阅读说明：本技术 一种农业有机废弃物的处理方法 (Treatment method of agricultural organic waste ) 是由 张晓亮 王爱萍 方维 刘杰 廖友辉 施银 于 2020-08-18 设计创作，主要内容包括：本发明公开一种农业有机废弃物的处理方法,包括以下步骤：秸秆类废弃物粉碎后进行黄贮,同时添加白腐菌进行预发酵；将处理后秸秆类废弃物与畜禽粪便类废弃物作为底物搅拌接种细菌后,送入发酵罐体进行干式厌氧发酵,获得沼气及沼液沼渣；沼液沼渣经压滤后得到一级沼液和一级沼渣；向一级沼液添加有益菌,进一步分离出沼气后得到二级沼液,二级沼液进行好氧发酵制得生物叶面肥；一级沼渣与有益菌混合后送入发酵槽,经好氧发酵后得到二级沼渣,二级沼渣过筛,筛下物为生物有机肥,筛上物送回发酵罐体进行干式厌氧发酵；沼气提纯后制得生物天然气。该处理工艺既解决了农业废弃物不当处理造成的问题,又将农业废弃物的转化为附加值高的肥料、能源等。(The invention discloses a method for treating agricultural organic waste, which comprises the following steps: crushing straw wastes, then performing yellow storage, and simultaneously adding white rot fungi for pre-fermentation; stirring the treated straw wastes and the livestock and poultry manure wastes as substrates, inoculating bacteria, and then sending the substrates into a fermentation tank for dry anaerobic fermentation to obtain biogas and biogas slurry and biogas residues; filter pressing the biogas slurry and the biogas residues to obtain primary biogas slurry and primary biogas residues; adding beneficial bacteria into the first-stage biogas slurry, further separating out biogas to obtain second-stage biogas slurry, and performing aerobic fermentation on the second-stage biogas slurry to obtain a biological foliar fertilizer; mixing the primary biogas residues with beneficial bacteria, feeding the mixture into a fermentation tank, performing aerobic fermentation to obtain secondary biogas residues, sieving the secondary biogas residues, returning sieved biomass to a fermentation tank body for dry anaerobic fermentation; and purifying the biogas to obtain the biogas. The treatment process not only solves the problem caused by improper treatment of the agricultural wastes, but also converts the agricultural wastes into fertilizers, energy and the like with high added values.)

1. The method for treating the agricultural organic waste is characterized by comprising the following steps of:

s1, preprocessing, namely crushing straw wastes, performing yellow storage, and adding white rot fungi for pre-fermentation;

s2, performing dry anaerobic fermentation, namely stirring and inoculating bacteria by taking the straw wastes and the livestock and poultry manure wastes treated in the step S1 as substrates, and then feeding the substrates into a fermentation tank for dry anaerobic fermentation to obtain biogas and biogas slurry and biogas residues;

s3, performing dry-wet separation, and performing pressure filtration on the biogas slurry and the biogas residues to obtain primary biogas slurry and primary biogas residues;

s4, preparing a biological foliar fertilizer, feeding the primary biogas slurry obtained in the step S3 into a storage tank, adding beneficial bacteria, fermenting and digesting, further separating biogas to obtain secondary biogas slurry, and performing aerobic fermentation on the secondary biogas slurry to obtain the biological foliar fertilizer;

s5, preparing a bio-organic fertilizer, mixing the primary biogas residue obtained in the step S3 with beneficial bacteria, feeding the mixture into a fermentation tank for aerobic fermentation to obtain secondary biogas residue, sieving the secondary biogas residue, wherein the undersize product is the bio-organic fertilizer, and the oversize product returns to the step S2 for the next round of dry anaerobic fermentation;

s6, preparing natural gas, and purifying the biogas slurry obtained in the steps S2 and S4 to obtain the biogas.

2. The processing method according to claim 1, wherein in the step S1, the addition amount of the white rot fungi is 2-3% o of the straw waste.

3. The method as claimed in claim 1, wherein in step S2, the mass ratio of the livestock and poultry manure waste to the straw waste processed in step S1 is 1: 4.

4. The process according to claim 3, wherein in step S2, the bacteria are methanogens.

5. The process according to claim 4, wherein in step S2, the dry anaerobic fermentation temperature is 40-45 ℃, the pH is 6.8-7.2, the concentration of TS is 25-30%, the ratio of C/N in the substrate is 20-25: 1.

6. the treatment method according to claim 1, wherein in the step S3, the solid content of the primary biogas residue is 18-22%.

7. The treatment method of claim 1, wherein in the step S4, the beneficial bacteria comprise Trichoderma viride, Aspergillus oryzae and Bacillus subtilis, and the adding amount of the beneficial bacteria is 2-2.5% of the mass of the primary biogas slurry.

8. The process of claim 7, wherein in said step S4,

the temperature of the fermentation digestion is 55-65 ℃;

the temperature of the aerobic fermentation is 35-45 ℃, the pH value is 6.8-7.8, and the concentration of oxygen is 15-25%.

9. The process of claim 1, wherein in said step S5,

the beneficial bacteria comprise azotobacter chroococcum, phosphate solubilizing bacteria and potassium solubilizing bacteria, and the adding amount of the beneficial bacteria is 2-3 per mill of the mass of the first-level biogas residues;

the temperature of the aerobic fermentation is 50-55 ℃, the pH is 7.0-7.5, the concentration of oxygen is 20-28%, and the fermentation time is 24-48 h;

and the secondary biogas residues pass through a roller screen with the aperture of 1.0 mm.

10. The process of claim 1, wherein in step S6, the biogas has a methane content of 98% or more.

Technical Field

The invention relates to the field of agricultural wastes, in particular to a method for treating agricultural organic wastes.

Background

The agricultural organic waste in China has high yield, mainly relates to waste generated in the industries of agricultural production, agricultural processing, livestock and poultry breeding and the like, and mainly comprises straw waste and livestock and poultry excrement waste; at present, the comprehensive utilization and industrialization degree of agricultural wastes is low, the economic benefit is poor, and the like, for example, agricultural wastes with additional values and low conversion rate are directly returned to the field, low-quality fuels, feeds and the like, and a part of agricultural wastes are directly discarded or burned, so that not only is the ecological environment seriously damaged, but also a huge resource waste is caused;

in view of the above circumstances, it is highly desirable to develop a treatment process for agricultural organic wastes, which can not only solve the problems of resource waste and environmental damage caused by improper treatment of agricultural wastes, but also convert agricultural wastes into bio-organic fertilizers, energy sources and the like with high added values, utilization rates and conversion efficiencies, thereby realizing resource utilization of agricultural wastes.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a method for treating agricultural organic wastes, which takes crop straws as main raw materials and adopts pre-fermentation and dry anaerobic fermentation, so that the water consumption in the fermentation process is greatly reduced, the acid-producing bacteria and the methanogenic bacteria are ensured to grow properly in respective reaction zones, the gas production efficiency is improved, then biogas is purified for power generation, biogas slurry and biogas residues are respectively prepared into a bio-organic fertilizer and a bio-foliar fertilizer through aerobic fermentation, the problems of resource waste and environmental damage caused by improper treatment of the agricultural wastes are solved, the agricultural wastes are converted into the bio-organic fertilizer, energy and the like with high added value, utilization rate and conversion efficiency, and the resource utilization of the agricultural wastes is realized.

In order to achieve the purpose, the invention adopts the following technical scheme:

the method for treating the agricultural organic waste is characterized by comprising the following steps of:

s1, preprocessing, namely crushing straw wastes, performing yellow storage, and adding white rot fungi for pre-fermentation;

s2, performing dry anaerobic fermentation, namely stirring and inoculating bacteria by taking the straw wastes and the livestock and poultry manure wastes treated in the step S1 as substrates, and then feeding the substrates into a fermentation tank for dry anaerobic fermentation to obtain biogas and biogas slurry and biogas residues;

s3, performing dry-wet separation, and performing pressure filtration on the biogas slurry and the biogas residues to obtain primary biogas slurry and primary biogas residues;

s4, preparing a biological foliar fertilizer, feeding the primary biogas slurry obtained in the step S3 into a storage tank, adding beneficial bacteria, fermenting and digesting, further separating biogas to obtain secondary biogas slurry, and performing aerobic fermentation on the secondary biogas slurry to obtain the biological foliar fertilizer;

s5, preparing a bio-organic fertilizer, mixing the primary biogas residue obtained in the step S3 with beneficial bacteria, feeding the mixture into a fermentation tank for aerobic fermentation to obtain secondary biogas residue, sieving the secondary biogas residue, wherein the undersize product is the bio-organic fertilizer, and the oversize product returns to the step S2 for the next round of dry anaerobic fermentation;

s6, preparing natural gas, and purifying the biogas slurry obtained in the steps S2 and S4 to obtain the biogas.

Preferably, in the step S1, the addition amount of the white rot fungi is 2 to 3 per mill of the amount of the straw waste.

Preferably, in the step S2, the mass ratio of the livestock and poultry manure waste to the straw waste processed in the step S1 is 1: 4.

Preferably, in step S2, the bacteria are methanobacteria.

Preferably, in the step S2, the temperature of the dry anaerobic fermentation is 40-45 ℃, the pH value is 6.8-7.2, the concentration of TS is 25-30%, and the ratio of C/N in the substrate is 20-25: 1.

preferably, in the step S3, the solid content of the primary biogas residue is 18% to 22%.

Preferably, in the step S4, the beneficial bacteria include trichoderma viride, aspergillus oryzae and bacillus subtilis, and the adding amount of the beneficial bacteria is 2-2.5% of the mass of the primary biogas slurry.

Preferably, in the step S4,

the temperature of the fermentation digestion is 55-65 ℃;

the temperature of the aerobic fermentation is 35-45 ℃, the pH value is 6.8-7.8, and the concentration of oxygen is 15-25%.

Preferably, in the step S5,

the beneficial bacteria comprise azotobacter chroococcum, phosphate solubilizing bacteria and potassium solubilizing bacteria, and the adding amount of the beneficial bacteria is 2-3 per mill of the mass of the first-level biogas residues;

the temperature of the aerobic fermentation is 50-55 ℃, the pH is 7.0-7.5, the concentration of oxygen is 20-28%, and the fermentation time is 24-48 h;

and the secondary biogas residues pass through a roller screen with the aperture of 1.0 mm.

Preferably, in the step S6, the content of methane in the biogas is greater than or equal to 98%.

The invention has the beneficial effects that:

1. the method for treating the agricultural organic wastes takes crop straws as main raw materials, adopts pre-fermentation and dry anaerobic fermentation, greatly reduces the water consumption in the fermentation process, ensures that acid-producing bacteria and methanogen are suitable for growing in respective reaction areas, improves the gas production efficiency, purifies the methane for power generation, and prepares biogas slurry and biogas residues into a biological organic fertilizer and a biological foliar fertilizer through aerobic fermentation respectively;

2. the method for treating the agricultural organic waste solves the problems of resource waste and environmental damage caused by improper treatment of the agricultural waste, converts the agricultural waste into biological organic fertilizer, energy and the like with high added value, utilization rate and conversion efficiency, and realizes resource utilization of the agricultural waste;

3. according to the method for treating the agricultural organic waste, only a small amount of biogas slurry is generated, and the biological foliar fertilizer is obtained after the beneficial bacteria and aerobic fermentation are added, so that the problem that a large amount of biogas slurry is difficult to treat in the fermentation process is effectively solved.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

fig. 1 is a process flow chart of the method for treating agricultural organic waste according to the embodiment.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way.

As shown in fig. 1, the method for treating agricultural organic waste provided by this embodiment includes the following steps:

s1, pretreatment

Crushing straw wastes into crushed materials with the particle size of less than 10mm by a crusher, directly performing yellow storage, adding white rot fungi during the yellow storage for pre-fermentation, and performing the yellow storage and the pre-fermentation at the same time at normal temperature; the sufficient supply of the straw waste is ensured, the time required by the lignin decomposition of the straw waste is saved, and the feasibility of long-term operation of a biogas project is ensured; wherein the addition amount of the white rot fungi is 2-3 per mill of the mass of the straw wastes.

In the process, the crushed straw waste is treated and stored in a yellow storage mode, the crushed straw waste is compacted by adding bacteria, the interior of the crushed straw waste forms an anaerobic state, and the straw waste is automatically fermented, decomposed and produced acid in the yellow storage process.

S2, Dry anaerobic fermentation

Taking the straw waste and the livestock and poultry manure waste treated in the step S1 as substrates, stirring and inoculating bacteria, sending into a fermentation tank, and carrying out fermentation at the temperature of 40-45 ℃ (a closed hot water circulation system is required to be arranged in a reactor structure in winter to ensure the temperature to be 40-45 ℃), the pH value to be 6.8-7.2, the concentration of TS (sulfur transport stream) to be 25-30%, and the C/N ratio in the substrates to be 20-25: 1, performing dry anaerobic fermentation under the condition of obtaining biogas and biogas slurry and biogas residues;

wherein the mass ratio of the livestock and poultry excrement waste to the straw waste treated in the step S1 is 1: 4; the bacteria are methane bacteria;

in the process, dry-type biogas anaerobic fermentation equipment is adopted, straw waste and livestock and poultry manure waste are subjected to fermentation treatment, the concentration of TS, the fermentation temperature and the pH value of biogas slurry can be well controlled, an acid-producing phase and a methane-producing phase are respectively carried out in different reaction zones, the suitable growth environment of acid-producing bacteria and methane-producing bacteria in respective reaction zones is ensured, the complementary and synergistic effects between the acid-producing bacteria and the methane-producing bacteria are enhanced, and the gas-producing efficiency is improved; in the process, straw waste is used as a raw material, and dry-type biogas anaerobic fermentation equipment is adopted, so that the water consumption in the fermentation process is greatly reduced, and the water resource is saved, therefore, only a small amount of biogas slurry is (relatively) generated in the process, and the biogas slurry is changed into a biological foliar fertilizer after aerobic fermentation, so that the problem that a large amount of biogas slurry is difficult to treat is effectively solved;

s3, carrying out dry-wet separation,

filter-pressing the biogas slurry and the biogas residues by a filter press to obtain primary biogas slurry and primary biogas residues; wherein the solid content of the first-stage biogas residue is 18-22%.

S4, preparing biological foliar fertilizer

Feeding the primary biogas slurry obtained in the step S3 into a storage tank, adding beneficial bacteria, fermenting and digesting at the temperature of 55-65 ℃, further separating biogas to obtain secondary biogas slurry, and feeding the biogas into a biogas storage chamber at the upper part of the storage tank; the secondary biogas slurry is left in a biogas slurry storage tank at the lower part of the storage tank; feeding the secondary biogas slurry into a liquid surface fertilizer workshop, and carrying out aerobic fermentation under the conditions that the temperature is 35-45 ℃, the pH is 6.8-7.8 and the concentration of oxygen is 18-25% to prepare a biological foliar fertilizer;

the beneficial bacteria comprise trichoderma viride, aspergillus oryzae and bacillus subtilis, and the adding amount of the beneficial bacteria is 2-2.5 per mill of the mass of the primary biogas slurry; the temperature of fermentation digestion is 55-65 ℃;

s5, preparing the bio-organic fertilizer

Mixing the primary biogas residue obtained in the step S3 with beneficial bacteria, then sending the mixture into a fermentation tank for aerobic fermentation, fermenting for 24-48 h under the conditions that the temperature is 50-55 ℃, the pH is 7.0-7.5 and the concentration of oxygen is 20-28%, releasing water vapor, reducing the material temperature, supplementing oxygen and further mixing to obtain secondary biogas residue, passing the secondary biogas residue through a rolling sieve with the aperture of 1.0mm, wherein the undersize is a biological organic fertilizer, and the oversize returns to the step S2 for the next round of dry anaerobic fermentation;

the beneficial bacteria comprise azotobacter chroococcum, phosphate-solubilizing bacteria and potassium-solubilizing bacteria, and the adding amount of the beneficial bacteria is 2-3 per mill of the mass of the first-grade biogas residues.

S6, preparation of biogas

And (4) purifying the biogas slurry obtained in the step S2 and the step S4 to obtain the biogas, wherein the content of methane in the biogas is more than or equal to 98%, and the biogas can provide power for urban new energy.

In the method, each determination index of the obtained biological foliar fertilizer conforms to the standard of foliar fertilizer containing organic matters (GB/T17419-2018);

in the method, all indexes of the obtained biological organic fertilizer meet the national industrial standard (NY 525 + 2012) of organic fertilizer and the agricultural industrial standard (NY884 + 2004) of the people's republic of China.