 15° C. or higher and a humidity of 75% or higher. The prepared fermentation liquid is stirred and mixed with cotton linters. Microorganisms begin to degrade and decompose impurities in the cotton linters. The fermentation time is 72 hours, so that the microorganisms can fully process the cotton linters.

[0011] S6, bleaching the fermented cotton with sodium hypochlorite bleach, washing and drying the fermented cotton after bleaching, and packaging the fermented cotton after drying;

[0012] S7. The residue of the fermentation liquid is processed into solid organic fertilizer.

[0013] The entire process in this application removes impurities in cotton linters through biodegradation technology, improves product quality, solves the problem of waste disposal, and achieves a win-win situation of environmental protection and economic benefits.

[0014] Preferably, in step S1, the enzyme production is induced by mixing sawdust, cottonseed hulls, hemicellulose and lignin materials in white capsule rake tooth fungus and birch fold inoculum to form high-yield ligninase, lignin is used as an inducer to stimulate the fungus to produce ligninase, sawdust, cottonseed hulls, hemicellulose and lignin materials are added to the culture medium, and the ratio of carbon source, nitrogen source and inorganic salt nutrients in the culture medium is adjusted, and the medium is placed in an environment with a temperature above 22°C for preparation;

[0015] Lignin as an inducer can promote the production of ligninase. As an important inducer in the growth process of fungi, lignin can stimulate fungi such as white capsule rake tooth fungus and birch fold inoculum to produce ligninase. These enzymes play an important role in the degradation of lignin and can improve the utilization rate of lignin materials by fungi.

[0016] Fungi such as white capsule rake tooth fungus and birch fold hole fungus grow faster at higher temperatures. Cultivating the culture medium in an environment with a temperature above 22°C can accelerate the growth rate of the fungi and shorten the fermentation cycle.

[0017] Preferably, in step S2, the cotton linters are steamed and bleached by preparing cotton linters as raw materials, mixing the cotton linters with a cooking liquid, and putting them into a cooking device for steaming. After the steaming is completed, the slurry is taken out for washing to remove the residue on the cotton linters, and the cotton linters are bleached with a bleaching agent. After the bleaching is completed, the linters are taken out for dehydration.

[0018] During the cooking process, impurities such as oil, fat, pectin, cotton husk, lignin, etc. in the cotton linters are effectively removed by chemical methods in an alkaline environment, which improves the purity of the cotton pulp. The dehydrated cotton pulp is more compact, which is convenient for subsequent processing and improves the overall production efficiency.

[0019] Preferably, the dehydration in step S2 is used to remove excess moisture in the cotton linters. The dehydration step is performed by placing the cotton linters raw materials on a mesh belt dehydrator for preliminary dehydration. The mesh belt dehydrator uses a mesh conveyor belt to filter out excess moisture in the slurry to reduce the moisture content of the cotton linters. The linters then enter the multi-roller pressing and dehydration zone, and the cotton linters are subjected to progressive pressurization dehydration by sequentially arranged pressing roller groups to further remove moisture from the cotton linters. The cotton linters are loosened by placing the cotton linters on a loosening device to break up and loosen the fibers of the cotton linters.

[0020] As a preliminary dehydration tool, the mesh belt dehydrator uses a mesh conveyor belt to effectively filter out excess water from the slurry, which initially reduces the moisture content of the cotton linters. The multi-roller pressing dehydration area further removes moisture from the cotton linters through progressive pressurization dehydration, so that the cotton linters reach a lower moisture content. This helps to reduce energy consumption and time in the subsequent drying process and improve production efficiency. The loosening equipment breaks up the cotton linters, making the originally tightly wound fibers loose, which helps to evenly distribute and mix the fibers in the subsequent processing process and improve the uniformity and consistency of the product.

[0021] Preferably, in step S3, an organic acid is added to the fermentation liquid in advance and stirred. After stirring for 3 minutes, a surfactant is added to the fermentation liquid and stirred continuously. After stirring for another 5 minutes, the fermentation liquid is placed on a table and allowed to stand to optimize the efficiency of fermentation.

[0022] Organic acids can adjust the pH value of the fermentation broth and provide a suitable growth environment for the fermenting microorganisms. The appropriate pH value is conducive to the metabolic activities of microorganisms, thereby improving the fermentation efficiency. Adjusting the pH value of the fermentation broth to the optimal growth range of the target microorganisms makes it easier for the microorganisms to absorb and utilize these nutrients, thereby accelerating the fermentation process, inhibiting the growth of bacteria in the fermentation broth, reducing the production of harmful substances, improving the purity and quality of the fermentation products, and increasing the activity of key enzymes in the fermentation process, thereby accelerating the fermentation reaction;

[0023] Surfactants have the ability to reduce the surface tension of the solution, which helps to improve the fluidity of the fermentation broth, make nutrients and oxygen more evenly distributed in the fermentation system, increase the stability and adaptability of the enzyme, prevent enzyme inactivation or passivation due to temperature fluctuations or stirring shear forces, enhance the dispersibility, permeability and action speed of organic acids, enable organic acids to better exert their efficacy, improve the performance of organic acids and fully release their effects, increase their viscosity and stability, and thus facilitate the control of the fermentation process and the separation and purification of the product.

[0024] Preferably, the polymerization degree verification in step S4 is performed by measuring the viscosity of the fermentation broth at 25° C. using an Ubbelohde viscometer, and comparing the measured result with the sample of the polymerization degree of the standard sample to determine the polymerization degree of the fermentation broth;

[0025] The degree of polymerization is one of the important indicators reflecting the characteristics of the product during the fermentation process. By monitoring the changes in the degree of polymerization, the stability and efficiency of the fermentation process can be evaluated and data support can be provided for process optimization.

[0026] Preferably, the stirring and mixing time in step S5 is 1 hour. After the stirring and mixing is completed, the mixture is left to stand still, waiting for the fermentation and degradation of microorganisms to process the cotton linters.

[0027] In the present application, when the prepared fermentation liquid and the pretreated cotton linters are sent to a dedicated stirring device, the device will start stirring, and the stirring time is set to 1 hour, which is enough to make the microbial strains in the fermentation liquid evenly distributed in every fiber gap of the cotton linters, and also helps the nutrients and enzymes in the fermentation liquid to fully penetrate into the cotton linters. After the stirring is completed, the equipment will automatically stop running, the mixture enters a static state, the microbial strains are degraded, and the fermentation liquid is used to decompose the lignin and hemicellulose components in the cotton linters. The ambient temperature needs to be maintained above 15°C and the humidity needs to be higher than 75%, which is conducive to the growth and reproduction of microorganisms. By observing the color, smell and texture changes of the mixture, the progress of the fermentation process and the activity state of the microorganisms can be preliminarily judged. Subsequently, subsequent bleaching, cleaning, drying and packaging processing steps can be carried out to finally obtain a cotton linter product that meets the requirements.

[0028] Preferably, in step S6, bleaching is performed by preparing auxiliary tools, including a stirrer, a thermometer and a pH meter, weighing a sodium hypochlorite solution, maintaining the operating environment in a well-ventilated environment, pretreating the fermented cotton, including removing impurities, cleaning and adjusting the pH, adjusting the pH of the fermented cotton to 9.5-10.5, and adjusting the pH by dripping hydrochloric acid or sodium carbonate. The pretreated fermented cotton is placed in a bleaching tank, and the prepared sodium hypochlorite solution is added. The stirrer is used to stir evenly so that the sodium hypochlorite solution fully penetrates into the fermented cotton for bleaching. After the bleaching is completed, the fermented cotton is fully rinsed with clean water to remove residual sodium hypochlorite and other impurities. The water is changed several times during the rinsing process until the rinse liquid is clear.

[0029] Preferably, in step S6, the washed fermented cotton is placed in front of a dryer for drying at a temperature of 50° C., and the refined cotton is packaged after drying;

[0030] In this application, the drying temperature is set to 50°C. Based on the comprehensive consideration of the material characteristics of fermented cotton and the drying efficiency, this temperature can effectively remove moisture without damaging the fiber structure of the fermented cotton, maintaining its original softness and toughness. At the same time, it also helps to kill residual microorganisms and improve the hygiene standards of the product.

[0031] Preferably, in step S6, the filtered residue is collected, the moisture of the residue is adjusted to between 45% and 50%, straw and sawdust are added to the residue to adjust the carbon-nitrogen ratio in the residue, and a fermentation machine is added, the residue is evenly sprinkled on the residue, and after stirring and mixing, it is placed in a fermentation tank for stacking fermentation, the fermentation time is 30 days, the fermentation tank is turned over every day, the fermentation is completed, and the solid organic fertilizer is obtained after being taken out and dried in the sun;

[0032] The reuse of fermentation liquid residue effectively reduces waste generated in agricultural, industrial and other processes, and reduces the risk of environmental pollution caused by these wastes. By converting waste into organic fertilizer, the recycling of resources is achieved, which is in line with the concepts of environmental protection and sustainable development.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] This application subverts the traditional chemical cooking and bleaching process, adopts microbial coupled fermentation technology, accurately controls the fermentation time, detects the degree of enzymatic hydrolysis of lignin and the uniformity of directional polymerization of cellulose, is superior to the effects of traditional steaming, bleaching, polymerization reduction and directional control of polymerization degree, narrows the polymerization degree range, improves the uniformity of fiber reaction, and achieves the technical indicator of polymerization degree fluctuation range of products with the same specifications of <80, efficiently removes impurities and refines, improves impurity removal efficiency, reduces impurities, ash, and metal ion content, and meets the quality requirements of the specialty paper and cellulose acetate markets. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a flowchart of the fermentation production steps of the present invention. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] Example 1

[0038] A method for producing refined cotton by coupled fermentation, wherein the fermentation production steps are as follows:

[0039] S1. Selecting microbial strains, the strains are active ligninase, white capsule rake tooth fungus and birch fold inoculum, using lignin as an induction to promote the formation of high-yield ligninase by white capsule rake tooth fungus and birch fold inoculum, and selecting the main components of the culture medium, preparing the microbial strains into a fermentation liquid in proportion, the ratio of white capsule rake tooth fungus to birch fold inoculum is 4:3, filtering treatment, filtering to remove solid residues in the fermentation liquid, and placing the fermentation liquid in a container for natural storage;

[0040] S2, preparing cotton linters, steaming and bleaching the cotton linters, and dehydrating and loosening the cotton linters;

[0041] S3, adding organic acid and surfactant to the fermentation liquid, stirring, standing, and optimizing fermentation efficiency;

[0042] S4, sampling the fermentation broth and verifying the degree of polymerization of the prepared fermentation broth;

[0043] S5. Fermentation is performed under an environment with an ambient temperature of 15° C. or higher and a humidity of 75% or higher. The prepared fermentation liquid is stirred and mixed with cotton linters. Microorganisms begin to degrade and decompose impurities in the cotton linters. The fermentation time is 72 hours, so that the microorganisms can fully process the cotton linters.

[0044] S6, bleaching the fermented cotton with sodium hypochlorite bleach, washing and drying the fermented cotton after bleaching, and packaging the fermented cotton after drying;

[0045] S7. The residue of the fermentation liquid is processed into solid organic fertilizer.

[0046] Comparative Example 1

[0047] Alkaline pulping process to process refined cotton steps:

[0048] A1. Raw material selection: Use impurity-free, high-quality cotton linters as raw materials;

[0049] A2. Preparation of alkali solution: The main component of the cooking liquid is sodium hydroxide. A certain concentration of sodium hydroxide solution is used to spray the loosened, impurity-removed and opened cotton linters, and the sodium hydroxide solution is fully and evenly penetrated into the cotton linters through extrusion to form alkali fibers.

[0050] A3. Under the action of auxiliary agents, the alkali-soaked alkali fiber is repeatedly sprayed and rolled to achieve full and uniform penetration of the alkali solution into the fiber, and the alkali solution generated during the rolling process is recycled and reused;

[0051] A4. Put the pretreated alkali fiber into a closed steaming ball, gradually increase the temperature in the steaming ball to a set value by heating in stages, and maintain a certain pressure and time for steaming;

[0052] A5. The cotton pulp after cooking is washed several times to remove impurities, and the pH value is adjusted. A bleaching agent is added for bleaching. After bleaching, a dechlorination treatment is required to remove residual chlorine elements, and the pH value is adjusted by washing;

[0053] A6. Excess water in the cotton pulp is removed by pressing or other methods, and the cotton pulp after water removal is dried to obtain finished refined cotton. The dried refined cotton is packaged for storage and transportation.

[0054] Table 1 below is a table of properties of the refined cotton prepared in the examples and comparative examples.

[0055] Group Example 1 Comparative Example 1 Degree of polymerization (DP) 14000 10000 Appearance Complete and undamaged Complete and undamaged Impurity content (%) 2.5 8.5

[0056] Table 1

[0057] Polymerization degree detection:

[0058] Prepare the refined cotton samples in the examples and comparative examples, ensure that they are clean and free of impurities, and cut the samples into pieces of appropriate size for subsequent dissolution and measurement;

[0059] Under standard temperature and humidity, accurately weigh a certain amount of refined cotton powder, 2.4 mg of powder, calculated based on the cotton fiber moisture content equal to 8% under standard temperature and humidity, and place it in a brown bottle;

[0060] Add copper wire and distilled water, then add copper ethylenediamine solution, remove the air in the bottle with nitrogen or hydrogen, seal the bottle mouth, and shake it in an oscillator for 2 hours to fully dissolve the cotton fiber;

[0061] Transfer the dissolved solution to the viscometer and balance it in a constant temperature water bath for 5 minutes to ensure that the solution temperature is constant;

[0062] Measure the time it takes for the solution to flow from one scale to another in the viscometer, and record this time as the outflow time of the measured liquid;

[0063] The elution time of the blank solution was measured in the same way as a reference;

[0064] The specific viscosity (ηsp) and intrinsic viscosity (η) of the solution were calculated based on the measured outflow time and the outflow time of the blank solution, and the degree of polymerization (DP) of the refined cotton was calculated using the Schutz-Blaschke formula.

[0065] Appearance inspection

[0066] Obtain the refined cotton samples in the comparative examples and the embodiments to ensure that the samples can reflect the quality of the entire batch of products;

[0067] Observe the color of refined cotton with naked eyes to see if it is uniform and consistent, whether there are different colored fibers or spots, check its glossiness to determine whether it meets the product standards, observe the morphological characteristics of refined cotton, such as fiber length, thickness, and curl, check whether its structure is tight, whether there is looseness or breakage, and carefully check whether the sample contains impurities, such as dust, oil stains, and metal chips;

[0068] Identify and record defects such as broken seeds, neps, and sterile seeds that may affect product quality and performance;

[0069] Observed appearance characteristics and test results are documented and scored against product standards.

[0070] Impurity content detection

[0071] Obtain samples and separate impurities from fibers in the samples. Common methods for separating impurities include manual picking and mechanical separation. During the separation process, it should be ensured that impurities are not missed or mixed with other impurities;

[0072] Observation and classification: carefully observe and classify the separated impurities, identify their types and sources, and classify them into organic impurities and inorganic impurities according to their properties;

[0073] Count and weigh various impurities, record their quantity and weight, and follow relevant standards or customer requirements when counting and weighing to ensure the accuracy and reliability of the data;

[0074] Impurity content calculation: Calculate the impurity content of refined cotton based on the weight of the impurities and the original mass of the sample. The impurity content is usually expressed as a percentage, and the calculation formula is: Impurity content = (impurity weight / original sample mass) × 100%.

[0075] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0076] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for producing refined cotton by coupled fermentation, characterized in that: The fermentation production steps are: S1, selecting microbial strains, the strains are active ligninase, white capsule rake tooth fungus and birch fold inoculum, using lignin as an induction to promote the formation of high-yield ligninase by white capsule rake tooth fungus and birch fold inoculum, and selecting the main components of the culture medium, preparing the microbial strains into a fermentation liquid according to a proportion, filtering and removing solid residues in the fermentation liquid, and placing the fermentation liquid in a container for natural storage; S2, preparing cotton linters, steaming and bleaching the cotton linters, and dehydrating and loosening the cotton linters; S3, adding organic acid and surfactant to the fermentation liquid, stirring, standing, and optimizing fermentation efficiency; S4, sampling the fermentation broth and verifying the degree of polymerization of the prepared fermentation broth; S5. Fermentation is performed under an environment with an ambient temperature of 15° C. or higher and a humidity of 75% or higher. The prepared fermentation liquid is stirred and mixed with cotton linters. Microorganisms begin to degrade and decompose impurities in the cotton linters. The fermentation time is 72 hours, so that the microorganisms can fully process the cotton linters. S6, bleaching the fermented cotton with sodium hypochlorite bleach, washing and drying the fermented cotton after bleaching, and packaging the fermented cotton after drying; S7. The residue of the fermentation liquid is processed into solid organic fertilizer.

2. The method for producing refined cotton by coupled fermentation according to claim 1, characterized in that: In step S1, enzyme production is induced by mixing sawdust, cottonseed hulls, hemicellulose and lignin materials in white capsule fungus and birch pore fungus to form high-yield ligninase. Lignin is used as an inducer to stimulate the fungus to produce ligninase. Sawdust, cottonseed hulls, hemicellulose and lignin materials are added to the culture medium, and the ratio of carbon source, nitrogen source and inorganic salt nutrients in the culture medium is adjusted. The medium is placed in an environment with a temperature above 22°C for preparation.

3. The method for producing refined cotton by coupled fermentation according to claim 1, characterized in that: In step S2, cotton linters are steamed and bleached by preparing cotton linters as raw materials, mixing the cotton linters with a cooking liquid, and putting them into a cooking device for steaming. After the steaming is completed, the slurry is taken out for washing to remove the residue on the cotton linters, and the cotton linters are bleached with a bleaching agent. After the bleaching is completed, the linters are taken out for dehydration.

4. The method for producing refined cotton by coupled fermentation according to claim 1, characterized in that: Dehydration in step S2 is used to remove excess moisture in the cotton linters. The dehydration step is performed by placing the cotton linters raw materials on a mesh belt dehydrator for preliminary dehydration. The mesh belt dehydrator uses a mesh conveyor belt to filter out excess moisture in the slurry to reduce the moisture content of the cotton linters. The linters then enter the multi-roller pressing and dehydration area, and the cotton linters are progressively pressurized and dehydrated by sequentially arranged pressing roller groups to further remove moisture from the cotton linters. The cotton linters are loosened by placing the cotton linters on a loosening device to break up and loosen the fibers of the cotton linters.

5. The method for producing refined cotton by coupled fermentation according to claim 1, characterized in that: In step S3, organic acid is added to the fermentation liquid in advance and stirred. After stirring for 3 minutes, surfactant is added to the fermentation liquid and stirred continuously. After stirring for another 5 minutes, the fermentation liquid is placed on a table and allowed to stand to optimize the efficiency of fermentation.

6. The method for producing refined cotton by coupled fermentation according to claim 1, characterized in that: In step S4, the polymerization degree is verified by using an Ubbelohde viscometer to measure the viscosity of the fermentation liquid at 25°C, and the measured result is compared with the standard sample polymerization degree sample to determine the polymerization degree of the fermentation liquid.

7. The method for producing refined cotton by coupled fermentation according to claim 1, characterized in that: The stirring and mixing time in step S5 is 1 hour. After the stirring and mixing is completed, the mixture is left to stand still to wait for the fermentation and degradation of microorganisms to treat the cotton linters.

8. The method for producing refined cotton by coupled fermentation according to claim 1, characterized in that: In step S6, auxiliary tools are prepared for bleaching, including a stirrer, a thermometer and a pH meter, and a sodium hypochlorite solution is weighed. The operating environment is kept in a well-ventilated environment, and the fermented cotton is pretreated, including removing impurities, cleaning and adjusting the pH value. The pH value of the fermented cotton is adjusted to 9.5-10.5, and the pH value is adjusted by adding hydrochloric acid or sodium carbonate. The pretreated fermented cotton is placed in a bleaching tank, and the prepared sodium hypochlorite solution is added. The stirrer is used to stir evenly so that the sodium hypochlorite solution fully penetrates into the fermented cotton for bleaching. After the bleaching is completed, the fermented cotton is fully rinsed with clean water to remove residual sodium hypochlorite and other impurities. The water is changed several times during the rinsing process until the rinse liquid is clear.

9. The method for producing refined cotton by coupled fermentation according to claim 1, characterized in that: In step S6, the washed fermented cotton is placed in front of a dryer for drying at a temperature of 50° C. After drying, the refined cotton is packaged.

10. The method for producing refined cotton by coupled fermentation according to claim 1, characterized in that: In step S6, the filtered residue is collected, the moisture of the residue is adjusted to between 45% and 50%, straw and sawdust are added to the residue to adjust the carbon-nitrogen ratio of the residue, and a fermentation machine is added to evenly sprinkle the residue, and after stirring and mixing, the residue is placed in a fermentation tank for stacking fermentation. The fermentation time is 30 days, the fermentation tank is turned over every day, the fermentation is completed, and the residue is taken out and dried to obtain a solid organic fertilizer.

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