CN115650776A - A Composting Method for Reducing Antibiotic Resistance Genes in Biogas Residue Organic Fertilizer - Google Patents

Abstract

The invention provides a composting method for reducing antibiotic resistance genes in biogas residue organic fertilizer, which comprises the following steps: s1, a step: mixing biogas residue, biogas slurry and the corrosion-promoting mature residue material, drying, and crushing to obtain mixed residue material particles; and S2, a step: adding a zymophyte solution into the mixed slag charge particles, and performing first-stage fermentation to obtain semi-fermented mixed particles; and S3, a step: adding biogas slurry into the semi-fermented mixed particles, fermenting, aging and spreading and drying in the air in the second stage. Before fermentation, the corrosion-promoting mature slag materials are respectively mixed with the biogas residues and the biogas slurry, and then the bacteria liquid is added for fermentation, so that the fermentation process can be effectively promoted, and complete fermentation is facilitated. And adding biogas slurry again in the fermentation process of the mixed slag particles, continuing fermentation, and aging and spreading and drying in the air, so that the abundance of antibiotic resistance genes in the obtained biogas residue organic fertilizer can be effectively reduced, and the harmlessness of biogas residues and the recycling of biogas slurry are realized.

Description

A Composting Method for Reducing Antibiotic Resistance Genes in Biogas Residue Organic Fertilizer

technical field

The invention belongs to the technical field of biogas residue fertilizers, and in particular relates to a composting method for reducing antibiotic resistance genes in biogas residue organic fertilizers.

Background technique

In recent years, my country's large-scale pig raising has developed rapidly, and the traditional rural pig raising retail households have decreased sharply, while intensive and specialized pig raising enterprises have increased year by year. It is estimated that the current annual output of large-scale pig farms in my country accounts for more than 70% of the total output. At the same time, the large-scale pig raising model has also brought new problems such as excessive concentration of manure and a large increase in flushing sewage. At present, the more common way to deal with these problems is to collect the full amount of livestock manure from large-scale pig farms, and then anaerobic fermentation to produce biogas. Biogas residue is the residue produced by anaerobic fermentation of aquaculture manure in a biogas digester or fermentation tank. Biogas residue is rich in organic matter, nutrients and enzymes, which can promote the growth of crops. Compared with chemical Fertilizer, biogas residue can fertilize the soil and improve the physical and chemical properties of the soil. It is a high-quality organic fertilizer.

However, biogas residues contain a large number of antibiotic resistance genes (ARGs), which cannot be completely eliminated through anaerobic fermentation, and a large number of ARGs still remain. Therefore, the organic fertilizer produced by aerobic composting using biogas residues will also contain a large amount of ARGs. The application of such organic fertilizer to the soil will endanger the soil environment, and may endanger human health after entering the food chain. More and more studies have detected the presence of ARGs in food-borne animals, vegetables, and drinking water. The enrichment of ARGs in the human body will eventually lead to drug resistance of the human intestinal flora, resulting in various intestinal diseases, and most of these diseases need to be treated with antibiotics, which will accelerate the exchange frequency of ARGs between humans and the environment, followed by The emergence of bacterial multidrug resistance and superbugs has also attracted people's attention.

In order to realize the harmless treatment of biogas residues, reduce the content of antibiotic resistance genes in biogas residue organic fertilizers, and control the risk of spreading antibiotic resistance genes, these are technical problems that need to be solved urgently in the production of biogas residue organic fertilizers.

Contents of the invention

Therefore, the object of the present invention is to solve the problem that the content of antibiotic resistance gene in the biogas residue organic fertilizer that the composting method in the prior art obtains is higher, and then provide a kind of composting method that reduces the antibiotic resistance gene in the biogas residue organic fertilizer .

The invention provides a composting method for reducing antibiotic resistance genes in biogas residue organic fertilizer, comprising the steps of:

Step S1: mixing biogas residue, biogas slurry and decomposition-promoting slag, drying, and pulverizing to obtain mixed slag particles;

Step S2: adding a fermentation bacteria solution to the mixed slag material particles, and undergoing the first stage of fermentation to obtain semi-fermented mixed particles;

Step S3: adding biogas slurry to the semi-fermented mixed granules, undergoing the second stage of fermentation, aging, and spreading to air.

Further, in the S1 step, the mass ratio of the biogas residue, the biogas slurry, and the decomposition-promoting residue is: 300-400:400-500:150-250.

Further, step S1 includes: mixing the biogas residue with the decay-promoting residue to obtain a first mixture, mixing the biogas slurry with the decay-promoting residue to obtain a second mixture, mixing the first mixture with the second mixture, drying and pulverizing , to obtain mixed slag particles.

Further, the mass ratio of biogas residue and decay-promoting residue in the first mixture is 300-400:50-100; the mass ratio of biogas slurry and decay-promoting residue in the second mixture is 400-500:100-150; the first mixture The mass ratio of the decomposing slag to the second mixture is 1:1-3.

Further, the particle size of the pulverized mixed slag particles is 0.2cm-0.5cm.

Further, in step S3, the mass ratio of semi-fermented mixed residue particles to biogas slurry is 800-1000:100-150.

Further, the slag for promoting decomposition is at least one of wood chips, mushroom slag and traditional Chinese medicine slag.

Further, in the S2 step, in the S2 step, the first-stage fermentation time is 5-15 days, preferably 5-7 days, and the second-stage fermentation time is 5-10 days, preferably 7-10 days .

Further, during the fermentation process, the piles are turned every 3-5 days.

Further, the total aging time is 15-30 days, and the pile is turned every 8-10 days during the aging process; the moisture content of the fermented pile obtained after being spread out to air is 30%-35%.

The present invention also provides biogas residue organic fertilizer base material prepared according to any one of the above-mentioned composting methods.

The technical solution of the present invention has the following advantages:

1. The preparation method of the biogas residue organic fertilizer base material provided by the present invention comprises, S1 step: take biogas residue, biogas slurry and mix with the decomposition-promoting residue material, dry, pulverize, obtain the mixed residue material particle; S2 step: add mixed residue Add fermentation bacteria solution to the material granules to carry out the first-stage fermentation; Step S3: add biogas slurry to the semi-fermented mixed granules to carry out the second-stage fermentation, aging, and spreading to dry. Before fermentation, the decomposition-promoting slag is mixed with biogas residue and biogas slurry, which is conducive to the thorough mixing of materials; then adding bacterial liquid for fermentation can effectively promote the fermentation process; adding biogas slurry again during the mixed particle fermentation process, Then continue to ferment, and after aging and air-drying treatment, the abundance of antibiotic resistance genes in the obtained biogas residue organic fertilizer can be effectively reduced, and the biogas residue can be harmless and the biogas slurry can be recycled as a resource.

2. The preparation method of biogas residue organic fertilizer base material provided by the present invention, by controlling the mass ratio of biogas residue and decay-promoting residue in the first mixture to 300-400:50-100; in the second mixture, biogas slurry and decay-promoting residue The mass ratio of the biogas residue is 400-500:100-150; the mass ratio of the first mixture to the second mixture is 1:1-3, which can effectively control the water content of the biogas residue and further accelerate the fermentation speed of the biogas residue , Improving the completeness of biogas residue fermentation can more effectively reduce the resistance genes in biogas residue.

3. The preparation method of the biogas residue organic fertilizer base material provided by the present invention, by optimizing the fermentation time of the first stage and the second stage fermentation and the interval between turning over during fermentation, or limiting the aging time and the interval between turning over during aging, And controlling the moisture content of the heap after drying can further improve the completeness of the fermentation of the biogas residue, increase the amount of metabolites, and improve the quality of the biogas residue organic fertilizer.

Detailed ways

In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments. This invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concept of the invention to those skilled in the art, and the present invention will only be defined by the appended claims. Biogas residues, biogas slurry, wood chips, and mushroom residues were all provided by Jiangxi Zhenghe Ecological Agriculture Co., Ltd., and their physical and chemical properties are shown in Table 1.

Table 1 physical and chemical properties

materials pH Organic carbon g/kg Total nitrogen g/kg Total phosphorus g/kg Total potassium g/kg Biogas residue 8.14 183.5 3.2 3.8 0.9 biogas slurry 7.73 9.2 1.0 0.7 0.5 sawdust 6.84 57.4 1.3 0.9 0.7 Mushroom residue 8.02 284.4 14.1 6.5 10.3

Example 1

The present embodiment provides a kind of composting method for reducing the antibiotic resistance gene in biogas residue organic fertilizer, comprises the steps:

Step S1: uniformly mix 350kg biogas residue and 50kg sawdust to obtain the first mixture, uniformly mix 450kg biogas slurry and 150kg sawdust to obtain the second mixture, mix the first mixture and the second mixture, dry and pulverize to obtain the average particle size Mixed slag particles with a diameter of 0.3cm;

S2 step: add 10kg fermented bacteria solution (the fermented bacteria solution is the composite bacteria of yeast, bacillus subtilis and lactic acid bacteria that mass ratio is 1:1:1 in the mixed slag material particle, fermented bacteria solution is that mass concentration is 5% fermentation Bacteria solution aqueous solution), carry out the first-stage fermentation, the time is 5 days, obtains semi-fermented mixed granule;

Step S3: Spray 150 kg of biogas slurry into the semi-fermented mixed granules, carry out the second stage of fermentation for 10 days, and then carry out aging and airing to obtain biogas residue organic fertilizer. The total time of fermentation is 15 days, and the pile is turned every 3 days during the fermentation process; the total time of aging is 25 days, and the pile is turned every 8 days during the aging process; The content is 33wt% to obtain biogas residue organic fertilizer.

Example 2

The present embodiment provides a kind of composting method for reducing the antibiotic resistance gene in biogas residue organic fertilizer, comprises the steps:

Step S1: uniformly mix 400kg biogas residue and 50kg mushroom residue to obtain the first mixture, uniformly mix 450kg biogas slurry and 100kg mushroom residue to obtain the second mixture, mix the first mixture and the second mixture, dry and pulverize to obtain Mixed slag particles with an average particle size of 0.3cm;

S2 step: add 10kg fermented bacteria solution (the fermented bacteria solution is the composite bacteria of yeast, bacillus subtilis and lactic acid bacteria that mass ratio is 1:1:1 in the mixed slag material particle, fermented bacteria solution is that mass concentration is 5% fermentation Bacteria solution aqueous solution), carry out the first-stage fermentation, the time is 5 days, obtains semi-fermented mixed granule;

Step S3: Spray 150 kg of biogas slurry into the semi-fermented mixed granules, carry out the second stage of fermentation for 10 days, and then carry out aging and airing to obtain biogas residue organic fertilizer. The total time of fermentation is 15 days, and the pile is turned every 3 days during the fermentation process; the total time of aging is 25 days, and the pile is turned every 8 days during the aging process; The content is 33wt% to obtain biogas residue organic fertilizer.

Example 3

A kind of composting method for reducing the antibiotic resistance gene in the biogas residue organic fertilizer provided by the present embodiment comprises the following steps:

Step S1: uniformly mix 350kg biogas residue and 50kg sawdust to obtain the first mixture, uniformly mix 450kg biogas slurry and 150kg sawdust to obtain the second mixture, mix the first mixture and the second mixture, dry and pulverize to obtain the average particle size Mixed slag particles with a diameter of 0.3cm;

S2 step: add 10kg fermented bacteria solution (the fermented bacteria solution is the composite bacteria of yeast, bacillus subtilis and lactic acid bacteria that mass ratio is 1:1:1 in the mixed slag material particle, fermented bacteria solution is that mass concentration is 5% fermentation Bacteria solution aqueous solution), carry out the first-stage fermentation, the time is 15 days, obtains semi-fermented mixed granule;

Step S3: Spray 150 kg of biogas slurry into the semi-fermented mixed granules to carry out the second stage of fermentation for 5 days, and then carry out aging and airing to obtain biogas residue organic fertilizer. The total time of fermentation is 20 days, and the pile is turned every 3 days during the fermentation process; the total time of aging is 25 days, and the pile is turned every 8 days during the aging process; The content is 33wt% to obtain biogas residue organic fertilizer.

Example 4

A kind of composting method for reducing the antibiotic resistance gene in the biogas residue organic fertilizer provided by the present embodiment comprises the following steps:

Step S1: Mix 350kg biogas residue, 200kg sawdust and 450kg biogas slurry evenly, dry and pulverize to obtain mixed slag particles with an average particle size of 0.3cm;

S2 step: add 10kg fermented bacteria solution (the fermented bacteria solution is the composite bacteria of yeast, bacillus subtilis and lactic acid bacteria that mass ratio is 1:1:1 in the mixed slag material particle, fermented bacteria solution is that mass concentration is 5% fermentation Bacteria solution aqueous solution), carry out the first-stage fermentation, the time is 5 days, obtains semi-fermented mixed granule;

Step S3: Spray 150 kg of biogas slurry into the semi-fermented mixed granules, carry out the second stage of fermentation for 10 days, and then carry out aging and airing to obtain biogas residue organic fertilizer. The total time of fermentation is 15 days, and the pile is turned every 3 days during the fermentation process; the total time of aging is 25 days, and the pile is turned every 8 days during the aging process; The content is 33wt% to obtain biogas residue organic fertilizer.

Comparative example 1

This comparative example provides a kind of composting method for reducing antibiotic resistance gene in biogas residue organic fertilizer, comprises the steps:

Step S1: uniformly mix 350kg biogas residue and 50kg sawdust to obtain the first mixture, uniformly mix 450kg biogas slurry and 150kg sawdust to obtain the second mixture, mix the first mixture and the second mixture, dry and pulverize to obtain the average particle size Mixed slag particles with a diameter of 0.3cm;

S2 step: add 10kg fermented bacteria solution (the fermented bacteria solution is the composite bacteria of yeast, bacillus subtilis and lactic acid bacteria that mass ratio is 1:1:1 in the mixed slag material particle, fermented bacteria solution is that mass concentration is 5% fermentation Bacteria solution aqueous solution), fermented, aged and air-dried to obtain biogas residue organic fertilizer. The fermentation time is 15 days, and the piles are turned every 3 days during the fermentation process; the total aging time is 25 days, and the piles are turned every 8 days during the aging process; the moisture content of the fermentation piles obtained after spreading 33wt% to obtain biogas residue organic fertilizer.

Comparative example 2

This comparative example provides a kind of composting method for reducing antibiotic resistance gene in biogas residue organic fertilizer, comprises the steps:

Step S1: uniformly mix 350kg biogas residue and 50kg sawdust to obtain the first mixture, uniformly mix 450kg biogas slurry and 150kg sawdust to obtain the second mixture, mix the first mixture and the second mixture, dry and pulverize to obtain the average particle size Mixed slag particles with a diameter of 0.3cm;

S2 step: add 10kg fermented bacteria solution (the fermented bacteria solution is the composite bacteria of yeast, bacillus subtilis and lactic acid bacteria that mass ratio is 1:1:1 in the mixed slag material particle, fermented bacteria solution is that mass concentration is 5% fermentation Bacteria solution aqueous solution) and 150kg biogas slurry were fermented, aged and aired to obtain biogas residue organic fertilizer. The fermentation time is 15 days, and the piles are turned every 3 days during the fermentation process; the total aging time is 25 days, and the piles are turned every 8 days during the aging process; the moisture content of the fermentation piles obtained after spreading 33wt% to obtain biogas residue organic fertilizer.

Experimental example 1

SPIN Kit for feces试剂盒(MPBiomedicals，CA，USA)提取，具体方法和步骤依据试剂盒说明书进行。然后使用

DNA Clean-up Kit(MoBio,CA，USA)对提取的总DNA进行纯化。提取的DNA浓度与质量(OD260/OD280)采用NanoDrop ND-1000分光光度计(NanoDrop Technologies,DE,USA)进行检测。采用实时荧光定量PCR(qPCR)方法对沼渣有机肥中的ARGs进行表征。对4类10个ARGs进行qPCR检测，即四环素类ARGs(tetX、tetT、tetM、tetG)，磺胺类ARGs(sul2、sul1)，喹诺酮类ARGs(qnrD、qnrB)，大环内脂类ARGs(ermB、ermA)。Test the abundance of antibiotic resistance genes (ARGs) in the biogas residue organic fertilizer that each embodiment and comparative example obtain, and test method is respectively as follows: Genome of biogas residue organic fertilizer uses

The SPIN Kit for feces kit (MPBiomedicals, CA, USA) was used for extraction, and the specific methods and steps were carried out according to the kit instructions. then use

DNA Clean-up Kit (MoBio, CA, USA) was used to purify the extracted total DNA. The concentration and quality (OD260/OD280) of extracted DNA were detected by NanoDrop ND-1000 spectrophotometer (NanoDrop Technologies, DE, USA). ARGs in biogas residue organic fertilizer were characterized by real-time fluorescent quantitative PCR (qPCR). qPCR detection was performed on 10 ARGs of 4 categories, namely tetracycline ARGs (tetX, tetT, tetM, tetG), sulfonamide ARGs (sul2, sul1), quinolone ARGs (qnrD, qnrB), macrolide ARGs (ermB , ermA).

The biogas residue organic fertilizer antibiotic resistance gene abundance that table 2 embodiment, comparative example make

The results are shown in Table 2. Compared with Comparative Example 1 and Comparative Example 2, the biogas residue organic fertilizer of Examples 1-4 of the present invention can significantly reduce tetracycline antibiotics, sulfonyl antibiotics, quinolone antibiotics, macrocyclic Total abundance of lactone antibiotic resistance genes. Moreover, compared with mushroom slag, wood chips as a slag material for promoting decomposition have a better effect on reducing antibiotic resistance genes in biogas residue organic fertilizers.

By comparing Example 1 with Example 3, it can be seen that in Example 1, controlling the fermentation time of the first stage and the second stage in the preferred range of the present invention can further reduce the abundance of biogas residue organic fertilizer antibiotic resistance genes.

From the comparison of Example 1 and Example 4, it can be seen that in Example 1, the abundance of antibiotic resistance genes can be further reduced by adopting the preferred method to prepare mixed slag particles.

Apparently, the above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or changes derived therefrom are still within the scope of protection of the present invention.

Claims (10)

1. A composting method for reducing antibiotic resistance genes in biogas residue organic fertilizer is characterized by comprising the following steps:

s1, a step: mixing biogas residue, biogas slurry and the corrosion-promoting mature residue material, drying, and crushing to obtain mixed residue material particles;

and S2, a step: adding a zymophyte solution into the mixed slag charge particles, and performing first-stage fermentation to obtain semi-fermented mixed particles;

and S3, a step: adding biogas slurry into the semi-fermented mixed particles, fermenting, aging and spreading and drying in the air in the second stage.

2. A composting method as claimed in claim 1, characterised in that the step S1 comprises mixing biogas residue with a decay-promoting slag charge to obtain a first mixture, mixing first biogas slurry with a decay-promoting slag charge to obtain a second mixture, mixing the first mixture with the second mixture, drying and comminuting to obtain mixed slag charge particles.

3. A composting method as claimed in claim 2, characterised in that the mass ratio of biogas residue to the pro-rotting slag material in the first mixture is 300-400:50-100, wherein the mass ratio of the biogas slurry to the decomposition promoting slag charge in the second mixture is 400-500:100-150, wherein the mass ratio of the decomposed slag promoting materials in the first mixture to the second mixture is 1:1-3.

4. A composting method as claimed in any one of the claims 1-3, characterised in that the particle size of the crushed mixed slag particles is between 0.2cm and 0.5cm.

5. A composting method as claimed in any one of claims 1-4, characterised in that in step S3, the mass ratio of semi-fermented mixed slag particles to biogas slurry is 800-1000:100-150.

6. A composting method as claimed in any one of claims 1-5, characterised in that the digestion promoting clinker is at least one of wood chips, mushroom residue and chinese herb residue.

7. A composting method as claimed in any of the claims 1-6, characterised in that in step S2 the fermentation time in the first stage is 5-15 days, preferably 5-7 days, and the fermentation time in the second stage is 5-10 days, preferably 7-10 days.

8. A composting method as claimed in any of the claims 1-7, characterised in that the pile is turned over every 3-5 days during the fermentation.

9. A composting method as claimed in any of the claims 1-8, characterised in that the total time of ageing is 15-30 days, the stack is turned over every 8-10 days during ageing, and the moisture content of the fermented stack obtained after spreading out is 30-35%.

10. A biogas residue organic fertilizer prepared by the composting method as claimed in any one of claims 1 to 9.