CN101548655A - Ecological closed cycle water fish-cultivating method - Google Patents

Abstract

The present invention belongs to an industrialization aquiculture field, particularly relates to a closed cycle water industrialized fish cultivating system. The system separates solid and liquid in a storage sedimentation basin and a backwater channel sedimentation and rotational flow pool sedimentation, the tiny particulate matter is separated and purified by a sandrock filtering bed of a one level biological filter based on the water particulate matter separation, the water purified by the one level biological filter is feed into a two stage biological filter, the biological film of biologic filling material in the one level and the two stage biological filters is degraded with ammonia nitrogen and azote nitrous acid, the total purifying rate of the water particulate matter reaches more than 99%, the culturing water is added with oxygen mechanically or by liquid oxygen, finally the water is disinfected and sterilized through a ultraviolet ray sterilizer, and the clean ecological water is feed into a fish pool, thus the waste water of the fish pool may be purified and used in repeat. The fish-cultivating system implements completely closed cycle water industrialized fish cultivation, the fish is out of a disease or less, and the fish survival is more than 80%.

Description

Ecological Closed Circulating Water Fish Culture Method

technical field

The invention belongs to the field of industrialized fish cultivation, and in particular relates to an ecological closed circulation water industrial cultivation system. It mainly uses natural seawater to build a pollution-free and healthy seafood industrialized breeding base.

Background technique

At present, the disease in the process of industrialized circulating water seawater fish farming has become a limiting factor in the development, and the root cause of the disease is that the circulating water system is not clean enough, and sediments such as feces and residual bait remain in the breeding system, polluting the water quality, and the sediment It is not only a source of water pollution, but also a material basis for breeding pathogens. Therefore, in the seawater industrialized circulating aquaculture in China, microfilters or curved sieves are mainly used to filter sediments, which can only filter out larger particles above 100 microns. Particles below 100 microns are still deposited in the aquaculture system. Over time, the bottom of the biofilter has a thickness of more than 100mm, and the sediment becomes corrupted and blackened, which becomes the root of the disease. Only by solving the root problem can a fundamental breakthrough in disease prevention be achieved.

For example, Xue Zhengrui, Jiang Hui, Chen Qingsheng et al. "Research and Development of Industrialized Circulating Water Fish Farming Engineering Technology" (Marine Aquaculture Research, Vol. 27, No. 4, 2006). In this journal, Xue Zhengrui and others focus on the use of mechanical filtration to remove suspended solids in the research of disease prevention. The disadvantage of microfilter filtration is that the removal rate of particulate suspended solids is low, and it still cannot fundamentally prevent the occurrence of diseases.

For example, the book "Sea Fish Aquaculture Theory and Technology" (China Agricultural Press, 2005) edited by Mr. Lei Jilin, an academician of the Chinese Academy of Engineering, comprehensively expounds the engineering design of industrial aquaculture of sea fish and the treatment of circulating water System, process route, etc., in which the particulate matter in the recirculating aquaculture system is still filtered by a microfilter, which is essentially a screen filter, particles larger than the mesh are intercepted, while particles smaller than the mesh are filtered and retained in the water body In the middle, pollute the water quality, breed pathogenic microorganisms, and cause fish diseases.

"Overview of Indoor High-density Recirculating Aquaculture Technology" (Fishery Modernization, Issue 3, 2006) written by Mr. Xie Qinghui of Taiwan Zhonghua Biotechnology Co., Ltd., although it is also a factory fish farming with recirculating water, it does not have efficient solid-liquid separation like the above Technology and disease are also big problems.

As another example, Mr. Chen Shulin from the Department of Biological Engineering of Washington State University in the United States introduced the water quality treatment method of the recirculating aquaculture system in "A Brief Introduction to the Water Quality Treatment Technology of Closed Recirculating Aquaculture" (Fishery Modernization, No. 5, 2004). The screen microfilter filters particulate matter; the other is the fine sand fluidized bed method. The working principle of the fine sand fluidized bed is that water flows upward from the bottom of the sand layer, and the water flow floats the sand particles. The purpose is to use the biofilm on the surface of the sand particles to degrade harmful substances in the water. ammonia nitrogen, nitrite nitrogen, etc., so it cannot filter particulate matter.

As another example, Tianjin Haifa Zhenpin Industrial Development Co., Ltd. is the largest circulating water industrialized fish farming enterprise in my country. The company uses curved sieves to filter sedimentary particles, mainly to filter out particles above 100 microns, and during the filtration process due to water erosion Many large particles are turned into small particles and remain in the water, resulting in turbidity and deposition of water quality, which becomes a hotbed for the growth of pathogens and affects the healthy breeding of fish.

In addition, Mr. Chen Xuefeng's "Factory Fish Farming Infrastructure Configuration" (Beijing Aquaculture, No. 4, 2003) uses a gravity-type valveless filter to filter particulate matter, which is a better solid-liquid separation method. The problem is: the head of the valveless filter is high, consumes a lot of energy, and the waste water from backwashing is not suitable for use in the circulating water fish farming system with low head and low energy consumption.

Most of the industrialized aquaculture in our country adopts the direct discharge type flowing water fish farming. According to statistics, the total area of the straight discharge type flowing water fish farming is about 3 million square meters. Circular purification treatment does not have the ability to prevent and control diseases, resulting in continuous and frequent occurrence of diseases, and diseases become restrictive factors for straight-line running water fish farming. The output is low, so most of them are losing money, and there is a serious underutilization, and the utilization rate of industrial fish farming facilities is less than 50%.

In the 21st century, a closed circulating water fish farming method appeared in our country. The scale is small, with a total scale of about ^30,000m2 . However, the disease has not been well controlled due to the emergence of the circulating aquaculture method. The level is low, especially the removal rate of particulate matter in the water body is not high, and the water quality is turbid, which affects the respiration of fish. In the long run, particulate matter is deposited in the recirculation culture system, corrupting water quality, and a large number of pathogens breed, resulting in fish disease and death, low survival rate, and even Individual manufacturers were wiped out and suffered serious losses. At present, my country's closed recirculating aquaculture system does not really realize completely closed recirculating aquaculture, but directly discharges the concentrated sewage in the recirculating system, polluting the environment, which belongs to the semi-closed recirculating aquaculture method, and the equipment and facilities The cost is higher, the total cost per square meter is 2000-3000 yuan (excluding land fees), and the project cost per square meter of the present invention is only 200-300 yuan.

In addition, the disease brings another potential harm, that is, the use of drugs to treat diseases in the breeding process, and even the phenomenon of drug abuse, resulting in drug residues in farmed products. Lost this excellent variety, after 3 years of hard work, it was restored in 2008.

The common outstanding problems of the above-mentioned direct discharge flow-type or closed (actually semi-closed) circulating water industrialized farming methods are: (1) unfavorable disease control in the breeding process, frequent occurrence of diseases, low survival rate, generally Below 40%, the whole is in a state of loss; (2) the general closed circulation water factory breeding project has high cost, high energy consumption, and sewage discharge, which is not conducive to popularization.

Contents of the invention

In view of the above-mentioned basic status quo, the purpose of this invention is to provide a kind of ecological closed circulating water fish farming method, which has the industrialization of green seafood food without getting sick or less sick in the fish farming process, no medicine, no residue, and zero discharge. The seawater fish farming base takes into account the realization of land saving, water saving, energy saving, pollution-free, low engineering cost, fully enclosed, fully controlled, easy to operate, and easy to promote.

The present inventor conducted in-depth exploratory research on the prevention of fish diseases, created a clean and ecological closed circulation water fish farming method, and completed the present invention on this basis.

In order to achieve the above object, the ecological closed circulating water fish culture method provided by the present invention comprises:

1. Water storage and sedimentation tank: build a water storage and sedimentation tank near the water intake near the coast. The water storage depth of the storage and sedimentation tank should be more than ^2m , and the area should be more than 20,000m2. A water pump station will be built beside the water storage tank to supply water to the water distribution workshop;

2. Water distribution workshop: The water distribution workshop is equipped with sand filters, clean water tanks, water distribution tanks, water pumps and plate heat exchangers; the water distribution workshop supplies water to the fish farming workshop, and the daily water supply is generally about 20%;

Among them, the natural seawater is pumped by the water pump station and sent to the sand filter tank. The water delivery pipe located on the upper part of the sand filter tank is made of polyethylene material, and holes are drilled around the pipe at a distance of 20-30mm, with a diameter of 8-10mm. The length of the pipe with holes is not less than 2000mm;

3. Fish pond: The size of the fish pond is designed according to the amount of water circulation. For example, once per hour, the area of the fish pond should be less than 30m ² /pond; The slope is 5%; the return pipes and sewage pipes in the fish pond are pre-buried under the bottom of the pond, and the central pipe is connected with a tee;

4. Backwater channel: The backwater channel is located on the outside of the fish pond, the channel width is 500mm, the height is the same as the top of the fish pond, the slope is 0.2%, and the bottom corner is arc-shaped; a trash blocking wall is set at the end of the backwater channel flow direction , with a height of 400mm, located at the place where the backwater flows to the final fish pond; on the inner side of the trash wall, a sewage outlet is set at a distance of 500mm from the wall; multiple sewage outlets are set at the bottom of the backwater channel, with a distance of 6-12m, and each sewage discharge There is a pot-bottom-shaped sewage collection tank with a diameter of 500mm, the depth of the sewage collection tank is 50mm, and a sewage outlet is set in the center of the sewage collection tank. The diameter of the sewage outlet is 110mm, and the sewage outlet leads to the sewage ditch;

5. Swirl pool: The swirl pool is located at the end of the backwater channel and the fish pond, and its bottom is 400mm deeper than the fish pond; the water inlet of the swirl pool is located 400mm above the bottom of the backwater channel, and the water inlet is tangent Installation is easy to form swirl flow; there is a sewage outlet in the center of the bottom of the swirl pool, with a centripetal slope of 10%, and the opening of the sewage outlet is connected to the sewage ditch; there is a channel at the level of the upper part of the swirl pool and the water inlet. The opening to the return pump tank should be larger than or equal to the water inlet;

6. Backwater pump tank: The backwater pump tank is located between the swirl pool and the water supply tank on one side of the biofilter, and a backwater pump is installed in it; the top of the backwater pump tank is at the same height as the swirl pool or fish pond, and the bottom Sewage discharge tank is provided, and the bottom angle is arc-shaped;

7. First-level biological filter: The filter bed of the first-level biological filter is mainly made of sand and gravel, and there is a fine sand layer. At the bottom of the sand layer, a sieve silk is laid. Under the sieve, there are pebbles. A layer of round hole plastic mesh. The backwash sewage pipe is installed at the top 100mm of the fine sand layer of the primary biological filter; the bottom of the filter is provided with a sewage outlet, and the slope is 2% lower towards the sewage outlet; the ratio of the area of the primary biological filter to the total area of the fish pond is 1: 7-10;

8. Secondary biological filter: The secondary biological filter depends on the area of the fish pond; the secondary biological filter is a three-dimensional biological filler purification tank, and the purified water flows in from the bottom of the primary biological filter, and then the secondary biological filter The upper part of the filter flows into the water supply tank, and the net width of the water supply tank is 600mm; the secondary biological filter supplies water to the water supply tank through the water hole on the upper part of the boundary wall. 10-12; the ratio of the area of the secondary biofilter to the fish pond is 1:14-17; the bottom of the secondary biofilter is provided with a sewage outlet, and the slope is 2% towards the sewage outlet; the boundary wall of the secondary biofilter 300-400mm lower than the primary biological filter;

Among them, there is a water passage between the primary and secondary biofilters, and a control valve is installed at the bottom of the water passage;

9. Sewage treatment pool: The sewage treatment pool is connected to the water distribution workshop through the sewage ditch; the sewage treatment pool includes a primary sewage treatment pool and a secondary sewage treatment pool, and aquatic plants, algae and shellfish that can purify fish farming wastewater are cultivated in the pool; The secondary sewage treatment pool is connected to the reservoir, and a sand filter wall is installed in the secondary sewage treatment pool. After the sewage purification reaches the standard, it is filtered by the sand filter wall and then flows into the reservoir for reuse.

10. Ultraviolet sterilizer: The ultraviolet sterilizer is installed at the front end of the water circulation and purification water supply tank.

In the present invention, according to the application characteristics, the biological filler involved, wherein the filler of the primary biofilter is mainly sand and gravel, the size of the sand is 0.5mm-1.5mm, and the size of the pebble is 20-150mm. The installation method is the filter bed type. The sand and gravel filler not only has the function of intercepting tiny particles, but also grows biofilm on its surface, and also has the function of purifying water quality.

According to the above-mentioned characteristics, the biological filler of the secondary biofilter involved is a three-dimensional filler, which is a brush-like three-dimensional elastic filler with a diameter of 150 mm made of polyethylene wire. Biofilm grows on the surface of the filamentary filler, which also has the effect of purifying water quality. Function.

According to the above-mentioned characteristics, the length of the secondary biological filler involved is 200mm from the bottom of the pool and 200mm from the top of the pool. Steel casing rings are pre-embedded on both sides of the pool wall. The distance between the rings is 200mm, symmetrical up and down, so as to fix the biological filler The pull wire, the soft plastic tube covered by the pull wire steel wire can play a rust-proof role, and the three-dimensional biological packing density is 49-81 pieces/m ² .

According to the above characteristics, each production unit is equipped with a water distribution workshop, and one production unit includes 8-10 aquaculture systems; the ratio of the area of the sand filter in the water distribution workshop to the area of the fish pond is 1:20, and the space at the bottom of the sand filter 800-1000mm, use reinforced concrete beams to support the sand and gravel filter material. The reinforced concrete beams are 120mm×120mm×3000mm. A layer of round-hole plastic plates are laid on the beams, and 200mm of pebbles are laid on it. The surface of the pebbles is paved with small pebbles. Lay 40-60 mesh sieve tulle on it, and lay washed fine sand on the sieve tulle, the fine sand particle diameter is 0.5-1.5mm, and the fine sand layer thickness is 500-700mm.

Among them, multiple sewage discharge pipes for backwashing are installed along the sides of the sand filter \wall at 100 mm above the sand layer, with a diameter of 110 mm and a distance of about 2 meters; the bottom of the sand filter \ is connected to the clean water pool through a valve; the volume of the clean water pool is 100 m ³ -200m ³ ; the clean water pool \ and the bottom of the water distribution pool (18) are connected by a butterfly valve with a diameter of 200mm, and its volume is the same as that of the clean water pool \.

According to the above characteristics, the total length of the backwater channel is about 60m and the width is 500mm; there is a pot-shaped groove with a diameter of 500mm at the bottom of the sewage outlet of the backwater channel, and the depth of the groove is 50mm; the sewage outlet in the center of the groove leads to the middle of the fish pond sewage ditch.

According to the above characteristics, the swirling pool has the same or slightly smaller area than the fish pond, and its bottom is 400mm deeper than the fish pond.

According to the above characteristics, the filter bed material of the primary biofilter involved is mainly sand and gravel, the thickness of the fine sand layer is 300mm, the bottom of the sand layer is laid with 40-60 mesh silk screen, and the bottom of the screen silk screen is pebbles, and the thickness of the pebble is 200mm And the bottom is to lay a layer of round-hole plastic mesh on the beam. The beam supporting the filter material of the filter bed is a reinforced concrete structure with a specification of 120mm×120mm×3000mm. , The ratio of the area of the primary biofilter to the total area of the fish pond is 1:7-10, and the boundary wall of the primary biofilter is 300-400mm higher than that of the secondary biofilter.

According to the above characteristics, the secondary biofilter and the water supply tank with a net width of 600mm on one side are connected through a water pipe with a diameter of 110mm on the upper part of the boundary wall; -12; the ratio of the secondary biofilter and the area of the fish pond is 1: 14-17; the bottom of the secondary biofilter (6) is provided with a sewage outlet, with a slope of 2% to the sewage outlet, and the pipe diameter of the sewage outlet is 160mm. And install the butterfly valve;

The water channel between the primary and secondary biofilters is connected through the bottom water valve, and a total of 3 to 5 butterfly valves with a diameter of 160mm-200mm are installed equidistantly.

According to the above-mentioned characteristics, the ultraviolet sterilizer is composed of a polyethylene tube, an ultraviolet lamp tube, a quartz casing, a ballast, etc.; the polyethylene pipe diameter is 400mm, the wall thickness is 8-10mm, the length is 1550mm, and the ultraviolet lamp tube is 75 watts. Single-ended wiring, lamp tube length 1540mm, equipped with appropriate ballasts, quartz sleeve diameter 25mm, length 1600mm, built-in ultraviolet lamp tubes, each ultraviolet sterilizer is equipped with 12 lamp tubes, and is installed on the side of the two ends of the ultraviolet phase sterilizer Weld the water inlet and outlet pipes, and weld 2 inspection holes on the upper part.

According to the above characteristics, the mentioned backwater pump is a mixed-flow pump, and its suction pipe is installed in an "n" shape with an elbow; the backwater pump may be equipped with a frequency converter.

The three-dimensional biological filler mentioned above is purchased by Jiangsu Yixing Environmental Protection Equipment Factory, and its length can be customized by the manufacturer according to the depth of the biological filter.

In a word, the present invention is an ecological closed circulating water fish farming method. Compared with the project cost of the traditional direct row flowing water factory fish farming, the investment amount is only increased by about 30%, but it is only the cost of other closed circulating water fish farming. 10% of the project cost, and the breeding output is about 5 times of the national average 6kg/m ² . Since it is a closed internal circulation breeding system, the water quality is purified through backwater sedimentation separation, cyclone sedimentation separation, biofilter filtration and biofilm, through water body oxygenation, ultraviolet disinfection, fish farming wastewater is purified and recycled, and a preventive system is established. The high-efficiency life guard system for disease occurrence has reached the purpose of not getting sick or less getting sick in fish farming. The focus of the present invention is to eliminate the material basis for the growth of pathogenic microorganisms through solid-liquid separation technology, and control the quantity of pathogenic microorganisms in a balanced state where fish do not get sick, thereby obtaining the effect of no or less disease in fish farming; in addition, the present invention Aiming at the outstanding problems in the industrialized recirculating aquaculture system of seawater fish——diseases, the first-level biofilter and the second-level biofilter are used to degrade harmful substances such as ammonia nitrogen and nitrite nitrogen, and the particles are separated by settling through the return channel. Three solid-liquid separation processes, such as the sedimentation separation of the backwater swirl tank and the sand filtration of the first-level biological filter, separate 99% of the particles and effectively prevent the occurrence of diseases. Solve it fundamentally, thoroughly remove particulate matter deposition pollution, eradicate the basis of disease, clean and healthy fish farming, and truly realize the ecological breeding method of fish farming without getting sick and less sick.

Description of drawings

Fig. 1 is a system plan view of the present invention;

Fig. 2 is the technological process of Fig. 1 ecological type closed circulation water fish farming method.

Detailed ways

The present invention will be further described below in conjunction with the embodiments of the accompanying drawings.

As shown in Figure 1, first select a site along the coast of natural seawater with no runoff pollution, convenient transportation, sufficient agricultural power, and broadband network information conditions, build a water storage sedimentation tank 1, and set a sluice 2 in the direction of the corresponding seawater. Generally, the size of the pool to be built is more than 20,000m ² . Water storage sedimentation tank 1 is dug deep as far as possible, reaches the degree of receiving water at high tide, reduces power water storage, saves electric power. If the soil quality of the storage and sedimentation tank 1 is too soft, slope protection shall be provided to avoid muddy water due to the impact of wind and waves. The water holding depth of the water storage sedimentation tank 1 should be more than 2m, which is conducive to maintaining stable water quality. Build geothermal well 3 near water storage sedimentation tank 1.

Then build water distribution workshop 4. The main function of the water distribution workshop 4 is to process raw water; the water distribution workshop 4 is mainly equipped with a sand filter tank 16, a clean water tank 17, a water distribution tank 18 and other supporting equipment. Purified water quality is advisable with natural gravity sand filter, and each production unit (8-10 cultivation system) builds a water distribution workshop, and the ratio of sand filter 16 areas and fish pond 7 areas is 1: 20. The bottom between the sand filter tank and the clear water tank 17 is installed with 3 cross-water butterfly valves, with a diameter of 200mm, through which the sand filter water 16 enters the clear water tank 17, and the sand filter tank 16 can also be backwashed by the water storage of the clear water tank 17. The bottom of the sand filter 16 slopes down toward the sewage outlet with a slope of 2%, and the diameter of the sewage outlet is 160 mm, controlled by a butterfly valve. Backwash sewage outlets are arranged around the sand filter 16, the sewage outlets are located 100mm above the sand layer, the diameter of the sewage outlets is 110mm, and they are controlled by internal intubation pipes or external valves. In addition, the sand filter tank 16, the clean water tank 17 and the water distribution tank 18 are arranged in sequence, the distance between each tank is 600 mm, and three butterfly valves with a diameter of 200 mm are installed between each tank to connect. The water distribution pool 18 is mainly used for temperature regulation and salt regulation. One side of the clear water pool 17 is a platform, on which equipment such as a pumping station 13, a plate exchanger (not marked in the figure), an oxygen station 10, etc. are installed. In addition, geothermal well 3, cold water well 2, power distribution room 11 and other equipment are configured. When the workshop needs to replenish water, the pumping station 13 pumps water from the water distribution pool 18 into the primary biofilter 5 to participate in the breeding cycle.

Build a biofilter. The main function of the biofilter is to filter out the tiny suspended particles that have not been completely precipitated and separated. At the same time, the nitrifying bacteria and nitrosating bacteria on the biofilm can degrade harmful substances such as NH ₃ and NO ₂ ^- in the water, so that the water quality is fully clear and purified. . The biological filter is divided into two stages, which flow up and down in series. The biofilter includes:

Primary biofilter 5. The specifications of the biological filter are 6m long x 6m wide x 3m deep. The filter bed is mainly made of sand and gravel, and the thickness of the fine sand layer is 300mm. Below is the pebble, the thickness of the pebble is 200mm, the beam supporting the pebble is a reinforced concrete structure, 120mm×120mm×3000mm, and then the small beam is supported by the longitudinal beam, the distance between the beams is 100mm, the distance between the beams is filled with pebbles, and a layer of round holes is laid on the bottom of the pebble Plastic plate mesh to prevent pebbles from leaking out. Install backwash sewage pipes on both sides of the pool wall at a distance of 100mm from the sand layer surface, with a diameter of 110mm, controlled by intubation or valves, and the backwash sewage enters the sewage ditch through the sewage pipe. The ratio of the area of the primary biofilter to the total area of the fish pond is 1:7-10, and the boundary wall of the primary biofilter is 300-400mm higher than that of the secondary biofilter, forming a pressure difference and a fast filtration speed.

Secondary biofilter 6. The number of stages can also be increased or decreased according to the needs. The size of the secondary biofilter is 6m×4m×3m. The three-dimensional biological filler is installed in the secondary biological filter. Biofilm grows on the surface of the three-dimensional biological filler, which can purify water quality. Purified water enters from the bottom and flows out from the top into the water supply tank. The net width of the water supply tank is 600mm. The secondary biofilter passes water to the water supply tank through the upper part of the boundary wall. The water hole diameter is 110mm. The ratio of the secondary biofilter to the area of the fish pond is 1:14-17.

Above-mentioned primary biofilter 5 and secondary biofilter 6 have a spacing of 600mm, and the bottoms of connected primary biofilter 5 and secondary biofilter 6 are installed with water valves, which are butterfly valves used in this embodiment; diameter 200mm , equidistant installation of three water valves. In addition, the primary biofilter 5 can be backwashed through the secondary biofilter 6, and backwashed 1-2 times a day.

Biological fillers are added to the primary biofilter 5 and the secondary biofilter 6 of the present invention. The biological filler of the primary biofilter 5 is mainly sand and gravel, and is installed in the form of a filter bed. The biological filler of the secondary biological filter 6 is a three-dimensional elastic filler with a diameter of 150-180mm. The length of the biological filler is 2.6m, 200mm from the bottom of the pool, and 200mm from the top of the pool. 200mm, symmetrical up and down, fixed biological filler wires, three-dimensional biological fillers are suspended in the secondary biological filter in a vertically fixed manner, and the density of three-dimensional biological fillers is 49-81 pieces/m ² .

Then set up fish pond 7. Fish pond 7 sizes are designed according to water circulation, and in the present embodiment, circulating water exceeds 1 time/h, and fish pond 7 specifications are (6m * 6m * 1m). The shape of the pool is square, with rounded corners, central drainage and return water, the diameter of the return water pipe is 160mm, and the centripetal slope of the pool bottom is 5%. If the amount of water circulation is increased, the fish pond can be appropriately enlarged, which is (6m×6m×1m)-(7m×7m×1m). The shape of the pool is square with rounded corners. The mouth and the backwater port are the same common port, with a centripetal slope of 5%; the return pipes and sewage pipes in the fish pond 7 are pre-buried under the bottom of the pool, and the central pipe is connected by a tee, and one side leads to the return water channel 8. The other side leads to the sewage ditch 9 with a pipe diameter of 160mm. Or the center pipe is connected with an elbow, and then the return pipe and the sewage pipe are connected with a tee. Water supply pipe is set by fish pond 7, and this water supply pipe adopts polyethylene material, is positioned at fish pond top, pond inner side, pipe top both sides and pond wall top level, can select water supply pipe diameter 160mm, 200mm and 250mm.

The diameter of the 7 water outlets in the fish pond is 75mm, controlled by a butterfly valve, installed diagonally and tangentially, so that the water entering the pond can form a swirling flow. The water entering the pool should be guided deep into the bottom of the pool, 100mm from the bottom, and the port is in the shape of a mouth, in the shape of a water spray, which can promote the rotation of the water flow.

Be located in fish pond 7 and set backwater and sewage pipeline. The return pipe is connected with the sewage pipe, the outlet is located at the center of the bottom of the fish pond 7, and is pre-buried at the bottom of the fish pond 7, then connects the return pipe and the sewage pipe with a tee, the exit of the return pipe is at the return channel 8, and the exit of the sewage pipe is at Sewage ditch 9 under the workshop passage. Both backwater and blowdown are controlled by intubation without valves.

Then set up the backwater channel 8. The backwater channel is designed for the settlement and separation of sediments. When the fish pond water returns to the backwater pump tank, most of the feces and residual bait are deposited at the bottom of the backwater channel 8 and pass through the sewage outlet. out of the culture system. Backwater channel 8 is located at fish pond 7 outsides, and channel is wide 500mm, and height is identical with the top of fish pond, and bottom angle arc shape is convenient to cleaning. Set up a trash wall at the end of the flow direction of the backwater channel, and set a sewage outlet 500mm away from the wall on the inner side of the trash wall, and the sewage outlet leads to the sewage ditch 9 . The backwater channel 8 is extended in ten fish ponds 7, and the slope is relatively gentle, and the slope is 0.2%. Every two fish ponds 7 are provided with a sewage outlet at the bottom of the backwater channel, pipe diameter 110mm, opening in the middle of the backwater channel, the intubation pipe control in the channel, and the outlet is in the sewage ditch. There is a pan-shaped groove with a diameter of 500mm around the intubation pipe of the sewage outlet in the return channel 8, and the depth of the groove is 50mm, which is convenient for the accumulation and discharge of sediment.

In the above, the end of the sewage ditch 9 is connected to a primary sewage treatment pool 14 and a secondary sewage treatment pool 15 , and is connected to the reservoir 1 through the secondary sewage treatment pool 15 . Like this, the concentrated sewage discharged from the sewage ditch 9 can be sent back to the reservoir 1 for recycling after being treated respectively by the primary sewage treatment pool 14 and a secondary sewage treatment pool 15. In the present invention, aquatic plants and algae are cultivated in the pools of the primary and secondary sewage treatment pools, and bottom sowing is suitable for benthic shellfish. After the sewage is purified up to the standard, it is filtered by the sand filter wall and then flows into the reservoir for reuse.

In this embodiment, the secondary biofilter 6 has a water supply tank 19, and there is a return pump tank 20 between the water supply tank 19 and the swirl pool 23. The specification of the return pump tank 20 is 2m long x 1.5m wide x deep 2m; a return pump is installed in it; the top is the same height as the swirl pool, and its surface is covered with wooden boards, which is convenient for operation and management. There is a sewage discharge tank at the bottom, the diameter of the sewage discharge tank is 600mm, and the bottom corner is arc-shaped, which is easy to clean. If the sewage ditch of the workshop is deep, the outlet of the sewage pipe can be connected to the sewage ditch.

A return pump 21 and an ultraviolet sterilizer 22 are installed at the return pump tank 20 . In the embodiment, the return water pump 21 is more suitable for the mixed flow pump according to the farming characteristics. Generally, a pump with an 8 o'clock diameter and a diameter of 200mm is used, and the water supply volume is 200m ³ -400m ³ . The water supply capacity of the motor is 200m ³ /h, and the water supply capacity of the 7.5 kilowatt motor is 400m ³ /h. If necessary, it can be further increased. The backwater pump 21 is equipped with a frequency converter to save electric energy.

The installation of the return pump 21: the suction pipe reaches the bottom of the return pump tank 20, 3-4 semicircular openings or enough suction holes are opened at the bottom of the nozzle, the diameter of the hole is 20mm, so as to facilitate water absorption, and the connection between the suction pipe and the water pump is connected with an elbow It is connected into an "n" shape, so that the water pump does not need to be filled when the power is off or the pump is stopped, and it can be filled with water after 1-3 minutes after starting up, which is convenient to use. The outlet pipe of the water pump is directly connected to the first-stage biological filter, and the water outlet adopts a watering can-shaped porous water spray, which is conducive to the removal of harmful gases such as CO ₂ and avoids damaging the biological filter bed.

The swirl pool 23 is then set up. Design the swirl pool 23 at the backwater end of the culture system, that is, the swirl pool 23 is set between the fish pond 7 and the return pump tank 20 . Its main function is to deposit the particles that have not been completely settled in the swirl pool 23 through cyclone centrifugation, deposit the particles in the center of the bottom of the pool, and discharge them out of the cultivation system. The specification of whirl pool 23 can be the same size as fish pond, also can be slightly less than fish pond. The bottom of the swirling pool should be 400mm darker than the fish pond, and the opening that enters the swirling pool 23 from the backwater channel 8 is located at the bottom of the backwater channel at 400mm. It is easy to install and generate larger swirl to obtain better centrifugal force. The sewage outlet is set at the center of the bottom of the pool, with a diameter of 160mm and a centripetal slope of 10%. The sewage outlet opens in the sewage ditch (the same fish pond). Open at the position where the swirl pool 23 top is level with the water inlet, the opening diameter should be greater than or equal to the water inlet diameter, so that backwater flows into the backwater pump groove.

The installation of the ultraviolet sterilizer 22: the ultraviolet sterilizer 22 is a cylindrical structure, and the outer wall is a polyethylene plastic tube with a diameter of 400 mm. Twelve 75-watt ultraviolet lamps are installed in the cylinder, with a total power of 900 watts. 12000h is appropriate, the length of the lamp tube is 1540mm, and the quartz tube with a diameter of 25mm outside the lamp tube. In addition to the lamp tube, the ballast is the key control point of the ultraviolet efficiency, and attention should be paid to its matching.

The upper part of the ultraviolet sterilizer 22 is installed to check and wipe the window. The two ends of the ultraviolet sterilizer are connected to the water inlet pipe and the water outlet pipe with a pipe diameter of 160mm or 200mm. Configure 1 UV sterilizer.

Installation of liquid oxygen oxygenation: Equipped with 1 to 2 high-pressure liquid oxygen tanks of 15m ³ , which are general-purpose equipment. Configure a suitable gasifier. The function of the gasifier is to change the oxygen from liquid to gas, and send it through the pipeline to the gas tank of the gas-liquid mixing pump installed on the water supply pipeline. Each breeding system uses a set of high-efficiency A gas-liquid mixing pump with a power of 0.7 kW to 1.5 kW, or install a special gas diffuser. This device does not need to consume electricity, and the oxygen dissolution effect of the former is better than that of the latter. The dissolved oxygen content of the water inlet of the fish pond is 15mg/L-20mg/L, and the dissolved oxygen content of the water outlet of the fish pond is not less than 5mg/L. In order to prevent the need for special operation of the single pool, several small air pumps should be equipped to meet temporary needs.

In addition, according to the actual situation, it is not necessary to use the liquid oxygen breeding system. Each system needs to install a 1.5 kW gas-liquid mixing pump to make the dissolved oxygen content of the fish pond inlet reach 10mg/L. Or use a Roots blower to increase oxygen. At this time, the breeding density should be appropriately reduced.

Establish water quality monitoring: establish a special water quality testing room. The main detection contents are: NH ₃ , NO ₂ ^- , DO, pH, suspended matter content, bacteria count, protozoan content and types in the pool bottom sediment.

Establish an alarm system: Closed recirculating aquaculture needs to install an alarm system, mainly including operating equipment alarms, fish activity status monitoring and workshop monitoring. Operating equipment refers to circulating water pumps, oxygen-increasing liquid mixing pumps, Roots blowers, etc. Once shut down, an alarm will be issued immediately; fish activity status monitoring refers to observing the activity status and health of fish through underwater cameras and screen displays ; Workshop monitoring refers to observing the status of the workshop and dealing with abnormal situations in time.

The overall structural design of the workshop: The roof of the workshop adopts an arched or triangular steel frame structure, and the beams are made of anti-corrosion-treated 60mm×120mm×4000mm square wood, covered with simple and cheap thermal insulation materials, which should meet the local wind pressure and snow pressure requirements. The exterior walls around the workshop are of brick-concrete structure, and thermal insulation boards are used to reduce the temperature impact caused by climate change. On the premise of safety and thermal insulation, the project cost is reduced as much as possible.

Figure 2 shows the process flow chart of the ecological closed circulation water fish farming method.

Firstly, the natural seawater is stored in the reservoir, and the seawater is pumped into the circulation system of the fish farming workshop after sand filtration, temperature adjustment, and salt adjustment in the water distribution workshop. After filling with new water, the breeding system in the workshop starts to circulate . The circulation path is: the water in the fish pond flows out in the form of swirling flow, enters the return channel, performs the first solid-liquid separation in the return channel, and then performs the second centrifugal solid-liquid separation in the swirling pool, and the solid-liquid separation The water flows into the return pump tank, and is pumped into the first-stage biofilter with a mixed-flow pump, where tiny particles and pathogenic microorganisms are further filtered out, and the water treated by the first-stage biofilter flows into the second-stage biofilter. The biofilm grows on the surface of the three-dimensional biofiller, and the biofilm degrades harmful substances such as ammonia nitrogen and nitrite nitrogen in the water. The purified water flows into the water supply tank, and oxygen can be increased by using liquid oxygen in the water supply tank or by using an aerator in the fish pond. , Oxygenated water flows from the water supply tank through the ultraviolet sterilizer to sterilize and sterilize, and finally the clean water and ecological water are sent to the fish pond to realize the healthy breeding of ecological closed circulating water.

Sewage treatment: It is necessary to backwash the first-level biological filter 1-2 times a day, discharge the sewage from the backwater channel 1-2 times, and discharge the sewage from the swirling pool 1-2 times. The concentrated sewage is discharged through the sewage ditch under the pedestrian passage in the workshop After entering the first-level sewage treatment tank, after the first-level sewage treatment, it flows into the second-level sewage treatment tank, and the second-level treated water that has passed the inspection flows into the storage tank for reuse of circulating water. This kind of recycling treatment system is truly realized. Completely enclosed circulating water for healthy fish farming.

For fully illustrating the effect of the present invention, see following concrete breeding example:

According to the method of the present invention, a ^2100m2 fish farming experiment workshop is established, in which the area of the fish pond is ^1440m2 , which is divided into 4 culture systems, and each culture system is composed of 10 fish ponds and biofilter, and the area of the biofilter ^{is 60m2} ×4, namely 240m ² , there are 40 fish ponds in total, each with an area of 36m ² . 80,000 spot-banded grouper (Epinephelus malabaricus) were stocked. The breeding period was one year, and 69,936 fish survived. The survival rate reached 87.42%, and the output per unit area reached 24.73Kg/m ² . The output is 49.46kg/m ³ , the total output is 35611.10kg, the output value is 2848888.00 yuan, the total cost is 12134.23 million yuan, the profit is 16354.65 million yuan, and the profit rate is 134.78%.

The second experimental cycle (12 months as a cycle) is in progress. From the analysis of the current breeding situation, the breeding effect is better than the first experimental cycle.

Claims (11)

1. An ecological closed circulation water fish farming method, characterized in that: (1) Water storage and sedimentation tank: build a water storage and sedimentation tank (1) near the water intake near the coast. The water storage depth of the water storage and sedimentation tank (1) should be more than 2m, and the area should be ^more than 20,000m2. It should be built by the side of the water storage tank. The water pumping station supplies water to the water distribution workshop; (2) Water distribution workshop: Sand filter tank (16), clear water tank (17), water distribution tank (18), return water pump and plate heat exchanger are arranged in water distribution workshop (4); from water distribution workshop (4) to fish farming workshop Supplementary water supply, generally about 20% of the daily water supply; Wherein, natural seawater is pumped into the sand filter tank (16) by the water pumping station (13), and the water delivery pipeline positioned at the top of the sand filter tank (16) is made of polyethylene material, and holes are drilled at intervals of 20 to 30 mm around the pipeline, with an aperture of 8- 10mm, the length of the perforated pipe is not less than 2000mm; (3) Fish pond: The size of the fish pond (7) is designed according to the amount of water circulation, such as 1 time/h, the area of the fish pond (7) should be less than 30m ² / pond; the shape of the pond is square, with rounded corners, and a center with Drainage and backwater, centripetal slope drops 5%; The backwater pipeline and the sewage pipeline in the fish pond (7) are all pre-buried under the bottom of the pond, and the center pipe is connected with a tee; (4) backwater channel: the backwater channel (8) is positioned at the outside of the fish pond (7), and the wide 500mm of the channel is the same as the top of the fish pond (7), with a slope of 0.2% and a circular arc at the bottom; The end of the flow direction of the water channel is provided with a trash wall, with a height of 400mm, located at the fish pond (7) where the backwater flows to the end; on the inner side of the trash wall, a sewage outlet is set at 500mm from the wall; the bottom of the backwater channel There are multiple sewage outlets with a distance of 6-12m. Each sewage outlet has a pot bottom-shaped sewage collection tank with a diameter of 500mm. The depth of the sewage collection tank is 50mm. There is a sewage discharge outlet in the center of the sewage collection tank. (5) whirlpool: this whirlpool (23) is located at the end of backwater channel (8) and fish pond (7), and its bottom of the pool is darker than fish pond 400mm; The water outlet is located 400mm above the bottom of the return channel, and the water inlet is set tangentially; there is a sewage outlet in the center of the bottom of the swirl pool, with a centripetal slope of 10%, and the opening of the sewage outlet is connected to the sewage ditch (9); the upper part of the swirl pool There is an opening leading to the return pump tank at a position level with the water inlet, and the opening should be larger than or equal to the water inlet; (6) Backwater pump tank: the backwater pump tank (20) is located between the swirl pool (23) and the water supply tank (19) on one side of the biofilter, and the backwater pump (20) is installed in it; the backwater pump tank ( 20) The top is at the same height as the swirling pool or the fish pond (7), and the bottom is provided with a sewage tank, and the bottom angle is arc-shaped; (7) Primary biofilter: The filter bed of primary biofilter (5) is mainly made of sand and gravel, and is provided with a fine sand layer, and a sieve silk net is laid at the bottom of the sand layer, and pebbles are placed under the sieve silk net. Lay a layer of round-hole plastic mesh under the pebbles; install a backwash sewage pipe at the top 100mm of the fine sand layer of the primary biological filter (5); The ratio of the area of the filter tank (5) to the total area of the fish pond is 1: 7-10; (8) secondary biofilter: secondary biofilter (6) depends on the area of the fish pond; secondary biofilter (6) is a three-dimensional biofiller purification tank, and purified water is obtained by the primary biofilter (5 ) flows into the bottom, and then flows into the water supply tank (19) from the top of the secondary biofilter (6), and the net width of the water supply tank is 600mm; the secondary biofilter (6) flows into the water supply tank ( 19) Water supply, the installation position of the water hole is 500mm from the top of the boundary wall, and 10-12 water holes are set; the ratio of the area of the secondary biofilter (6) to the fish pond (7) is 1:14- 17. The bottom of the secondary biofilter (6) is provided with a sewage outlet, with a slope of 2% to the sewage outlet; the boundary wall of the secondary biofilter is 300-400mm lower than the primary biofilter; Among them, there is a water passage between the primary and secondary biofilters, and a control valve is installed at the bottom of the water passage; (9) Sewage treatment pool: the sewage treatment pool is connected with the water distribution workshop (4) through the sewage ditch; the sewage treatment pool includes the first-level sewage treatment pool (14) and the second-level sewage treatment pool (15), and the cultivation in the pool can purify fish Aquatic plants, algae and shellfish of wastewater; the secondary sewage treatment pool is connected with the reservoir (1), and a sand filter wall is set in the secondary sewage treatment pool (15), and the purified water flows into the reservoir (1) through the sand filter wall ). (10) Ultraviolet sterilizer: this ultraviolet sterilizer (22) is installed on the front end of the water circulation purification water supply tank (19). 2. The ecological closed-type circulating water fish farming method according to claim 1, characterized in that: the filler of the first-stage biological filter (5) is mainly sandstone, and the size of the sand grains is 0.5mm-1.5mm. The size of the pebbles is 20-150mm, and the installation mode of the primary biological filter (5) is a filter bed type. 3. The ecological closed circulating water fish farming method according to claim 1, characterized in that: the biological filler of the secondary biofilter (6) is a three-dimensional filler made of polyethylene silk with a diameter of 150 mm. Brush-shaped three-dimensional elastic filler, and biofilm grows on the surface of the filamentary filler. 4. The ecological closed circulating water fish farming method according to claim 3, characterized in that: the length of the secondary biological filler is 200 mm from the bottom of the pool, and 200 mm from the top of the pool, and steel casing rings are pre-embedded on both sides of the pool wall , the distance between the rings is 200mm, and the upper and lower sides are symmetrical, so as to fix the guy wire of the biological filler. The soft plastic tube covered with the steel wire of the guy wire can prevent rust, and the density of the three-dimensional biological filler is 49-81 pieces/m ² . 5. The ecological closed circulating water fish farming method according to claim 3, characterized in that: each production unit is equipped with a water distribution workshop (4), and one production unit includes 8-10 breeding systems; The ratio of the area of the sand filter to the area of the fish pond is 1:20, the space at the bottom of the sand filter is 800-1000mm, and the sand and gravel filter material is supported by a reinforced concrete beam. The specification of the reinforced concrete beam is 120mm×120mm×3000mm. A layer of round-hole plastic board, on which 200mm of pebbles are laid, and the surface of the pebbles is paved with small pebbles, and a 40-60 mesh sieve is laid on it, and fine sand washed with water is laid on the sieve, and the particle size of the fine sand is 0.5-1.5mm, fine sand layer thickness 500-700mm. Wherein above the sand layer 100mm, a plurality of blowdown pipes for backwashing are installed along both sides of the sand filter tank (16) wall, with a pipe diameter of 110 mm and a distance of about 2 meters; the bottom of the sand filter tank (16) is communicated with the clear water tank through a valve; The clean water pool has a volume of 100m ³ -200m ³ ; the bottom of the clean water pool (17) and the water distribution pool (18) are connected by a butterfly valve with a diameter of 200mm, and its volume is the same as that of the clean water pool (17). 6. The ecological closed circulating water fish farming method according to claim 1, characterized in that: the total length of the backwater channel (8) is about 60m, and the width is 500mm; there is a sewage outlet at the bottom of the backwater channel (8) with a diameter of 500mm The bottom of the pot shape groove, groove depth 50mm; Groove center establishes drain outlet and leads to fish pond (7) middle part drain ditch. 7. The ecological closed circulating water fish farming method according to claim 1, characterized in that: the swirl pool (23) has the same or slightly smaller area than the fish pond (7), and the bottom of the pond is larger than the fish pond (7). (7) 400mm deep. 8. The ecological closed circulating water fish farming method according to claim 1, characterized in that: the filter bed material of the primary biofilter (5) is mainly sand and gravel, the thickness of the fine sand layer is 300mm, and the bottom of the sand layer is Lay 40-60 mesh sieve silk net, pebbles under the sieve silk net, the thickness of the pebbles is 200mm and the bottom is to lay a layer of round-hole plastic net on the beam, and the beam supporting the filter material of the filter bed is a reinforced concrete structure, the specification It is 120mm * 120mm * 3000mm, supports the small crossbeam with the longitudinal beam again, the distance between the crossbeams is 100mm, the ratio of the area of the primary biofilter (5) and the total area of the fish pond (7) is 1: 7-10, the primary The boundary wall of the biofilter (5) is 300-400mm higher than the secondary biofilter. 9. The ecological closed circulating water fish farming method according to claim 1, characterized in that: the secondary biofilter (6) and the water supply tank (19) with a net width of 600 mm on one side pass through the upper part of the boundary wall with a diameter of The 110mm water pipe is connected; the installation position of the water pipe is 500mm from the top of the boundary wall, and 10-12 water holes are set; the ratio of the area of the secondary biofilter (6) to the fish pond (7) is 1:14 -17; The bottom of the secondary biofilter (6) is provided with a sewage outlet, with a slope of 2% to the sewage outlet, the pipe diameter of the sewage outlet is 160mm, and a butterfly valve is installed; The water channel between the primary and secondary biofilters is connected through the bottom water valve, and a total of 3 to 5 butterfly valves with a diameter of 160mm-200mm are installed equidistantly. 10. The ecological closed circulating water fish farming method according to claim 1, characterized in that: the ultraviolet sterilizer (22) is composed of polyethylene tubes, ultraviolet lamp tubes, quartz sleeves, ballasts, etc.; Tube diameter 400mm, wall thickness 8-10mm, length 1550mm, UV lamp tube 75 watts, single-ended wiring, lamp tube length 1540mm, equipped with appropriate ballast, quartz sleeve diameter 25mm, length 1600mm, built-in UV lamp tube, each A UV sterilizer is installed with 12 lamp tubes, and the water inlet and outlet pipes are welded on the sides of both ends of the UV sterilizer, and 2 inspection holes are welded on the upper part. 11. The ecological closed circulating water fish farming method according to claim 1, characterized in that: the backwater pump (21) is a mixed-flow pump, and its suction pipe is installed in an "n" shape with an elbow; the backwater pump (21) Or configure the drive.

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