Biogas slurry concentration treatment system and treatment method

Abstract

The invention discloses a biogas slurry concentration treatment system and a treatment method. The biogas slurry concentration treatment system comprises a biogas slurry pool (1), a sand filter pool (2), a first regulating pool (3), a semi-coke adsorption tower (4), a second regulating pool (5), a security filter (6), a reverse osmosis device (7), a concentration pool (8) and a clear water pool (9). Compared with the prior art, the invention has the following advantages and beneficial effects: 1. The adsorption capacity of the semi-coke is utilized to adsorb heavy metals in the biogas slurry, thereby reducing the content of heavy metals in the biogas slurry, which is beneficial to the subsequent utilization of the biogas slurry; 2. The step-by-step filtration of the sand filter pool can be completed in the same reactor, and does not affect their mutual work, and does not need to provide power; 3. The volume of the biogas slurry after treatment is reduced to 30% of the original volume, and a high-concentration biogas slurry fertilizer is obtained. At the same time, the remaining 70% of the clear water can be directly used for irrigation.

Description

Technical Field

[0001] The present invention belongs to the field of environmental protection, and more specifically, relates to a biogas slurry concentration treatment system and a treatment method. Background Art

[0002] my country is a large agricultural country. The long-term application of chemical fertilizers and pesticides has caused the soil to become compacted, fertility has decreased, the environment and soil have been polluted, and the sustainable production of agriculture has been affected. In addition, the sharp rise in the prices of agricultural production materials such as chemical fertilizers in recent years has increased the cost of agricultural production. There is an urgent need to find a high-quality, efficient and affordable fertilizer that can partially replace chemical fertilizers, improve the soil. Biogas residues and liquid biogas contain rich nutrients that are very beneficial to the growth of plants and microorganisms.

[0003] Biogas slurry is rich in nitrogen, phosphorus, potassium and other nutrients, and is a good liquid fertilizer. Since biogas slurry is produced by anaerobic fermentation, the problems of large biogas slurry output, high processing cost, difficult storage and transportation, and low nutrient content in biogas projects are not conducive to its industrialization and commercialization. Therefore, it is very important to separate and concentrate the nutrients in biogas slurry to reduce its volume and increase the nutrient elements, while reducing the content of heavy metals and organic matter in biogas slurry to achieve harmless biogas slurry and resource utilization, which is very important for the further development and utilization of biogas slurry. Summary of the invention

[0004] The object of the present invention is to solve the above-mentioned problem and provide a biogas slurry concentration treatment system and treatment method, which are suitable for biogas slurry concentration and purification treatment.

[0005] In order to achieve the above object, the present invention provides a biogas slurry concentration treatment system, which comprises a biogas slurry tank, a sand filter tank, a first regulating tank, a semi-coke adsorption tower, a second regulating tank, a security filter, a reverse osmosis device, a concentration tank and a clear water tank;

[0006] A first aspect of the present invention provides a biogas slurry concentration treatment system, which comprises a biogas slurry tank, a sand filter tank, a first regulating tank, a semi-coke adsorption tower, a second regulating tank, a security filter, a reverse osmosis device, a concentration tank and a clear water tank;

[0007] The biogas slurry pool is connected to the water inlet at the top of the sand filter tank;

[0008] The water outlet at the bottom of the sand filter tank is connected to the first regulating tank;

[0009] The first regulating tank is connected to the water inlet at the top of the semi-coke adsorption tower;

[0010] The water outlet at the bottom of the semi-coke adsorption tower is connected to the second regulating tank;

[0011] The second regulating tank is connected to the water inlet at the bottom of the security filter;

[0012] The water outlet at the top of the security filter is connected to the water inlet at the top of the reverse osmosis device;

[0013] The water outlet at the upper part of the reverse osmosis device is connected to the clean water tank, and the water outlet at the lower part of the reverse osmosis device is connected to the concentration tank.

[0014] As a preferred solution, the connection method is pipeline connection.

[0015] As a preferred solution, the concentration tank is also connected to the first regulating tank through a pipeline.

[0016] As a preferred solution, a pressure pump is provided between the concentration tank and the first regulating tank for conveying the concentrated liquid in the concentration tank to the first regulating tank.

[0017] As a preferred solution, a pressure pump is provided between the biogas slurry pool and the sand filter pool for conveying the biogas slurry in the biogas slurry pool to the sand filter pool.

[0018] As a preferred solution, a pressure pump is provided between the first regulating tank and the semi-coke adsorption tower for conveying the biogas slurry in the first regulating tank to the semi-coke adsorption tower.

[0019] As a preferred solution, a pressure pump is provided between the second regulating tank and the security filter for conveying the biogas slurry in the second regulating tank to the security filter.

[0020] As a preferred solution, a valve is provided at the water inlet near the top of the sand filter tank.

[0021] As a preferred embodiment, the filler of the semi-coke adsorption tower is semi-coke, the particle size of the semi-coke is 100-120 mesh, and the specific surface area is 20m 2 / g-30m 2 / g.

[0022] As a preferred solution, the sand filter tank comprises a first sand filter tank, a first water collection space, a second sand filter tank and a second water collection space arranged in sequence from top to bottom;

[0023] The first water collection space is used to contain the biogas slurry filtered by the first sand filter tank; when the biogas slurry fills the first water collection space, it flows into the second sand filter tank under the action of gravity and upper water pressure.

[0024] The second water collection space is used to contain the biogas slurry filtered by the second sand filter.

[0025] As a preferred solution, the biogas slurry pool is connected to the water inlet of the first water collection space;

[0026] The water outlet of the first water collection space is connected to the first regulating tank;

[0027] The water outlet of the second water collection space is connected to the first regulating tank;

[0028] A valve is provided at one end close to the water inlet of the first water collection space;

[0029] Valves are provided between the first water collection space, the second water collection space and the first regulating tank.

[0030] As a preferred solution, the filler of the first sand filter is coarse and fine sand with a fineness modulus of 3.1-3.7.

[0031] As a preferred solution, the filler of the second sand filter is 50-100 mesh quartz sand.

[0032] A second aspect of the present invention provides a biogas slurry concentration treatment method, using the above-mentioned treatment system, the biogas slurry concentration treatment method comprises the following steps:

[0033] The biogas in the biogas pool is sequentially passed through the sand filter, the first regulating tank, the semi-coke adsorption tower, the second regulating tank, the security filter and the reverse osmosis device to complete the concentration and purification of the biogas. The concentrated biogas enters the concentration tank, and the purified biogas enters the clean water tank.

[0034] Further preferably, when the treatment system of the present invention is working, the biogas slurry is pumped from the biogas slurry tank into the sand filter tank by a pressure pump, passes through the first sand filter tank, the first water collection space, the second sand filter tank and the second water collection space in the sand filter tank, and the large particles of suspended matter are intercepted by coarse and fine sand in the first sand filter tank, and the small particles of suspended matter in the biogas slurry are intercepted by quartz sand in the second sand filter tank; enters the first regulating tank, and then enters the semi-coke adsorption tower by a sewage pump so that the heavy metals in the biogas slurry are adsorbed by the semi-coke to complete the adsorption of heavy metals; then enters the second regulating tank, and enters the security filter by a pressure pump to remove fine substances in the biogas slurry, such as tiny quartz sand and semi-coke particles, to complete further filtration; finally, the biogas slurry enters the reverse osmosis device through the security filter for reverse osmosis membrane layering treatment to complete the concentration and purification of the biogas slurry, and the concentrated biogas slurry enters the concentration tank, and the purified biogas slurry enters the clear water tank. Among them, when the heavy metal concentration and the concentration effect in the concentration tank meet the national standard requirements, the concentrated biogas slurry can be used as biogas slurry fertilizer. Usually, the volume of the treated biogas slurry is reduced to about 30% of the original volume, and the clean water can be used for farmland irrigation; when the heavy metal concentration and the concentration effect in the concentration tank do not meet the requirements, the biogas slurry in the concentration tank is injected into the first regulating tank through a pressure pump and mixed with the biogas slurry in the regulating tank, and then the above steps are performed to ensure that the concentration meets the requirements.

[0035] According to the present invention, when the first sand filter in the above-mentioned biogas slurry concentration treatment system fails, the biogas slurry can be directly transported to the second sand filter through a pressure pump, filtered by the second sand filter, the filtrate flows to the second water collection space, and then enters the first regulating tank for the next step of treatment. When the second sand filter in the above-mentioned biogas slurry concentration treatment system fails, the biogas slurry can be directly transported to the first sand filter through a pressure pump, filtered by the first sand filter, the filtrate flows to the first water collection space without passing through the second sand filter, and then enters the first regulating tank for the next step of treatment. Of course, the occurrence of the above phenomenon is a special case.

[0036] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0037] 1. Utilize the adsorption capacity of semi-coke to adsorb heavy metals in biogas slurry, thereby reducing the content of heavy metals in biogas slurry, which is beneficial to the subsequent utilization of biogas slurry;

[0038] 2. The step-by-step filtration of the sand filter can be completed in the same reactor without affecting each other's work and without the need for power supply;

[0039] 3. After treatment, the volume of biogas slurry is reduced to 30% of the original volume, and high-concentration biogas slurry fertilizer is obtained. At the same time, the remaining 70% of clean water can be used directly for irrigation.

[0040] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0042] Figure 1 The schematic diagram shows the structure of a biogas slurry concentration treatment system according to an embodiment of the present invention.

[0043] Figure 2 A schematic structural diagram of a sand filter tank according to an embodiment of the present invention is shown.

[0044] Explanation of the accompanying drawings: 1-slurry tank, 2-sand filter tank, 3-first regulating tank, 4-semi-coke adsorption tower, 5-second regulating tank, 6-security filter, 7-reverse osmosis device, 8-concentration tank, 9-clear water tank, 21-first sand filter tank, 22-first water collection space, 23-second sand filter tank, 24-second water collection space. DETAILED DESCRIPTION

[0045] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0046] Example 1

[0047] This embodiment provides a biogas slurry concentration treatment system, such as Figure 1 , Figure 2 As shown, the biogas slurry concentration treatment system includes a biogas slurry tank 1, a sand filter tank 2, a first regulating tank 3, a semi-coke adsorption tower 4, a second regulating tank 5, a security filter 6, a reverse osmosis device 7, a concentration tank 8 and a clear water tank 9;

[0048] The biogas slurry tank 1 is connected to the water inlet pipe at the top of the sand filter tank 2;

[0049] The sand filter 2 includes a first sand filter 21, a first water collection space 22, a second sand filter 23 and a second water collection space 24 arranged in sequence from top to bottom; the first water collection space 22 is used to hold the biogas slurry filtered by the first sand filter 21; the second water collection space 24 is used to hold the biogas slurry filtered by the second sand filter 23.

[0050] The biogas slurry tank 1 is connected to the water inlet pipe of the first water collection space 22;

[0051] The water outlet of the first water collection space 22 is connected to the first regulating tank 3 through a pipeline; the water outlet of the second water collection space 24 is connected to the first regulating tank 3 through a pipeline;

[0052] A valve is provided at one end close to the water inlet of the first water collecting space 22;

[0053] Valves are provided between the first water collecting space 22 , the second water collecting space 24 and the first regulating tank 3 .

[0054] The filling material of the first sand filter 21 is coarse and fine sand with a fineness modulus of 3.1-3.7, and the filling material of the second sand filter 23 is quartz sand with a mesh size of 50-100.

[0055] The first regulating tank 3 is connected to the water inlet pipe at the top of the semi-coke adsorption tower 4;

[0056] The water outlet at the bottom of the semi-coke adsorption tower 4 is connected to the second regulating tank 5 by a pipeline;

[0057] The second regulating tank 5 is connected to the water inlet pipe at the bottom of the security filter 6, and a pressure pump is provided between them;

[0058] The water outlet at the top of the security filter 6 is connected to the water inlet pipe at the top of the reverse osmosis device 7;

[0059] The water outlet at the top of the reverse osmosis device 7 is connected to the clean water tank 9 through a pipeline, and the water outlet at the bottom of the reverse osmosis device 7 is connected to the concentration tank 8 through a pipeline.

[0060] The concentration tank 8 is also connected to the first regulating tank 3 through a pipeline;

[0061] A pressure pump is provided between the concentration tank 8 and the first regulating tank 3 for transporting the concentrated liquid in the concentration tank 8 to the first regulating tank 3 .

[0062] A pressure pump is provided between the biogas slurry tank 1 and the sand filter tank 2, for conveying the biogas slurry in the biogas slurry tank 1 to the sand filter tank 2;

[0063] A pressure pump is provided between the first regulating tank 3 and the semi-coke adsorption tower 4 for transporting the biogas slurry in the first regulating tank 3 to the semi-coke adsorption tower 4;

[0064] A pressure pump is provided between the second regulating tank 5 and the security filter 6 for conveying the biogas slurry in the second regulating tank 5 to the security filter 6 .

[0065] A valve is provided at the water inlet near the top of the sand filter tank 2 .

[0066] The filling material of the semi-coke adsorption tower 4 is semi-coke, the particle size of the semi-coke is 100-120 mesh, and the specific surface area is 20m 2 / g-30m 2 / g.

[0067] The above-mentioned biogas slurry concentration treatment system is used to treat a certain biogas slurry. The biogas slurry is pumped from the biogas slurry tank 1 into the sand filter 2 by a pressure pump, passes through the first sand filter 21, the first water collection space 22, the second sand filter 23 and the second water collection space 24 in the sand filter 2, enters the first regulating tank 3, and then enters the semi-coke adsorption tower 4 by a sewage pump to complete the adsorption of heavy metals, and then enters the second regulating tank 5, and enters the security filter 6 by a pressure pump to complete further filtration, and finally the biogas slurry enters the reverse osmosis device 7 from the security filter 6 to complete the concentration and purification of the biogas slurry, and the concentrated biogas slurry enters the concentration tank 8, and the purified biogas slurry enters the clean water tank 9.

[0068] Table 1 Various indicators after biogas slurry concentration

[0069] index Raw biogas slurry After concentration Shimizu Volume(L) 12 3.6 8.4 Ammonia nitrogen (mg / L) 730.48 2429.94 2.14 TP(mg / L) 41.67 13.34 0.24 COD(mg / L) 7260.00 24112.69 37.42 Cu 0.845 --- 0.111 Zn 1.533 --- 0.156 Cd 0.033 --- .003

[0070] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A biogas slurry concentration treatment system, characterized in that: The biogas slurry concentration treatment system comprises a biogas slurry tank (1), a sand filter tank (2), a first regulating tank (3), a semi-coke adsorption tower (4), a second regulating tank (5), a security filter (6), a reverse osmosis device (7), a concentration tank (8) and a clear water tank (9); The sand filter (2) comprises a first sand filter (21), a first water collection space (22), a second sand filter (23) and a second water collection space (24) which are arranged in sequence from top to bottom; The first water collection space (22) is used to contain the biogas slurry filtered by the first sand filter (21); The second water collection space (24) is used to contain the biogas slurry filtered by the second sand filter (23); The biogas slurry pool (1) is connected to the water inlet of the first water collection space (22); The water outlet of the first water collection space (22) is connected to the first regulating tank (3); The water outlet of the second water collection space (24) is connected to the first regulating tank (3); A valve is provided at one end close to the water inlet of the first water collection space (22); Valves are provided between the first water collection space (22), the second water collection space (24) and the first regulating tank (3); The filler of the first sand filter (21) is coarse and fine sand with a fineness modulus of 3.1-3.7; The filling material of the second sand filter (23) is 50-100 mesh quartz sand; The water outlet at the bottom of the sand filter tank (2) is connected to the first regulating tank (3); The first regulating tank (3) is connected to the water inlet at the top of the semi-coke adsorption tower (4); The water outlet at the bottom of the semi-coke adsorption tower (4) is connected to the second regulating tank (5); The second regulating tank (5) is connected to the water inlet at the bottom of the security filter (6); The water outlet at the top of the security filter (6) is connected to the water inlet at the top of the reverse osmosis device (7); The water outlet at the top of the reverse osmosis device (7) is connected to the clean water tank (9), and the water outlet at the bottom of the reverse osmosis device (7) is connected to the concentration tank (8); The concentration tank (8) is also connected to the first regulating tank (3) via a pipeline; A pressure pump is provided between the concentration tank (8) and the first regulating tank (3), for transporting the concentrated liquid in the concentration tank (8) to the first regulating tank (3); The filler of the semi-coke adsorption tower (4) is semi-coke, the particle size of the semi-coke is 100-120 mesh, and the specific surface area is 20m 2 / g-30m 2 / g.

2. The biogas slurry concentration treatment system according to claim 1, wherein: The connection method is pipeline connection.

3. The biogas slurry concentration treatment system according to claim 1, wherein: A pressure pump is provided between the biogas slurry tank (1) and the sand filter tank (2), and is used to transport the biogas slurry in the biogas slurry tank (1) to the sand filter tank (2); A pressure pump is provided between the first regulating tank (3) and the semi-coke adsorption tower (4), and is used to transport the biogas slurry in the first regulating tank (3) to the semi-coke adsorption tower (4); A pressure pump is provided between the second regulating tank (5) and the security filter (6) for conveying the biogas slurry in the second regulating tank (5) to the security filter (6).

4. A biogas slurry concentration treatment method, characterized in that: Using the treatment system according to any one of claims 1 to 3, the biogas slurry concentration treatment method comprises the following steps: The biogas slurry in the biogas slurry pool (1) is sequentially passed through a sand filter (2), a first regulating pool (3), a semi-coke adsorption tower (4), a second regulating pool (5), a security filter (6), and a reverse osmosis device (7) to complete the concentration and purification of the biogas slurry. The concentrated biogas slurry enters a concentration pool (8), and the purified biogas slurry enters a clean water pool (9).

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