Pig urine resource utilization method and prepared organic fertilizer

Abstract

The invention provides a pig urine resource utilization method and a prepared organic fertilizer, and belongs to the technical field of resource utilization. Comprising the steps that pig urine is subjected to filtering, ultrafiltration concentration and sterilization, concentrated pig urine is prepared, an adsorption passivator is added, stirring adsorption passivation is conducted, the adsorption passivator is separated, passivated concentrated pig urine is obtained, a biochar adsorbent is added, stirring adsorption and filtering are conducted, a solid is a high-ammonia-nitrogen adsorbent and is used for preparing adsorption slow-release fungus balls, and filtrate is high-value pig urine; adding the traditional Chinese medicine residues and the enzymolysis plant amino acid solution, adding zymophyte for fermentation, and concentrating to obtain pig urine-Chinese herbal medicine fermented materials; and adding the adsorption slow-release bacteria balls, and uniformly stirring and mixing to obtain the organic fertilizer. The prepared organic fertilizer can slowly release nutrient substances and soil improvement bacteria, slowly improve the soil quality and improve the crop yield and disease resistance on one hand, agricultural waste can be recycled, waste is turned into wealth, the cost is low, the preparation method is simple, and far-reaching significance is achieved.

Description

Technical Field

[0001] This invention relates to the field of resource utilization technology, specifically to a method for the resource utilization of pig urine and the resulting organic fertilizer. Background Technology

[0002] Currently, pig farms in rural areas of my country discharge massive amounts of pig urine and manure daily. While current manure separation technology can only address the issue of turning pig manure into a valuable resource (after separation, it is dried and processed into organic solid fertilizer), pig urine treatment technology is lacking. Large quantities are discarded or directly discharged into land or rivers, polluting the surrounding environment with harmful bacteria and heavy metals. On the other hand, decades of overuse of chemical fertilizers in these rural areas have led to severe soil compaction and acidification, urgently requiring organic fertilizers to restore the soil's ecological cycle. Many brands of organic fertilizers are already on the market, but their prices are far higher than chemical fertilizers. Although farmers have recognized the importance of using organic fertilizers, they still rely on chemical fertilizers due to planting costs. If patented technology could be used to convert the massive amounts of pig urine in various regions into cost-effective organic liquid fertilizer, it would have broad market prospects and align with the national health industry policy.

[0003] The research team led by Professor Li Guoxue from the College of Resources and Environment at China Agricultural University focuses on the resource utilization of pig urine and the development of high-value-added organic fertigation. They employ pig urine pretreatment technology, which involves concentrating nitrogen and potassium elements in pig urine through membrane separation. This is combined with tea bran fermentation broth (containing Bacillus amyloliquefaciens) and industrial enzymatic hydrolysis of plant amino acid solutions (such as monosodium glutamate factory waste liquid) to produce a fully nutritious organic fertigation. Experimental results from a test base in Hebei Province show that this fertigation can increase the vitamin C content of leafy vegetables by 25% and reduce the nitrate content by 30%.

[0004] The research team led by Researcher Xu Peizhi at the Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, focuses on the co-fermentation of pig urine and tea bran. Specifically, they utilize the tea saponins in the tea bran to inhibit ammonia volatilization, and add a compound microbial agent (lactic acid bacteria + photosynthetic bacteria) to convert urea in pig urine into amino acid chelated nitrogen. They employ micronutrient fortification technology, adding seaweed extract (a natural source of zinc and boron) and EDTA-chelated iron to enhance the availability of micronutrients in water and fertilizer. In collaboration with Wens Foodstuff Group, they developed "Wens Green Energy No. 1" organic water and fertilizer, which has been promoted in citrus orchards in Zhaoqing, Guangdong, resulting in a 40% reduction in chemical fertilizer use per acre and an increase in sugar content of 2-3 degrees Brix.

[0005] The research team led by Huang Fengqiu at the Institute of Soil and Fertilizer, Hunan Academy of Agricultural Sciences, has developed a triple-product process combining tea bran, pig urine, and amino acids. The first stage involves solid-state fermentation of tea bran and pig manure to produce solid organic fertilizer. The second stage involves mixing pig urine with tea bran extract and industrial amino acids (such as glutamic acid), followed by microbial mineralization to generate water-soluble small-molecule organic matter. This technology has been licensed to Hunan Jinye Zhongwang Technology Co., Ltd., which processes 200,000 tons of pig urine annually. The resulting fertigation is primarily used in tobacco cultivation, increasing the potassium content of tobacco leaves by 15%-20%.

[0006] Professor Liao Hong's team at Fujian Agriculture and Forestry University has developed a tea saponin enhancement technology. This technology retains 5%-8% of the tea saponins in tea bran, which combine with nitrogen in pig urine to form an organic water-soluble fertilizer with antibacterial properties, reducing soil-borne diseases such as bacterial wilt. In collaboration with Fujian Luquan Ecological Agriculture, they have launched the "Tea Rhyme" series of water-soluble fertilizers. Application in Anxi Tieguanyin tea gardens has reduced pesticide use by 50% and increased the tea polyphenol content of tea leaves by 12%.

[0007] Currently, the resource utilization of pig urine often faces the following technical challenges:

[0008] 1. Raw material stability issues:

[0009] 1) Pig urine is easily perishable, and ammonia volatilization loss can reach 50% during storage. It is necessary to add acidifying agents (such as phosphoric acid) or low-temperature concentration equipment, which increases costs.

[0010] 2) The sources of tea bran are scattered, and the content of tea saponins fluctuates greatly (5%-15%), which affects the consistency of products.

[0011] 2. Process complexity:

[0012] The combination of amino acids and trace elements is prone to producing precipitation (such as Fe). 3+ (Together with phosphate), it requires nano-coating or layered addition technology, which makes the process difficult.

[0013] 3. High cost pressure:

[0014] High-quality amino acids (such as fish protein hydrolyzed amino acids) cost 8,000-12,000 yuan / ton, and most companies have switched to using industrial waste liquid, but there is a risk of heavy metal contamination.

[0015] 4. High ammonia nitrogen and high salinity: Traditional composting is prone to volatilization loss, resulting in low nitrogen utilization rate of organic fertilizer.

[0016] 5. Heavy metals (Cu, As, Zn) and antibiotic residues:

[0017] Feed additives cause excessive levels of heavy metals and antibiotics (such as tetracycline and sulfonamides) in pig urine, posing ecological risks if directly returned to the fields.

[0018] 6. High moisture content and foul-smelling gases:

[0019] The process is energy-intensive and produces gases such as H2S and NH3 that pollute the environment.

[0020] Therefore, there is a need to develop a practical and economically valuable method for the resource utilization of pig urine. Summary of the Invention

[0021] The purpose of this invention is to propose a method for the resource utilization of pig urine and the resulting organic fertilizer. The method involves mixing the prepared pig urine-traditional Chinese medicine fermentation product with adsorbent slow-release bacterial balls. On the one hand, this method can slowly release nutrients and soil-improving bacteria, gradually improve soil quality, increase crop yield and disease resistance, and on the other hand, it can also make resource utilization of agricultural waste, turning waste into treasure. Moreover, the cost is low, the preparation method is simple, and it has far-reaching significance.

[0022] The technical solution of this invention is implemented as follows:

[0023] This invention provides a method for the resource utilization of pig urine, comprising the following steps:

[0024] (1) Pig urine is filtered, concentrated by ultrafiltration, and sterilized to obtain concentrated pig urine;

[0025] (2) Add an adsorption and passivation agent to concentrated pig urine, stir to adsorb and passivate, separate the adsorption and passivation agent, and obtain passivated concentrated pig urine;

[0026] (3) Add biochar adsorbent to passivated concentrated pig urine, stir to adsorb, filter, the solid is a high ammonia nitrogen adsorbent, which is used to prepare adsorbed slow-release bacterial balls, and the filtrate is high-value pig urine.

[0027] (4) Add Chinese medicine residue and enzymatic hydrolysis of plant amino acids to high-value pig urine, add fermentation bacteria seed liquid for fermentation, concentrate, and obtain pig urine-Chinese herbal medicine fermentation product.

[0028] (5) Add adsorbent slow-release bacterial balls to pig urine-Chinese herbal medicine fermentation product, stir and mix evenly to obtain organic fertilizer.

[0029] As a further improvement of the present invention, the relative density of the concentrated pig urine in step (1) is 1.03-1.06.

[0030] As a further improvement of the present invention, the mass ratio of concentrated pig urine to adsorption passivating agent in step (2) is 100:3-5, the stirring adsorption passivation time is 15-35 min, and the preparation method of the adsorption passivating agent is as follows:

[0031] S1. Preparation of phytic acid-intercalated montmorillonite: Montmorillonite was added to water, phytic acid and sodium dodecylbenzenesulfonate were added, the intercalation reaction was stirred, filtered, washed and dried to obtain phytic acid-intercalated montmorillonite.

[0032] S2. Ferric chloride and ferrous chloride were added to water, and ammonia was added dropwise under inert gas protection. The mixture was heated and stirred to react, centrifuged, washed, dried, and calcined to obtain nano-Fe3O4. β-Cyclodextrin was added to Tris-HCl solution, along with nano-Fe3O4 and tannic acid. The mixture was heated and stirred to react, separated by a magnet, washed, and dried to obtain nano-Fe3O4 modified β-Cyclodextrin.

[0033] S3. Phytic acid-intercalated montmorillonite was added to water, along with dipotassium hydrogen phosphate, calixarene, and nano-ferric oxide-modified β-cyclodextrin. The mixture was subjected to hydrothermal reaction, magnetic separation, washing, and drying to obtain the adsorption passivating agent.

[0034] As a further improvement of the present invention, the mass ratio of montmorillonite, phytic acid and sodium dodecylbenzenesulfonate in step S1 is 15-20:5-7:2-3, and the stirring intercalation reaction time is 1-2 hours.

[0035] As a further improvement of the present invention, in step S2, the mass ratio of ferric chloride, ferrous chloride, and ammonia is 3.24:1.26:3-5, the calcination temperature is 500-600℃, and the time is 1-3h; the mass ratio of β-cyclodextrin, nano-ferric oxide, and tannic acid is 3-6:2-3:1-2; in step S3, the mass ratio of phytic acid-intercalated montmorillonite, dipotassium hydrogen phosphate, calixarene, and β-cyclodextrin is 10:0.5-1:1-2:3-4, and the hydrothermal reaction temperature is 120-130℃, and the time is 20-24h.

[0036] As a further improvement of the present invention, the mass ratio of passivated concentrated pig urine and biochar adsorbent in step (3) is 10:2-3. The preparation method of the biochar adsorbent is as follows: after crushing the straw, heat it to 600-700℃ and carbonize it for 2-4 hours. Add the product to concentrated nitric acid for 20-30 minutes, filter, wash, and dry to obtain pretreated biochar. Add the pretreated biochar to a Tris-HCl solution with pH=8.5-9.5, add tannic acid, the mass of which is 20-30 wt% of the pretreated biochar, heat to 50-60℃, stir and react for 3-5 hours, centrifuge, wash, and dry to obtain the biochar adsorbent.

[0037] As a further improvement of the present invention, the mass ratio of the high-value pig urine, Chinese medicine residue and enzymatic hydrolysis of plant amino acid solution in step (4) is 20-40:15-22:30-55, the Chinese medicine residue is the waste residue after extraction of South African leaves and / or Artemisia annua, the enzymatic hydrolysis of plant amino acid solution is the waste liquid of monosodium glutamate factory, the fermentation bacteria is Bacillus subtilis or Bacillus licheniformis, and the fermentation conditions are 20-25℃ and the time is 48-72h.

[0038] As a further improvement of the present invention, the mass ratio of pig urine-Chinese herbal medicine fermentation product and adsorbent slow-release bacterial balls in step (5) is 10:0.5-1, and the preparation method of the adsorbent slow-release bacterial balls is as follows:

[0039] T1. Add Taili biological agent to water, add sodium alginate and lecithin, stir and mix evenly, add to fish oil, emulsify, add calcium chloride, stir and mix evenly, solidify at room temperature, centrifuge, wash, dry, and obtain sodium alginate bacterial balls.

[0040] T2. Add the high ammonia nitrogen adsorbent to Tris-HCl solution, add dopamine hydrochloride, heat and stir to react, centrifuge, wash, and dry to obtain the modified high ammonia nitrogen adsorbent;

[0041] T3. Add the high ammonia nitrogen adsorbent to water, add sodium alginate bacterial balls, stir to adhere, filter, wash, and dry to obtain adsorption slow-release bacterial balls.

[0042] As a further improvement of the present invention, the mass ratio of Taili biological agent, sodium alginate, lecithin and calcium chloride in step T1 is 3-5:8-10:0.5-1:0.2-0.5; the pH value of the Tris-HCl solution in step T2 is 8.5-10; the mass ratio of the high ammonia nitrogen adsorbent and dopamine hydrochloride is 8-10:2-3; the temperature of the heating and stirring reaction is 45-55℃ and the time is 3-5h; and the mass ratio of the high ammonia nitrogen adsorbent and sodium alginate bacterial balls in step T3 is 4-7:10.

[0043] This invention further protects an organic fertilizer produced by the above-mentioned method for the resource utilization of pig urine.

[0044] The present invention has the following beneficial effects:

[0045] This invention prepares an adsorption passivating agent using inexpensive montmorillonite as a raw material. Phytic acid and sodium dodecylbenzenesulfonate are intercalated into the montmorillonite to expand the interlayer spacing and increase its specific surface area. The intercalated phytic acid has a good adsorption and passivation effect on heavy metal ions and also acts as a bridge to couple calixarene and nano-ferric oxide-modified β-cyclodextrin onto the montmorillonite. This allows it to effectively adsorb antibiotics (such as tetracycline and sulfonamides) and organic pollutants. The organic portion of the antibiotics can easily enter the cavities of the calixarene or cyclodextrin, thus achieving a better adsorption and passivation effect. Furthermore, the ferric oxide-modified β-cyclodextrin facilitates magnetic separation of the adsorption passivating agent, improving its operability. After passivation, under a strong magnetic field, the ferric oxide undergoes magnetic vibration, which helps the adsorbed heavy metal ions and organic pollutants desorb into the solvent, completing the regeneration of the adsorption passivating agent and improving its industrial applicability.

[0046] This invention prepares a biochar adsorbent using agricultural waste straw as raw material. After carbonization, the straw is treated with concentrated nitric acid to give it hydroxyl groups on its surface. However, the number of hydroxyl groups is insufficient to efficiently fix large amounts of ammonia nitrogen in pig urine. Therefore, after surface modification with tannic acid, the hydroxyl content is significantly increased, enabling the formation of hydrogen bonds to efficiently fix large amounts of ammonia nitrogen in pig urine, thus significantly reducing the amount of ammonia nitrogen in pig urine. The resulting high ammonia nitrogen adsorbent is further coated on the surface of sodium alginate microspheres containing Taili biological agents. Taili biological agents include beneficial bacteria such as Lactobacillus bruneri, yeast, Bacillus natto, and potassium- and phosphorus-solubilizing bacteria, as well as their rich amino acids, active enzymes, growth factors, various vitamins, antioxidants, and other metabolites. Polydopamine improves the adhesion between the two and allows the adsorbed ammonia nitrogen compounds to be released slowly and controlled into the soil, thereby improving soil nutrition and slowly releasing soil-improving bacteria (nitrogen-fixing bacteria and phosphorus-solubilizing bacteria), thus improving the growth environment of crops and increasing crop yield.

[0047] This invention involves fermenting high-value pig urine (purified to remove heavy metal ions, antibiotics, and organic pollutants) and reducing ammonia nitrogen with traditional Chinese medicine residue (waste residue from extracts of South African leaves and / or Artemisia annua) and an enzymatically hydrolyzed plant amino acid solution. The sesquiterpene lactones in South African leaves and the antiparasitic components of Artemisia annua, combined with the degradation by microorganisms, enable the fertilizer to inhibit soil-borne diseases such as Pythium spp. in melons and fruits, thus reducing the incidence of crop diseases. Through the combination of South African leaves and Artemisia annua, the fertilizer has both growth-promoting (flavonoids) and disease-resistant (artemisinin) functions, while also enabling the resource utilization of the enzymatically hydrolyzed plant amino acid solution and traditional Chinese medicine residue.

[0048] This invention mixes the prepared pig urine-Chinese herbal medicine ferment with adsorbent slow-release bacterial balls, which can slowly release nutrients and soil-improving bacteria, gradually improve soil quality, increase crop yield and disease resistance, and also make resource-efficient use of agricultural waste, turning waste into treasure. Moreover, it is low-cost, simple to prepare, and has far-reaching significance. Detailed Implementation

[0049] The technical solutions in the embodiments of the present invention will be clearly and completely described 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.

[0050] Bacillus subtilis, ATCC6633, 20 billion CFU / g; Bacillus licheniformis, ATCC14580, 20 billion CFU / g.

[0051] Taili Bio-initiated bacterial agent is a compound bacterial preparation purchased from Taili Bio-initiated. It contains high concentrations of Lactobacillus bruneri, yeast, Bacillus natto, and potassium- and phosphorus-solubilizing bacteria.

[0052] The enzymatic hydrolysed plant amino acid solution is a 50% enzymatic hydrolysed amino acid liquid containing proline, threonine, lysine, glycine, and aspartic acid, purchased from Sichuan Genwo Agricultural Technology Co., Ltd.

[0053] Preparation method of inoculum seed solution: Inoculate the inoculum into slant culture medium, incubate at 25℃ and 150 r / min for 18-24 h to obtain a culture with a bacterial count of 10. 8 -10 9 CFU / mL bacterial seed solution.

[0054] Preparation Example 1: Preparation of Adsorption Passivating Agent

[0055] The method is as follows:

[0056] S1. Preparation of phytic acid-intercalated montmorillonite: 15g of montmorillonite was added to 500mL of water, along with 5g of phytic acid and 2g of sodium dodecylbenzenesulfonate. The intercalation reaction was stirred for 1h, filtered, washed, and dried to obtain phytic acid-intercalated montmorillonite.

[0057] S2. Add 3.24g of ferric chloride and 1.26g of ferrous chloride to 200mL of water. Under nitrogen protection, add 3g of ammonia dropwise, heat to 80℃, stir and react for 5h, centrifuge, wash, dry, and calcine at 500℃ for 1h to obtain nano-ferric oxide; add 3g of β-cyclodextrin to 200mL of Tris-HCl solution with pH=9, add 2g of nano-ferric oxide and 1g of tannic acid, heat to 60℃, stir and react for 4h, separate with a magnet, wash, and dry to obtain nano-ferric oxide modified β-cyclodextrin;

[0058] S3. Add 10g of phytic acid-intercalated montmorillonite to 300mL of water, add 0.5g of dipotassium hydrogen phosphate, 1g of calixarene and 3g of nano-ferric oxide modified β-cyclodextrin, and hydrothermally react at 120℃ for 20h. Separate by magnet, wash and dry to obtain the adsorption passivating agent.

[0059] Preparation Example 2: Preparation of Adsorption Passivating Agent

[0060] The method is as follows:

[0061] S1. Preparation of phytic acid-intercalated montmorillonite: 20g of montmorillonite was added to 500mL of water, along with 7g of phytic acid and 3g of sodium dodecylbenzenesulfonate. The intercalation reaction was stirred for 2h, filtered, washed, and dried to obtain phytic acid-intercalated montmorillonite.

[0062] S2. Add 3.24g of ferric chloride and 1.26g of ferrous chloride to 200mL of water. Under nitrogen protection, add 5g of ammonia dropwise, heat to 80℃, stir and react for 5h, centrifuge, wash, dry, and calcine at 600℃ for 3h to obtain nano-ferric oxide; add 6g of β-cyclodextrin to 200mL of Tris-HCl solution with pH=9, add 3g of nano-ferric oxide and 2g of tannic acid, heat to 60℃, stir and react for 4h, separate with a magnet, wash, and dry to obtain nano-ferric oxide modified β-cyclodextrin;

[0063] S3. Add 10g of phytic acid-intercalated montmorillonite to 300mL of water, add 1g of dipotassium hydrogen phosphate, 2g of calixarene and 4g of nano-ferric oxide modified β-cyclodextrin, and hydrothermally react at 130℃ for 24h. Separate by magnet, wash and dry to obtain the adsorption passivating agent.

[0064] Preparation Example 3: Preparation of Adsorption Passivating Agent

[0065] The method is as follows:

[0066] S1. Preparation of phytic acid-intercalated montmorillonite: 17g of montmorillonite was added to 500mL of water, along with 6g of phytic acid and 2.5g of sodium dodecylbenzenesulfonate. The intercalation reaction was stirred for 1.5h, filtered, washed, and dried to obtain phytic acid-intercalated montmorillonite.

[0067] S2. Add 3.24g of ferric chloride and 1.26g of ferrous chloride to 200mL of water. Under nitrogen protection, add 4g of ammonia dropwise, heat to 80℃, stir and react for 5h, centrifuge, wash, dry, and calcine at 550℃ for 2h to obtain nano-ferric oxide; add 4.5g of β-cyclodextrin to 200mL of Tris-HCl solution with pH=9, add 2.5g of nano-ferric oxide and 1.5g of tannic acid, heat to 60℃, stir and react for 4h, separate with a magnet, wash, and dry to obtain nano-ferric oxide modified β-cyclodextrin;

[0068] S3. Add 10g of phytic acid-intercalated montmorillonite to 300mL of water, add 0.7g of dipotassium hydrogen phosphate, 1.5g of calixarene and 3.5g of nano-ferric oxide modified β-cyclodextrin, and hydrothermally react at 125℃ for 22h. Separate by magnetization, wash and dry to obtain the adsorption passivating agent.

[0069] Comparative Preparation Example 1

[0070] The difference from Preparation Example 3 is that phytic acid was not added in step S1.

[0071] Specifically as follows:

[0072] S1. Preparation of intercalated montmorillonite: 17g of montmorillonite was added to 500mL of water, 2.5g of sodium dodecylbenzenesulfonate was added, the intercalation reaction was stirred for 1.5h, filtered, washed and dried to obtain intercalated montmorillonite.

[0073] Comparative Preparation Example 2

[0074] The difference from Preparation Example 3 is that no calixarene was added in step S3.

[0075] Specifically as follows:

[0076] S3. Add 10g of phytic acid-intercalated montmorillonite to 300mL of water, add 0.7g of dipotassium hydrogen phosphate and 5g of nano-ferric oxide modified β-cyclodextrin, and hydrothermally react at 125℃ for 22h. Separate with a magnet, wash, and dry to obtain the adsorption passivating agent.

[0077] Comparative preparation example 3

[0078] The difference from Preparation Example 3 is that nano-ferric oxide modified β-cyclodextrin was not added in step S3.

[0079] Specifically as follows:

[0080] S3. Add 10g of phytic acid-intercalated montmorillonite to 300mL of water, add 0.7g of dipotassium hydrogen phosphate and 5g of calixarene, and perform a hydrothermal reaction at 125℃ for 22h. Separate with a magnet, wash, and dry to obtain the adsorption passivating agent.

[0081] Comparative preparation example 4

[0082] The difference compared to Preparation Example 3 is that steps S2 and S3 were not performed.

[0083] Specifically as follows:

[0084] S1. Preparation of phytic acid-intercalated montmorillonite: 17g of montmorillonite was added to 500mL of water, along with 6g of phytic acid and 2.5g of sodium dodecylbenzenesulfonate. The intercalation reaction was stirred for 1.5h, filtered, washed, and dried to obtain phytic acid-intercalated montmorillonite, which is the adsorption and passivation agent.

[0085] Preparation Example 4: Preparation of Biochar Adsorbent

[0086] The method is as follows:

[0087] After crushing, the straw was heated to 600℃ and carbonized for 2 hours. The product was then treated in concentrated nitric acid for 20 minutes, filtered, washed, and dried to obtain pretreated biochar. 10g of the pretreated biochar was added to 150mL of Tris-HCl solution with pH=8.5, along with 2g of tannic acid. The mixture was heated to 50℃ and stirred for 3 minutes. After centrifugation, washing, and drying, the biochar adsorbent was obtained.

[0088] Preparation Example 5: Preparation of Biochar Adsorbent

[0089] The method is as follows:

[0090] After crushing, the straw was heated to 700℃ and carbonized for 4 hours. The product was then treated in concentrated nitric acid for 30 minutes, filtered, washed, and dried to obtain pretreated biochar. 10g of the pretreated biochar was added to 200mL of Tris-HCl solution with pH=9.5, along with 3g of tannic acid. The mixture was heated to 60℃ and stirred for 5 hours. After centrifugation, washing, and drying, the biochar adsorbent was obtained.

[0091] Preparation Example 6: Preparation of Biochar Adsorbent

[0092] The method is as follows:

[0093] After crushing, the straw was heated to 650℃ and carbonized for 3 hours. The product was then treated in concentrated nitric acid for 25 minutes, filtered, washed, and dried to obtain pretreated biochar. 10g of the pretreated biochar was added to 200mL of Tris-HCl solution with pH=9, along with 2.5g of tannic acid. The mixture was heated to 55℃ and stirred for 4 hours. After centrifugation, washing, and drying, the biochar adsorbent was obtained.

[0094] Comparative preparation example 5

[0095] The difference compared to Preparation Example 6 is that no tannic acid modification was performed.

[0096] Specifically as follows:

[0097] After crushing, the straw is heated to 650℃ and carbonized for 3 hours. The product is then treated in concentrated nitric acid for 25 minutes, filtered, washed, and dried to obtain pretreated biochar, which is the biochar adsorbent.

[0098] Example 1

[0099] This embodiment provides a method for the resource utilization of pig urine, including the following steps:

[0100] (1) Pig urine is filtered, concentrated by ultrafiltration, and sterilized to obtain concentrated pig urine. The density of water under relative standard conditions is 1.03.

[0101] The levels of antibiotics and heavy metals in the separated urine samples were determined. Antibiotics were analyzed using UPLC-MS-MS on a Thermos LTQ Orbitrap XL instrument. Quality control was performed using blank samples, parallel samples, and standard substances. Heavy metals Cu and Cr were determined using flame atomic absorption spectrometry on a Thermo MKII M6 atomic absorption spectrometer, and As was determined using atomic fluorescence spectrometry on a Beijing Rayleigh AF-610E atomic fluorescence spectrometer. The results are shown in Table 1.

[0102] Table 1

[0103]

[0104] (2) Add 3g of the adsorption passivating agent prepared in Example 1 to 100g of concentrated pig urine, stir and adsorb and passivate for 15min, separate the adsorption passivating agent to obtain passivated concentrated pig urine; determine the residual content of antibiotics and heavy metals in the separated urine, calculate the removal rate, and the results are shown in Table 2.

[0105] Table 2

[0106]

[0107] The contents of COD, ammonia nitrogen, Kjeldahl nitrogen, and total phosphorus in the separated urine were determined. The methods were as follows: COD was determined using the potassium dichromate method (GB / T 11914-1989); total phosphorus (TP) was determined using the potassium dichromate method (GB 11893-11989); Kjeldahl nitrogen (TKN) was determined using the potassium dichromate method (GB 11891-1989); and ammonia nitrogen was determined by titration. The results are shown in Table 3.

[0108] Table 3

[0109] project COD content (mg / L) Ammonia nitrogen content (mg / L) Kjeldahl nitrogen content (mg / L) Total phosphorus (mg / L) content 185925.3 58624.4 89534.2 158.2

[0110] (3) Add 2g of the biochar adsorbent prepared in Example 4 to 10g of passivated concentrated pig urine, stir and adsorb for 30min, filter, the solid is a high ammonia nitrogen adsorbent, which is used to prepare adsorbed slow-release bacterial balls, and the filtrate is high-value pig urine; determine the COD, ammonia nitrogen, Kjeldahl nitrogen and total phosphorus content in the separated urine, calculate the removal rate, and the results are shown in Table 4.

[0111] Table 4

[0112] project COD removal rate (%) Ammonia nitrogen removal rate (%) Kjeldahl nitrogen removal rate (%) Total phosphorus removal rate (%) content 88.4 82.5 77.7 78.5

[0113] The preparation method of adsorbent slow-release bacterial balls is as follows:

[0114] T1. Add 3g of Taili biological agent to 300mL of water, add 8g of sodium alginate and 0.5g of lecithin, stir and mix for 15min, add to 500mL of fish oil, emulsify at 8000r / min for 15min, add 0.2g of calcium chloride, stir and mix, solidify at room temperature for 30min, centrifuge, wash, dry, and obtain sodium alginate bacterial balls;

[0115] T2. Add 8g of high ammonia nitrogen adsorbent to 150mL of Tris-HCl solution, add 2g of dopamine hydrochloride, heat to 45℃, stir and react for 3h, centrifuge, wash, and dry to obtain modified high ammonia nitrogen adsorbent.

[0116] T3. Add 4g of high ammonia nitrogen adsorbent to 200mL of water, add 10g of sodium alginate bacterial balls, stir and adhere for 30min, filter, wash, and dry to obtain adsorption slow-release bacterial balls.

[0117] (4) Add 15g of Chinese herbal medicine residue (waste residue after extraction of South African leaves and Artemisia annua, mass ratio 1:1) and 30g of enzymatic hydrolysis of plant amino acid solution to 20g of high-value pig urine, add Bacillus subtilis seed liquid, inoculate at 2v / v%, ferment at 20℃, 150r / min for 48h, concentrate, and obtain pig urine-Chinese herbal medicine fermentation product.

[0118] (5) Add 0.5g of adsorbent slow-release bacterial balls to 10g of pig urine-Chinese herbal medicine fermentation product, stir and mix for 30min to obtain organic fertilizer.

[0119] Example 2

[0120] This embodiment provides a method for the resource utilization of pig urine, including the following steps:

[0121] (1) Pig urine is filtered, concentrated by ultrafiltration, and sterilized to obtain concentrated pig urine with a density of 1.06 relative to standard conditions.

[0122] The levels of antibiotics and heavy metals in the separated urine were determined. The results are shown in Table 5.

[0123] Table 5

[0124]

[0125] (2) Add 5g of the adsorption passivating agent prepared in Preparation Example 2 to 100g of concentrated pig urine, stir and adsorb and passivate for 35min, separate the adsorption passivating agent, and obtain passivated concentrated pig urine;

[0126] The levels of antibiotics and heavy metals in the separated urine were measured, and the removal rate was calculated. The results are shown in Table 6.

[0127] Table 6

[0128]

[0129] The COD, ammonia nitrogen, Kjeldahl nitrogen, and total phosphorus content in the separated urine were determined. The results are shown in Table 7.

[0130] Table 7

[0131] project COD content (mg / L) Ammonia nitrogen content (mg / L) Kjeldahl nitrogen content (mg / L) Total phosphorus (mg / L) content 225962.6 62864.6 96826.5 189.6

[0132] (3) Add 3g of the biochar adsorbent prepared in Example 5 to 10g of passivated concentrated pig urine, stir and adsorb for 30min, filter, the solid is a high ammonia nitrogen adsorbent, which is used to prepare adsorbed slow-release bacterial balls, and the filtrate is high-value pig urine; determine the COD, ammonia nitrogen, Kjeldahl nitrogen and total phosphorus content in the separated urine, calculate the removal rate, and the results are shown in Table 8.

[0133] Table 8

[0134] project COD removal rate (%) Ammonia nitrogen removal rate (%) Kjeldahl nitrogen removal rate (%) Total phosphorus removal rate (%) content 88.9 82.1 76.6 79.2

[0135] The preparation method of adsorbent slow-release bacterial balls is as follows:

[0136] T1. Add 5g of Taili biological agent to 300mL of water, add 10g of sodium alginate and 1g of lecithin, stir and mix for 15min, add to 500mL of fish oil, emulsify at 8000r / min for 15min, add 0.5g of calcium chloride, stir and mix, solidify at room temperature for 30min, centrifuge, wash, dry, and obtain sodium alginate bacterial balls;

[0137] T2. Add 10g of high ammonia nitrogen adsorbent to 150mL of Tris-HCl solution, add 3g of dopamine hydrochloride, heat to 55℃, stir and react for 5h, centrifuge, wash, and dry to obtain modified high ammonia nitrogen adsorbent.

[0138] T3. Add 7g of high ammonia nitrogen adsorbent to 200mL of water, add 10g of sodium alginate bacterial balls, stir and adhere for 30min, filter, wash, and dry to obtain adsorption slow-release bacterial balls.

[0139] (4) Add 22g of Chinese herbal medicine residue (waste residue after extraction of South African leaves and Artemisia annua, mass ratio 1:1) and 55g of enzymatic hydrolysis of plant amino acid solution to 40g of high-value pig urine, add Bacillus licheniformis seed liquid, inoculate at 2v / v%, ferment at 25℃, 150r / min for 72h, concentrate, and obtain pig urine-Chinese herbal medicine fermentation product;

[0140] (5) Add 1g of adsorbent slow-release bacterial balls to 10g of pig urine-Chinese herbal medicine fermentation product, stir and mix for 30 minutes to obtain organic fertilizer.

[0141] Example 3

[0142] This embodiment provides a method for the resource utilization of pig urine, including the following steps:

[0143] (1) Pig urine is filtered, concentrated by ultrafiltration, and sterilized to obtain concentrated pig urine with a density of 1.04 relative to standard conditions.

[0144] The levels of antibiotics and heavy metals in the separated urine were determined. The results are shown in Table 9.

[0145] Table 9

[0146]

[0147] (2) Add 4g of the adsorption passivating agent prepared in Preparation Example 3 to 100g of concentrated pig urine, stir and adsorb and passivate for 25min, separate the adsorption passivating agent, and obtain passivated concentrated pig urine;

[0148] The levels of antibiotics and heavy metals in the separated urine were measured, and the removal rate was calculated. The results are shown in Table 10.

[0149] Table 10

[0150]

[0151] The COD, ammonia nitrogen, Kjeldahl nitrogen, and total phosphorus content in the separated urine were determined. The results are shown in Table 11.

[0152] Table 11

[0153] project COD content (mg / L) Ammonia nitrogen content (mg / L) Kjeldahl nitrogen content (mg / L) Total phosphorus (mg / L) content 206336.6 58962.6 91563.6 145.7

[0154] (3) Add 2.5g of the biochar adsorbent prepared in Example 6 to 10g of passivated concentrated pig urine, stir and adsorb for 30min, filter, the solid is a high ammonia nitrogen adsorbent, which is used to prepare adsorbed slow-release bacterial balls, and the filtrate is high-value pig urine.

[0155] The COD, ammonia nitrogen, Kjeldahl nitrogen, and total phosphorus content in the separated urine were measured, and the removal rate was calculated. The results are shown in Table 12.

[0156] Table 12

[0157] project COD removal rate (%) Ammonia nitrogen removal rate (%) Kjeldahl nitrogen removal rate (%) Total phosphorus removal rate (%) content 90.2 85.6 81.5 80.5

[0158] The preparation method of adsorbent slow-release bacterial balls is as follows:

[0159] T1. Add 4g of Taili biological agent to 300mL of water, add 9g of sodium alginate and 0.7g of lecithin, stir and mix for 15min, then add to 500mL of fish oil, stirring at 8000r / min. Emulsify for 15 minutes, add 0.35g of calcium chloride, stir to mix, and solidify at room temperature. Centrifuge for 30 minutes, wash, dry, and obtain sodium alginate bacterial balls;

[0160] T2. Add 9g of high ammonia nitrogen adsorbent to 150mL of Tris-HCl solution, add 2.5g of dopamine hydrochloride, heat to 50℃, stir and react for 4h, centrifuge, wash, and dry to obtain the modified high ammonia nitrogen adsorbent.

[0161] T3. Add 5.5g of high ammonia nitrogen adsorbent to 200mL of water, add 10g of sodium alginate bacterial balls, stir and adhere for 30min, filter, wash, and dry to obtain adsorption slow-release bacterial balls.

[0162] (4) Add 18g of Chinese herbal medicine residue (waste residue after extraction of South African leaves and Artemisia annua, mass ratio 1:1) and 45g of enzymatic hydrolysis of plant amino acid solution to 30g of high-value pig urine, add Bacillus subtilis seed liquid, inoculate at 2v / v%, ferment at 22℃, 150r / min for 56h, concentrate, and obtain pig urine-Chinese herbal medicine fermentation product.

[0163] (5) Add 0.7g of adsorbent slow-release bacterial balls to 10g of pig urine-Chinese herbal medicine fermentation product, stir and mix for 30min to obtain organic fertilizer.

[0164] Comparative Example 1

[0165] The difference from Example 3 is that the adsorption passivating agent was prepared by Comparative Preparation Example 1.

[0166] The residual content of antibiotics and heavy metals in concentrated pig urine and passivated concentrated pig urine were determined separately, and the removal rate was calculated. The results are shown in Table 13.

[0167] Table 13

[0168]

[0169] Comparative Example 2

[0170] The difference from Example 3 is that the adsorption passivating agent was prepared by Comparative Preparation Example 2.

[0171] The levels of antibiotics and heavy metals in concentrated and passivated concentrated pig urine were determined separately, and the removal rates were calculated. The results are shown in Table 14.

[0172] Table 14

[0173]

[0174] Comparative Example 3

[0175] The difference from Example 3 is that the adsorption passivating agent was prepared by Comparative Preparation Example 3.

[0176] The levels of antibiotics and heavy metals in concentrated and passivated concentrated pig urine were determined separately, and the removal rates were calculated. The results are shown in Table 15.

[0177] Table 15

[0178]

[0179] Comparative Example 4

[0180] The difference from Example 3 is that the adsorption passivating agent was prepared by Comparative Preparation Example 4.

[0181] The residual contents of antibiotics and heavy metals in concentrated pig urine and passivated concentrated pig urine were determined separately, and the removal rate was calculated. The results are shown in Table 16.

[0182] Table 16

[0183]

[0184] Comparative Example 5

[0185] The difference from Example 3 is that the biochar adsorbent was prepared by Comparative Preparation Example 5.

[0186] The COD, ammonia nitrogen, Kjeldahl nitrogen, and total phosphorus contents in passivated concentrated pig urine and high-value pig urine were measured respectively, and the removal rate was calculated. The results are shown in Table 17.

[0187] Table 17

[0188] project COD removal rate (%) Ammonia nitrogen removal rate (%) Kjeldahl nitrogen removal rate (%) Total phosphorus removal rate (%) content 85.2 79.3 72.5 68.7

[0189] Comparative Example 6

[0190] The difference compared to Example 3 is that no rhizobia were added in the preparation of the adsorbed slow-release bacterial balls.

[0191] Comparative Example 7

[0192] The difference compared to Example 3 is that Bacillus megaterium was not added in the preparation of the adsorbed slow-release bacterial balls.

[0193] Comparative Example 8

[0194] The difference compared to Example 3 is that no adsorbed slow-release bacterial balls were added.

[0195] Comparative Example 9

[0196] The difference from Example 3 is that no Chinese herbal medicine residue was added in step (4).

[0197] Specifically as follows:

[0198] (4) Add 45g of enzymatic hydrolysis plant amino acid solution (MSG factory waste liquid) to 48g of high-value pig urine, add Bacillus subtilis seed liquid, inoculate at 2v / v%, ferment at 22℃, 150r / min for 56h, concentrate to obtain pig urine fermentation product.

[0199] Comparative Example 10

[0200] The difference from Example 3 is that no enzymatic hydrolysis of plant amino acid solution was added in step (4).

[0201] Specifically as follows:

[0202] (4) Add 18g of Chinese herbal medicine residue (waste residue after extraction of South African leaves and Artemisia annua, mass ratio 1:1) to 75g of high-value pig urine, add Bacillus subtilis seed liquid, inoculate at 2v / v%, ferment at 22℃, 150r / min for 56h, concentrate to obtain pig urine-Chinese herbal medicine fermentation product.

[0203] Test Example 1

[0204] The crop used was white-stemmed water spinach, purchased from Shicheng Seed Co., Ltd. It was sealed in a glass jar before the experiment. Pots measuring 18*17*12cm were used for the pot experiment. Naturally air-dried topsoil was used as the test soil, and soil samples from this topsoil were examined using a 2mm sieve.

[0205] The control group, Examples 1-3, and Comparative Examples 5-10 were each treated three times. 2.5 kg of the test soil was mixed with 5 g of the prepared organic fertilizer, placed in flowerpots, and allowed to stand for a period of time before the pot experiment was conducted. No organic fertilizer was added to the control group.

[0206] Water spinach seeds were sterilized by soaking in a 2% H2O2 solution for 10 minutes, then rinsed clean. Healthy and plump seeds were selected for pot experiments, with 20 seeds sown per pot. The pot experiment lasted 30 days. During the experiment, water was added according to a 20% moisture content using a weighing method. The growth of the water spinach was observed after the pot experiment was completed.

[0207] Yield increase rate (%) = (Average weight of water spinach in each treatment group - Average weight of water spinach in the control group) / Average weight of water spinach in the control group × 100%

[0208] The results are shown in Table 18.

[0209] Table 18

[0210] Group Average germination rate (%) Production increase rate (%) control group 70 / Example 1 95 43.2 Example 2 95 44.5 Example 3 96.7 45.8 Comparative Example 5 80 24.3 Comparative Example 6 86.7 32.4 Comparative Example 7 81.7 33.7 Comparative Example 8 75 27.8 Comparative Example 9 78.3 29.4 Comparative Example 10 83.3 32.2

[0211] As can be seen from the table above, the organic fertilizers prepared in Examples 1-3 of this invention can effectively promote water spinach growth and increase yield.

[0212] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for the resource utilization of pig urine, characterized in that, Includes the following steps: (1) Pig urine is filtered, concentrated by ultrafiltration, and sterilized to obtain concentrated pig urine; (2) Add an adsorption and passivation agent to concentrated pig urine, stir to adsorb and passivate, separate the adsorption and passivation agent, and obtain passivated concentrated pig urine; (3) Add biochar adsorbent to passivated concentrated pig urine, stir to adsorb, filter, the solid is a high ammonia nitrogen adsorbent, which is used to prepare adsorbed slow-release bacterial balls, and the filtrate is high-value pig urine. (4) Add Chinese medicine residue and enzymatic hydrolysis of plant amino acids to high-value pig urine, add fermentation bacteria seed liquid for fermentation, concentrate, and obtain pig urine-Chinese herbal medicine fermentation product. (5) Add adsorbent slow-release bacterial balls to pig urine-Chinese herbal medicine fermentation product, stir and mix evenly to obtain organic fertilizer.

2. The method for resource utilization of pig urine according to claim 1, characterized in that, The relative density of the concentrated pig urine mentioned in step (1) is 1.03-1.

06.

3. The method for resource utilization of pig urine according to claim 1, characterized in that, In step (2), the mass ratio of concentrated pig urine to adsorption passivating agent is 100:3-5, and the stirring adsorption passivation time is 15-35 min. The preparation method of the adsorption passivating agent is as follows: S1. Preparation of phytic acid-intercalated montmorillonite: Montmorillonite was added to water, phytic acid and sodium dodecylbenzenesulfonate were added, the intercalation reaction was stirred, filtered, washed and dried to obtain phytic acid-intercalated montmorillonite. S2. Ferric chloride and ferrous chloride were added to water, and ammonia was added dropwise under inert gas protection. The mixture was heated and stirred to react, centrifuged, washed, dried, and calcined to obtain nano-Fe3O4. β-Cyclodextrin was added to Tris-HCl solution, along with nano-Fe3O4 and tannic acid. The mixture was heated and stirred to react, separated by a magnet, washed, and dried to obtain nano-Fe3O4 modified β-Cyclodextrin. S3. Phytic acid-intercalated montmorillonite was added to water, along with dipotassium hydrogen phosphate, calixarene, and nano-ferric oxide-modified β-cyclodextrin. The mixture was subjected to hydrothermal reaction, magnetic separation, washing, and drying to obtain the adsorption passivating agent.

4. The method for resource utilization of pig urine according to claim 1, characterized in that, In step S1, the mass ratio of montmorillonite, phytic acid, and sodium dodecylbenzenesulfonate is 15-20:5-7:2-3, and the stirring and intercalation reaction time is 1-2 hours.

5. The method for resource utilization of pig urine according to claim 1, characterized in that, In step S2, the mass ratio of ferric chloride, ferrous chloride, and ammonia is 3.24:1.26:3-5, the calcination temperature is 500-600℃, and the time is 1-3 hours. The mass ratio of β-cyclodextrin, nano-ferric oxide, and tannic acid is 3-6:2-3:1-2. In step S3, the mass ratio of phytic acid-intercalated montmorillonite, dipotassium hydrogen phosphate, calixarene, and β-cyclodextrin is 10:0.5-1:1-2:3-4, the hydrothermal reaction temperature is 120-130℃, and the time is 20-24 hours.

6. The method for resource utilization of pig urine according to claim 1, characterized in that, In step (3), the mass ratio of passivated concentrated pig urine to biochar adsorbent is 10:2-3. The biochar adsorbent is prepared by crushing straw, heating it to 600-700℃, carbonizing it for 2-4 hours, adding the product to concentrated nitric acid for 20-30 minutes, filtering, washing, and drying to obtain pretreated biochar. The pretreated biochar is added to a Tris-HCl solution with pH = 8.5-9.5, and tannic acid is added. The mass of the tannic acid is 20-30 wt% of the pretreated biochar. The mixture is heated to 50-60℃, stirred for 3-5 hours, centrifuged, washed, and dried to obtain the biochar adsorbent.

7. The method for resource utilization of pig urine according to claim 1, characterized in that, The mass ratio of high-value pig urine, Chinese herbal medicine residue, and enzymatically hydrolyzed plant amino acid solution in step (4) is 20-40:15-22:30-55. The Chinese herbal medicine residue is the waste residue after extraction of South African leaves and / or Artemisia annua. The enzymatically hydrolyzed plant amino acid solution is the waste liquid from a monosodium glutamate factory. The fermentation bacteria are Bacillus subtilis or Bacillus licheniformis. The fermentation conditions are 20-25℃ and the time is 48-72h.

8. The method for resource utilization of pig urine according to claim 1, characterized in that, In step (5), the mass ratio of pig urine-fermented traditional Chinese medicine and adsorbent slow-release bacterial balls is 10:0.5-1. The preparation method of the adsorbent slow-release bacterial balls is as follows: T1. Add Taili biological agent to water, add sodium alginate and lecithin, stir and mix evenly, add to fish oil, emulsify, add calcium chloride, stir and mix evenly, solidify at room temperature, centrifuge, wash, dry, and obtain sodium alginate bacterial balls. T2. Add the high ammonia nitrogen adsorbent to Tris-HCl solution, add dopamine hydrochloride, heat and stir to react, centrifuge, wash, and dry to obtain the modified high ammonia nitrogen adsorbent; T3. Add the high ammonia nitrogen adsorbent to water, add sodium alginate bacterial balls, stir to adhere, filter, wash, and dry to obtain adsorption slow-release bacterial balls.

9. The method for resource utilization of pig urine according to claim 8, characterized in that, In step T1, the mass ratio of Taili biological agent, sodium alginate, lecithin, and calcium chloride is 3-5:8-10:0.5-1:0.2-0.

5. In step T2, the pH value of the Tris-HCl solution is 8.5-10. The mass ratio of the high ammonia nitrogen adsorbent to dopamine hydrochloride is 8-10:2-3. The temperature of the heating and stirring reaction is 45-55℃, and the time is 3-5 hours. In step T3, the mass ratio of the high ammonia nitrogen adsorbent to sodium alginate bacterial balls is 4-7:

10.

10. An organic fertilizer prepared by the method of pig urine resource utilization as described in any one of claims 1-9.

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