Method for degradation and reuse of discarded cellulose product

Abstract

A method for degradation and reuse of a discarded cellulose product, comprising the use of a recovered discarded cellulose product and the use of a mixed bacterial strain of Trichoderma viride, Trichoderma reesei, Aspergillus niger, and Trichoderma pseudokoningii to perform fermentation, thereby obtaining a cellulase crude product.

Description

Method for degrading and recycling waste cellulose products Technical Field

[0001] The invention relates to a method for degrading and recycling discarded cellulose products. Background Art

[0002] Cellulose is a macromolecular polysaccharide insoluble in organic solvents and water, found naturally in plant cell walls. Due to the vast natural supply of cellulose, cellulose fibers with various crystalline structures can be produced through direct extraction or various chemical processes, followed by spinning. These fibers, known for their excellent mechanical properties, breathability, dyeability, and low cost, are widely used in clothing and home furnishings. However, the widespread use of cellulose fibers has led to an increasingly serious problem in the disposal of waste cellulose products. Currently, incineration and landfilling are common methods, both of which pose environmental risks and have low utilization rates. Biodegradation of cellulose products refers to the process by which discarded cellulose products undergo natural decomposition by microorganisms in the environment, such as bacteria, mold, and algae, causing them to lose their original form. However, complete degradation through natural degradation is estimated to take more than a year. Currently, there are five main methods for evaluating the biodegradability of textile materials: activated sludge, soil decomposition, aerobic composting, specific microbial or enzyme methods, and anaerobic testing. Niu Jiantao and others studied the biodegradation of washed cotton, linen, and viscose fibers by Aspergillus oryzae for two weeks. Infrared spectroscopy revealed no new substances produced, but only some damage to the fiber's internal structure. Lin Yanping also studied pulverized cellulose products and added them to compost for high-temperature composting. After three months, the degradation rate of the cellulose products was greater than 50%. Other studies have shown that recycling 1 kg of used clothing can reduce carbon dioxide emissions by 3.6 kg and save 6,000 liters of industrial water.

[0003] Based on the above issues, the applicant conducted research on the above issues and resulted in this case. Technical issues

[0004] The object of the present invention is to provide a method for degrading and recycling waste cellulose products, which can improve the degradation efficiency of cellulose products and reduce costs. Technical Solutions

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for degrading and recycling waste cellulose products, comprising the following steps:

[0007] Step A, the recycled waste cellulose products are pre-sorted and crushed to tear the fabric into fabric fragments;

[0008] Step B, treating the fabric fragments in a 2%-6% H2SO4 solution for 12 to 16 hours, wherein the mass ratio of the H2SO4 solution to the fabric fragments is (1-2):(2-4);

[0009] Step C, adding bran and / or soybean meal as a nitrogen source to the solution of step B, with a mass ratio of the nitrogen source to the fabric fragments being (1-2):(8-9), adding 20-60 mL of the nutrient solution per kilogram of the fabric fragments, and mixing uniformly to form a mixed material;

[0010] Step D: adjusting the water content of the mixture to 55%-65% and the pH to 4.5-6.5, and sterilizing the mixture;

[0011] Step E: inoculating the mixed material with a mixed strain at a mass fraction of 5%-10%, wherein the mixed strain is a culture solution of two or more of Trichoderma viride, Trichoderma reesei, Aspergillus niger, and Trichoderma pseudokoningii;

[0012] In step F, the mixture treated in step E is subjected to aerobic fermentation at a temperature of 20-35°C for 20-30 days. The cellulase activity is monitored. When the enzyme activity reaches a peak, the enzyme koji is air-dried to obtain a crude cellulase product.

[0013] As a preferred embodiment of the present invention, the waste cellulose products include cotton fibers, hemp fibers, and sugarcane fibers.

[0014] As a preferred embodiment of the present invention, the nitrogen source is a mixture of bran and soybean meal, and the mass ratio of bran to soybean meal is 2-4.

[0015] As a preferred embodiment of the present invention, the nutrient solution includes 0.5-4 g / L ammonium sulfate, 1-3 g / L potassium dihydrogen phosphate, 1-3 g / L magnesium sulfate and the balance water.

[0016] As a preferred embodiment of the present invention, the concentration of mycelium in the culture solution is controlled at 3-8 g / L.

[0017] As a preferred embodiment of the present invention, the culture solution is prepared by adding 200 g of potatoes to 1000 mL of water, boiling for 30 minutes, filtering with gauze, and adding water to 1000 mL.

[0018] As a preferred embodiment of the present invention, the culture time of the strain is 45-50 hours and the culture temperature is 28-32°C.

[0019] As a preferred embodiment of the present invention, the diameter of the fabric fragments is ≤10 cm or the length is ≤10 cm.

[0020] As a preferred embodiment of the present invention, the processing temperature in step B is room temperature and the processing is carried out in a sealed environment.

[0021] As a preferred embodiment of the present invention, the sterilization temperature in step D is 121° C. and the sterilization time is 30 min. Beneficial effects

[0022] After adopting the technical solution of the present invention, a dry dilute acid pretreatment method is used to preliminarily separate some modified additives in the cellulose product from the cellulose material, and cavities are formed inside the cellulose product to facilitate subsequent microbial degradation. The present invention adopts mixed strains for collaborative degradation, which makes up for the shortcomings of a single strain, such as an incomplete enzyme system and low enzyme production, and improves the microbial degradation efficiency. The present invention adds nitrogen source auxiliary materials such as bran and soybean meal, and adds a nutrient solution, and fully reuses the cellulose raw material to obtain crude cellulase. The crude cellulase can turn waste cellulose products into treasure, and the enzyme production cost is lower than that of traditional methods. Its social and economic benefits will be very obvious. The crude cellulase obtained by the present invention can be applied to a straw cellulose pretreatment process, and can reduce the cost of using part of the cellulase. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Type your figure caption description paragraph here. Best Mode for Carrying Out the Invention

[0024] Type here the best mode description paragraph of the invention. Modes for Carrying Out the Invention

[0025] In order to better understand the technical solution of the present invention, it is described in more detail below with reference to embodiments.

[0026] Example 1

[0027] Recycled waste cellulose products (taking cotton fiber products as an example, the same below) are pre-sorted and crushed, and the products are torn into fabric fragments with a diameter of ≤10 cm using a double-shaft shredder; 2% by mass dilute sulfuric acid is added, and the mass ratio of dilute sulfuric acid to fiber product is 2:2, and the mixture is sealed at room temperature for 16 hours; nitrogen sources bran and soybean meal are added, with a mass ratio of bran:soybean meal = 2, and the addition amount to the fabric dry basis mass ratio is 1:9, and 20 mL / kg of nutrient solution is added to the fabric dry basis, and the mixture is evenly mixed to obtain a mixture; the water content of the mixture is adjusted to 55%, and then the pH of the mixture is adjusted to 6.5, and a mixed strain of 5% by mass (Trichoderma viride: Trichoderma reesei: Aspergillus niger: Trichoderma pseudokoningii culture solution volume ratio of 1:2:1:1) is inoculated, the mycelium concentration of the inoculum is controlled at 5 g / L, and aerobic fermentation (i.e., aerobic fermentation, using conventional techniques in the field of biochemistry) is carried out at 30°C for 30 days to obtain a crude cellulase with a filter paper enzyme activity of 200 IU / g dry koji.

[0028] Example 2

[0029] The recycled waste cellulose products were pre-sorted and crushed, and the products were torn into fragments with a diameter of ≤10 cm using a double-shaft shredder; 4% dilute sulfuric acid was added, and the mass ratio of dilute sulfuric acid to fiber products was 2:3, and the products were sealed at room temperature for 14 hours; nitrogen sources bran and soybean meal were added, and the mass ratio of the two was bran:soybean meal = 3, and the addition amount was 2:8 to the fabric dry basis ratio, and 20 mL / kg of nutrient solution was added and mixed evenly to obtain a mixed material; the water content of the mixed material was adjusted to 60%, and then the pH of the mixed material was adjusted to 5.5, and 8% of mixed strains (vitriol: trichoderma reesei: aspergillus niger: trichoderma pseudokoningii culture solution volume ratio of 1:1:1:2) were inoculated, the mycelium concentration of the inoculum was controlled at 8 g / L, and the mixture was fermented with oxygen at 30°C for 25 days, and the filter paper enzyme activity of the obtained crude cellulase reached 220 IU / g dry koji.

[0030] Example 3

[0031] The recycled waste cellulose products were pre-sorted and crushed, and the products were torn into fragments with a diameter of ≤10 cm using a double-shaft shredder; 6% dilute sulfuric acid was added, with a mass ratio of dilute sulfuric acid to fiber products of 1:4, and the products were sealed at room temperature for 12 hours; nitrogen sources bran and soybean meal were added, with a mass ratio of bran:soybean meal = 4, and an addition ratio of 1:8 to the fabric dry basis, 20 mL / kg of nutrient solution was added, and the mixture was evenly mixed to obtain a mixture; the water content of the mixture was adjusted to 65%, and then the pH of the mixture was adjusted to 4.5, 10% of mixed strains (vitriol: trichoderma reesei: aspergillus niger: trichoderma pseudokoningii culture solution volume ratio of 2:1:1:1) were inoculated, the mycelium concentration of the inoculum was controlled at 3 g / L, and the mixture was fermented with oxygen at 30°C for 20 days to obtain a crude cellulase with a filter paper enzyme activity of 210 IU / g dry koji.

[0032] Comparative Example

[0033] In each comparative example, except for the use of a single bacterial species for fermentation, other conditions were the same as those in Example 1.

[0034] The filter paper enzyme activity of crude cellulase obtained by fermentation with a single strain of Trichoderma viride reached 45 IU / g dry koji.

[0035] The filter paper enzyme activity of crude cellulase obtained by fermentation with a single strain of Trichoderma reesei reached 70 IU / g dry koji.

[0036] The filter paper enzyme activity of crude cellulase obtained by fermentation with a single strain of Trichoderma pseudokoningii reached 170 IU / g dry koji.

[0037] The filter paper enzyme activity of crude cellulase obtained by fermentation with a single strain of Aspergillus niger reached 62 IU / g dry koji.

[0038] In this application, IU refers to the amount of enzyme required to degrade filter paper and release 1 μmol of glucose per minute under the conditions of 37°C, pH 5.5, and reaction time of 60 min.

[0039] In each example and comparative example, Trichoderma viride, Trichoderma reesei, Aspergillus niger, and Trichoderma pseudokoningii were cultured in a culture medium. The culture medium was prepared as follows: 200 g of potato was added to 1000 mL of water, boiled for 30 min, filtered through four layers of gauze, and filled with water to 1000 mL. The culture time was 45-50 h and the culture temperature was 28-32 ° C.

[0040] In the present application: Trichoderma viride AS 3.3711, Trichoderma reesei ATCC 56764, Trichoderma mapseudokoningii 3.3002, Aspergillus niger CGMCC 3.316 are all directly available from the market.

[0041] Of course, the protection scope of the present invention is not limited to this embodiment, and anyone making similar changes thereto shall be deemed to be within the scope of patent protection of the present invention. Industrial Applicability

[0042] The present invention can improve the degradation efficiency of cellulose products and reduce costs. Sequence Listing Free Content

[0043] Type your sequence listing free description paragraph here.

Claims

1. A method for degrading and recycling waste cellulose products, characterized in that: The method comprises the following steps: step A, the recycled waste cellulose products are preliminarily subjected to a sorting and crushing process to tear the fabric into fabric fragments; Step B, placing the fabric fragments in a H2SO4 solution with a mass fraction concentration of 2%-6% for 12 to 16 hours, and the mass ratio of the H2SO4 solution to the fabric fragments is (1-2):(2-4); Step C, adding bran and / or soybean meal as a nitrogen source to the solution of step B, the mass ratio of the nitrogen source to the fabric fragments is (1-2):(8-9), 20-60 mL of the nutrient solution is added per kilogram of the fabric fragments, and the mixture is mixed uniformly to form a mixed material; Step D, adjusting the water content of the mixed material to 55%-65% and the pH to 4.5-6.5, and performing sterilization treatment; Step E, inoculating the mixed material with a mass fraction of 5%-10% of a mixed strain, wherein the mixed strain is a culture solution of two or more of Trichoderma viride, Trichoderma reesei, Aspergillus niger, and Trichoderma pseudokoningii; In step F, the mixed material treated in step E is subjected to aerobic fermentation at a fermentation temperature of 20-35° C. for a fermentation time of 20-30 days, and the cellulase activity is monitored. When the enzyme activity reaches a peak, the enzyme koji is air-dried to obtain a crude cellulase product.

2. The method for degrading and recycling waste cellulose products according to claim 1, characterized in that: The waste cellulose products include cotton fibers, hemp fibers and sugarcane fibers.

3. The method for degrading and recycling waste cellulose products according to claim 2, characterized in that: The nitrogen source is a mixture of bran and soybean meal, and the mass ratio of bran to soybean meal is 2-4.

4. A method for degrading and recycling waste cellulose products as claimed in claim 3, characterized in that: The nutrient solution includes 0.5-4 g / L of ammonium sulfate, 1-3 g / L of potassium dihydrogen phosphate, 1-3 g / L of magnesium sulfate and the balance of water.

5. The method for degrading and recycling waste cellulose products according to claim 4, characterized in that: The concentration of mycelium in the culture solution is controlled at 3-8 g / L.

6. A method for degrading and recycling waste cellulose products as claimed in claim 5, characterized in that: The culture solution was prepared in the following manner: 200 g of potato was added to 1000 mL of water, boiled for 30 min, filtered with gauze, and filled with water to 1000 mL.

7. The method for degrading and recycling waste cellulose products according to claim 6, characterized in that: The culture time of the strain is 45-50h and the culture temperature is 28-32℃.

8. The method for degrading and recycling waste cellulose products according to claim 7, characterized in that: The diameter of the fabric fragment is ≤10 cm or the length is ≤10 cm.

9. The method for degrading and recycling waste cellulose products according to claim 8, characterized in that: The processing temperature of step B is room temperature and the processing is carried out in a sealed environment.

10. The method for degrading and recycling waste cellulose products according to claim 9, characterized in that: The sterilization temperature in step D is 121° C. and the sterilization time is 30 min.

11. [Corrected 03.12.2024 in accordance with Rule 26][Deleted]