A method for preparing a cow bedding material using cow manure

Abstract

The present application belongs to the field of bioengineering technology, and particularly relates to a method for preparing cow bedding material from cow manure, comprising the following steps: step one, preparing bedding matrix from fresh cow manure; step two, preparing modified straw-rice husk; step three, preparing modified biochar-zeolite compound; step four, mixing and fermenting the bedding matrix, modified straw-rice husk, modified biochar-zeolite compound, coconut shell fiber, wheat bran, potassium dihydrogen phosphate and compound microbial agent at a mass ratio of (45-55):(10-20):(5-15):(15-25):(3-7):(1-2):(2-3); and step five, spraying iron sulfate-silicon dioxide solution and chitosan-tea polyphenol solution on the surface in sequence; the present application breaks through the bottleneck of the prior art in the three dimensions of safety, functionality and economy by means of physical dehydration, chemical activation, biological fermentation and functional composite design, and realizes closed-loop utilization of cow breeding waste.

Description

Technical Field

[0001] This invention belongs to the field of bioengineering technology, specifically relating to a method for preparing cow bedding material using cow manure. Background Technology

[0002] In-situ fermentation bed farming technology utilizes the basic theories of microbiology, ecology, and fermentation engineering. It involves laying a certain thickness of organic bedding material in the cattle shed, using active functional microorganisms as carriers of matter and energy. Through the growth and reproduction of highly active beneficial functional bacteria, animal manure and waste are degraded and consumed, achieving the goal of pollution-free and zero-emission farming. This farming technology is a new type of environmentally friendly ecological farming technology.

[0003] Currently, commonly used cattle bedding materials include: 1) Traditional bedding materials such as sawdust, wood chips, sand, and straw. While sawdust and wood chips have good water absorption, their cost continues to rise, and they pose a risk of fungal (such as Aspergillus flavus) contamination. Sand, although having good drainage, is prone to compaction, increasing the rate of hoof injuries and is difficult to separate from manure. Straw is inexpensive but has poor water absorption, is prone to mold, requires frequent replacement, and has high maintenance costs. 2) Manure recycling bedding involves separating the solid and liquid components of cattle manure, with the solid portion being briefly composted and used as bedding. However, during the preparation process, there may be problems such as incomplete inactivation of pathogens (such as E. coli and Salmonella residues) and insufficient dehydration, leading to damp bedding and bacterial growth. 3) Using biogas project residues as bedding, but this still suffers from severe damage to the fiber structure, poor water absorption, and accumulation of heavy metals (such as copper and zinc).

[0004] Therefore, providing a novel method for preparing cow bedding material using cow manure as a raw material has become an urgent problem to be solved. Summary of the Invention

[0005] To address the above problems, this invention provides a method for preparing cow bedding material using cow manure, specifically comprising the following steps:

[0006] Step 1: Take fresh cow manure with a moisture content of ≥80%, filter it through a sieve with a pore size of 3-5mm to remove large particles of impurities, and then filter it with a filter press until the moisture content of the filter cake is 55-65%. Mix the filter cake with wood ash at a mass ratio of 20:1 to obtain the bedding substrate.

[0007] Step 2: Mix crop straw and rice husks, dry at 50-60℃ to constant weight, pulverize and pass through a 40-50 mesh sieve, mix the powder with an alkaline solution, stir at 70-80℃ and 120-150 rpm for 2-2.5 hours, filter, remove the filtrate, wash the filter residue with clean water until the pH of the washing solution is ≤7.8, then mix the filter residue with the enzymatic hydrolysate, stir at 40-50℃ and 150-180 rpm for 1-1.5 hours, filter, remove the filtrate, and dry the filter residue at 45-50℃ until the moisture content is ≤12%, to obtain modified straw-rice husk.

[0008] Preferably, the crop straw is one or more selected from corn straw, rice straw, wheat straw, sorghum straw, barley straw, and oat straw. Most preferably, the crop straw is corn straw.

[0009] Preferably, the mass ratio of the crop straw, rice husk, alkaline solution and enzymatic hydrolysate is (1-3):(1-3):(8-24):(8-24).

[0010] Preferably, the alkaline solution is a potassium hydroxide solution with a mass fraction of 8-10% or a sodium hydroxide solution with a mass fraction of 8-10%.

[0011] Preferably, the enzymatic hydrolysate comprises cellulase, hemicellulase, pectinase, xylanase, and water in a mass ratio of 3:1:1:1000.

[0012] Step 3: Mix and pulverize biochar, attapulgite and zeolite, pass through a 60-70 mesh sieve, then mix with organic acid solution, sonicate at 50-60℃ and 30-40kHz for 20-30 minutes, filter, remove the filtrate, and dry the filter residue at 100-120℃ to constant weight to obtain modified biochar-zeolite composite.

[0013] Preferably, the mass ratio of biochar, attapulgite, zeolite, and organic acid solution is 2:1:1:16.

[0014] Preferably, the organic acid solution is a citric acid solution with a mass fraction of 8-10% or an acetic acid solution with a volume fraction of 10-12%.

[0015] Step 4: Mix the bedding substrate, modified straw-rice husk, modified biochar-zeolite composite, coconut shell fiber, wheat bran, potassium dihydrogen phosphate, and EM inoculant in a mass ratio of (45-55):(10-20):(5-15):(15-25):(3-7):(1-2):(2-3), adjust the pH to 6.8-7.2 with sodium carbonate, ferment at 67-70% humidity and 50-70℃ for 4-5 days. After fermentation, dry the fermented material at 60-65℃ until the moisture content is ≤12% to obtain the initial bedding product.

[0016] Preferably, the mass ratio of bedding substrate, modified straw-rice husk, modified biochar-zeolite composite, coconut shell fiber, wheat bran, potassium dihydrogen phosphate and EM inoculant is 50:15:10:20:5:1:2.

[0017] Preferably, the pile is turned over once every 5-6 hours within 0-24 hours after the start of fermentation; once every 10-12 hours within 24-72 hours after the start of fermentation; and once every 22-24 hours after 72 hours after the start of fermentation.

[0018] Step 5: Spray ferric sulfate-silica solution onto the surface of the initial bedding material, with a spraying amount of 2-3% of the initial bedding material weight. After natural drying, spray chitosan-tea polyphenol solution onto the surface, with a spraying amount of 3-4% of the initial bedding material weight. After natural drying, the cow bedding material is obtained.

[0019] Preferably, the ferric sulfate-silica solution comprises ferric sulfate, nano-silica, and water in a mass ratio of 3:1:1000.

[0020] Preferably, the chitosan-tea polyphenol solution comprises chitosan, tea polyphenols, acetic acid, and water in a ratio of 2g:1g:4mL:100mL.

[0021] The present invention has the following advantages:

[0022] (1) This invention uses EM agent in combination with staged turning and fermentation to ensure the complete elimination of pathogens such as bacteria, viruses and parasites. Modified biochar-zeolite complex is added to inhibit the reproduction of microorganisms by adsorbing ammonia in the cowshed, which significantly improves the hygiene and safety of the bedding, reduces the incidence of mastitis in dairy cows, and avoids the incomplete elimination of pathogens caused by the existing bedding composting temperature not meeting the standard or the composting time not being sufficient.

[0023] (2) In this invention, sodium hydroxide solution is used to destroy the lignin-cellulose composite structure, and cellulase and hemicellulase further depolymerize the fibers, thereby increasing the porosity of straw and rice husks and improving the liquid absorption rate of the bedding. Coconut shell fiber is then added to enhance the tensile strength of the bedding and extend its service life, thus avoiding the problem of low liquid absorption rate of unmodified straw.

[0024] (3) This invention uses citric acid to activate biochar, zeolite and attapulgite to enhance ammonia adsorption capacity. Zeolite and attapulgite form ion exchange channels to lock ammonium ions and significantly reduce ammonia release. Spraying ferric sulfate-silica solution solidifies free ammonia, and spraying chitosan-tea polyphenol solution reduces the activity of urea-decomposing bacteria. This solves the problem of rapid decomposition of urea in manure into ammonia, which leads to excessive ammonia concentration in cattle sheds.

[0025] (4) In this invention, wood ash is added to cow manure to precipitate heavy metal ions in an alkaline environment. After biochar, zeolite and attapulgite are loaded with citric acid, heavy metals are chelated with citric acid to reduce the risk of heavy metal residue in bedding.

[0026] (5) This invention uses cow manure as the main material to replace commercial electrical materials, coconut shell fiber to replace commercial fiber, and straw and rice husks are modified and utilized to reduce the cost of agricultural waste treatment. Detailed Implementation

[0027] The technical solutions in the embodiments of the invention are described clearly and completely below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Example 1

[0029] Step 1: Take fresh cow manure with a moisture content of ≥80%, filter it through a sieve with a pore size of 4mm to remove large particles of impurities, and then filter it with a filter press until the moisture content of the filter cake is 60%. Mix the filter cake with wood ash at a mass ratio of 20:1 to obtain the bedding substrate.

[0030] Step 2: Mix corn stalks and rice husks, dry at 55℃ to constant weight, pulverize through a 45-mesh sieve, mix the powder with a 10% sodium hydroxide solution, stir at 75℃ and 150 rpm for 2 hours, filter, remove the filtrate, wash the residue with water until the pH of the washing liquid is ≤7.8, then mix the residue with the enzymatic hydrolysate, stir at 45℃ and 180 rpm for 1 hour, filter, remove the filtrate, and dry the residue at 45℃ until the moisture content is ≤12%, obtaining modified straw-rice husk. The mass ratio of corn stalks, rice husks, 10% sodium hydroxide, and enzymatic hydrolysate is 3:2:20:20. The enzymatic hydrolysate includes cellulase, hemicellulase, pectinase, xylanase, and water in a mass ratio of 3:1:1:1000.

[0031] Step 3: Mix and pulverize the biochar, attapulgite, and zeolite, pass through a 65-mesh sieve, then mix with a 10% (w / w) citric acid solution, sonicate at 55°C and 40kHz for 30 minutes, filter, remove the filtrate, and dry the filter residue at 110°C to constant weight to obtain the modified biochar-zeolite composite. The mass ratio of biochar, attapulgite, zeolite, and organic acid solution is 2:1:1:16.

[0032] Step 4: Mix the bedding substrate, modified straw-rice husk, modified biochar-zeolite composite, coconut shell fiber, wheat bran, potassium dihydrogen phosphate, and EM inoculant in a mass ratio of 50:15:10:20:5:1:2, and adjust the pH to 6.8-7.2 with sodium carbonate. Ferment at 60℃ and 68% humidity for 5 days. Turn the pile every 5-6 hours from 0-24 hours after fermentation begins; turn it every 10-12 hours from 24-72 hours after fermentation begins; and turn it every 22-24 hours after 72 hours of fermentation begins. After fermentation is complete, dry the fermented material at 60℃ until the moisture content is ≤12% to obtain the initial bedding product.

[0033] Step 5: Spray a ferric sulfate-silica solution onto the surface of the initial bedding material, with a spraying amount of 3% of the initial bedding material's weight. After natural drying, spray a chitosan-tea polyphenol solution, with a spraying amount of 4% of the initial bedding material's weight. After natural drying, the cow bedding material is obtained. The ferric sulfate-silica solution comprises ferric sulfate, nano-silica, and water in a mass ratio of 3:1:1000. The chitosan-tea polyphenol solution comprises chitosan, tea polyphenols, acetic acid, and water in a ratio of 2g:1g:4mL:100mL.

[0034] Experimental Example 1

[0035] 1. Sample preparation

[0036] Experimental group: Cow mattress material was prepared according to the method in Example 1.

[0037] Control group 1: Traditional composting bedding material prepared according to steps one and four of Example 1 (after solid-liquid separation of cow dung in step one, no modified straw-rice husk, modified biochar-zeolite complex and coconut shell fiber were added, and composting was carried out directly according to step four).

[0038] Control group 2: Sawdust livestock bedding produced by Shijiazhuang Xueli Agricultural Products Co., Ltd.

[0039] Refer to GB / T 13091-2018 "Detection of Salmonella in Feed"

[0040] Take 10g of bedding material sample and add it to 90mL of sterile physiological saline. After shaking for 30min, take the supernatant and inoculate it into selective culture medium for Salmonella and Escherichia coli, respectively. After incubation at 37℃ for 48h, count the colonies (CFU / g). The results are shown in Table 1.

[0041] Table 1

[0042] E. coli Not detected <![CDATA[2.1×10 3 ]]> <![CDATA[8.7×10 2 ]]> <![CDATA[≤1×10 3 ]]> salmonella Not detected <![CDATA[1.5×10 2 ]]> Not detected Not detectable Total bacterial count <![CDATA[4.2×10 2 ]]> <![CDATA[3.8×10 4 ]]> <![CDATA[1.1×10 5 ]]> <![CDATA[≤1×10 4 ]]>

[0043] Experimental Example 2

[0044] 1. Liquid absorption rate determination

[0045] Take 10g of dry bedding material sample, accurately weigh it and record the weight as W0, soak it in deionized water for 30 minutes, remove it and drain it for 1 minute, then accurately weigh it and record the weight as W. t The absorption rate and drainage rate were calculated, and the results are shown in Table 2.

[0046] Liquid absorption rate = (W) t -W0) / W0×100%.

[0047] Drainage rate: A pressure of 10 kPa (simulating the weight of a cow) is applied to saturated absorbent bedding, and the weight of the bedding after drainage is recorded as W. G Calculate the drainage ratio:

[0048] Liquid retention rate = (W) t -W G ) / (W t -W0)×100%.

[0049] 2. Natural drying rate test

[0050] The saturated absorbent pad was placed in an environment of 25℃ / 70% humidity, and the moisture evaporation rate was recorded for 24 hours. The results are shown in Table 2.

[0051] 3. Compressive strength test

[0052] The pad material was compressed into a Φ50mm×20mm cylinder using a universal testing machine (ISO 604 standard) at a compression rate of 5mm / min. The stress value at 50% deformation was recorded, and the results are shown in Table 2.

[0053] Table 2

[0054] Liquid absorption rate (%) 386±12 152±9 95±5 Drainage rate (%) 78.3±3.1 42.6±2.8 35.2±2.5 24-hour drying rate (%) 85.7±2.4 61.3±3.7 48.9±3.0 Compressive strength (kPa) 18.7±0.8 6.2±0.5 >100 (compacted)

[0055] Experimental Example 3

[0056] 1. Simulate the environment of a cowshed

[0057] In a sealed chamber (1m) 3 A 5cm thick bedding material is laid in the room, with a temperature of 25±1℃ and a humidity of 70%.

[0058] Add 200 mL of simulated cow urine (urea solution with a nitrogen content of 1.5 g / L) daily.

[0059] 2. Ammonia monitoring

[0060] The indophenol blue spectrophotometric method (GB / T 18204.25) was used to collect gas samples every 12 hours and monitor them continuously for 72 hours. The results are shown in Table 3.

[0061] Table 3

[0062]

[0063] Test Example 4

[0064] 1. Heavy metal detection

[0065] According to GB 13078-2017 "Feed Hygiene Standard"

[0066] After microwave digestion of the samples, the heavy metal content was determined by ICP-MS, and the results are shown in Table 4.

[0067] 2. Service life verification

[0068] The bedding material (20cm thick) was laid in the dairy farm, and the time when the first crusting and mold appeared was recorded. The results are shown in Table 4.

[0069] Table 4

[0070] Copper (mg / kg) 8.3±0.7 42.5±3.1 ≤50 Zinc (mg / kg) 62.1±4.2 187.3±10.8 ≤150 Cadmium (mg / kg) Not detected 0.8±0.1 ≤1 Average service life 28-32 days 10-15 days -

[0071] As shown in Tables 1-4, no Escherichia coli / Salmonella were detected in the bovine bedding material prepared by this invention, indicating that the bovine bedding material prepared by this invention has high safety and is basically free of pathogens.

[0072] The cattle bedding material prepared by this invention has good water absorption (386%), drainage (78.3%) and drying efficiency (85.7% water loss in 24 hours). It can quickly absorb manure and urine to prevent surface dampness. When cattle lie down, it can quickly drain water to keep the upper layer of the bedding dry, and then the remaining moisture evaporates quickly to keep the cattle shed dry.

[0073] The boar bedding material prepared by this invention can efficiently volatilize ammonia, with an ammonia release of only 83.6 mg / m³. 3 It is 44% below the standard limit.

[0074] The service life of the cow mattress material prepared by this invention is significantly extended, with continuous use for more than 28 days, reducing the cost of later maintenance.

[0075] The boar mattress material prepared by this invention has extremely low heavy metal residue, with zinc residue only 1 / 3 of that in control group 1, which is far below the safety limit.

[0076] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing cow bedding material using cow manure, characterized in that, Includes the following steps: Step 1: Fresh cow manure is filtered and then pressed until the filter cake has a moisture content of 55-65%. The filter cake is then mixed with wood ash to obtain the bedding substrate. Step 2: Mix and dry the crop straw and rice husks, crush them, mix the powder with an alkaline solution, filter, remove the filtrate, mix the filter residue with an enzymatic hydrolysate, filter, remove the filtrate, and dry the filter residue until the moisture content is ≤12% to obtain modified straw-rice husk. Step 3: Mix and crush biochar, attapulgite and zeolite, then mix and soak them with organic acid solution, filter, remove the filtrate, and dry the filter residue to constant weight to obtain modified biochar-zeolite composite. Step 4: Mix the bedding substrate, modified straw-rice husk, modified biochar-zeolite composite, coconut shell fiber, wheat bran, potassium dihydrogen phosphate, and compound microbial agent in a mass ratio of (45-55):(10-20):(5-15):(15-25):(3-7):(1-2):(2-3), adjust the pH to 6.8-7.2, ferment for 4-5 days, and then dry the fermented material until the moisture content is ≤12% to obtain the initial bedding product. Step 5: Spray ferric sulfate-silica solution and chitosan-tea polyphenol solution onto the surface of the initial bedding material in sequence, and then allow it to dry naturally to obtain cow bedding material; The alkaline solution mentioned in step two is a potassium hydroxide solution or a sodium hydroxide solution with a mass fraction of 8-10%. The enzymatic hydrolysate includes cellulase, hemicellulase, pectinase, xylanase and water in a mass ratio of 3:1:1:1000.

2. The method for preparing cow bedding material using cow manure according to claim 1, characterized in that, The mass ratio of crop straw, rice husk, alkaline solution and enzymatic hydrolysate in step two is (1-3):(1-3):(8-24):(8-24).

3. The method for preparing cow bedding material using cow manure according to claim 1, characterized in that, The mass ratio of biochar, attapulgite, zeolite, and organic acid solution in step three is 2:1:1:

16.

4. The method for preparing cow bedding material using cow manure according to claim 1, characterized in that, The organic acid solution mentioned in step three is a citric acid solution with a mass fraction of 8-10% or an acetic acid solution with a volume fraction of 10-12%.

5. A method for preparing cow bedding material using cow manure according to claim 1, characterized in that, The mass ratio of the bedding substrate, modified straw-rice husk, modified biochar-zeolite composite, coconut shell fiber, wheat bran, potassium dihydrogen phosphate, and compound microbial agent in step four is 50:15:10:20:5:1:

2.

6. A method for preparing cow bedding material using cow manure according to claim 1, characterized in that, In step four, within 0-24 hours after the start of fermentation, turn the pile once every 5-6 hours; within 24-72 hours after the start of fermentation, turn the pile once every 10-12 hours; after 72 hours after the start of fermentation, turn the pile once every 22-24 hours.

7. A method for preparing cow bedding material using cow manure according to claim 1, characterized in that, The ferric sulfate-silica solution in step five comprises ferric sulfate, nano-silica, and water in a mass ratio of 3:1:1000; the chitosan-tea polyphenol solution comprises chitosan, tea polyphenols, acetic acid, and water in a ratio of 2g:1g:4mL:100mL.

8. A method for preparing cow bedding material using cow manure according to claim 1, characterized in that, In step five, the amount of ferric sulfate-silica solution sprayed is 2-3% of the initial weight of the padding material, and the amount of chitosan-tea polyphenol solution sprayed is 3-4% of the initial weight of the padding material.

9. The bovine mattress material prepared by the method according to any one of claims 1-8.

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