CN113321560B - A method and device for producing high-efficiency organic liquid fertilizer using biogas slurry - Google Patents

Abstract

The present invention provides a method and a device for producing high-efficiency organic liquid fertilizer by utilizing biogas slurry. The method comprises the following steps: S1. Primary treatment of raw materials, using ferrate and bacteriostatic agent to perform primary deodorization and sterilization on the biogas slurry , filtered to obtain the primary treatment solution; S2. Reprocessing of raw materials, using micro-nano bubble water to further deodorize the primary treatment solution and remove suspended fine particle insolubles, and filter to obtain biogas slurry stock solution; S3. Liquid fertilizer production, biogas slurry stock solution According to the different formulas set, it can be freely mixed with nitrogen solution, phosphorus solution, potassium solution, organic solution and medium and trace element mother liquor to obtain biogas slurry liquid fertilizer with comprehensive nutrients suitable for different crops. The invention also provides a device used in the method for producing high-efficiency organic liquid fertilizer by utilizing biogas slurry. The method provided by the invention has simple process, low construction cost and high degree of automation; the biogas slurry fertilizer prepared by the method has improved commerciality, comprehensive nutrients and flexible formula, and can realize the maximum utilization of biogas slurry.

Description

A method and device for producing high-efficiency organic liquid fertilizer from biogas slurry

technical field

The invention relates to the field of resource utilization of agricultural waste, and more specifically relates to a method and a device for producing high-efficiency organic liquid fertilizer by utilizing biogas slurry.

Background technique

Biogas slurry refers to the residue after anaerobic fermentation of various organic matter such as human and animal manure and straw. With the development of scale and intensification of my country's breeding industry, the main treatment methods for the large amount of livestock and poultry manure produced are generally through biogas projects, that is, through anaerobic biodegradation to treat high-concentration organic wastewater. The current treatment methods of biogas slurry can be divided into low-cost natural ecological purification, high-cost factory treatment and high value-added development and utilization, but these treatment processes will greatly increase the treatment cost; on the other hand, although biogas slurry is It is a by-product of the anaerobic digestion process, but it is also an environmentally friendly fertilizer that can be widely used in agricultural production, and is an important content of the resource utilization of agricultural waste advocated by the state.

With the continuous improvement of the degree of automation of agricultural production, fertilizer consumption presents a trend of high concentration, liquidization and compounding. Liquid fertilizers account for nearly 40% in the United States, and liquid fertilizers are almost always used in Israeli fields with a high degree of water and fertilizer integration. In addition, countries such as the United Kingdom, Belgium, and the Netherlands also use liquid fertilizers in large quantities. Biogas slurry is a good liquid fertilizer, which is mainly composed of water. Biogas slurry has dual functions in crop growth, one is as a biological fertilizer containing nitrogen, phosphorus, potassium and various trace elements, and the other is as a biological pesticide containing amino acids, growth hormones and antibiotics. A large number of studies have shown that biogas slurry is a high-quality, full-effect organic fertilizer. On the basis of ensuring the improvement of crop quality and yield, it can replace or partially replace chemical fertilizers, and has a very wide range of applications. It can be used not only as base fertilizer, but also as top dressing or foliar fertilizer.

In foreign countries, the use of biogas slurry to produce commercial fertilizers is generally concentrated by means of multi-effect steam, and the cost of equipment investment is high. At this stage, it is difficult to promote and apply it on a large scale in my country. Domestic use of biogas slurry to produce commercial fertilizers is quite different from that of foreign countries. Domestically, auxiliary materials (mainly inorganic nutrients) are added to the biogas slurry to ensure that the biogas slurry commercial fertilizer meets national and industry standards. However, the composition of biogas slurry is complex, which contains a large number of microorganisms, salt ions and solid suspended matter, and direct field application is likely to cause blockage of irrigation equipment; at the same time, reasons such as incomplete deodorization of biogas slurry also cause liquid fertilizers containing biogas slurry The commerciality of fertilizers is not high, resulting in low enthusiasm for fertilizer production. Chinese invention patent CN105819589A discloses a method for removing the odor of biogas slurry. This invention only uses ferrate and bacteriostatic agent for deodorization, but the deodorization of ferrate is mainly to oxidize such as hydrogen sulfide (H ₂ S), Methyl mercaptan (CH ₃ SH), methyl sulfide (CH ₃ ) ₂ S), ammonia (NH ₃ ) and other odorous substances, while the odorous substances in biogas slurry include not only hydrogen sulfide (H ₂ S), ammonia (NH ₃ ), including indole, volatile phenol, etc., and only using ferrate to deodorize cannot completely remove the odor in the biogas slurry; meanwhile, the biogas slurry fertilizer prepared by this method is the biogas slurry stock solution, and it needs to be used If it is diluted, it needs to add a lot of water if it is used for irrigation. Therefore, for the treatment of biogas slurry, it is necessary to study a new biogas slurry treatment method to obtain a more thorough deodorization and more water-saving biogas slurry treatment solution.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the defects and deficiencies of the above-mentioned existing biogas slurry fertilizers, and provide a method for producing high-efficiency organic liquid fertilizers using biogas slurry. The water is further deodorized and impurity removed to obtain biogas slurry stock solution; the biogas slurry stock solution is mixed to obtain liquid fertilizers with different nutrient ratios.

The first object of the present invention is to provide a method for producing high-efficiency organic liquid fertilizer from biogas slurry.

The second object of the present invention is to provide a device used in the method of producing high-efficiency organic liquid fertilizer from biogas slurry.

Above-mentioned purpose of the present invention is given to realize by following technical scheme:

A method for utilizing biogas slurry to produce high-efficiency organic liquid fertilizer, comprising the following steps:

S1. Primary treatment of raw materials: use ferrate and bacteriostat to deodorize and sterilize biogas slurry, and filter to obtain primary treatment liquid;

S2. Raw material reprocessing: use micro-nano bubble water to further deodorize the primary treatment liquid and remove suspended fine particle insoluble matter, and filter to obtain biogas slurry;

S3. Liquid fertilizer production: The biogas slurry stock solution is freely mixed with nitrogen solution, phosphorus solution, potassium solution, organic solution and medium and trace element mother liquor according to the different formulas set, to obtain a comprehensive nutrient biogas slurry liquid fertilizer suitable for different crops .

Bubbles with a diameter of less than 100 μm are called microbubbles, and bubbles with a diameter of less than 100 nm are called nanobubbles. The diameter of micro-nano bubbles is between micro-bubbles and nano-bubbles, and refers to bubbles with diameters ranging from tens of microns to hundreds of nanometers when bubbles occur. Compared with ordinary bubbles, micro-nano bubbles have the characteristics of long residence time in water, high mass transfer efficiency, high interface potential, and free radical release. The surface of micro-nano bubbles has a negative charge, which is higher than that of ordinary bubbles. Usually, the surface charge of micro-nano bubbles is -50~-30mV. It can produce very dense and delicate bubbles in biogas slurry water, which will not appear to merge and expand and rupture The phenomenon. Utilizing the negative charge of micro-nano bubbles, it can absorb positively charged substances in water, remove organic suspended solids or pollutants in water, and achieve the purification effect of solid-liquid separation; some studies have also found that micro-nano bubbles have strong oxidizing properties, which can make Bacteria are inactivated. The substances that produce odor during the biogas slurry treatment process are mainly composed of ammonia, hydrogen sulfide, indole, and volatile phenols. Most of the odor-generating substances are organic compounds. These substances have active groups, are prone to chemical reactions, and are particularly easy to be oxidized. In the present invention, the double oxidation of micro-nano bubbles and ferrate can achieve the purpose of rapid deodorization . In addition, micro-nano bubbles can also inactivate bacteria and reduce the reproduction of harmful microorganisms in biogas slurry. This application uses the double oxidation of ferrate and micro-nano bubble water to quickly remove the source of odor in the biogas slurry, and the deodorization is sufficient; at the same time, the use of micro-nano bubble water also saves the water demand for the production of liquid fertilizer. The liquid fertilizer prepared by the method of the invention has higher nutritional value and higher commerciality, and can meet the requirements of various irrigation facilities; the method is easy to operate, simple in technology, low in cost, and can realize maximum utilization of biogas slurry.

Preferably, the primary treatment of raw materials in the step S1 is to first add ferrate with a mass of 0.001% to 0.02% of the biogas slurry, and then add a bacteriostatic agent with a mass of 0.001% to 0.02% of the biogas slurry for 5 to 12 hours of mixed reaction. Primary deodorization and sterilization.

Preferably, the filtering in step S1 is double filtering through the first filter and the second filter.

Further preferably, the pore sizes of the filters in the step S1 are respectively 850 μm and 250 μm.

Preferably, in the step S1, the ferrate is potassium ferrate or sodium ferrate, and the antibacterial agent is 2-bromo-2-nitro-1.3-propanediol.

Preferably, the raw material reprocessing in step S2 is to mix the micro-nano-bubble water with the primary treatment liquid, and the mixing volume ratio of the micro-nano-bubble water to the biogas slurry is 2-5:1.

Preferably, the micro-nano-bubble water in the step S2 comes from the circulating water produced by the nano-bubble generator, and the gas source of the nano-bubble generator is air.

Preferably, the filtering in step S2 is filtering through disc filters.

Further preferably, the filtration precision in the step S2 is 106 μm.

Preferably, the nitrogen solution in step S3 includes urea solution and urea ammonium nitrate solution; the phosphorus solution is monoammonium phosphate solution; and the potassium solution is potassium chloride solution.

A device used in the method of producing high-efficiency organic liquid fertilizer by using biogas slurry, the device is composed of a biogas slurry treatment device and a liquid fertilizer mixing device. The biogas slurry treatment device includes: nano-bubble generator 1, bubble pool 2, filter tank 3, filter screen 4, slag outlet 5, first valve 6, second valve 7, first centrifugal pump 8, biogas slurry treatment Pool 10, second centrifugal pump 11, filter assembly 12; liquid fertilizer mixing device includes biogas slurry raw material tank 13, first pneumatic valve 14, third centrifugal pump 15, nitrogen solution tank 16, second pneumatic valve 17, fourth Centrifugal pump 18, phosphorus solution tank 19, third pneumatic valve 20, fifth centrifugal pump 21, potassium solution tank 22, fourth pneumatic valve 23, sixth centrifugal pump 24, medium and trace element tank 25, fifth pneumatic valve 26, The seventh centrifugal pump 27, mixing tank 29, flow meter 30, eighth centrifugal pump 31, electromagnetic valve 32, terminal controller 33; one end of the bubble pool 2 is connected to the nano-bubble generator 1, and the other end is connected to the first valve 6 ; The filter tank 3 is provided with a filter screen 4 and a slag discharge port 5, and the slag discharge port 5 is arranged at the bottom of the filter tank 3, and the end of the filter tank 3 near the filtrate is connected with a second valve 7; the first valve 6 and the second valve 7 are commonly connected to the first centrifugal pump 8, and are connected to the biogas slurry treatment pond 10 through the first centrifugal pump 8; The feed port of the liquid raw material tank 13 is connected; the discharge port of the biogas slurry raw material tank 13 is connected with the feed port of the mixing tank 29 through the main pipeline, and a first pneumatic valve 14 and a second pneumatic valve 14 are arranged near the discharge port of the biogas liquid raw material tank 13. Three centrifugal pumps 15; Nitrogen solution tank 16, phosphorus solution tank 19, potassium solution tank 22, medium and trace element tank 25. Each solution tank is connected with the main pipeline through branch pipelines, and the second pneumatic valve 17 and the second pneumatic valve 17 are respectively arranged on each branch pipeline. Four centrifugal pumps 18, the third pneumatic valve 20 and the fifth centrifugal pump 21, the fourth pneumatic valve 23 and the sixth centrifugal pump 24, the fifth pneumatic valve 26 and the seventh centrifugal pump 27; the mixing tank 29 passes through the eighth centrifugal pump 31 Connected to the electromagnetic valve 32, a flow meter 30 is also arranged between the mixing tank 29 and the eighth centrifugal pump 31, and the terminal controller 33 includes a manual controller 331 and a remote control terminal 332 for controlling each valve to control each tank body fluid output.

Preferably, the filter pool 3 adopts a high-low drop design, and the filter screen 4 includes a first filter screen 41 and a second filter screen 42 .

Further preferably, the pore sizes of the first filter 41 and the second filter 42 are 850 μm and 250 μm, respectively.

Preferably, a stirrer 9 is also provided in the biogas slurry treatment pond 10 .

Preferably, the mixing tank 29 is also provided with a stirring unit 28 .

Preferably, the biogas slurry treatment pond 10 can also carry out aerobic fermentation or mixed culture with aerobic microorganisms as required.

Preferably, the filter assembly 12 is a disc filter with a filter precision of 106 μm.

Preferably, the system remote control terminal 332 adopts PLC programming for automatic control.

Preferably, the mixing tank 29 is provided with a weighing device to control the amount of different raw materials added.

Preferably, the terminal controller 33 can automatically calculate the required dosage of different raw material fertilizer solutions according to the field data collected by the agronomist.

As a specific method of use of the above-mentioned device:

The collected anaerobically fermented biogas slurry is directly injected into the filter tank 3, ferrate is added to the filter tank 3 for oxidation and deodorization, and a bacteriostatic agent is added to prevent the growth of bacteria. The second filter 42 pre-filters, and injects the pre-filtered biogas slurry into the biogas slurry treatment pond 10 by controlling the second valve 7 and the centrifugal pump 8 . The water source in the bubble pool is the water source continuously treated by the nano-bubble generator 1, the dissolved oxygen concentration in the water reaches a saturated concentration, and the dissolved oxygen content in the water is close to 4ppm. The micro-nano bubble water is injected into the biogas slurry treatment pond through the control of the first valve 6 and the centrifugal pump 8, fully stirred with the biogas slurry and then left to stand, which can further remove the source of odorous substances in the biogas slurry, and at the same time remove the fine particles suspended in the biogas slurry. insoluble particles. The treated biogas slurry is injected into the 106 μm filter assembly 12 through the second centrifugal pump 11 , and the biogas slurry flows into the biogas slurry raw material tank 13 after being filtered. The opening and closing of the pneumatic valves of the biogas slurry raw material tank 13, the nitrogen solution tank 16, the phosphorus solution tank 19, the potassium solution tank 22 and the medium and trace element tank 15 and the operation of each tank centrifugal pump are controlled by the terminal controller 33. Pour into the mixing tank 29 and mix. The mixing tank 29 is provided with a mixing unit 28, which can ensure that different raw materials are mixed evenly. required formula liquid fertilizer. Finally, the finished biogas slurry fertilizer is output through the centrifugal pump 31 for commercial packaging or directly transported to the field. The flow meter 30 controls the extraction amount of the finished fertilizer, and the electromagnetic valve 32 controls the discharge.

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

(1) The present invention provides a method of using biogas slurry to produce high-efficiency organic liquid fertilizer, using ferrate and micro-nano bubble water to fully deodorize, the content of substances that produce odor before and after biogas slurry treatment is significantly lower, and the content of hydrogen sulfide The reduction rate reached 100%, and the reduction rates of indole and volatile phenol content reached 84.67% and 77.65%, respectively. The deodorization is sufficient and the commerciality of biogas slurry is improved; different biogas slurry fertilizers are prepared according to different growth needs of crops, and the nutrients are comprehensive. , flexible formula, high degree of automation, flexible use, and wide application range.

(2) The method provided by the present invention has a simple production process and relatively low construction cost. The biogas slurry fertilizer prepared by the method can meet the requirements of various irrigation facilities and can realize the maximum utilization of the biogas slurry. The invention does not produce waste liquid in the production process of fully utilizing the biogas slurry, and greatly saves the water source consumed in the production of liquid fertilizer by using the micro-nano bubble water. In order to realize the recycling of agricultural waste resources, it provides an effective way, fundamentally solves the problem of biogas slurry utilization, and realizes the transformation of "waste" into treasure and efficient utilization.

(3) The present invention provides a method for utilizing biogas slurry to produce high-efficiency organic liquid fertilizer. The device and equipment are simple and suitable for industrialization and large-scale production of high-efficiency organic liquid fertilizer from biogas slurry in areas where the aquaculture industry is relatively concentrated. Production can improve the comprehensive utilization benefits of biogas slurry.

Description of drawings

Figure 1 is a schematic structural view of a device used in a method for producing high-efficiency organic liquid fertilizer from biogas slurry in Example 1 of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but the embodiments do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the technical field.

Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

Embodiment 1 A device used in the method of producing high-efficiency organic liquid fertilizer from biogas slurry

A device used in the method of producing high-efficiency organic liquid fertilizer by using biogas slurry, the device is composed of a biogas slurry treatment device and a liquid fertilizer mixing device. The biogas slurry treatment device includes: nano-bubble generator 1, bubble pool 2, filter tank 3, filter screen 4, slag outlet 5, first valve 6, second valve 7, first centrifugal pump 8, biogas slurry treatment Pool 10, second centrifugal pump 11, filter assembly 12; liquid fertilizer mixing device includes biogas slurry raw material tank 13, first pneumatic valve 14, third centrifugal pump 15, nitrogen solution tank 16, second pneumatic valve 17, fourth Centrifugal pump 18, phosphorus solution tank 19, third pneumatic valve 20, fifth centrifugal pump 21, potassium solution tank 22, fourth pneumatic valve 23, sixth centrifugal pump 24, medium and trace element tank 25, fifth pneumatic valve 26, The seventh centrifugal pump 27, mixing tank 29, flow meter 30, eighth centrifugal pump 31, electromagnetic valve 32, terminal controller 33; one end of the bubble pool 2 is connected to the nano-bubble generator 1, and the other end is connected to the first valve 6 ; The filter tank 3 is provided with a filter screen 4 and a slag discharge port 5, and the slag discharge port 5 is arranged at the bottom of the filter tank 3, and the end of the filter tank 3 near the filtrate is connected with a second valve 7; the first valve 6 and the second valve 7 are commonly connected to the first centrifugal pump 8, and are connected to the biogas slurry treatment pond 10 through the first centrifugal pump 8; The feed port of the liquid raw material tank 13 is connected; the discharge port of the biogas slurry raw material tank 13 is connected with the feed port of the mixing tank 29 through the main pipeline, and a first pneumatic valve 14 and a second pneumatic valve 14 are arranged near the discharge port of the biogas liquid raw material tank 13. Three centrifugal pumps 15; Nitrogen solution tank 16, phosphorus solution tank 19, potassium solution tank 22, medium and trace element tank 25. Each solution tank is connected with the main pipeline through branch pipelines, and the second pneumatic valve 17 and the second pneumatic valve 17 are respectively arranged on each branch pipeline. Four centrifugal pumps 18, the third pneumatic valve 20 and the fifth centrifugal pump 21, the fourth pneumatic valve 23 and the sixth centrifugal pump 24, the fifth pneumatic valve 26 and the seventh centrifugal pump 27; the mixing tank 29 passes through the eighth centrifugal pump 31 Connected to the electromagnetic valve 32, a flow meter 30 is also arranged between the mixing tank 29 and the eighth centrifugal pump 31, and the terminal controller 33 includes a manual controller 331 and a remote control terminal 332 for controlling each valve to control each tank body fluid output.

The use method and principle of the device:

The collected anaerobically fermented biogas slurry is directly injected into the filter tank 3, ferrate is added to the filter tank 3 for oxidation and deodorization, and a bacteriostatic agent is added to prevent the growth of bacteria. The second filter 42 pre-filters, and injects the pre-filtered biogas slurry into the biogas slurry treatment pond 10 by controlling the second valve 7 and the centrifugal pump 8 . The water source in the bubble pool is the water source continuously treated by the nano-bubble generator 1, the dissolved oxygen concentration in the water reaches a saturated concentration, and the dissolved oxygen content in the water is close to 4ppm. The micro-nano bubble water is injected into the biogas slurry treatment pond through the control of the first valve 6 and the centrifugal pump 8, fully stirred with the biogas slurry and then left to stand, which can further remove the source of odorous substances in the biogas slurry, and at the same time remove the fine particles suspended in the biogas slurry. insoluble particles. The treated biogas slurry is injected into the 106 μm filter assembly 12 through the second centrifugal pump 11 , and the biogas slurry flows into the biogas slurry raw material tank 13 after being filtered. The opening and closing of the pneumatic valves of the biogas slurry raw material tank 13, the nitrogen solution tank 16, the phosphorus solution tank 19, the potassium solution tank 22 and the medium and trace element tank 15 and the operation of each tank centrifugal pump are controlled by the terminal controller 33. Pour into the mixing tank 29 and mix. The mixing tank 29 is provided with a mixing unit 28, which can ensure that different raw materials are mixed evenly. required formula liquid fertilizer. Finally, the finished biogas slurry fertilizer is output through the centrifugal pump 31 for commercial packaging or directly transported to the field. The flow meter 30 controls the extraction amount of the finished fertilizer, and the electromagnetic valve 32 controls the discharge.

Embodiment 2 A method of utilizing biogas slurry to produce high-efficiency organic liquid fertilizer

A method for utilizing biogas slurry to produce high-efficiency organic liquid fertilizer, comprising the following steps:

(1) Primary treatment of raw materials: Potassium ferrate with 0.005% biogas slurry mass is added to the filter tank, and the reaction time after mixing is 10h for oxidation and deodorization. After deodorization is completed, 2-bromo-2-nitrate with 0.01% biogas slurry mass is added Base-1.3-propanediol bacteriostatic agent to prevent harmful microorganisms from re-breeding; at the same time, use 850μm and 250μm double filter screens to double-filter the primary treatment liquid of the anaerobic fermentation biogas slurry.

(2) Raw material reprocessing: use a nano-bubble generator to prepare a water source containing a large number of micro-nano bubbles, inject the water source rich in micro-nano bubbles and the primary treatment liquid of biogas slurry into the mixing tank, and the micro-nano bubble water and biogas slurry The volume ratio of the primary treatment liquid is 5:1. Stir it with a mixer and let it stand for 24 hours. Use micro-nano bubbles to fully remove odorous substances and suspended fine particles of insoluble matter. After retreatment, the biogas slurry is injected by pump ③ and the filtration accuracy is 106 μm. The disc filter group is used to obtain biogas slurry stock solution after filtration.

(3) Liquid fertilizer production: The biogas slurry is used as the raw material for the production of liquid fertilizers, and freely mixed with nitrogen solution, phosphorus solution, potassium solution, organic solution and medium and trace element mother liquor according to different formulas to obtain suitable for different crops. It is a liquid fertilizer containing biogas slurry that can be applied to various irrigation facilities with comprehensive nutrients. The nitrogen solution is a urea solution, the phosphorus solution is a monoammonium phosphate solution, the potassium solution is a potassium chloride solution, and the source of the medium and trace element solution is a mixed solution of various medium and trace elements.

Embodiment 3 A method of utilizing biogas slurry to produce high-efficiency organic liquid fertilizer

A method for utilizing biogas slurry to produce high-efficiency organic liquid fertilizer, comprising the following steps:

(1) Primary treatment of raw materials: Potassium ferrate with 0.01% biogas slurry mass is added to the filter tank, and the reaction time after mixing is 10h for oxidation and deodorization. After deodorization is completed, 2-bromo-2-nitrate with 0.01% biogas slurry mass is added Base-1.3-propanediol bacteriostatic agent to prevent harmful microorganisms from re-breeding; at the same time, use 850μm and 250μm double filter screens to double-filter the primary treatment liquid of the anaerobic fermentation biogas slurry.

(2) Raw material reprocessing: use a nano-bubble generator to prepare a water source containing a large number of micro-nano bubbles, inject the water source rich in micro-nano bubbles and the primary treatment liquid of biogas slurry into the mixing tank, and the micro-nano bubble water and biogas slurry The volume ratio of the primary treatment liquid is 5:1. Stir it with a mixer and let it stand for 24 hours. Use micro-nano bubbles to fully remove odorous substances and suspended fine particles of insoluble matter. After retreatment, the biogas slurry is injected by pump ③ and the filtration accuracy is 106 μm. The disc filter group is used to obtain biogas slurry stock solution after filtration.

(3) Liquid fertilizer production: The biogas slurry is used as the raw material for the production of liquid fertilizers, and freely mixed with nitrogen solution, phosphorus solution, potassium solution, organic solution and medium and trace element mother liquor according to different formulas to obtain suitable for different crops. It is a liquid fertilizer containing biogas slurry that can be applied to various irrigation facilities with comprehensive nutrients. The nitrogen solution is a urea solution, the phosphorus solution is a monoammonium phosphate solution, the potassium solution is a potassium chloride solution, and the source of the medium and trace element solution is a mixed solution of various medium and trace elements.

Embodiment 4 A method of utilizing biogas slurry to produce high-efficiency organic liquid fertilizer

A method for utilizing biogas slurry to produce high-efficiency organic liquid fertilizer, comprising the following steps:

(1) Primary treatment of raw materials: Potassium ferrate with 0.005% biogas slurry mass is added to the filter tank, and the reaction time after mixing is 10h for oxidation and deodorization. After deodorization is completed, 2-bromo-2-nitrate with 0.01% biogas slurry mass is added Base-1.3-propanediol bacteriostatic agent to prevent harmful microorganisms from re-breeding; at the same time, use 850μm and 250μm double filter screens to double-filter the primary treatment liquid of the anaerobic fermentation biogas slurry.

(2) Raw material reprocessing: use a nano-bubble generator to prepare a water source containing a large number of micro-nano bubbles, inject the water source rich in micro-nano bubbles and the primary treatment liquid of biogas slurry into the mixing tank, and the micro-nano bubble water and biogas slurry The volume ratio of the primary treatment liquid is 2:1. Stir it with a mixer and let it stand for 24 hours. Use micro-nano bubbles to fully remove odorous substances and suspended fine particles of insoluble matter. After retreatment, the biogas slurry is injected by pump ③ and the filtration accuracy is 106 μm. The disc filter group is used to obtain biogas slurry stock solution after filtration.

(3) Liquid fertilizer production: The biogas slurry is used as the raw material for the production of liquid fertilizers, and freely mixed with nitrogen solution, phosphorus solution, potassium solution, organic solution and medium and trace element mother liquor according to different formulas to obtain suitable for different crops. It is a liquid fertilizer containing biogas slurry that can be applied to various irrigation facilities with comprehensive nutrients. The nitrogen solution is a urea solution, the phosphorus solution is a monoammonium phosphate solution, the potassium solution is a potassium chloride solution, and the source of the medium and trace element solution is a mixed solution of various medium and trace elements.

Embodiment 5 A method of utilizing biogas slurry to produce high-efficiency organic liquid fertilizer

A method for utilizing biogas slurry to produce high-efficiency organic liquid fertilizer, comprising the following steps:

(1) Primary treatment of raw materials: Potassium ferrate with 0.01% biogas slurry mass is added to the filter tank, and the reaction time after mixing is 10h for oxidation and deodorization. After deodorization is completed, 2-bromo-2-nitrate with 0.01% biogas slurry mass is added Base-1.3-propanediol bacteriostatic agent to prevent harmful microorganisms from re-breeding; at the same time, use 850μm and 250μm double filter screens to double-filter the primary treatment liquid of the anaerobic fermentation biogas slurry.

(2) Raw material reprocessing: use a nano-bubble generator to prepare a water source containing a large number of micro-nano bubbles, inject the water source rich in micro-nano bubbles and the primary treatment liquid of biogas slurry into the mixing tank, and the micro-nano bubble water and biogas slurry The volume ratio of the primary treatment liquid is 2:1. Stir it with a mixer and let it stand for 24 hours. Use micro-nano bubbles to fully remove odorous substances and suspended fine particles of insoluble matter. After retreatment, the biogas slurry is injected by pump ③ and the filtration accuracy is 106 μm. The disc filter group is used to obtain biogas slurry stock solution after filtration.

(3) Liquid fertilizer production: The biogas slurry is used as the raw material for the production of liquid fertilizers, and freely mixed with nitrogen solution, phosphorus solution, potassium solution, organic solution and medium and trace element mother liquor according to different formulas to obtain suitable for different crops. It is a liquid fertilizer containing biogas slurry that can be applied to various irrigation facilities with comprehensive nutrients. The nitrogen solution is a urea solution, the phosphorus solution is a monoammonium phosphate solution, the potassium solution is a potassium chloride solution, and the source of the medium and trace element solution is a mixed solution of various medium and trace elements.

Comparative example 1

A method for utilizing biogas slurry to produce high-efficiency organic liquid fertilizer, comprising the following steps:

(1) Raw material treatment: Add potassium ferrate with 0.02% biogas slurry mass in the filter tank, and oxidize and deodorize after mixing for 10 hours. After deodorization, add 2-bromo-2-nitro with 0.01% biogas slurry mass -1.3-Propanediol antibacterial agent prevents harmful microorganisms from re-breeding; at the same time, the primary treatment liquid is double-filtered by anaerobic fermentation biogas slurry by using a double filter of 850 μm and 250 μm; 106μm disc filter group, after filtration, biogas slurry stock solution is obtained.

(2) Liquid fertilizer production: The biogas slurry is used as the raw material for the production of liquid fertilizers, and freely mixed with nitrogen solution, phosphorus solution, potassium solution, organic solution, and medium and trace element mother liquor according to different formulas to obtain suitable for different crops. It is a liquid fertilizer containing biogas slurry that can be applied to various irrigation facilities with comprehensive nutrients. The nitrogen solution is a urea solution, the phosphorus solution is a monoammonium phosphate solution, the potassium solution is a potassium chloride solution, and the source of the medium and trace element solution is a mixed solution of various medium and trace elements.

Comparative example 2

A method for utilizing biogas slurry to produce high-efficiency organic liquid fertilizer, comprising the following steps:

(1) Primary treatment of raw materials: The primary treatment liquid is double-filtered biogas slurry undergoing anaerobic fermentation by using double filter screens of 850 μm and 250 μm.

(2) Raw material reprocessing: use a nano-bubble generator to prepare a water source containing a large number of micro-nano bubbles, inject the water source rich in micro-nano bubbles and the primary treatment liquid of biogas slurry into the mixing tank, and the micro-nano bubble water and biogas slurry The volume ratio of the primary treatment liquid is 6:1. Stir with a mixer and let it stand for 24 hours. Use micro-nano bubbles to fully remove odorous substances and suspended fine particles of insoluble matter. After retreatment, the biogas slurry is injected by pump ③ and the filtration accuracy is 106 μm. The disc filter group is used to obtain biogas slurry stock solution after filtration.

(3) Liquid fertilizer production: The biogas slurry is used as the raw material for the production of liquid fertilizers, and freely mixed with nitrogen solution, phosphorus solution, potassium solution, organic solution and medium and trace element mother liquor according to different formulas to obtain suitable for different crops. It is a liquid fertilizer containing biogas slurry that can be applied to various irrigation facilities with comprehensive nutrients. The nitrogen solution is a urea solution, the phosphorus solution is a monoammonium phosphate solution, the potassium solution is a potassium chloride solution, and the source of the medium and trace element solution is a mixed solution of various medium and trace elements.

The influence of embodiment 6 biogas slurry treatment method on biogas slurry

1. Effect of biogas slurry treatment method on odorous substances produced by biogas slurry

Analyze the relevant components of the odor before and after the treatment of the biogas slurry in Examples 2 to 5, and use the Nessler colorimetric method to measure the concentration of ammonia; adopt the iodometric method to measure the concentration of hydrogen sulfide; adopt the HPLC method to measure the concentration of indole; The concentrations of volatile phenols were determined by 4-aminoantipyrine spectrophotometry.

The changes in the content of odorous substances before and after biogas slurry treatment are shown in Table 1.

Table 1: Changes in the content of odorous substances before and after biogas slurry treatment

It can be seen from Table 1 that the contents of ammonia, hydrogen sulfide, indole, and volatile phenol, which are the source of odor before and after the biogas slurry treatment, were significantly reduced, and none of them were detected in the treated biogas slurry under the combined deodorization. For hydrogen sulfide, the decrease rate of its content reaches 100%; the decrease rate of the content of indole and volatile phenol is also very obvious. At the same time, it is also found through comparative examples that the deodorization effect of the water source using a higher amount of potassium ferrate or micro-nano bubbles alone is lower than the combined treatment of potassium ferrate and micro-nano bubbles in a small amount.

2. Effect of biogas slurry treatment method on nutrient content of biogas slurry

Analyze the nutrient content of the biogas slurry before and after the biogas slurry treatment in Examples 2-5, and measure the total nitrogen concentration by titration after distillation; measure the total phosphorus concentration by using ascorbic acid color spectrophotometry; measure the total organic carbon by using potassium dichromate titration concentration.

The changes in nutrient content before and after biogas slurry treatment are shown in Table 2.

Table 2: Changes in nutrient content before and after biogas slurry treatment

It can be seen from Table 2 that the nutrient components before and after biogas slurry treatment showed a downward trend, and the nutrient content of Example 2 and Example 3 decreased relatively greatly due to the large dilution ratio. The nutrient content also showed a downward trend after the treatment of the control ratio, but the decline was limited.

3. Effects of biogas slurry treatment methods on the number of microorganisms in biogas slurry

The number of microorganisms in the biogas slurry in Examples 2 to 5 before and after treatment was analyzed, and the dilution plate method was used for determination.

The changes in the number of microorganisms before and after biogas slurry treatment are shown in Table 3

Table 3: Changes in the number of microorganisms before and after biogas slurry treatment

It can be seen from Table 3 that the number of microorganisms decreased significantly after biogas slurry treatment, especially in the combined deodorization treatment, fecal coliform bacteria were not detected. However, it can also be seen that the mixing ratio of the amount of potassium ferrate added to the nano-bubble water has little effect on microorganisms. Through the comparative ratio, it is also found that the number of residual microorganisms in the biogas slurry under the single treatment method still exists in large quantities, which may cause certain risks to the later application. In comparison, the application safety factor of the biogas slurry fertilizer under the combined treatment is higher.

Embodiment 7 Biogas slurry liquid fertilizer field application test

(1) Test background

Test site: Xiupo Village, Huashi Town, Fangcheng District, Fangchenggang City, Guangxi Zhuang Autonomous Region

Trial time: March 2020-August 2020

Test crop: watermelon

Test soil: sandy soil

Irrigation facilities: drip irrigation

Test plan: In this test, two treatments were set up: liquid compound fertilizer prepared from biogas slurry prepared in Example 2 of the present invention, solid compound fertilizer and conventional fertilization (only compound fertilizer). Conventional fertilization adopts "Garshli" macroelement water-soluble fertilizer (N:P:K 16:16:16) widely used by local growers.

The formula for preparing liquid compound fertilizer from biogas slurry is: 20 parts of biogas slurry treatment stock solution, 7 parts of nitrogen solution, 4 parts of phosphorus solution, 8 parts of potassium solution, and 0.1 part of medium and trace element solution. The pump injects the fertilizer liquid into the field irrigation pipeline, and at the same time ensures that the EC value of the fertilizer and water in the field is below 4. Conventional fertilization is to pour a large amount of water-soluble granular fertilizer into the fertilizer-dissolving tank to dissolve, and then apply it to the field through drip irrigation.

(2) The test results are shown in Table 4 and Table 5.

Table 4: Effects of biogas slurry fertilizer and conventional fertilizer on watermelon root growth

Table 5: Effects of biogas slurry fertilizer and conventional fertilizer on watermelon yield

It can be seen from Table 4 and 5 that biogas slurry fertilizer can significantly promote the growth of watermelon roots, and the total root length, total root surface area and root tip number are significantly increased compared with conventional fertilizers. The length, total root surface area and root tip number increased by 46.07%, 47.09% and 51.83% respectively; the effect of biogas slurry fertilizer on watermelon production was also very obvious, and the yield increase rate reached 33.56%.

When the biogas slurry fertilizer prepared by the method of the invention is used for irrigation, neither the filter nor the dripper is clogged, and the irrigation facilities operate normally.

The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the above-mentioned embodiment, and any other changes, modifications, substitutions, combinations, Simplifications should be equivalent replacement methods, and all are included in the protection scope of the present invention.

Claims (3)

1. A method for producing high-efficiency organic liquid fertilizer by utilizing biogas slurry is characterized by comprising the following steps: s1, primary treatment of raw materials: performing primary deodorization and sterilization on the biogas slurry by using ferrate and a bacteriostatic agent, and filtering to obtain primary treatment liquid;

s2, raw material reprocessing: further deodorizing the primary treatment liquid by using micro-nano bubble water, removing suspended fine particle insoluble substances, and filtering to obtain biogas slurry stock solution;

s3, liquid fertilizer production: freely mixing the biogas slurry stock solution with a nitrogen solution, a phosphorus solution, a potassium solution, an organic solution and a medium-trace element mother solution according to different set formulas to obtain a biogas slurry liquid fertilizer with comprehensive nutrients suitable for different crops;

the raw material primary treatment in the step S1 is to add ferrate accounting for 0.01 percent of the mass of the biogas slurry, perform mixed reaction for 10h, and then add bacteriostatic accounting for 0.01 percent of the mass of the biogas slurry for primary deodorization and sterilization;

in the step S1, ferrate is potassium ferrate, and the bacteriostatic agent is 2-bromo-2-nitro-1.3-propanediol;

the step S2 of raw material reprocessing is to mix micro-nano bubble water and primary treatment liquid, wherein the volume ratio of the micro-nano bubble water to the mixed biogas slurry is 5:1; stirring the mixed solution and standing for 24 h;

in the step S1, the filtering is double filtering by using two filter screens;

the device adopted by the method consists of a biogas slurry treatment device and a liquid fertilizer mixing device; the biogas slurry treatment device comprises: the device comprises a nano bubble generator (1), a bubble water tank (2), a filtering tank (3), a filter screen (4), a slag discharge port (5), a first valve (6), a second valve (7), a first centrifugal pump (8), a biogas slurry treatment tank (10), a second centrifugal pump (11) and a filtering assembly (12); the liquid fertilizer mixing device comprises a biogas slurry raw material tank (13), a first pneumatic valve (14), a third centrifugal pump (15), a nitrogen solution tank (16), a second pneumatic valve (17), a fourth centrifugal pump (18), a phosphorus solution tank (19), a third pneumatic valve (20), a fifth centrifugal pump (21), a potassium solution tank (22), a fourth pneumatic valve (23), a sixth centrifugal pump (24), a medium trace element tank (25), a fifth pneumatic valve (26), a seventh centrifugal pump (27), a mixing tank (29), a flowmeter (30), an eighth centrifugal pump (31), an electromagnetic valve (32) and a terminal controller (33); one end of the bubble pool (2) is connected with the nano bubble generator (1), and the other end of the bubble pool is connected with the first valve (6); a filter screen (4) and a slag discharge port (5) are arranged in the filter tank (3), the slag discharge port (5) is arranged at the bottom of the filter tank (3), and one end of the filter tank (3) close to the filtrate is connected with a second valve (7); the first valve (6) and the second valve (7) are connected to a first centrifugal pump (8) together and are connected with a biogas slurry treatment pool (10) through the first centrifugal pump (8); the biogas slurry treatment tank (10) is connected with one end of a filtering component (12) through a second centrifugal pump (11), and the other end of the filtering component (12) is connected with a feed inlet of a biogas slurry raw material tank (13); a discharge port of the biogas slurry raw material tank (13) is connected with a feed port of the mixing tank (29) through a main pipeline, and a first pneumatic valve (14) and a third centrifugal pump (15) are arranged near the discharge port of the biogas slurry raw material tank (13); the nitrogen solution tank (16), the phosphorus solution tank (19), the potassium solution tank (22) and the medium and trace element tank (25) are connected with the main pipeline through branch pipelines, and a second pneumatic valve (17) and a fourth centrifugal pump (18), a third pneumatic valve (20) and a fifth centrifugal pump (21), a fourth pneumatic valve (23) and a sixth centrifugal pump (24), a fifth pneumatic valve (26) and a seventh centrifugal pump (27) are respectively arranged on each branch pipeline; the mixing tank (29) is connected with the electromagnetic valve (32) through an eighth centrifugal pump (31), and a flow meter (30) is arranged between the mixing tank (29) and the eighth centrifugal pump (31); the terminal controller (33) comprises a manual controller (331) and a remote control end (332) and is used for controlling each valve to control the liquid outlet amount of each tank body;

the filter screen (4) comprises a first filter screen (41) and a second filter screen (42);

the aperture of the first filter screen (41) and the aperture of the second filter screen (42) are respectively 850 mu m and 250 mu m.

2. The method as claimed in claim 1, wherein a stirrer (9) is further arranged in the biogas slurry treatment tank (10).

3. Method according to claim 1, characterized in that a stirring aggregate (28) is also arranged in the mixing tank (29).

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