Advanced treatment device based on biogas slurry and treatment method thereof

Abstract

The invention discloses an advanced treatment device based on biogas slurry and a treatment method thereof. The advanced treatment device comprises a homogenizing tank and a hydrolysis tank which are arranged side by side; the anaerobic fermentation tank is respectively connected with the output ends of the homogenizing tank and the hydrolysis tank through pipelines so as to ferment the mixture, and the output end of the anaerobic fermentation tank is connected with a solid-liquid separator for separating a fermented product; the biogas residue collector is arranged at the output end of the solid-liquid separator and is used for collecting biogas residues to form a solid fertilizer; according to the biogas slurry, ammonia nitrogen, phosphorus and suspended matter pollutants in the biogas slurry are effectively removed through multiple methods such as physical, chemical and biological methods, pollution of the pollutants to soil, surface water and underground water is reduced, methane and carbon dioxide are generated through anaerobic fermentation of the biogas slurry and can be effectively collected and utilized through follow-up separation and liquefaction, and the biogas slurry is recycled. And after deep treatment, the remaining biogas slurry can be made into treated biogas slurry to be sold as an organic fertilizer, so that the resource utilization of wastes is realized, and the sustainable development of economy is promoted.

Description

Technical Field

[0001] The present invention specifically relates to a biogas slurry-based deep treatment device and a treatment method thereof. Background Art

[0002] As an important product in the process of agricultural waste treatment, biogas slurry is rich in organic matter and nutrients, such as nitrogen, phosphorus, potassium, and various trace elements and bioactive substances such as hydrolases, amino acids, and organic acids. These ingredients have multiple effects on crop growth, prevention and control of crop diseases, and improvement of soil properties. However, biogas slurry also contains heavy metal ions, organic pollutants, antibiotics, high base components, and biogas fermentation raw materials may contain pathogenic microorganisms. If biogas slurry is directly applied to farmland without sufficient treatment or improper treatment, it may cause pathogenic microorganisms to spread in the environment and increase the risk of disease outbreaks. In order to facilitate the use of farmland, biogas slurry treatment processes mainly include: natural precipitation method, fermentation treatment method, and bioactive agent modification method.

[0003] The existing natural sedimentation method has a long treatment cycle and is unable to remove harmful substances, tiny particles and microorganisms dissolved in the biogas slurry. The key to the fermentation treatment method is the precise control of the fermentation conditions. Too high or too low temperature may inhibit the activity of microorganisms, slow down the fermentation process, and even lead to fermentation failure. The control of humidity is related to the stability of the fermentation environment. Fermentation treatment cannot remove pollutants in the biogas slurry very well. Although the biosurfactant modification method can improve the structure and properties of the biogas slurry, it is not effective in removing harmful substances in the biogas slurry. It also requires professional microorganisms and biosurfactant technologies, and has a high technical threshold. For this reason, we propose a deep treatment device based on biogas slurry and a treatment method thereof. Summary of the invention

[0004] The purpose of the present invention is to provide a deep treatment device based on biogas slurry and a treatment method thereof, so as to solve the problems that the natural sedimentation method proposed in the above background technology cannot remove harmful substances, tiny particles and microorganisms dissolved in the biogas slurry, the fermentation treatment method has great difficulty in controlling temperature and humidity and cannot remove harmful substances in the biogas slurry, and the bioactive agent modification method has poor removal effect on harmful substances in the biogas slurry and has great technical difficulty.

[0005] To achieve the above object, the present invention provides the following technical solution: a biogas slurry deep treatment device, comprising:

[0006] A homogenization tank and a hydrolysis tank, wherein the homogenization tank and the hydrolysis tank are arranged side by side;

[0007] An anaerobic fermentation tank is connected to the output ends of the homogenization tank and the hydrolysis tank through pipelines to ferment the mixture, and the output end of the anaerobic fermentation tank is connected to a solid-liquid separator for separating the fermented product;

[0008] A biogas residue collector is arranged at the output end of the solid-liquid separator to collect the biogas residue to form solid fertilizer;

[0009] A sedimentation tank is arranged at the other output end of the solid-liquid separator to precipitate and purify the biogas slurry;

[0010] A flocculant processing module is arranged at the output end of the sedimentation tank to process the flocculants after precipitation;

[0011] The biogas slurry treatment module is arranged at the other output end of the sedimentation tank to treat the biogas slurry to form liquid fertilizer.

[0012] Preferably, the floc processing module includes a floc collection tank, a centrifuge and a flocculant regeneration tank, the input end of the floc collection tank is connected to the output end of the sedimentation tank, the output end of the floc collection tank is connected to the centrifuge, the output end of the centrifuge is connected to the input end of the sludge collector through a pipeline to transport the sludge to the sludge collector, and the other output end of the centrifuge is connected to the flocculant regeneration tank for regenerating the flocculant.

[0013] Preferably, the output end of the flocculant regeneration tank is connected to the flocculant input end of the sedimentation tank.

[0014] Preferably, the biogas slurry treatment module comprises a filter, a plasma reactor and a membrane separator, the filter is connected to the other output end of the sedimentation tank, and the output end of the filter is provided with a plasma reactor, and one end of the plasma reactor is provided with a membrane separator for separating and concentrating the biogas slurry to form liquid fertilizer.

[0015] Preferably, an evaporation tank for preliminary concentration of the biogas slurry is provided between the plasma reactor and the membrane separator.

[0016] Preferably, the membrane material used in the membrane separator is tetrafluoroethylene.

[0017] Preferably, the other output end of the filter is connected to a floc processing module.

[0018] Preferably, the anaerobic fermentation tank is provided with a first connecting pipe connected to an external gas purification module to process the fermentation gas.

[0019] A biogas slurry deep treatment device and a treatment method thereof, comprising the following steps:

[0020] Step A: pre-treating the organic waste, and then passing the treated material into an anaerobic fermentation tank for fermentation, and collecting and processing the fermented biogas residue to form solid fertilizer;

[0021] Step B: The fermented biogas slurry enters the sedimentation tank for sedimentation, and the sediment is processed to form biogas residue and regenerated flocculant, and the regenerated flocculant is put back into the sedimentation tank for use;

[0022] Step C: The precipitated liquid is processed in sequence through a filter, a plasma reactor and a membrane separator to form liquid fertilizer.

[0023] A biogas slurry deep treatment device and a treatment method thereof, comprising the following detailed steps;

[0024] Step A: livestock manure enters a homogenization tank and is added with water to form a suspended solid. The straw is crushed and then enters a hydrolysis tank for acidification. Some macromolecular organic matter is decomposed into small molecular organic matter by the action of hydrolases. The two raw materials are pretreated and mixed and then enter an anaerobic fermentation tank for fermentation. The fermentation and decomposition gases are methane and carbon dioxide, which are collected from the top of the anaerobic fermentation tank and enter a purification module to finally obtain LNG and liquid CO2. The biogas slurry and biogas residue are collected from the bottom of the anaerobic fermentation tank. The biogas residue is first separated by a solid-liquid separator and then collected by a biogas residue collector. Further processing can produce solid fertilizer.

[0025] Step B: The biogas slurry separated by the solid-liquid separator enters the sedimentation tank and is added with a flocculant. The suspended matter, colloidal particles and heavy metal ion pollutants in the sewage gradually aggregate to form larger flocs and settle under the action of gravity. The flocculants at the bottom of the sedimentation tank are collected by a flocculant collection tank, and active substances are added and the pH value in the flocculant collection tank is adjusted to redissolve the flocculant. The biogas residue is then separated from the dissolved flocculant by a centrifuge, and the solids are collected by a biogas residue collector. The flocculant enters the flocculant regeneration tank for evaporation and concentration to achieve cyclic regeneration;

[0026] Step C: After the biogas slurry leaves the sedimentation tank, it enters the filter for filtration to further reduce the insoluble substances in the biogas slurry, and then enters the plasma reactor. Under the action of plasma discharge, other types of macromolecular organic matter in the biogas slurry are further decomposed into small molecules, and pathogenic microorganisms in the biogas slurry are killed. The biogas slurry treated by the plasma reactor is transported to the evaporation tank for standing, and evaporation concentration is used to reduce the water content in the biogas slurry. After standing, the biogas slurry is pressurized and enters the membrane separator. Under the action of the membrane separator, the biogas slurry is further concentrated, and the concentrated liquid is collected to obtain the product liquid fertilizer. At the same time, the clear liquid output through the liquid outlet meets the pollutant emission standard.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] In this patent, the pollutants in the biogas slurry are effectively removed through various methods such as physical, chemical and biological methods, reducing its pollution to the soil, surface water and groundwater, which plays an important role in plant absorption and soil protection during the use of liquid fertilizer. The biogas slurry first produces methane and carbon dioxide through anaerobic fermentation, which can be effectively collected and utilized through subsequent separation and liquefaction. The remaining biogas slurry can be processed and sold as organic fertilizer after deep treatment, thus realizing the resource utilization of biogas waste and promoting the sustainable development of the economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the process of the present invention.

[0030] In the figure: 1. Homogenization tank; 2. Hydrolysis tank; 3. Anaerobic fermentation tank; 4. Solid-liquid separator; 5. Sludge collector; 6. Sedimentation tank; 7. Flocculant collection tank; 8. Centrifuge; 9. Flocculant regeneration tank; 10. Filter; 11. Plasma reactor; 12. Evaporation tank; 13. Membrane separator. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] See also Figure 1 The present invention provides a technical solution: a deep treatment device based on biogas slurry, comprising:

[0033] Homogenization tank 1 and hydrolysis tank 2 are arranged side by side, so that livestock manure can be added into homogenization tank 1, water can be added to form suspended matter, and the dispersion of raw materials can be increased. After the straw is crushed, it enters hydrolysis tank 2 for acidification, which improves biodegradability, decomposes macromolecular organic matter into small molecular organic matter, and promotes subsequent degradation;

[0034] The anaerobic fermentation tank 3 is connected to the output ends of the homogenization tank 1 and the hydrolysis tank 2 through pipelines to ferment the mixture, and the treated straw and livestock manure are mixed and fermented. The output end of the anaerobic fermentation tank 3 is connected to a solid-liquid separator 4 for separating the fermented product;

[0035] A biogas residue collector 5 is arranged at the output end of the solid-liquid separator 4 to collect the biogas residue to form solid fertilizer. The biogas liquid is separated from the biogas residue by the solid-liquid separator 4 and can be processed into solid fertilizer after passing through the biogas residue collector 5;

[0036] The sedimentation tank 6 is arranged at the other output end of the solid-liquid separator 4 to precipitate and purify the biogas slurry, so as to facilitate the contaminants such as suspended matter, colloidal particles and heavy metal ions in the biogas slurry to be aggregated into large flocs for sedimentation and separation, thereby improving the purification effect of the biogas slurry;

[0037] A flocculant processing module is arranged at the output end of the sedimentation tank 6 to process the precipitated flocculants to form biogas residue and regenerate the flocculant for use;

[0038] The biogas slurry processing module is arranged at the other output end of the sedimentation tank 6 to process the biogas slurry to form liquid fertilizer.

[0039] Preferably, the flocculant processing module includes a flocculant collecting tank 7, a centrifuge 8 and a flocculant regeneration tank 9. The input end of the flocculant collecting tank 7 is connected to the output end of the sedimentation tank 6. The output end of the flocculant collecting tank 7 is connected to the centrifuge 8. The output end of the centrifuge 8 is connected to the input end of the sludge collector 5 through a pipeline to transport the sludge to the sludge collector 5, so as to form the sludge to make solid fertilizer. The other output end of the centrifuge 8 is connected to the flocculant regeneration tank 9 for regenerating the flocculant, so as to facilitate the recycling and regeneration of the flocculant.

[0040] Preferably, the output end of the flocculant regeneration tank 9 is connected to the flocculant input end of the sedimentation tank 6 to facilitate the use of the regenerated flocculant.

[0041] Preferably, the biogas slurry treatment module includes a filter 10, a plasma reactor 11 and a membrane separator 13. The filter 10 is connected to the other output end of the sedimentation tank 6, and the output end of the filter 10 is provided with a plasma reactor 11. One end of the plasma reactor 11 is provided with a membrane separator 13 for separating and concentrating the biogas slurry to form liquid fertilizer, so as to concentrate the purified biogas slurry to form liquid fertilizer.

[0042] Preferably, an evaporation tank 12 for preliminarily concentrating the biogas slurry is provided between the plasma reactor 11 and the membrane separator 13, so as to better concentrate the biogas slurry.

[0043] Preferably, the membrane material used in the membrane separator 13 is tetrafluoroethylene.

[0044] Preferably, the other output end of the filter 10 is connected to a flocculant processing module to facilitate utilization of the filtered flocculants.

[0045] Preferably, the anaerobic fermentation tank 3 is provided with a first connecting pipe connected to an external gas purification module to process the fermentation gas, so as to facilitate the utilization of the gas generated by the fermentation.

[0046] A biogas slurry deep treatment device and a treatment method thereof, comprising the following steps:

[0047] Step A: pre-treating the organic waste, and then passing the treated material into the anaerobic fermentation tank 3 for fermentation, and collecting and processing the biogas residue after fermentation to form solid fertilizer;

[0048] Step B: The fermented biogas enters the sedimentation tank 6 for precipitation, and the precipitate is processed to form biogas residue and regenerated flocculant, and the regenerated flocculant is re-entered into the sedimentation tank 6 for use;

[0049] Step C: The precipitate is sequentially processed through a filter 10, a plasma reactor 11 and a membrane separator 13 to form liquid fertilizer.

[0050] A biogas slurry deep treatment device and a treatment method thereof, comprising the following detailed steps;

[0051] Step A: The livestock and poultry manure enters the homogenization tank 1 and is added with water to form a suspended solid, which is convenient for increasing the dispersion of the raw materials. After the straw is crushed, it enters the hydrolysis tank 2 for acidification, and some macromolecular organic matter is decomposed into small molecular organic matter by the action of hydrolases, which increases the difficulty of biomass degradation. The two raw materials are pretreated and mixed and enter the anaerobic fermentation tank 3 for fermentation. The fermentation temperature is controlled between 50-60°C. Under the action of methanogens, the small molecular substances such as acetic acid produced after the hydrolysis of the straw and livestock and poultry manure are further converted and decomposed. The fermented and decomposed gases are methane and carbon dioxide, which are collected from the top of the anaerobic fermentation tank 3 and enter the purification module to finally obtain LNG and liquid CO2. The biogas slurry and biogas residue are collected from the bottom of the anaerobic fermentation tank 3, and the biogas residue is first separated by the solid-liquid separator 4, and then collected by the biogas residue collector 5. Further processing can make solid fertilizer;

[0052] Step B: The biogas slurry separated by the solid-liquid separator 4 enters the sedimentation tank 6 and is added with a flocculant. The suspended matter, colloidal particles and heavy metal ion pollutants in the sewage gradually gather to form larger flocs and settle under the action of gravity. The flocculants at the bottom of the sedimentation tank 6 are collected by the flocculant collecting tank 7. Active substances are added and the pH value in the flocculant collecting tank 7 is adjusted to redissolve the flocculant. The biogas residue is separated from the dissolved flocculant by the centrifuge 8. The solids are collected by the biogas residue collector 5. The flocculant enters the flocculant regeneration tank 9 for evaporation and concentration to achieve cyclic regeneration.

[0053] Step C: After the biogas slurry leaves the sedimentation tank 6, it enters the filter 10 for filtration to further reduce the insoluble substances in the biogas slurry, and then enters the plasma reactor 11. Under the action of plasma discharge, other types of macromolecular organic matter in the biogas slurry are further decomposed into small molecules, and pathogenic microorganisms in the biogas slurry are killed, so that the nutrient content of the produced liquid fertilizer after deep treatment is more stable and easy to be absorbed and utilized by crops. The biogas slurry treated by the plasma reactor 11 is transported to the evaporation tank 12 for standing, and evaporation concentration is used to reduce the water content in the biogas slurry. After standing, the biogas slurry is pressurized to 1.5MPa and then enters the membrane separator 13. Under the action of the membrane separator 13, the biogas slurry is further concentrated, and the concentrated liquid is collected to obtain the product liquid fertilizer. At the same time, the clear liquid output from the permeate outlet meets the pollutant emission standard.

[0054] The biogas slurry deep treatment process of the present invention has the following advantages: 1. Environmentally friendly: biogas slurry is effectively removed of pollutants such as ammonia nitrogen, phosphorus, suspended matter, etc. through various methods such as physical, chemical and biological methods, reducing its pollution to soil, surface water and groundwater. By adopting advanced treatment processes and equipment, it is ensured that the indicators of the treated biogas slurry meet the national emission standards. 2. Improving the quality of liquid fertilizer production: through the combination of precipitation, plasma and membrane separation technology, the pollutants in the wastewater in the biogas slurry are oxidized and degraded under the high energy of plasma, and the heavy metal ions undergo redox reactions and are converted into insoluble substances or precipitates; harmful substances such as drug residues and harmful pathogens are also effectively removed, which plays an important role in plant absorption and soil protection during the use of liquid fertilizer. 3. Significant economic benefits: biogas slurry first produces methane and carbon dioxide through anaerobic fermentation, which can be effectively collected and utilized through subsequent separation and liquefaction. The remaining biogas slurry can be made into treated organic fertilizer for sale after deep treatment, and biogas waste is utilized as a resource to promote the sustainable development of the economy.

[0055] The present invention can remove or transform harmful substances in biogas slurry through deep treatment process, thereby solving the problem of biogas slurry treatment, reducing environmental pollution, and realizing resource utilization of aquaculture waste. This process combines anaerobic fermentation, plasma and membrane separation technology in sequence. The harmful substances in biogas slurry are deeply decomposed and transformed into small molecules or inorganic substances such as nitrogen and phosphorus, while killing pathogenic microorganisms in biogas slurry, improving the soil environment, and improving the quality of liquid fertilizer production. Reduce the use of traditional chemical fertilizers, reduce agricultural production costs, and at the same time improve the quality and yield of agricultural products, promoting sustainable agricultural development.

[0056] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A deep treatment device based on biogas slurry, characterized in that: include: A homogenization tank (1) and a hydrolysis tank (2), wherein the homogenization tank (1) and the hydrolysis tank (2) are arranged side by side; An anaerobic fermentation tank (3) is connected to the output ends of the homogenization tank (1) and the hydrolysis tank (2) through pipelines to ferment the mixture, and the output end of the anaerobic fermentation tank (3) is connected to a solid-liquid separator (4) for separating the fermented product; A biogas residue collector (5) is arranged at the output end of the solid-liquid separator (4) to collect the biogas residue to form solid fertilizer; A sedimentation tank (6) is arranged at the other output end of the solid-liquid separator (4) to precipitate and purify the biogas slurry; A flocculant processing module is arranged at the output end of the sedimentation tank (6) to process the flocculants after precipitation; The biogas slurry processing module is arranged at the other output end of the sedimentation tank (6) to process the biogas slurry to form liquid fertilizer.

2. The biogas slurry deep treatment device according to claim 1, characterized in that: The flocculant processing module comprises a flocculant collection tank (7), a centrifuge (8) and a flocculant regeneration tank (9); the input end of the flocculant collection tank (7) is connected to the output end of the sedimentation tank (6); the output end of the flocculant collection tank (7) is connected to the centrifuge (8); the output end of the centrifuge (8) is connected to the input end of the biogas residue collector (5) through a pipeline to transport biogas residue to the biogas residue collector (5); the other output end of the centrifuge (8) is connected to the flocculant regeneration tank (9) for regenerating the flocculant.

3. The deep treatment device based on biogas slurry according to claim 2 is characterized in that: The output end of the flocculant regeneration tank (9) is connected to the flocculant input end of the sedimentation tank (6).

4. The biogas slurry deep treatment device according to claim 1, characterized in that: The biogas slurry treatment module comprises a filter (10), a plasma reactor (11) and a membrane separator (13); the filter (10) is connected to the other output end of the sedimentation tank (6); the output end of the filter (10) is provided with a plasma reactor (11); one end of the plasma reactor (11) is provided with a membrane separator (13) for separating and concentrating biogas slurry to form liquid fertilizer.

5. The biogas slurry deep treatment device according to claim 4, characterized in that: An evaporation tank (12) for preliminarily concentrating the biogas slurry is provided between the plasma reactor (11) and the membrane separator (13).

6. The biogas slurry deep treatment device according to claim 4, characterized in that: The membrane material used in the membrane separator (13) is tetrafluoroethylene.

7. The biogas slurry deep treatment device according to claim 4, characterized in that: The other output end of the filter (10) is connected to a flocculant processing module.

8. The biogas slurry deep treatment device according to claim 1, characterized in that: The anaerobic fermentation tank (3) is provided with a first connecting pipe connected to an external gas purification module to process the fermentation gas.

9. The biogas slurry deep treatment device and treatment method according to claim 1, characterized in that: The steps include: Step A: pre-treating the organic waste, and then passing the treated material into an anaerobic fermentation tank (3) for fermentation, and collecting and processing the biogas residue after fermentation to form solid fertilizer; Step B: The fermented biogas slurry enters the sedimentation tank (6) for sedimentation, and the sediment is processed to form biogas residue and regenerated flocculant, and the regenerated flocculant is re-entered into the sedimentation tank (6) for use; Step C: The precipitate is sequentially processed through a filter (10), a plasma reactor (11) and a membrane separator (13) to form liquid fertilizer.

10. A biogas slurry deep treatment device and a treatment method thereof according to claim 9, characterized in that: The detailed steps are as follows; Step A: livestock manure enters a homogenization tank (1) and water is added to form a suspended substance. After the straw is crushed, it enters a hydrolysis tank (2) for acidification. Some macromolecular organic matter is decomposed into small molecular organic matter by the action of hydrolases. The two raw materials are pretreated and mixed and then enter an anaerobic fermentation tank (3) for fermentation. The fermented and decomposed gases are methane and carbon dioxide. The two gases are collected from the top of the anaerobic fermentation tank (3) and enter a purification module to finally obtain LNG and liquid CO2. The biogas slurry and biogas residue are collected from the bottom of the anaerobic fermentation tank (3). The biogas residue is first separated by a solid-liquid separator (4) and then collected by a biogas residue collector (5). It can be further processed to produce solid fertilizer. Step B: The biogas slurry separated by the solid-liquid separator (4) enters the sedimentation tank (6) and is added with a flocculant. The suspended matter, colloidal particles and heavy metal ion pollutants in the sewage gradually aggregate to form larger flocs and settle under the action of gravity. The flocculants at the bottom of the sedimentation tank (6) are collected by the flocculant collection tank (7). Active substances are added and the pH value in the flocculant collection tank (7) is adjusted to redissolve the flocculant. The biogas residue and the dissolved flocculant are separated by a centrifuge (8). The solids are collected by the biogas residue collector (5). The flocculant liquid enters the flocculant regeneration tank (9) for evaporation and concentration to achieve cyclic regeneration. Step C: After the biogas slurry leaves the sedimentation tank (6), it enters the filter (10) for filtration to further reduce the insoluble substances in the biogas slurry, and then enters the plasma reactor (11). Under the action of plasma discharge, other types of macromolecular organic matter in the biogas slurry are further decomposed into small molecules, and pathogenic microorganisms in the biogas slurry are killed. The biogas slurry treated by the plasma reactor (11) is transported to the evaporation tank (12) for standing, and evaporation concentration is used to reduce the water content in the biogas slurry. After standing, the biogas slurry is pressurized and enters the membrane separator (13). Under the action of the membrane separator (13), the biogas slurry is further concentrated, and the concentrated liquid is collected to obtain the product liquid fertilizer. At the same time, the clear liquid produced by the permeate outlet meets the pollutant emission standard.

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