A factory-scale circulating aquaculture water treatment system based on electrochemical treatment

Abstract

The present invention discloses a factory recirculating aquaculture water treatment system based on electrochemical treatment, which relates to the technical field of water treatment. In view of the existing problems, the following solutions are proposed. It includes a culture pond, a pretreatment unit, an electrochemical treatment module, and a post-treatment unit. The pretreatment unit includes a microfilter connected to the culture pond, and also includes a buffer tank, a circulation water pump, and a precision filter arranged in sequence. The buffer tank is also connected to a protein skimmer. The electrochemical treatment module degrades ammonia nitrogen and sterilizes microorganisms by performing an electrolytic oxidation reaction on the water body. The post-treatment unit is used to remove the by-products electrolyzed by the electrochemical treatment module. In the present invention, the conversion efficiency of ammonia nitrogen in the water body is high, and it is electrolytically oxidized into nitrogen, reducing the formation of nitrite and nitrate; it can simultaneously achieve efficient removal of microbial pathogens (such as vibrio) and CO2; the system is easy to achieve intelligent precise control and has a low operating cost.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and in particular to an industrial circulating aquaculture water treatment system based on electrochemical treatment. Background Art

[0002] Factory-based recirculating aquaculture is not affected by seasons and breaks away from the constraints of the natural environment in traditional aquaculture. It can achieve high-density farming and shorten the farming cycle. It also has the characteristics of saving water and land and ensuring the food safety of aquatic products (no antibiotics). It is the main development model of the aquaculture industry in the future.

[0003] The quality of the water environment of factory-scale circulating aquaculture depends on the purification capacity of the water treatment system. At present, the core of 99% of water treatment systems at home and abroad is biological filtration, relying on biofilm to purify ammonia nitrogen, nitrite and other substances harmful to fish. For example, the announcement number is CN106035190B, and the name is a dual-channel water treatment method for seawater factory-scale circulating water system, which belongs to the field of fishery facilities and equipment technology. It is based on the currently commonly used factory-scale circulating aquaculture system biofilm method for water treatment, and adds a shellfish algae ecological filtration channel, using the principle of harmonious symbiosis of multi-trophic marine organisms such as fish, shrimp, shellfish, algae, and ginseng, through the rapid growth and renewable characteristics of large seaweed, and the ability of shellfish to filter residual bait, feces and other particulate organic matter in the aquaculture water. However, biological filtration also has many problems: the biological fillers in the biological filtration pool need to be nitrifying bacteria biofilmed in advance, especially for marine aquaculture, the biofilm growth time is very long, as short as one month, and as long as more than 2 months, which will lead to delays in production plans and affect the normal production cycle and output; the construction of biological filtration pools requires a large area, about 1 / 4-1 / 2 of the aquaculture area, one is the high civil engineering cost; the other is the large area occupied, which will greatly reduce the production area and reduce the output; the biological filter is the core of the entire circulating water treatment system, once the water quality indicators such as pH value, alkalinity, dissolved oxygen If problems occur, the nitrifying bacteria purification system of the biological filter will be damaged or even collapse, and the entire breeding system will be paralyzed and all the breeding species will face death. At present, the design and discharge of sewage in most biological filter pools are defective, and the aging biofilm shedding is not handled in time. Over time, it will greatly affect the purification efficiency of the biological filter, and also affect the quality of aquaculture, such as increasing the earthy smell of fish, which seriously affects the taste of fish. The nitrifying bacteria in the biological filter degrade ammonia nitrogen into nitrite and nitrate. During the degradation process, it is easy to cause excessive nitrite, which greatly increases the risk of fish poisoning. Summary of the invention

[0004] The invention provides an industrial circulating aquaculture water treatment system based on electrochemical treatment, which solves the problem of efficient water treatment and purification.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A factory-scale circulating aquaculture water treatment system based on electrochemical treatment comprises a culture pond, a pre-treatment unit, an electrochemical treatment module and a post-treatment unit, wherein the pre-treatment unit comprises a microfilter connected to the culture pond, and further comprises a buffer tank, a circulating water pump and a precision filter arranged in sequence, the buffer tank is also connected to a protein separator, the electrochemical treatment module degrades ammonia nitrogen and sterilizes microorganisms by performing electrolytic oxidation reaction on the water body, and the post-treatment unit is used to remove the by-products of electrolysis of the electrochemical treatment module.

[0007] Preferably, the electrochemical treatment module includes an electrolytic cell and a power control cabinet for controlling the electrolytic cell.

[0008] Preferably, the electrolytic cells are provided with multiple groups connected in parallel, and each group is independently provided with a power supply control cabinet.

[0009] Preferably, the tubular shell of the electrolytic cell is made of U-PVC material, and 5 electrode groups are arranged in the electrolytic cell, each electrode group contains 5 pairs of rectangular electrode sheets RuO-Ti, and the effective area of ​​the anode is 0.57 m 2 .

[0010] Preferably, the post-processing unit includes an activated carbon filter and a CO 2 Remover, the CO 2 The output end of the remover is communicated with the breeding pond.

[0011] Preferably, the precision filters are provided in multiple parallel configurations.

[0012] Preferably, the activated carbon filter is also connected to an ozone generator.

[0013] Beneficial effects of the present invention:

[0014] 1. Through the factory-scale circulating aquaculture water treatment system, the electrochemical treatment module occupies a small area and can be modularly combined, and used in single or multiple groups in parallel; the ammonia nitrogen conversion efficiency in the water body is high, and the ammonia nitrogen is mainly oxidized into nitrogen gas, reducing the formation of nitrite and nitrate; it can simultaneously achieve microbial pathogens (Vibrio, etc.), CO 2 Efficient removal.

[0015] 2. Through this factory-scale circulating water aquaculture water treatment system, the purification equipment units are reasonably combined, with fewer facilities and "plug and play". It does not require nitrifying bacteria to be attached in advance and is not easily affected by water quality fluctuations. It is easy to achieve intelligent and precise control and has low operating costs. It is suitable for high-density circulating water aquaculture in various stages such as seedling cultivation and adult fish cultivation. It can also be used for aquaculture vessels, occupies a small area, and has highly automated and intelligent management and control. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic flow chart of a factory-scale circulating aquaculture water treatment system based on electrochemical treatment proposed by the present invention.

[0017] Numbers in the figure: 1. Breeding pond; 2. Microfiltration machine; 3. Buffer tank; 4. Protein separator; 5. Circulating water pump; 6. Precision filter; 7. Electrolyzer; 8. Power supply control cabinet; 9. Activated carbon filter; 10. CO 2 Remover. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0019] Reference Figure 1 A factory-scale circulating aquaculture water treatment system based on electrochemical treatment comprises a culture pond 1, a pre-treatment unit, an electrochemical treatment module and a post-treatment unit. The pre-treatment unit comprises a microfilter 2 connected to the culture pond 1, and also comprises a buffer tank 3, a circulating water pump 5 and a precision filter 6 arranged in sequence. The buffer tank 3 is also connected to a protein separator 4. The electrochemical treatment module degrades ammonia nitrogen and sterilizes microorganisms by electrolytic oxidation reaction of the water body. The post-treatment unit comprises an activated carbon filter 9 and a CO2 filter connected to the activated carbon filter 9. 2 Remover 10, activated carbon filter 9 is also connected to an ozone generator, which regularly releases ozone into the activated carbon filter 9 to prevent the activated carbon from being saturated and blocked by adsorption, and plays a role in regenerating the activated carbon. The concentration of ozone added is maintained at 0.1 mg / L, CO 2 The output end of the remover 10 is connected to the aquaculture pond 1, and the residual chlorine, disinfection by-products, chlorate, perchlorate and bromate and other electrolysis by-products are removed by activated carbon adsorption filtration. The post-processing unit is used to remove the by-products of electrolysis of the electrochemical treatment module. The water purified by the activated carbon filter 9 enters the CO 2 Remover 10, further removes N from the water 2 , CO 2 , CO, H 2 The harmful gases such as nitrogen and nitrogen are removed and then flow back to the culture pond 1 by gravity, forming a fully closed circulating water culture system.

[0020] The discharge water in the breeding pond 1 flows by gravity into the microfilter 2 through the pipeline to remove large particles such as residual bait and feces in the water; the effluent of the microfilter 2 flows by gravity into the protein separator 4 through the pipeline to further remove fine particles and organic matter in the water; the effluent of the protein separator 12 enters the buffer adjustment tank 13 for water regulation; the water in the buffer adjustment tank 13 is pumped into the precision filter 15 by the water pump 14 to further remove tiny particles, and then enters the water inlet of the electrolytic cell 21 in the electrochemical treatment module 2, and ammonia nitrogen is degraded and microorganisms are sterilized and removed by electrolytic oxidation reaction of the water.

[0021] The electrochemical treatment module includes an electrolytic cell 7 and a power control cabinet 8 for controlling the electrolytic cell 7; the electrolytic cell 7 is provided with multiple groups connected in parallel, each group is provided with a power control cabinet 8, the tubular shell of the electrolytic cell 7 is made of U-PVC material, and there are 5 electrode groups in the electrolytic cell 7, each electrode group contains 5 pairs of rectangular electrode sheets (RuO2-Ti), and the effective area of ​​the anode is 0.57 m 2 ; Precision filter 6 is provided with multiple parallel connections; Using the above technical solution, 20m 3 The aquaculture pond (breeding species is sea bass) is used for circulating water treatment, the water salinity is 37g / L, and the aquaculture density is 20-45 kg / m 3 , water circulation rate: 20 m 3 / h, the data collection range is 5-25 weeks, and the electrochemical module uses 4 sets of parallel electrolytic cells (independent power supply), so that the system can remove more than 90% of ammonia nitrogen, the maximum removal rate of ammonia nitrogen is 3.4 mg / (L·s), and the ammonia nitrogen removal capacity is 1670.0 mg TAN / m 3 , which are higher than the ability of conventional bioreactors to remove ammonia nitrogen; the minimum water replenishment rate of the system is 300L / kg fish, which can be reduced by about 50% compared with the water replenishment of conventional RAS systems; the removal rate of harmful bacteria such as Vibrio in the system is ≥99.9%, which helps to stabilize the microbial colonies in the breeding pond. The energy consumption of the electrochemical treatment unit of the system is less than 3.5 kWh / kg. It will not affect the quality of aquaculture and the taste quality of fish; the technical solution of the present application will not degrade ammonia nitrogen into nitrite and nitrate, will not cause excessive nitrite, and greatly reduce the risk of fish poisoning.

[0022] Working principle: The drainage water in the breeding pond 1 flows into the microfilter 2 through the pipeline by gravity, and large particles such as residual bait and feces in the water are removed; the effluent of the microfilter 2 flows into the buffer tank 3 and the protein separator 4 by gravity through the pipeline, and the fine particles and organic matter in the water are further removed, and the buffer tank 3 performs water conditioning; the water in the buffer tank 3 is pumped into the precision filter 6 through the circulating water pump 5 to further remove tiny particles, and then enters the water inlet of the electrolytic cell 7 in the electrochemical treatment module, and the water is subjected to electrolytic oxidation reaction. , ammonia nitrogen degradation and microbial sterilization and removal are carried out. The water body after electrolytic oxidation enters the water inlet of the activated carbon filter 9 of the post-treatment unit from the water outlet of the electrolytic cell 7, and the residual chlorine, disinfection by-products, chlorate, perchlorate and bromate and other electrolysis by-products are removed by activated carbon adsorption filtration; the water body purified by the activated carbon filter 9 enters the CO2 remover 10 to further remove harmful gases such as N2, CO2, CO, H2 in the water body, and then returns to the breeding pond 1 by gravity, forming a fully closed circulating water breeding system.

[0023] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0024] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0025] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A factory-scale circulating aquaculture water treatment system based on electrochemical treatment, comprising an aquaculture pond (1), a pre-treatment unit, an electrochemical treatment module and a post-treatment unit, It is characterized in that The pre-treatment unit comprises a microfilter (2) connected to the culture pond (1), and also comprises a buffer tank (3), a circulating water pump (5) and a precision filter (6) arranged in sequence, the buffer tank (3) is also connected to a protein separator (4), the electrochemical treatment module performs an electrolytic oxidation reaction on the water body to degrade ammonia nitrogen and sterilize microorganisms, and the post-treatment unit is used to remove the by-products of electrolysis of the electrochemical treatment module; The electrochemical treatment module comprises an electrolytic cell (7) and a power supply control cabinet (8) for controlling the electrolytic cell (7); The electrolytic cells (7) are provided with a plurality of groups connected in parallel, and each group is independently provided with a power supply control cabinet (8); The tubular shell of the electrolytic cell (7) is made of U-PVC material. Five electrode groups are arranged in the electrolytic cell (7). Each electrode group contains five pairs of rectangular electrode sheets (RuO2-Ti). The effective area of ​​the anode is 0.57 m 2 ; The post-treatment unit comprises an activated carbon filter (9) and a CO 2 Remover (10), the CO 2 The output end of the remover (10) is connected to the breeding pond (1); The precision filter (6) is provided with a plurality of parallel connections; The activated carbon filter (9) is also connected to an ozone generator.

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