Method for synchronously treating kitchen garbage and garden waste by using compound enzyme

Abstract

The invention provides a method for synchronously treating kitchen waste and garden waste by using a compound enzyme, which specifically comprises the following steps: preparing a compound enzyme preparation, pretreating the kitchen waste and the garden waste, and performing enzymolysis on the compound enzyme preparation to prepare an organic fertilizer, and belongs to the technical field of solid waste treatment. According to the prepared compound enzyme preparation, the silicon-based polyphosphazene and zinc double-layer complex is adopted for immobilizing the compound enzyme, the original activity of the compound enzyme can be guaranteed, and the immobilization efficiency of the compound enzyme is effectively improved; the temperature-sensitive unit responds to release the unlinking agent in the enzymolysis temperature rising process, the aldehyde group contained in the unlinking agent interacts with the hydroxyl group in the welan gum double-helix network, the compound enzyme in the immobilized enzyme structure is released, and the enzyme activity is improved. Protein, fat, cellulose and the like in the kitchen waste and the garden waste are decomposed, conversion of organic solid waste is accelerated, the reaction process is 2-3 h, and rapid recycling of the waste is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of solid waste treatment, and in particular relates to a method for simultaneously treating kitchen waste and garden waste by using a composite enzyme. Background Art

[0002] Although food waste contains rich organic matter and nutrients, its high salt and high fat characteristics not only limit its direct utilization, but also cause serious pollution to the environment; although garden waste is rich in lignin and cellulose, its nutritional value is relatively low. It decomposes slowly under natural conditions, resulting in idle resources and occupying a large amount of space. It can be seen that food waste and garden waste have good complementarity in the types of organic matter and nutritional value they contain. Therefore, research on how to efficiently and simultaneously process two different types of organic waste can realize resource utilization and turn waste into treasure.

[0003] Existing technologies for the treatment of organic solid waste can be divided into non-biological treatment and biological treatment. Non-biological treatment methods mainly include incineration, landfill and mechanical crushing, etc. Biological treatment includes enzyme treatment and microbial fermentation (aerobic composting and anaerobic digestion). Among them, although the odor and sewage generated during the composting process have a great impact on the surrounding environment, landfill occupies land and poses a serious threat to the environment, especially groundwater resources. Incineration has a large one-time investment and high operating costs, and the air pollution is relatively serious. Anaerobic digestion has high costs and complex technology, and a long treatment cycle.

[0004] Enzyme treatment of organic solid waste is highly efficient and specific. When composite enzyme preparations are directly applied to waste treatment, their enzymatic activity will be affected due to the complex components in the waste, reducing the enzymatic efficiency. Therefore, enzyme immobilization technology is used to improve the stability of the enzyme. However, physical adsorption in the existing enzyme immobilization technology will cause weak adsorption, easy detachment of the enzyme, and low immobilization effect; the embedding method is prone to enzyme accumulation, reducing the contact area between the reactant and the enzyme, thereby affecting the catalytic effect; covalent cross-linking of immobilized enzymes will cause functional groups to change the active center site of the enzyme, resulting in reduced enzyme activity. Therefore, studying the optimization method of immobilized enzymes can improve the efficiency of enzyme treatment of organic solid waste and promote the resource utilization of organic solid waste. Summary of the invention

[0005] Technical problems to be solved: In view of the above technical problems, the purpose of the present invention is to provide a method for simultaneously treating kitchen waste and garden waste with a composite enzyme, and the specific steps include preparation of a composite enzyme preparation, pretreatment of kitchen waste and garden waste, and enzymatic hydrolysis of the composite enzyme preparation to produce organic fertilizer, which belongs to the technical field of solid waste treatment. The composite enzyme preparation prepared by the present invention uses a silicon-based polyphosphazene and a zinc double-layer complex to fix the composite enzyme, which can ensure the original activity of the composite enzyme and effectively improve the fixation efficiency of the composite enzyme; and then load it into the double helix zipper structure of the wellan gum to enhance the resistance of the composite enzyme to the external environment. In the process of increasing the enzymatic hydrolysis temperature, the temperature-sensitive unit responds to release the unzipping agent, and the aldehyde group contained in the unzipping agent interacts with the hydroxyl group in the double helix network of the wellan gum, releasing the composite enzyme in the immobilized enzyme structure, decomposing the protein, fat and cellulose in the kitchen waste and garden waste, and at the same time, the zinc ion further improves the activity of the composite enzyme and accelerates the conversion of organic solid waste.

[0006] Technical solution: A method for simultaneously treating kitchen waste and garden waste with a composite enzyme, comprising the following steps: S1. The complex enzyme is fixed in a silicon-based polyphosphazene and zinc double-layer complex, and then loaded into Weilan gum to prepare a complex enzyme preparation; S2. Kitchen waste and garden waste are mixed evenly in a mass ratio of (5-10):(1-5), and crushed to form an enzymatic hydrolysis base; S3. Add the enzymatic base material into the reaction tank, adjust the humidity to 55-60%, add 1-5% compound enzyme preparation for enzymatic hydrolysis, cool and package, and make organic fertilizer.

[0007] Furthermore, the complex enzyme in step S1 is composed of two or more of the following enzymes: protease, amylase, lipase, cellulase, xylanase, laccase, saccharifying enzyme, and peroxidase.

[0008] Furthermore, the conditions for enzymolysis in step S3 are: enzymolysis temperature 50-70° C., and enzymolysis time 2-3 h.

[0009] Furthermore, the specific operation method of step S1 includes the following steps: Step 1. Polyaminocyclotriphosphazene and carboxylated mesoporous silica are placed in N,N-dimethylformamide reagent, and ultrasonically treated for 2-3 hours, and purified and dried to obtain silicon-based polyphosphazene; Step 2. Immerse the silicon-based polyphosphazene in a complex enzyme solution with a concentration of 10-30 mg / mL, fix it at 20-40°C for 3-5 hours, and wash it thoroughly to obtain the silicon-based polyphosphazene immobilized enzyme; Step 3. Add water to zinc nitrate, terphenyl-2,2′,4,4′-tetracarboxylic acid, and 1,2-di(4-pyridyl)ethylene, dissolve and mix evenly, and catalytically heat at 140-160° C. for 12-24 hours to prepare a zinc double-layer complex; Step 4. The silicon-based polyphosphazene immobilized enzyme and the zinc double-layer complex are uniformly dissolved, ultrasonically treated to obtain an immobilized composite enzyme, added with a Welan gum solution containing glyoxal microspheres for treatment for 2-3 hours, and vacuum dried to obtain a composite enzyme preparation; The depolymerizing agent microspheres are prepared by uniformly dropping the depolymerizing agent into an acrylic acid-acrylonitrile graft copolymer solution.

[0010] Furthermore, in step 1, the mass ratio of polyaminocyclotriphosphazene to carboxylated mesoporous silica is (1-4): (3-5).

[0011] Furthermore, the conditions for the ultrasonic treatment in step 1 are: treatment temperature 40-60° C., ultrasonic power 200-600W.

[0012] Furthermore, in step 3, the molar ratio of zinc nitrate, terphenyl-2,2′,4,4′-tetracarboxylic acid and 1,2-di(4-pyridyl)ethylene is (2-4):(1.5-3):(1-1.5).

[0013] Furthermore, in step 4, the mass ratio of the silicon-based polyphosphazene immobilized enzyme to the zinc double-layer complex is (3.5-5): (1-2).

[0014] Furthermore, in step 4, the mass fraction of the depolymerizing agent microspheres is 10-25%.

[0015] Furthermore, in step 4, the depolymerizing agent includes glyoxal, malondialdehyde or glutaraldehyde.

[0016] Beneficial Effects

[0017] 1. In the present invention, polyaminocyclotriphosphazene and carboxylated mesoporous silica are combined with each other through amide bonds formed between amino groups and carboxyl groups to obtain silicon-based polyphosphazene. The introduction of carboxylated mesoporous silica can increase the pore density and binding sites in the polyaminocyclotriphosphazene structure, and can covalently bind multiple enzymes. At the same time, the amino group induces the silicification of silica, enhances the interaction between silicon-based polyphosphazene and the enzyme, protects the original activity of the composite enzyme, improves the fixation efficiency of the composite enzyme, and prolongs the cycle time of the immobilized enzyme.

[0018] 2. The present invention adopts a zinc double-layer complex to load the silicon-based polyphosphazene immobilized enzyme. The carboxyl group and the hydroxyl group in the zinc double-layer complex form hydrogen bonds with the groups in the silicon-based polyphosphazene, and the silicon-based polyphosphazene immobilized enzyme is embedded in the double-layer structure to form a "sandwich structure", thereby preventing the accumulation of the immobilized enzyme from affecting the activity of the enzyme. At the same time, the double layers of the zinc double-layer complex encapsulating the silicon-based polyphosphazene immobilized enzyme are self-assembled into a three-dimensional spherical structure through hydrogen bonding, thereby further improving the fixation efficiency and stability of the immobilized enzyme.

[0019] 3. The welan gum in the present invention can form a double-helix zipper network structure, and the network structure can embed the spherical carrier formed by the self-assembly of the zinc double-layer complex. In the enzymatic hydrolysis heating process, the acrylic acid-acrylonitrile graft copolymer shows a temperature response to release glyoxal. The aldehyde group of glyoxal can interact with the hydroxyl group in the double-helix zipper network of the welan gum and form an acetal bond, just like a zipper is opened, releasing the composite immobilized enzyme to enzymatically hydrolyze macromolecules such as protein, fat, lignin, cellulose, etc. in organic solid waste. At the same time, zinc ions can improve the catalytic efficiency of the enzyme, accelerate the enzymatic hydrolysis process of organic solid waste, and improve the conversion efficiency of substances.

[0020] 4. The immobilized enzyme method provided by the present invention can not only broaden the treatment pathways for organic solid waste, but also provide an optimization method for the high-efficiency catalysis of enzymes, which is helpful to promote the resource utilization of organic solid waste. It has the advantages of high efficiency, short treatment time and low pollution, and provides a solid technical guarantee for the harmless and resource-based treatment of organic solid waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The enzyme fixation rate and decomposition efficiency of Examples 1-6, Comparative Example 1 and Comparative Example 2 are shown. DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with embodiments, which are explanations of the present invention and are not limited to the following embodiments: Example 1

[0023] A method for preparing an immobilized complex enzyme comprises the following steps: Step 1. Dissolve 20 g of polyaminocyclotriphosphazene and 40 g of carboxylated mesoporous silica in N,N-dimethylformamide reagent, perform ultrasonic treatment at 45° C. and 400 W for 2 h, purify and dry to obtain silicon-based polyphosphazene; Step 2. Prepare the complex enzyme into a complex enzyme solution with a concentration of 20 mg / mL, add silicon-based polyphosphazene and fix it at 25°C for 4 hours, and wash it thoroughly to obtain silicon-based polyphosphazene immobilized enzyme; Step 3. 2 mol of zinc nitrate, 1.5 mol of terphenyl-2,2′,4,4′-tetracarboxylic acid, and 1 mol of 1,2-di(4-pyridyl)ethylene are dissolved in water and mixed evenly, and catalytically heated at 160° C. for 18 h to prepare a zinc double-layer complex; Step 4. Dissolve 40 g of silicon-based polyphosphazene immobilized enzyme and 15 g of zinc double-layer complex evenly, and perform ultrasonic treatment at 45° C. and 400 W for 2 h to obtain an immobilized complex enzyme.

[0024] Example 2

[0025] A method for preparing an immobilized complex enzyme comprises the following steps: Step 1. 30 g of polyaminocyclotriphosphazene and 40 g of carboxylated mesoporous silica were dissolved in N,N-dimethylformamide reagent, and ultrasonically treated at 40° C. and 500 W for 2 h, and purified and dried to obtain silicon-based polyphosphazene; Step 2. Prepare the complex enzyme into a complex enzyme solution with a concentration of 20 mg / mL, add silicon-based polyphosphazene and fix it at 25°C for 4 hours, and wash it thoroughly to obtain silicon-based polyphosphazene immobilized enzyme; Step 3. 2 mol of zinc nitrate, 1.5 mol of terphenyl-2,2′,4,4′-tetracarboxylic acid, and 1 mol of 1,2-di(4-pyridyl)ethylene are dissolved in water and mixed evenly, and catalytically heated at 160° C. for 18 h to prepare a zinc double-layer complex; Step 4. Dissolve 40 g of silicon-based polyphosphazene immobilized enzyme and 15 g of zinc double-layer complex evenly, and perform ultrasonic treatment at 45° C. and 400 W for 3 h to obtain an immobilized complex enzyme.

[0026] Example 3

[0027] A method for preparing an immobilized complex enzyme comprises the following steps: Step 1. Dissolve 20 g of polyaminocyclotriphosphazene and 30 g of carboxylated mesoporous silica in N,N-dimethylformamide reagent, perform ultrasonic treatment at 45° C. and 400 W for 2 h, purify and dry to obtain silicon-based polyphosphazene; Step 2. Prepare the complex enzyme into a complex enzyme solution with a concentration of 20 mg / mL, add silicon-based polyphosphazene and fix it at 25°C for 4 hours, and wash it thoroughly to obtain silicon-based polyphosphazene immobilized enzyme; Step 3. 2 mol of zinc nitrate, 1.5 mol of terphenyl-2,2′,4,4′-tetracarboxylic acid, and 1 mol of 1,2-di(4-pyridyl)ethylene are dissolved in water and mixed evenly, and catalytically heated at 160° C. for 18 h to prepare a zinc double-layer complex; Step 4. Dissolve 40 g of silicon-based polyphosphazene immobilized enzyme and 15 g of zinc double-layer complex evenly, and perform ultrasonic treatment at 45° C. and 400 W for 2 h to obtain an immobilized complex enzyme.

[0028] Example 4

[0029] A method for preparing an immobilized complex enzyme comprises the following steps: Step 1. Dissolve 20 g of polyaminocyclotriphosphazene and 40 g of carboxylated mesoporous silica in N,N-dimethylformamide reagent, perform ultrasonic treatment at 45° C. and 400 W for 2 h, purify and dry to obtain silicon-based polyphosphazene; Step 2. Prepare the complex enzyme into a complex enzyme solution with a concentration of 30 mg / mL, add silicon-based polyphosphazene and fix it at 20°C for 4 hours, and wash it thoroughly to obtain silicon-based polyphosphazene immobilized enzyme; Step 3. 2 mol of zinc nitrate, 1.5 mol of terphenyl-2,2′,4,4′-tetracarboxylic acid, and 1 mol of 1,2-di(4-pyridyl)ethylene are dissolved in water and mixed evenly, and catalytically heated at 160° C. for 18 h to prepare a zinc double-layer complex; Step 4. Dissolve 40 g of silicon-based polyphosphazene immobilized enzyme and 15 g of zinc double-layer complex evenly, and perform ultrasonic treatment at 45° C. and 400 W for 2 h to obtain an immobilized complex enzyme.

[0030] Example 5

[0031] A method for preparing an immobilized complex enzyme comprises the following steps: Step 1. Dissolve 20 g of polyaminocyclotriphosphazene and 40 g of carboxylated mesoporous silica in N,N-dimethylformamide reagent, perform ultrasonic treatment at 50° C. and 500 W for 2.5 h, purify and dry to obtain silicon-based polyphosphazene; Step 2. Prepare the complex enzyme into a complex enzyme solution with a concentration of 20 mg / mL, add silicon-based polyphosphazene and fix it at 25°C for 4 hours, and wash it thoroughly to obtain silicon-based polyphosphazene immobilized enzyme; Step 3. 3 mol of zinc nitrate, 2 mol of terphenyl-2,2′,4,4′-tetracarboxylic acid, and 1 mol of 1,2-di(4-pyridyl)ethylene are dissolved in water and mixed evenly, and catalytically heated at 140° C. for 24 hours to prepare a zinc double-layer complex; Step 4. Dissolve 40 g of silicon-based polyphosphazene immobilized enzyme and 15 g of zinc double-layer complex evenly, and perform ultrasonic treatment at 45° C. and 400 W for 2 h to obtain an immobilized complex enzyme.

[0032] Example 6 A method for preparing an immobilized complex enzyme comprises the following steps: Step 1. Dissolve 20 g of polyaminocyclotriphosphazene and 40 g of carboxylated mesoporous silica in N,N-dimethylformamide reagent, perform ultrasonic treatment at 40° C. and 600 W for 2 h, purify and dry to obtain silicon-based polyphosphazene; Step 2. Prepare the complex enzyme into a complex enzyme solution with a concentration of 20 mg / mL, add silicon-based polyphosphazene and fix it at 25°C for 4 hours, and wash it thoroughly to obtain silicon-based polyphosphazene immobilized enzyme; Step 3. 2 mol of zinc nitrate, 1.5 mol of terphenyl-2,2′,4,4′-tetracarboxylic acid, and 1 mol of 1,2-di(4-pyridyl)ethylene are dissolved in water and mixed evenly, and catalytically heated at 160° C. for 18 h to prepare a zinc double-layer complex; Step 4. Dissolve 50 g of silicon-based polyphosphazene immobilized enzyme and 20 g of zinc double-layer complex evenly, and perform ultrasonic treatment at 40° C. and 600 W for 2 h to obtain an immobilized complex enzyme.

[0033] Comparative Example 1 The difference between this comparative example and Example 1 is that no carboxylated mesoporous silica is added.

[0034] A method for preparing an immobilized complex enzyme comprises the following steps: Step 1. Prepare a composite enzyme solution with a concentration of 20 mg / mL, add 20 g of polyaminocyclotriphosphazene, fix at 25°C for 4 hours, and wash thoroughly to obtain polyphosphazene immobilized enzyme; Step 2. 2 mol of zinc nitrate, 1.5 mol of terphenyl-2,2′,4,4′-tetracarboxylic acid, and 1 mol of 1,2-di(4-pyridyl)ethylene are dissolved in water and mixed evenly, and catalytically heated at 160° C. for 18 h to prepare a zinc double-layer complex; Step 3. Dissolve 40 g of polyphosphazene immobilized enzyme and 15 g of zinc double-layer complex evenly, and treat with ultrasound at 45° C. and 400 W for 2 h to obtain an immobilized complex enzyme.

[0035] Comparative Example 2 The difference between this comparative example and Example 1 is that no zinc double-layer complex is used.

[0036] A method for preparing an immobilized complex enzyme comprises the following steps: Step 1. Dissolve 20 g of polyaminocyclotriphosphazene and 40 g of carboxylated mesoporous silica in N,N-dimethylformamide reagent, perform ultrasonic treatment at 45° C. and 400 W for 2 h, purify and dry to obtain silicon-based polyphosphazene; Step 2. Prepare the complex enzyme into a complex enzyme solution with a concentration of 20 mg / mL, add silicon-based polyphosphazene and fix it at 25° C. for 4 hours, and wash it thoroughly to obtain silicon-based polyphosphazene immobilized enzyme.

[0037] Physical and chemical indicators Enzyme immobilization rate The enzyme immobilization rates of Examples 1-6 and Comparative Examples 1-2 were determined using the Coomassie Brilliant Blue method.

[0038] Decomposition efficiency 20 g of kitchen waste and 20 g of garden waste were mixed evenly, crushed and sieved, and an appropriate amount of agar was added. The mixture was sterilized under high pressure at 121°C for 20 min to prepare a test medium. 1 mL of immobilized enzyme solution was added to the center of the test medium using a pipette and kept at 50°C for 2 h. The decomposition efficiency was calculated based on the ratio of the enzymatic hydrolysis area to the test medium area.

[0039] Depend on Figure 1 It can be seen that the enzyme fixation rate and decomposition efficiency of the immobilized complex enzyme prepared in the embodiment are higher than those in comparative examples 1 and 2, especially the enzyme fixation rate and decomposition efficiency of embodiment 1 are the highest. Because comparative example 1 only uses polyaminocyclotriphosphazene to first fix the complex enzyme, and then loads it into the zinc double-layer complex to prepare the immobilized complex enzyme, while comparative example 2 does not use the zinc double-layer complex to prepare the immobilized enzyme, the results show that the addition of carboxylated mesoporous silica in the embodiment can make the carboxyl group interact with the amino group in the polyaminocyclotriphosphazene to form an amide bond, increase the binding site of the immobilized enzyme, and improve the fixation efficiency of the immobilized enzyme. At the same time, the amino group induces the silicification of the carboxylated mesoporous silica, enhances the interaction between the silicon-based polyphosphazene and various enzymes, and improves the enzyme fixation rate of the immobilized complex enzyme; in addition, the silicon-based polyphosphazene immobilized enzyme is combined with the zinc double-layer complex to form a "sandwich structure", which can effectively prevent the problem of immobilized enzyme accumulation affecting the activity, and the zinc ion can also activate the activity of various enzymes, further improving the decomposition efficiency of the immobilized enzyme.

[0040] Example 7

[0041] A method for simultaneously treating kitchen waste and garden waste using a composite enzyme comprises the following steps: S1. The immobilized composite enzyme prepared in Example 1 was added to a solution of glyoxal microspheres (mass fraction of 20%) in Weilan gum for 2 h, and then vacuum dried to obtain a composite enzyme preparation; wherein the glyoxal microspheres were prepared by uniformly dripping glyoxal into an acrylic acid-acrylonitrile graft copolymer solution; S2.500g of kitchen waste and 500g of garden waste are mixed evenly and crushed to form an enzymatic base material; S3. Add the enzymatic base material into the reaction tank, adjust the humidity to 55%, add 25g of compound enzyme preparation and enzymatically hydrolyze for 2h at 70℃, cool and package to make organic fertilizer.

[0042] Example 8

[0043] A method for simultaneously treating kitchen waste and garden waste using a composite enzyme comprises the following steps: S1. The immobilized complex enzyme prepared in Example 1 was added to a solution of glyoxal-loaded microspheres (mass fraction of 10%) in Weilan gum and treated for 2 h, and vacuum dried to obtain a complex enzyme preparation; wherein the glyoxal microspheres were prepared by uniformly dripping glyoxal into an acrylic acid-acrylonitrile graft copolymer solution; S2.500g of kitchen waste and 500g of garden waste are mixed evenly and crushed to form an enzymatic base material; S3. Add the enzymatic base material into the reaction tank, adjust the humidity to 60%, add 25g of compound enzyme preparation and perform enzymatic hydrolysis at 70℃ for 1.5h, cool and package to make organic fertilizer.

[0044] Example 9

[0045] A method for simultaneously treating kitchen waste and garden waste using a composite enzyme comprises the following steps: S1. The immobilized composite enzyme prepared in Example 1 was added to a solution of glyoxal microspheres (mass fraction of 20%) in Weilan gum for 3 h, and vacuum dried to obtain a composite enzyme preparation; wherein the glyoxal microspheres were prepared by uniformly dripping glyoxal into an acrylic acid-acrylonitrile graft copolymer solution; S2. 600 g of kitchen waste and 400 g of garden waste are mixed evenly and crushed to form an enzymatic base material; S3. Add the enzymatic base material into the reaction tank, adjust the humidity to 60%, add 25g of compound enzyme preparation and perform enzymatic hydrolysis at 70℃ for 1.5h, cool and package to make organic fertilizer.

[0046] Example 10

[0047] A method for simultaneously treating kitchen waste and garden waste using a composite enzyme comprises the following steps: S1. The immobilized composite enzyme prepared in Example 1 was added to a solution of glyoxal microspheres (mass fraction of 20%) in Weilan gum and treated for 2 h, and then vacuum dried to obtain a composite enzyme preparation; wherein the glyoxal microspheres were prepared by uniformly dripping glyoxal into an acrylic acid-acrylonitrile graft copolymer solution; S2.700g of kitchen waste and 300g of garden waste are mixed evenly and crushed to form an enzymatic base material; S3. Add the enzymatic base material into the reaction tank, adjust the humidity to 55%, add 25g of compound enzyme preparation and perform enzymatic hydrolysis at 70℃ for 3h, cool and package to make organic fertilizer.

[0048] Comparative Example 3 The difference between this comparative example and Example 7 is that the welan gum carrying glyoxal microspheres is not added.

[0049] A method for simultaneously treating kitchen waste and garden waste using a composite enzyme comprises the following steps: S1. The immobilized complex enzyme prepared in Example 1 was vacuum dried to obtain a complex enzyme preparation; S2.500g of kitchen waste and 500g of garden waste are mixed evenly and crushed to form an enzymatic base material; S3. Add the enzymatic base material into the reaction tank, adjust the humidity to 55%, add 25g of compound enzyme preparation and enzymatically hydrolyze for 2h at 70℃, cool and package to make organic fertilizer.

[0050] Comparative Example 4 The difference between this comparative example and Example 7 is that the welan gum is not loaded with glyoxal microspheres.

[0051] A method for simultaneously treating kitchen waste and garden waste using a composite enzyme comprises the following steps: S1. The immobilized complex enzyme prepared in Example 1 was added to the Weilan gum solution and treated for 2 h, and vacuum dried to obtain a complex enzyme preparation; S2.500g of kitchen waste and 500g of garden waste are mixed evenly and crushed to form an enzymatic base material; S3. Add the enzymatic base material into the reaction tank, adjust the humidity to 55%, add 25g of compound enzyme preparation and enzymatically hydrolyze for 2h at 70℃, cool and package to make organic fertilizer.

[0052] Performance Testing (1) Degradation rate of substances in waste The lignin degradation rate, cellulose degradation rate, fat degradation rate, carbohydrate degradation rate and protein degradation rate of Examples 7-10, Comparative Examples 3 and 4 were determined, wherein lignin was determined by the nitric acid-ethanol method, cellulose was determined by 72% concentrated sulfuric acid hydrolysis method, fat content was determined by Soxhlet extraction method, carbohydrate degradation rate was determined by DNS (3,5-dinitrosalicylic acid) colorimetry, and protein was determined by fully automatic Kjeldahl nitrogen determination method.

[0053] Table 1 Degradation rate of each component of Examples 7-10, Comparative Example 3 and Comparative Example 4 Lignin degradation rate (%) Cellulose degradation rate (%) Fat degradation rate (%) Degradation rate of carbohydrates (%) Protein degradation rate (%) Example 7 95.29 90.32 89.75 86.75 88.45 Example 8 93.41 89.48 88.27 86.32 87.23 Example 9 92.15 88.21 87.44 85.84 87.69 Example 10 92.88 89.03 88.59 85.97 88.10 Comparative Example 3 85.24 80.47 83.18 79.87 80.36 Comparative Example 4 86.77 81.69 84.43 80.33 82.58 As can be seen from Table 1, the lignin degradation rate, cellulose degradation rate, fat degradation rate, carbohydrate degradation rate, and protein degradation rate of Examples 7-10 are all higher than those of Comparative Examples 3 and 4, indicating that the double-helix zipper network structure of wellan gum can better encapsulate the immobilized complex enzyme, ensuring that it is less affected by the complex environment of the enzymatic hydrolysis base composed of kitchen waste and garden waste. In addition, during the increase of enzymatic hydrolysis temperature, the acrylic acid-acrylonitrile graft copolymer has temperature-sensitive properties, and the microsphere structure releases glyoxal. The aldehyde group of glyoxal forms an acetal bond with the hydroxyl group in wellan gum to open the double-helix zipper network, releasing the immobilized complex enzyme, and multiple enzymes synergistically act on proteins, fats, cellulose, lignin and other substances in the enzymatic hydrolysis base, efficiently converting them into organic fertilizers.

[0054] (2) Performance indicators of organic fertilizers According to NY / T 525-2021 "Organic Fertilizer", the performance indicators of the organic fertilizer prepared in Example 7, Comparative Example 3 and Comparative Example 4 were measured, including organic matter content, total nutrient mass fraction, moisture content, pH, Escherichia coli count, total arsenic and total cadmium in heavy metals, and seed germination number.

[0055] Table 2 Organic fertilizer performance indicators of Example 7, Comparative Example 3 and Comparative Example 4 Performance Indicators Example 7 Comparative Example 3 Comparative Example 4 Organic matter content (%) 60.24 55.27 56.75 Total nutrient mass fraction (%) 5.73 4.21 4.59 Moisture content (%) 23.46 29.70 27.51 pH 7.3 6.2 6.6 Fecal coliform count (pcs / g) 40 70 52 Total arsenic (mg / kg) 3.25 5.81 4.77 Total cadmium (mg / kg) 0.62 1.47 1.05 Seed germination number (%) 97.52 81.74 85.29 It can be seen from Table 2 that the performance indicators of the organic fertilizer prepared in Example 7, Comparative Example 3 and Comparative Example 4 all meet the requirements of NY / T 525-2021 "Organic Fertilizer", and the performance indicators of the organic fertilizer prepared in Example 7 are better than those in Comparative Example 3 and Comparative Example 4, indicating that the immobilized composite enzyme embedded in welan gum can stably play a degrading role in the complex components of the enzymatic hydrolysis base (composed of kitchen waste and garden waste), and can decompose protein, fat, lignin and cellulose to the greatest extent, convert them into organic matter, improve the performance quality of organic fertilizer, and promote the resource utilization of kitchen waste and garden waste.

[0056] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the above disclosed methods and technical contents without departing from the spirit and technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of protection of the technical solution of the present invention.

Claims

1. A method for simultaneously treating kitchen waste and garden waste using a composite enzyme, characterized in that: The following steps are involved: Step S1. immobilizing the complex enzyme in a silicon-based polyphosphazene and zinc double-layer complex, and then loading it into Welan gum to prepare a complex enzyme preparation; Step S2. The kitchen waste and the garden waste are mixed evenly in a mass ratio of (5-10):(1-5), and crushed to form an enzymatic hydrolysis base material; Step S3. Add the enzymatic base material into the reaction tank, adjust the humidity to 55-60%, add 1-5% compound enzyme preparation for enzymatic hydrolysis, cool and package, and make organic fertilizer.

2. The method for simultaneously treating kitchen waste and garden waste with a composite enzyme according to claim 1, characterized in that: The complex enzyme in step S1 is composed of two or more of the following enzymes: protease, amylase, lipase, cellulase, xylanase, laccase, saccharifying enzyme, and peroxidase.

3. The method for simultaneously treating kitchen waste and garden waste with a composite enzyme according to claim 1, characterized in that: The conditions for enzymolysis in step S3 are: enzymolysis temperature 50-70° C., and enzymolysis time 2-3 h.

4. The method for simultaneously treating kitchen waste and garden waste with a composite enzyme according to claim 1, characterized in that: The specific preparation method of the composite enzyme preparation in step S1 comprises the following steps: Step 1. dissolving polyaminocyclotriphosphazene and carboxylated mesoporous silica and subjecting them to ultrasonic treatment for 2-3 hours, purifying and drying to obtain silicon-based polyphosphazene; Step 2. Immerse the silicon-based polyphosphazene in a complex enzyme solution with a concentration of 10-30 mg / mL, fix it at 20-40° C. for 3-5 hours, and wash it thoroughly to obtain the silicon-based polyphosphazene immobilized enzyme; Step 3. Add water to zinc nitrate, terphenyl-2,2′,4,4′-tetracarboxylic acid, and 1,2-di(4-pyridyl)ethylene, dissolve and mix evenly, and catalytically heat at 140-160° C. for 12-24 hours to prepare a zinc double-layer complex; Step 4. The silicon-based polyphosphazene immobilized enzyme and the zinc double-layer complex are uniformly dissolved, ultrasonically treated to obtain an immobilized complex enzyme, and then a Welan gum solution containing depolymerizing agent microspheres is added for treatment for 2-3 hours, and vacuum dried to obtain a complex enzyme preparation; The depolymerizing agent microspheres are prepared by uniformly dropping the depolymerizing agent into an acrylic acid-acrylonitrile graft copolymer solution.

5. The method for simultaneously treating kitchen waste and garden waste with a composite enzyme according to claim 4, characterized in that: In the step 1, the mass ratio of polyaminocyclotriphosphazene to carboxylated mesoporous silica is (1-4): (3-5).

6. The method for simultaneously treating kitchen waste and garden waste with a composite enzyme according to claim 4, characterized in that: The conditions of the ultrasonic treatment in step 1 are: treatment temperature 40-60° C., ultrasonic power 200-600W.

7. The method for simultaneously treating kitchen waste and garden waste with a composite enzyme according to claim 4, characterized in that: In the step 3, the molar ratio of zinc nitrate, terphenyl-2,2′,4,4′-tetracarboxylic acid and 1,2-di(4-pyridyl)ethylene is (2-4):(1.5-3):(1-1.5).

8. The method for simultaneously treating kitchen waste and garden waste with a composite enzyme according to claim 4, characterized in that: In step 4, the mass ratio of the silicon-based polyphosphazene immobilized enzyme to the zinc double-layer complex is (3.5-5): (1-2).

9. The method for simultaneously treating kitchen waste and garden waste with a composite enzyme according to claim 4, characterized in that: The mass fraction of the denaturant microspheres in step 4 is 10-25%.

10. The method for simultaneously treating kitchen waste and garden waste with a composite enzyme according to claim 4, characterized in that: The depolymerizing agent includes glyoxal, malondialdehyde or glutaraldehyde.

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