Denitrification device suitable for industrial aquaculture system

Abstract

The utility model belongs to the technical field of biological denitrification of industrial aquaculture water, and particularly relates to a denitrification device suitable for an industrial aquaculture system. Comprising an aerobic nitrification zone, a carbon source zone, an aerobic denitrification zone and a suspended particle removal zone which are communicated in sequence, a filter material is arranged in the aerobic nitrification zone, and the aerobic nitrification zone is used for carrying out biological oxidation on aquaculture water to generate nitrate; the upper part of the carbon source region is filled with carbon sources; the aerobic denitrification area is used for reducing nitrate in the water body into nitrogen; the suspended particle removal area is used for removing suspended particles in the water body. A water inlet pipe is arranged at the bottom of one side wall of the aerobic nitrification area, an aerobic nitrification area overflow port is formed in the upper part of the other side wall of the aerobic nitrification area, and the internal space of the aerobic nitrification area is distributed in a shape; a water outlet pipe is arranged at the bottom of the side wall of the suspended particle removal area. According to the device, aerobic nitrification, aerobic denitrification and suspended particulate matter removal are organically integrated, intensification and modularization are realized, the device is simple in structure and convenient to operate, and the culture denitrification effect is effectively improved.

Description

Technical Field

[0001] This utility model belongs to the field of biological denitrification technology for aquaculture in factory farming, and specifically relates to a denitrification device suitable for factory farming systems. Background Technology

[0002] With global population growth and increasing demand for aquatic resources, traditional aquaculture methods (such as cage culture and pond culture) face severe environmental pressures, particularly regarding water pollution, eutrophication, and the development of drug resistance. Factory-style recirculating aquaculture technology, through comprehensive monitoring and optimized management of the aquaculture water, can minimize negative environmental impacts, ensure water quality, and avoid eutrophication. Simultaneously, the factory-style aquaculture system provides a controlled environment, allowing for precise regulation of water quality, temperature, oxygen levels, and light, thereby significantly improving aquaculture efficiency. Compared to traditional methods, factory-style aquaculture systems can achieve higher yields in a smaller space, shorten the aquaculture cycle, and produce healthier aquatic animals than those raised in open water. With continuous technological advancements, decreasing costs, and increasing market demand, the application of factory-style aquaculture systems will become more widespread, making it the mainstream model for future aquaculture.

[0003] Currently, many factory-scale aquaculture facilities rely on large-scale water exchanges and the use of microbial agents to control water quality. Even the more advanced factory-scale recirculating aquaculture systems currently only have nitrifying biological filters. Nitrifying biological filters can utilize specific microbial communities to transform and remove harmful substances in the aquaculture water, especially ammonia nitrogen (NH3) and nitrite (NO2). - ) is converted into nitrate (NO3) - This helps maintain stable water quality and the health of aquatic animals. However, with the increase in feed intake and the continuous processes of ammonia oxidation and nitrification, nitrates (NO3) in factory-scale circulating water systems increase. - It can accumulate up to 500 mg / L. Studies have shown that higher levels of NO3... - The concentration can harm farmed species; moreover, it does not meet wastewater discharge standards. Therefore, intensive aquaculture systems urgently need to add biological nitrogen removal devices that integrate nitrification and denitrification. Utility Model Content

[0004] To address the aforementioned problems, the purpose of this invention is to provide a denitrification device suitable for factory farming systems, thereby solving the problems of low denitrification efficiency and high by-product concentration in traditional denitrification processes.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention provides a nitrogen removal device suitable for factory-scale aquaculture systems, comprising an aerobic nitrification zone, a carbon source zone, an aerobic denitrification zone, and a suspended particle removal zone connected in sequence. The aerobic nitrification zone contains filter media and is used to biologically oxidize the aquaculture water to generate nitrates. The carbon source zone is filled with carbon source material at the top, allowing the aquaculture water to obtain organic carbon source as it flows through the carbon source zone. The aerobic denitrification zone is used to reduce nitrates in the water to nitrogen gas. The suspended particle removal zone is used to remove suspended particles from the water.

[0007] The aerobic nitrification zone has an inlet pipe at the bottom of one side wall and an overflow port for the aerobic nitrification zone that communicates with the carbon source zone at the top of the other side wall. The internal space of the aerobic nitrification zone is S-shaped.

[0008] The upper part of the carbon source zone is filled with the carbon source through a mesh bag or box. The carbon source is a biodegradable polymer with a stable carbon release rate. The bottom of the carbon source zone is provided with a carbon source zone underflow port that communicates with the aerobic denitrification zone.

[0009] The aerobic denitrification zone is equipped with a three-dimensional elastic packing material, which serves as a substrate for inoculating aerobic denitrifying bacteria.

[0010] The upper side wall of the aerobic denitrification zone is provided with an aerobic denitrification zone overflow port that communicates with the suspended particle removal zone.

[0011] The bottom of the aerobic nitrification zone, carbon source zone and aerobic denitrification zone are all equipped with nano-aeration discs (10).

[0012] The suspended particle removal zone is inhabited by filter-feeding bivalves.

[0013] A water outlet pipe is provided at the bottom of the side wall of the suspended particle removal zone.

[0014] The denitrification device is a rectangular box structure.

[0015] The advantages and positive effects of this utility model are as follows:

[0016] 1. This utility model provides a denitrification device suitable for factory farming systems, which organically integrates aerobic nitrification, aerobic denitrification, and suspended particulate matter removal into one unit, realizing the intensification and modularization of the denitrification device. The device has a simple structure, is easy to operate, and can effectively improve the denitrification effect in aquaculture.

[0017] 2. This invention employs an aerobic denitrification reaction, which can reduce nitrates to harmless nitrogen gas in a shorter time, resulting in higher efficiency than traditional denitrification methods. In traditional anaerobic denitrification processes, ammonia nitrogen (NH3) and nitrite (NO2) are reduced to nitrogen gas. -As an intermediate product of the reaction, nitrates often have toxic effects on aquatic organisms and may even cause water pollution. In contrast, this invention uses aerobic denitrification, which typically reduces nitrates to nitrogen gas, reducing the accumulation of intermediate products. The subsequent connection to a simultaneous nitrification-denitrification zone avoids the accumulation of nitrites during the reaction process, greatly reducing potential toxicity risks.

[0018] 3. The present invention uses denitrifying bacteria in an aerobic environment, which are more likely to maintain relatively stable metabolic activity. The operation and maintenance are simpler than those of anaerobic denitrification systems, and the sensitivity to the environment is reduced.

[0019] 4. Compared with traditional anaerobic denitrification, this invention uses aerobic denitrification, which does not produce greenhouse gases such as methane (CH4). In anaerobic denitrification, excessive carbon sources may lead to the production of methane, a potent greenhouse gas. Aerobic denitrification, on the other hand, primarily produces nitrogen (N2), the most abundant gas in the atmosphere, which has no negative impact on the environment.

[0020] 5. This utility model adopts aerobic denitrification, which can not only remove nitrogen pollutants, but also help maintain the oxygen concentration in the water. The treated water can be directly transferred to the aquaculture pond for recycling, thereby improving the water utilization rate. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a denitrification device suitable for factory farming systems according to the present invention;

[0022] Figure 2 This is a top view of a denitrification device suitable for factory farming systems according to this utility model.

[0023] In the diagram: A is the aerobic nitrification zone, B is the carbon source zone, C is the aerobic denitrification zone, D is the suspended particle removal zone, 1 is the inlet pipe, 2 is the filter media, 3 is the overflow outlet of the aerobic nitrification zone, 4 is the carbon source, 5 is the underflow outlet of the carbon source zone, 6 is the three-dimensional elastic packing, 7 is the overflow outlet of the aerobic denitrification zone, 8 is the oyster shell, 9 is the outlet pipe, and 10 is the nano aeration disc. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Currently, most factory-style aquaculture enterprises remove ammonia nitrogen (NH3) and nitrite (NO2) from the aquaculture water by changing large amounts of water. - Toxic substances such as nitrifying biological filters are present in some industrialized recirculating aquaculture systems, and these systems do not address the accumulation of nitrates (NO3) and other harmful substances. -Some studies have proposed using anaerobic denitrification for water treatment, that is, using anaerobic denitrifying bacteria to remove nitrates (NO3) from the water. - (1) The dissolved oxygen content in the tailwater of factory farming systems is mostly above 6.0 mg / L, while traditional denitrification treatment mostly occurs under anaerobic conditions and requires deoxygenation treatment. (2) Due to the low efficiency of microbial metabolism under anaerobic conditions, the reaction rate is slow. This means that the volume and residence time of the denitrification reactor need to be long enough to ensure sufficient nitrate removal. (3) In the process of anaerobic denitrification, in addition to generating nitrogen, some byproducts may also be generated, such as hydrogen sulfide (H2S) and methane (CH4). These byproducts are toxic to the environment and aquatic organisms at high concentrations, and may even threaten the operation of the denitrification system itself.

[0026] Based on this, the present invention aims to provide a denitrification device suitable for factory farming systems to overcome the shortcomings of the prior art.

[0027] See Figure 1 and Figure 2 As shown, this utility model provides a denitrification device suitable for factory-scale aquaculture systems, comprising an aerobic nitrification zone A, a carbon source zone B, an aerobic denitrification zone C, and a suspended particle removal zone D connected in sequence. The aerobic nitrification zone A contains filter media 2 and is used for biological oxidation of the aquaculture water to generate nitrates. The carbon source zone B is filled with a carbon source 4, allowing the aquaculture water to obtain organic carbon sources as it flows through it. The aerobic denitrification zone C is used to reduce nitrates in the water to nitrogen gas. The suspended particle removal zone D is used to remove suspended particles from the water. The aquaculture effluent sequentially passes through the aerobic nitrification zone A, carbon source zone B, aerobic denitrification zone C, and suspended particle removal zone D for denitrification.

[0028] See Figure 1 As shown in the embodiment of this utility model, the denitrification device is a rectangular box structure. Nano-aeration discs 10 are provided at the bottom of the aerobic nitrification zone A, the carbon source zone B, and the aerobic denitrification zone C. An inlet pipe 1 is provided at the bottom of one side wall of the aerobic nitrification zone A, and an overflow port 3 communicating with the carbon source zone B is provided at the top of the other side wall. The internal space of the aerobic nitrification zone A is S-shaped, which facilitates water exchange.

[0029] Specifically, the aquaculture water enters the aerobic nitrification zone A through inlet pipe 1. The filter media 2 in aerobic nitrification zone A is K5 filter media, which can naturally form a biofilm and generate a large number of nitrifying bacteria after 1-2 weeks, thus removing ammonia nitrogen (NH3) and nitrite (NO2) from the water. - Biological oxidation to nitrate (NO3) - ).

[0030] In this embodiment of the invention, the upper part of the carbon source zone B is filled with carbon source 4 through a mesh bag or filter box. The carbon source 4 is a biodegradable polymer with a stable carbon release rate. The bottom of the carbon source zone B is provided with a carbon source zone bottom outlet 5 that communicates with the aerobic denitrification zone C. The aquaculture water flows through the carbon source zone B to obtain organic carbon source and enters the aerobic denitrification zone C from the carbon source zone bottom outlet 5.

[0031] Specifically, carbon source needs to be filled into the carbon source zone B, 3 meters below the overflow outlet of the aerobic nitrification zone, using either hanging mesh bags or added filter boxes. Polycaprolactone (PCL), with its stable carbon release rate, can provide an effective carbon source for the device, and the carbon source filling volume can be adjusted according to water quality indicators. For example, when the nitrate (NO3) level in the water is below 5 mg / L, the carbon source filling volume occupies 1 / 10 of carbon source zone B; when the nitrate (NO3) level in the water is above 30 mg / L, the carbon source filling volume occupies 1 / 2 of carbon source zone B.

[0032] In this embodiment of the invention, the aerobic denitrification zone C is provided with a three-dimensional elastic packing material 6, such as a brush; the three-dimensional elastic packing material 6 serves as the substrate for inoculating aerobic denitrifying bacteria. With the three-dimensional elastic packing material 6 as the substrate, the inoculation of aerobic denitrifying bacteria requires 1-2 weeks to mature. The upper side wall of the aerobic denitrification zone C is provided with an aerobic denitrification zone overflow port 7, which communicates with the suspended particle removal zone D.

[0033] Specifically, aerobic denitrifying bacteria utilize organic carbon sources to convert nitrates (NO3) into nitrogen dioxide. - ) is restored to N2.

[0034] In this embodiment of the invention, the aquaculture water enters the suspended particle removal zone D through the overflow outlet 7 of the aerobic denitrification zone. The bottom of the side wall of the suspended particle removal zone D is equipped with an outlet pipe 9. Specifically, depending on the water quality conditions, the suspended particle removal zone D can be used for cage culture (multiple cages can be placed if necessary) to raise filter-feeding bivalve animals, such as oysters, which filter-feed the suspended particles in the aquaculture water, thereby removing particulate organic nitrogen from the water and reducing the concentration of suspended particles.

[0035] This invention provides a nitrogen removal device suitable for factory farming systems. The aerobic denitrification reaction can reduce nitrates to harmless nitrogen gas in a short time, with higher efficiency than traditional nitrogen removal methods. In the traditional anaerobic denitrification process, ammonia nitrogen (NH3) and nitrite (NO2) are reduced to nitrogen gas. -As an intermediate product of the reaction, nitrates often have toxic effects on aquatic organisms and may even cause water pollution. In contrast, aerobic denitrification typically reduces nitrates to nitrogen gas, reducing the accumulation of intermediate products. Connecting to a simultaneous nitrification-denitrification zone avoids the accumulation of nitrites during the reaction, greatly reducing potential toxicity risks. Denitrifying bacteria in aerobic environments maintain relatively stable metabolic activity, making operation and maintenance simpler than anaerobic denitrification systems and reducing environmental sensitivity. Compared to traditional anaerobic denitrification, aerobic denitrification does not produce greenhouse gases such as methane (CH4). In anaerobic denitrification, excessive carbon sources can lead to the production of methane, a potent greenhouse gas. Aerobic denitrification primarily produces nitrogen (N2), the most abundant gas in the atmosphere, which has no negative environmental impact. Aerobic denitrification not only removes nitrogen pollutants but also helps maintain oxygen concentration in the water. The treated water can be directly transferred to aquaculture ponds for recycling, improving water utilization efficiency.

[0036] This invention organically integrates aerobic nitrification, aerobic denitrification, and suspended particulate matter removal into one unit, realizing the intensification and modularization of the denitrification device. The device has a simple structure, is easy to operate, and can effectively improve the denitrification effect in aquaculture.

[0037] The above description is merely an embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, extensions, etc., made within the spirit and principles of this utility model are included within the scope of protection of this utility model.

Claims

1. A nitrogen removal device suitable for factory farming systems, characterized in that, It includes an aerobic nitrification zone (A), a carbon source zone (B), an aerobic denitrification zone (C), and a suspended particulate removal zone (D) connected in sequence. The aerobic nitrification zone (A) is equipped with filter media (2) and is used to biologically oxidize the aquaculture water to generate nitrates. The carbon source zone (B) is filled with carbon source (4) at the top, so that the aquaculture water can obtain organic carbon source by flowing through the carbon source zone (B). The aerobic denitrification zone (C) is used to reduce nitrates in the water to nitrogen gas. The suspended particulate removal zone (D) is used to remove suspended particles in the water.

2. The nitrogen removal device for factory farming systems according to claim 1, characterized in that, The aerobic nitrification zone (A) has an inlet pipe (1) at the bottom of one side wall and an aerobic nitrification zone overflow port (3) at the top of the other side wall, which is connected to the carbon source zone (B). The internal space of the aerobic nitrification zone (A) is S-shaped.

3. The nitrogen removal device for factory farming systems according to claim 1, characterized in that, The upper part of the carbon source zone (B) is filled with the carbon source (4) through a mesh bag or box. The carbon source (4) is a biodegradable polymer with a stable carbon release rate. The bottom of the carbon source zone (B) is provided with a carbon source zone underflow port (5) that is connected to the aerobic denitrification zone (C).

4. The nitrogen removal device for factory farming systems according to claim 1, characterized in that, The aerobic denitrification zone (C) is equipped with a three-dimensional elastic packing material (6), which serves as a substrate for inoculating aerobic denitrifying bacteria.

5. The nitrogen removal device for factory farming systems according to claim 1, characterized in that, The upper side wall of the aerobic denitrification zone (C) is provided with an aerobic denitrification zone overflow port (7) that communicates with the suspended particle removal zone (D).

6. The nitrogen removal device for factory farming systems according to claim 1, characterized in that, The bottom of the aerobic nitrification zone (A), carbon source zone (B) and aerobic denitrification zone (C) are all equipped with nano-aeration discs (10).

7. The nitrogen removal device for factory farming systems according to claim 1, characterized in that, The suspended particle removal zone (D) contains filter-feeding bivalves.

8. The nitrogen removal device for factory farming systems according to claim 1, characterized in that, The bottom of the side wall of the suspended particle removal zone (D) is provided with a water outlet pipe (9).

9. The denitrification device for factory farming systems according to claim 1, characterized in that, The denitrification device is a rectangular box structure.

Images