Aquatic organism seedling culture and seedling cultivation seawater treatment system based on natural ecological cycle

Abstract

The invention discloses an aquatic organism seedling culture and seedling cultivation seawater treatment system based on natural ecological circulation, which comprises a natural sedimentation tank, a secondary sedimentation algae culture tank, a multi-stage dark sedimentation tank, a primary sand filter tank and a secondary sand filter tank, the tail end of the secondary sand filter tank is connected with a water storage tank, and a water pump is arranged to be connected with a water storage tower; a seawater concentration device and an ultrafiltration device are further arranged between the water storage tower and the aquatic organism nursery pond, the secondary precipitation algae breeding pond can be directly connected with the juvenile mollusk temporary breeding pond and can be directly used for juvenile mollusk breeding, and the sand filtering pond is further provided with a backwashing design so that recycling can be facilitated; the seawater passing through the first sand filtration device, the second sand filtration device, the concentration device and the ultrafiltration device can be used for breeding larvae of aquatic organisms; according to the water treatment system disclosed by the invention, by virtue of a multi-stage structural design and in cooperation with natural environment regulation and control of illumination and sun shading, the defects of chemical and biological purification and the defects of pure physical sand filtration are avoided in a natural ecological manner, so that supply of water for large-batch breeding of aquatic organisms and shellfish culture is guaranteed, and different requirements of large factories are met.

Description

Technical Field

[0001] The invention relates to the technical field of seawater treatment for aquatic organism seedling and seedling cultivation, and in particular to a seawater treatment system for aquatic organism seedling and seedling cultivation based on natural ecological cycle. Background Art

[0002] As people's living standards improve, consumers' recognition and demand for seafood are increasing, which has led to the continuous development of marine aquaculture. Marine aquaculture is a way of artificially cultivating seafood in areas such as mudflats and shallow seas using seawater, which is an important way of aquaculture in my country. Before aquaculture, the seawater used needs to be purified to ensure that the seawater used for aquaculture meets the standards and reduce the harm of pollutants to aquaculture products.

[0003] In addition, data from the "2023 East China Sea Marine Ecological Early Warning Monitoring Bulletin" released by the State Oceanic Administration showed that the marine environmental pollution situation in the East China Sea is still severe. A total of 24 red tides have been found in the East China Sea, with an annual cumulative area of ​​1,016 square kilometers, of which 17 harmful red tides have occurred, with a cumulative area of ​​869 square kilometers; in addition, the nearshore seawater in the East China Sea is generally mixed with a large amount of mud and impurities. The current pre-treatment of aquaculture source water, the ordinary physical sand filtration scheme, cannot remove organic matter and some impurities in the water, affecting subsequent aquaculture or seedling cultivation. The introduction of chemical methods for treatment may, on the one hand, cause secondary pollution problems, and on the other hand, will also lead to a substantial increase in costs. The biological method is highly dependent on site maintenance and the participation of equipment. Therefore, conventional simple biological treatment is not necessary. Summary of the invention

[0004] In view of the prior art, the purpose of the present invention is to provide a water treatment system for aquatic biological seedling and seedling cultivation based on natural ecological cycles, which adopts physical methods to carry out multi-stage sedimentation, dark sedimentation and multi-stage sand filtration on seawater in natural sea areas, so as to pre-treat the source water fully. In addition, the pretreatment system of the present invention has a simple structure and a long maintenance cycle and can adapt to the installation of large or small areas.

[0005] In order to achieve the above purpose, the technical solution adopted by the present invention is: a seawater treatment system for aquatic organism seedling and seedling cultivation based on natural ecological cycle, including a natural sedimentation tank, the natural sedimentation tank is provided with a water diversion pipeline or a steep gate gate connected to the natural sea area, the water diversion pipeline or the steep gate gate is used to lead the seawater in the natural sea area into a large natural sedimentation tank, the natural sedimentation tank is provided with 60-100 mu, which is used to preliminarily precipitate the suspended sediment impurities in the seawater of the natural sea area;

[0006] The secondary sedimentation algae breeding pool is set up with an area of ​​15-20 mu and a steep gate is set between the natural sedimentation pool. The steep gate leads the upper relatively clear seawater in the natural sedimentation pool after one sedimentation into the secondary sedimentation algae breeding pool. The secondary sedimentation algae breeding pool is connected to a multi-stage dark sedimentation pool. The natural sedimentation pool and the secondary sedimentation algae breeding pool are both set up in a natural environment. After the seawater in the natural sedimentation pool to the secondary sedimentation algae breeding pool is precipitated and continuously exposed to sunlight, abundant natural algae in the seawater will be formed in the water body;

[0007] A multi-stage dark sedimentation tank is provided, wherein a large tank of 5,000 cubic meters is provided and divided into a plurality of dark sedimentation sub-tanks. A sunshade net is also provided above the multi-stage dark sedimentation tank. The partition walls between the dark sedimentation sub-tanks include an overflow wall with an overflow pipe at the upper part and a bottom seepage wall with a water outlet at the lower part. The dark sedimentation sub-tanks are also provided with a seepage board and a pebble sedimentation layer. The multi-stage dark sedimentation tank is used for multi-stage layer-by-layer filtration and sedimentation of algae carcasses that die in the seawater due to lack of light.

[0008] The primary sand filter tank is provided with a water pump to extract seawater in the dark sedimentation sub-tank after sedimentation at the end of the multi-stage dark sedimentation tank. The primary sand filter tank includes an overflow sedimentation tank, a multi-layer filter tank and a bottom infiltration tank. The main pipeline connected to the water pump is provided with a tee to connect a first branch pipe and a second branch pipe. The first branch pipe is connected to the bottom infiltration tank. The bottom infiltration tank is used to supply water to the overflow sedimentation tank. The overflow sedimentation tank is used to supply water to the multi-layer filter tank. An overflow pipe is provided between the overflow sedimentation tank and the multi-layer filter tank. The second branch pipe is connected to the multi-layer filter tank. The first branch pipe and the second branch pipe are both provided with valves to control the water flow on and off.

[0009] The multi-layer filter tank is connected to the overflow sedimentation tank water inlet through an overflow pipe, a water outlet cavity with a water outlet pipe is arranged at the bottom, a permeable plate is arranged on the top of the water outlet cavity, and multiple layers of filter materials are arranged on the permeable plate, including a fine sand layer, a sandstone layer, and a pebble layer arranged in sequence from top to bottom. A sewage pipe is arranged above the fine sand layer, and the sewage pipe is connected to the drainage channel outside the multi-layer filter tank. The water outlet of the second branch pipe is connected to the water outlet cavity, and the water outlet cavity is also connected to a high-pressure air pump;

[0010] A secondary sand filter tank, which is configured in the same manner as the primary sand filter tank, except that a sunshade net is provided on the top thereof, and the end of the secondary sand filter tank is connected to a water storage tank, and a water pump is provided to connect to a water storage tower;

[0011] A seawater regulating device is also provided between the water storage tower and the breeding and nursery pond. The seawater regulating device includes an ultrafiltration device or an osmotic pressure device for controlling and regulating the salinity of the purified seawater.

[0012] As a further arrangement of the above scheme, after the seawater in the natural sea area is introduced into the natural sedimentation tank, it is left to stand for 15 days per tide, and the steep gate is opened to put the seawater that has undergone preliminary sedimentation in the natural sedimentation tank into the secondary sedimentation algae breeding pond. After the seawater has been left to stand in the secondary sedimentation algae breeding pond for 7 days, the pump can be turned on to pump the seawater through the pumping pipe into the multi-stage dark sedimentation tank for further treatment or introduce it into the intermediate breeding pond for juvenile shellfish on the tidal flat, and the algae that multiply in large quantities in the secondary sedimentation algae breeding pond can be used as bait for juvenile shellfish.

[0013] As a further arrangement of the above scheme, the steep gate is located between the natural sedimentation tank and the secondary sedimentation algae breeding pool, and the steep gate opens a waterway from top to bottom for seawater to flow gradually downward from the upper layer of the natural sedimentation tank to the secondary sedimentation algae breeding pool. The natural sedimentation tank and the secondary sedimentation algae breeding pool are used to carry out two long-term sedimentation of silt in the seawater, and based on sunlight, after a certain period of sedimentation, the native algae in the relatively clear seawater multiply in large numbers to reduce the large amount of organic matter in the seawater in the natural sea area.

[0014] As a further arrangement of the above scheme, based on the arrangement of overflow wall and bottom seepage wall in the multi-stage dark sedimentation tank, the dark sedimentation sub-tank is further divided into an overflow sub-tank and a bottom seepage sub-tank. Both the overflow sub-tank and the bottom seepage sub-tank are provided with seepage boards and pebble layers arranged on the seepage boards. A cavity is also arranged at the bottom of the seepage board. The seawater in the overflow sub-tank and the bottom seepage sub-tank performs Z-shaped deflection relative to the overflow sub-tank and the bottom seepage sub-tank. The sunshade net is used to reduce or eliminate the large-scale death and precipitation of algae caused by sunlight.

[0015] As a further configuration of the above scheme, the second branch pipe and high-pressure air pump arranged in the primary sand filter tank are used to start the backwash function after closing the outlet pipe. Water is flushed in the outlet chamber through the second branch pipe. The backwash water flows back through the permeable plate and flows up the multiple layers of filter material. The high-pressure air pump cooperates to form a water-gas mixture and breaks up the multiple layers of filter material to fully clean them.

[0016] As a further configuration of the above scheme, the sewage pipe includes a drainage pipe fixed on the wall of the multi-layer filter tank and a pipe blocking member, the pipe blocking member includes a hollow tube matching the drainage pipe opening upward, and the hollow tube is plugged into the drainage pipe to form a blocked sewage pipe.

[0017] As a further configuration of the above scheme, the high-pressure air pump is provided with an air duct, the opening of the air duct is arranged relatively to the lower side of the permeability plate, and a plurality of rows of jet pipes are arranged on the side of the air duct relatively away from the sewage pipe of the multi-layer filter tank wall, and the jet pipes are controlled by an air valve arranged outside the multi-layer filter tank to spray.

[0018] As a further configuration of the above scheme, the particle size of fine sand in the fine sand layer is 1-2mm, the particle size of sand and gravel in the sand and gravel layer is 3-5mm, the particle size of pebble in the pebble layer is 5-6cm, the thickness of fine sand layer is 50cm, the thickness of sand and gravel layer is 40cm, and the thickness of pebble layer is 30cm.

[0019] Beneficial effects: The characteristics of the seawater seedling raising and aquaculture water treatment system based on natural ecology provided by the present invention include:

[0020] 1. The East China Sea is relatively turbid, and the large amount of silt and impurities in the natural sea water are treated by multi-stage sedimentation. In the sedimentation process, with the help of sunlight, the algae in the water body can reproduce in large quantities based on photosynthesis and absorb organic nutrients in the water body. The generated seawater rich in natural algae can also be supplied to the breeding pond, saving costs;

[0021] 2. After using sedimentation to initially separate the impurities in the seawater, it is introduced into a dark sedimentation tank without light, causing a large number of algae to die. In combination with bottom seepage and pebble arrays, the water flow rate is reduced to accelerate the precipitation of dead algae and impurities in the seawater. Dead algae can also serve as natural condensation nuclei and biological attachments. Small particles will adhere to the surface of the algae or its residual structure. The algae itself has a certain volume and weight. When suspended particles are attached, the overall weight increases and the sedimentation rate will be accelerated;

[0022] 3. The dark sedimentation tank is designed with a Z-shaped baffle. The overflow and bottom seepage are combined with layers of pebbles to enhance the filtration effect. The multi-stage baffles of the Z-shaped design further reduce the flow rate of seawater. The overflow takes the relatively clear seawater from the upper layer into the next sub-tank, which improves the purification effect.

[0023] 4. The sand filter tank extracts the sedimentation tank water, and an overflow is set in front of the sand filter tank. First, it can further precipitate, and second, it reduces the water flow rate of the filter tank, making it closer to the natural water seepage. The impurities filtered and precipitated are not easily disturbed by the water flow. The sand filter tank is equipped with a simple and convenient backwashing device, and a high-pressure air pump is set to perform air-water mixed backwashing through the air guide pipe. The air pipe distribution setting enables the air-carrying water body to be distributed and fully stirred and washed with the filter material, and by controlling the air pipe jet, the turbid sewage is easier to be discharged close to the sewage outlet;

[0024] 5. The sand filter pool is set up with two levels of light and no light. After secondary breeding, the organic matter in the water body is further reduced. The pool water after dark sand filtration is placed in a water tower and then passed through an ultrafiltration membrane or osmotic pressure technology. It can be directly used for seedling cultivation or breeding. Among them, the ultrafiltration membrane only allows the solvent (such as water molecules), inorganic salts and small molecular organic matter in the solution to pass through, while the suspended matter, colloids, proteins and microorganisms in the solution. Macromolecular substances such as proteins, so as to achieve the purpose of purification or separation. The seawater regulating device is adjusted according to the seawater osmotic pressure, which is used to control and adjust the salinity of the purified seawater to meet the needs of seedling cultivation;

[0025] The marine biological seedling and cultivation water treatment system of the present invention has a simple structure and is easy to set up. It can adaptively adjust the size of the device according to the conditions of the site. Through a multi-level structural design, it cooperates with the natural environment regulation of lighting and shading, avoids the disadvantages of chemical and biological purification and the shortcomings of simple physical sand filtration in a natural ecological way, thereby ensuring the supply of large quantities of aquaculture water to meet the aquaculture needs of large factory areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the structural composition of the water treatment system of the present invention.

[0027] Figure 2 It is a schematic diagram of the structure of the sand filter of the present invention.

[0028] Figure 3 It is a cross-sectional schematic diagram of the sand filter tank of the present invention.

[0029] Figure 4 It is a schematic diagram of the structure of the sand filter overflow sedimentation tank and the bottom infiltration tank of the present invention.

[0030] Figure 5 It is a schematic diagram of the multi-layer filter structure of the present invention.

[0031] Reference numerals: 1, natural sedimentation tank; 10, natural sea area; 11, water diversion pipeline; 12, steep gate; 2, secondary sedimentation algae breeding pool; 3, multi-stage dark sedimentation tank; 31, dark sedimentation sub-tank; 311, overflow sub-tank; 312, bottom seepage sub-tank; 32, sunshade net; 33, partition wall; 34, overflow pipe; 35, overflow wall; 36, water outlet; 37, bottom seepage wall; 38, seepage board; 39, pebble sedimentation layer; 4, primary sand filter; 41, water pump; 411, main pipeline; 413, first branch pipe; 414. Second branch pipe; 42. Overflow sedimentation tank; 43. Multi-layer filter tank; 431. Outlet pipe; 432. Outlet cavity; 433. Perforated plate; 434. Multi-layer filter material; 4341. Fine sand layer; 4342. Sand and gravel layer; 4343. Pebble layer; 435. Sewage pipe; 436. High-pressure air pump; 44. Bottom infiltration tank; 45. Valve; 5. Secondary sand filter tank; 61. Pump; 62. Water storage tower; 63. Breeding and nursery pond; 7. Seawater regulating device; 9. Intermediate culture pond for juvenile shellfish on mudflats. DETAILED DESCRIPTION

[0032] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0033] like Figure 1-5The aquatic organism seedling and seedling cultivation seawater treatment system based on natural ecological cycle of the present invention shown in the figure comprises a natural sedimentation tank 1, the natural sedimentation tank 1 is provided with a water diversion pipeline 11 or a steep gate 12 connected to the natural sea area 10, the water diversion pipeline 11 or the steep gate 12 is used to lead the seawater of the natural sea area 10 into the large natural sedimentation tank 1, the natural sedimentation tank 1 is provided with 60-100 mu, which is used to preliminarily precipitate the suspended sediment impurities in the seawater of the natural sea area 10;

[0034] The secondary sedimentation algae breeding pool 2 is set at 15-20 mu and a steep gate 12 is set between the natural sedimentation pool 1. The steep gate 12 leads the upper relatively clear seawater in the natural sedimentation pool 1 after a sedimentation into the secondary sedimentation algae breeding pool 2. The secondary sedimentation algae breeding pool 2 is connected to the multi-stage dark sedimentation pool 3. The natural sedimentation pool 1 and the secondary sedimentation algae breeding pool 2 are both set in a natural environment. After the seawater in the natural sedimentation pool 1 to the secondary sedimentation algae breeding pool 2 is precipitated and continuously exposed to sunlight, abundant seawater natural unicellular algae seaweed will be formed in the water body;

[0035] The multi-stage dark sedimentation tank 3 is provided with a large tank of 5,000 cubic meters and divided into a plurality of dark sedimentation sub-tanks 31. A sunshade net 32 ​​is also provided above the multi-stage dark sedimentation tank 3. The partition wall 33 between the dark sedimentation sub-tanks 31 includes an overflow wall 35 with an overflow pipe 34 at the upper part and a bottom seepage wall 37 with a water outlet 36 at the lower part. The dark sedimentation sub-tanks 31 are also provided with a seepage board 38 and a pebble sedimentation layer 39. The multi-stage dark sedimentation tank 3 is used for multi-stage layer-by-layer filtration and sedimentation of algae carcasses that die in the seawater due to lack of light.

[0036] The primary sand filter 4 is provided with a water pump 41 to extract the seawater in the dark sedimentation sub-tank 31 after sedimentation at the end of the multi-stage dark sedimentation tank 3. The primary sand filter 4 includes an overflow sedimentation tank 42, a multi-layer filter tank 43 and a bottom infiltration tank 44. The main pipeline 411 connected to the water pump 41 is provided with a three-way connection between a first branch pipe 413 and a second branch pipe 414. The first branch pipe 413 is connected to the bottom infiltration tank 44. The bottom infiltration tank 44 is used to supply water to the overflow sedimentation tank 42. The overflow sedimentation tank 42 is used to supply water to the multi-layer filter tank 43. An overflow pipe 34 is provided between the overflow sedimentation tank 42 and the multi-layer filter tank 43. The second branch pipe 414 is connected to the multi-layer filter tank 43. The first branch pipe 413 and the second branch pipe 414 are both provided with valves 45 to control the water flow on and off.

[0037] The multi-layer filter tank 43 is connected to the overflow sedimentation tank 42 through the overflow pipe 34, and a water outlet chamber 432 with a water outlet pipe 431 is arranged at the bottom of the multi-layer filter tank 43. A perforated plate 433 is arranged on the top of the water outlet chamber 432. A multi-layer filter material 434 is arranged on the perforated plate 433, including a fine sand layer 4341, a sandstone layer 4342, and a pebble layer 4343 arranged in sequence from top to bottom. A sewage pipe 435 is arranged 2-3 cm above the fine sand layer 4341, and the sewage pipe 435 is connected to the drainage channel outside the multi-layer filter tank 43. The water outlet of the second branch pipe 414 is connected to the water outlet chamber 432, and the water outlet chamber 432 is also connected to a high-pressure air pump 436;

[0038] The secondary sand filter tank 5 is configured in the same manner as the primary sand filter tank 4, except that a sunshade net 32 ​​is provided on the top thereof, and the end of the secondary sand filter tank 5 is connected to a water storage tank, and a water pump 61 is provided to connect to a water storage tower 62; a seawater regulating device 7 is also provided between the water storage tower 62 and the breeding and seedling raising pool 63, and the seawater regulating device 7 includes an ultrafiltration device or an osmotic pressure device, which is used to control and regulate the salinity of the purified seawater.

[0039] As a further arrangement of the above scheme, after the seawater in the natural sea area 10 is introduced into the natural sedimentation tank 1, it is left to stand for 15 days per tide, and the steep gate 12 is opened to put the seawater that has undergone preliminary sedimentation in the natural sedimentation tank 1 into the secondary sedimentation algae breeding pool 2. After the seawater has been standing in the secondary sedimentation algae breeding pool 2 for 7 days, the pump can be turned on to pump the seawater into the multi-stage dark sedimentation tank 3 through the pumping pipe for further treatment or introduce it into the intermediate breeding pool 9 for juvenile shellfish on the tidal flats, and the algae that have been bred in large quantities in the secondary sedimentation algae breeding pool 2 can be used as bait for juvenile shellfish.

[0040] As a further arrangement of the above scheme, the steep gate 12 is located between the natural sedimentation tank 1 and the secondary sedimentation algae breeding pool 2, and the steep gate 12 opens a waterway from top to bottom for seawater to flow gradually downward from the upper layer of the natural sedimentation tank 1 to the secondary sedimentation algae breeding pool 2. The natural sedimentation tank 1 and the secondary sedimentation algae breeding pool 2 are used to carry out two long-term sedimentation of silt in the seawater, and based on sunlight, after a certain period of sedimentation, the native algae in the relatively clear seawater multiply in large numbers to reduce a large amount of organic matter in the seawater in the natural sea area.

[0041] As a further arrangement of the above scheme, based on the arrangement of the overflow wall 35 and the bottom seepage wall 37 in the multi-stage dark sedimentation tank 3, the dark sedimentation sub-tank 31 is further divided into an overflow sub-tank 311 and a bottom seepage sub-tank 312. Both the overflow sub-tank 311 and the bottom seepage sub-tank 312 are provided with a seepage board 38 and a pebble layer 39 arranged on the seepage board 38. A cavity 381 is also arranged at the bottom of the seepage board 38. The seawater in the overflow sub-tank 311 and the bottom seepage sub-tank 312 performs Z-shaped deflection relative to the overflow sub-tank 311 and the bottom seepage sub-tank 312. The sunshade net 32 ​​is used to reduce or eliminate the large-scale death and precipitation of algae caused by sunlight.

[0042] As a further configuration of the above scheme, the second branch pipe 414 and the high-pressure air pump 436 provided in the primary sand filter tank 4 are used to start the backwashing function after closing the outlet pipe 431. Water is flushed in the outlet chamber 432 through the second branch pipe 414. The backwashing water flows back through the permeable plate 433 and flows up the multi-layer filter material 434. The high-pressure air pump 436 forms a water-gas mixture and simultaneously breaks up the multi-layer filter material 434 for thorough cleaning.

[0043] As a further configuration of the above scheme, the sewage pipe 435 includes a drainage pipe fixed on the wall of the multi-layer filter tank 43 and a pipe blocking member 4351. The pipe blocking member 4351 includes a hollow tube matching the drainage pipe opening upward. After the hollow tube is plugged into the drainage pipe, the sewage pipe 435 is blocked.

[0044] As a further configuration of the above scheme, the high-pressure air pump 436 is provided with an air duct, the opening of which is relatively located at the lower side of the permeable plate 433, and a plurality of rows of jet pipes are arranged on the side of the air duct relatively away from the sewage pipe 435 on the wall of the multi-layer filter tank 43, and the jet pipes are controlled by an air valve arranged outside the multi-layer filter tank 43 to spray.

[0045] As a further configuration of the above scheme, the particle size of fine sand in the fine sand layer 4341 is 1-2 mm, the particle size of sand and gravel in the sand and gravel layer 4342 is 3-5 mm, the particle size of pebble in the pebble layer 4343 is 5-6 cm, the thickness of the fine sand layer 4341 is 50 cm, the thickness of the sand and gravel layer 4342 is 40 cm, and the thickness of the pebble layer 4343 is 30 cm.

[0046] When the seawater seedling raising and aquaculture water treatment system based on natural ecological cycle of the present invention is used, it needs to go through a staged process of seawater sedimentation and sedimentation purification. The whole process generally takes 20-30 days, wherein the seawater in the natural sea area 10 needs to be precipitated for nearly 15 days after being introduced into the natural sedimentation tank 1. It is worth noting that one meaning of this setting is that a steep gate 12 may be set between the water inlet side of the natural sedimentation tank 1 and the natural sea area 10. When the water level in the natural sedimentation tank 1 is low, the steep gate 12 is opened at the highest period of the tidal flood water level to allow seawater to flow back into the natural sedimentation tank 1. Then, the steep gate 12 is closed after the tide recedes to complete the first-level water storage work. After the seawater in the natural sedimentation tank 1 is statically precipitated, the suspended silt and impurities therein will slowly precipitate. At the same time, the exposure to sunlight also causes some unicellular algae of the natural water ecology therein to begin to reproduce.

[0047] After entering the secondary sedimentation algae breeding pool 2, the seawater is placed again for 7 days. The natural sedimentation pool 1 is transferred to the secondary sedimentation algae breeding pool 2 by draining the clearer seawater from the upper layer. The seawater in the secondary sedimentation algae breeding pool 2 is clearer, and the seawater without a large amount of silt and impurities can be penetrated by sunlight, which is conducive to the photosynthetic growth of algae. The natural unicellular algae in the seawater will reproduce in large quantities, and the seawater will be slowly filled with a large amount of algae. In this process, an aeration device can be added to introduce air to increase the dissolved oxygen in the seawater to help the photosynthesis of algae. After 7 days of secondary sedimentation and algae reproduction, not only is the water for breeding with a large amount of unicellular algae that can be used as food for shellfish juveniles (if necessary, it can be introduced into the intermediate breeding pool 9 for shellfish juveniles on the beach for breeding), but the reproduction of algae can consume nutrients in the water body.

[0048] After the seawater containing a large amount of algae is pumped into the multi-stage dark sedimentation tank 3, a sunshade net 32 ​​is set above the multi-stage dark sedimentation tank 3. The algae lose sunlight and can no longer photosynthesize, resulting in a large number of deaths. The dead algae are suspended in the seawater to form a large amount of flocs. The dead algae corpses can serve as adsorption nuclei to further adsorb fine impurities in the seawater. After entering the multi-stage dark sedimentation tank 3, the seawater is filtered through the overflow sub-tank 311 and the bottom seepage sub-tank 312 at intervals. The layer-by-layer filtration further enhances the purification effect of the seawater. In detail, after entering the multi-stage dark sedimentation tank 3, the seawater will pass through the overflow sub-tank 311 and the bottom seepage sub-tank 312 in sequence. The bottom seepage board 38 of 311 then flows up through the pebble layer 39, then flows into the bottom seepage pool 312 through the overflow pipe 34 on the overflow wall 35 near the top, then passes through the pebble layer 39 of the bottom seepage pool 312, the seepage board 38 and the bottom seepage wall 37 from the bottom water outlet 36 to enter the bottom of the next overflow sub-pool 311, and flows up through the pebble layer 39 from the bottom seepage board 38 again, and the above-mentioned deflection is circulated for many times. The flow mode of the water flow adopts natural flow, overflow and other modes. Pumping pumps are set in the frontmost pool and the end pool. The height difference of the water level in the middle forms the flow of water itself, reduces the turbulence in the water, and improves the sedimentation effect.

[0049] Further, the seawater purified by the multi-stage dark sedimentation tank 3 is pumped into the sand filter tank, which is configured as a primary sand filter tank 4 and a secondary sand filter tank 5. The difference between the primary sand filter tank 4 is that the primary sand filter tank 4 is located under natural sunlight, while the secondary sand filter tank 5 is provided with a sunshade net 32 ​​for shading. The purpose is still to prevent algae reproduction that may occur during the sand filtration process, and to kill them by shading them before filtering them.

[0050] It is worth noting that the primary sand filter 4 of the present embodiment is divided into three sub-tanks, which are connected to the bottom infiltration tank 44, the overflow sedimentation tank 42 and the multi-layer filter 43 with main functions according to the direction of water flow. The main pipeline 411 draining from the multi-stage dark sedimentation tank 3 is branched into a first branch pipe 413 and a second branch pipe 414 through the setting of a valve 45. The first branch pipe 413 is connected to the upper end of the bottom infiltration tank 44 through an opening. A water outlet is set at the bottom of the bottom infiltration tank 44 to connect to the overflow sedimentation tank 42. Seawater flows in from the upper end of the bottom infiltration tank 44 through a U-shaped flow, overflows from the overflow pipe 34 on the upper part of the overflow sedimentation tank 42 to the multi-layer filter 43, and then passes through the multi-layer filter material 434 from top to bottom, flows into the water outlet cavity 432 from the perforated plate 433, and then discharges water in combination with the water outlet pipe 431.

[0051] The second branch pipe 414 is directly connected to the water outlet chamber 432. The purpose of setting the second branch pipe 414 is to achieve backwashing of the multi-layer filter tank 43. The backwashing setting structure of this embodiment is simple and easy to operate. The steps include: ① The operator first removes the pipe plugging member 4351 on the sewage pipe 435, then closes the water outlet of the water outlet pipe 431, and then closes the first branch pipe 413;

[0052] ② Then open the valve 45 of the second branch pipe 414 that was previously closed. At this time, the extracted seawater no longer enters the bottom infiltration tank 44 from the first branch pipe 413, but enters the water outlet chamber 432 from the second branch pipe 414. The water outlet chamber 432 is located below the perforated plate 433. The bottom water inlet and outlet pipe 431 cannot discharge water, and the high-pressure water will surge upward to lift the compacted multi-layer filter material 434.

[0053] ③ And further, in order to perform backwashing better, the sand filter tank of this embodiment is also provided with a high-pressure air pump 436, and the air pipe is connected to the water outlet chamber 432. During backwashing, the high-pressure air pump 436 is synchronously turned on to press high-pressure air into the water outlet chamber 432, and mixed with the backwashed seawater to form a water-gas mixture. The seawater is made turbulent by the airflow, and the compaction of the multi-layer filter material 434 is more easily broken up based on the high-pressure air, so that the impurities and sludge intercepted by the multi-layer filter material 434 during forward filtration are pushed upward and discharged from the sewage pipe 435 to the drainage channel with the upwelling seawater, so as to achieve the cleaning of the multi-layer filter material 434 and enable it to be recycled;

[0054] The above operation can be implemented in both the primary sand filter 4 and the secondary sand filter 5, so as to realize convenient cleaning of the filter material and facilitate periodic recycling; the seawater coming out of the secondary sand filter 5 is then pumped to the water storage tower 62, at which time the impurities and inorganic nutrients in the seawater have been purified, and the staff then adjusts the salinity of the seawater and adds nutrients through the seawater regulating device 7 according to needs, through concentration, ultrafiltration, etc., to transform it into biological seedling breeding seawater suitable for aquaculture needs.

[0055] Compared with the prior art, the treatment system of the present invention is characterized in that, firstly, it utilizes the natural ecological method, and basically no additional chemical or biological means are involved in the entire purification process. Some of the power equipment and water pumps used in the present invention are relatively economical in electricity consumption, and can be supplied by setting up solar power generation. The cost of the purification system is relatively low except for the later use of the site, which conforms to the sustainable development of environmental protection ecology. Moreover, based on the growth of natural unicellular algae seaweed, it absorbs nutrients in natural seawater, which can not only reduce the over-nutrition of the water body, but also form food for shellfish juveniles. In the process of purifying seawater, new uses are developed to meet the needs of the breeding pool. In addition, the dead seaweed corpses caused by dark precipitation form an adsorption nucleus to purify the water body. The pond mud formed by the filtered seaweed corpses can also be ultrafiltered and briquette, and finally used to develop as a fertilizer raw material for agricultural planting. In addition, the multi-stage dark sedimentation tank structure of the present invention allows seawater to pass through layer-by-layer filtration overflow and bottom seepage through Z-shaped deflection, which reduces the flow rate and improves the sedimentation effect. The sand filter tank is provided with branch pipes, which introduces the backwash filter tank design and facilitates the application of the whole set of equipment. In summary, the water treatment system of the present invention, through a multi-stage structural design, cooperates with the natural environment regulation of lighting and shading, and avoids the disadvantages of chemical and biological purification and the shortcomings of simple physical sand filtration in a natural ecological way, thereby ensuring the supply of large quantities of aquaculture water to meet the aquaculture needs of large factory areas.

[0056] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A seawater treatment system for aquatic organism seedling and seedling cultivation based on natural ecological cycle, characterized in that: include: A natural sedimentation tank (1), the natural sedimentation tank is provided with a water diversion pipeline (11) or a steep gate (12) connected to the natural sea area (10), the water diversion pipeline (11) or the steep gate (12) is used to divert seawater from the natural sea area (10) into the large natural sedimentation tank (1), the natural sedimentation tank (1) is provided with an area of ​​60-100 mu, and is used to preliminarily precipitate suspended sediment impurities in the seawater of the natural sea area (10); The secondary sedimentation algae breeding pool (2) is set up with an area of ​​15-20 mu and a steep gate (12) is set up between the secondary sedimentation algae breeding pool (2) and the natural sedimentation pool (1). The steep gate (12) leads the upper relatively clear seawater in the natural sedimentation pool (1) after a sedimentation into the secondary sedimentation algae breeding pool (2). The secondary sedimentation algae breeding pool (2) is connected to a multi-stage dark sedimentation pool (3). The natural sedimentation pool (1) and the secondary sedimentation algae breeding pool (2) are both set up in a natural environment. After the seawater in the secondary sedimentation algae breeding pool (2) passes through the natural sedimentation pool (1), it is precipitated and continuously exposed to sunlight, and abundant natural unicellular algae seaweed will be formed in the water body. A multi-stage dark sedimentation tank (3) is provided with a large tank of 5,000 cubic meters and divided into a plurality of dark sedimentation sub-tanks (31). A sunshade net (32) is also provided above the multi-stage dark sedimentation tank (3). The partition walls (33) between the dark sedimentation sub-tanks (31) include an overflow wall (35) with an overflow pipe (34) at the upper part and a bottom seepage wall (37) with a water outlet (36) at the lower part. The dark sedimentation sub-tanks (31) are also provided with a seepage board (38) and a pebble sedimentation layer (39). The multi-stage dark sedimentation tank (3) is used for multi-stage layer-by-layer filtration and sedimentation of algae carcasses that die in seawater due to lack of light. A primary sand filter (4) is provided with a water pump (41) for extracting seawater from a dark sedimentation sub-tank (31) after sedimentation at the end of a multi-stage dark sedimentation tank (3). The primary sand filter (4) comprises an overflow sedimentation tank (42), a multi-layer filter tank (43) and a bottom infiltration tank (44). A main pipeline (411) connected to the water pump (41) is provided with a tee connecting a first branch pipe (413) and a second branch pipe (414). The first branch pipe (413) is connected to the bottom infiltration tank (44). The bottom infiltration tank (44) is used to supply water to the overflow sedimentation tank (42). The overflow sedimentation tank (42) is used to supply water to the multi-layer filter tank (43). An overflow pipe (34) is provided between the overflow sedimentation tank (42) and the multi-layer filter tank (43). The second branch pipe (414) is connected to the multi-layer filter tank (43). Valves (45) are provided on the first branch pipe (413) and the second branch pipe (414) to control the on and off of water flow. The multi-layer filter tank (43) is connected to the overflow sedimentation tank (42) through an overflow pipe (34), and a water outlet chamber (432) with a water outlet pipe (431) is arranged at the bottom of the multi-layer filter tank (43). A permeable plate (433) is arranged at the top of the water outlet chamber (432). Multiple layers of filter material (434) are arranged on the permeable plate (433), including a fine sand layer (4341), a sandstone layer (4342), and a pebble layer (4343) arranged in sequence from top to bottom. A sewage pipe (435) is arranged 2-3 cm above the fine sand layer (4341), and the sewage pipe (435) is connected to a drainage channel outside the multi-layer filter tank (43). The water outlet of the second branch pipe (414) is connected to the water outlet chamber (432), and the water outlet chamber (432) is also connected to a high-pressure air pump (436); A secondary sand filter (5), wherein the secondary sand filter (5) is configured in the same manner as the primary sand filter (4), except that a sunshade net (32) is provided on the top thereof, and the end of the secondary sand filter (5) is connected to a water storage tank, and a water pump (61) is provided to connect to a water storage tower (62); A seawater regulating device (7) is also provided between the water storage tower (62) and the breeding and nursery pond (63). The seawater regulating device (7) comprises an ultrafiltration device or an osmotic pressure device for controlling and regulating the salinity of the purified seawater.

2. The seawater treatment system for aquatic organism seedling and seedling cultivation based on natural ecological cycle according to claim 1 is characterized in that: After the seawater in the natural sea area (10) is introduced into the natural sedimentation tank (1), it is allowed to stand for 15 days (one tide), and the steep gate (12) is opened to place the seawater that has undergone preliminary sedimentation in the natural sedimentation tank (1) into the secondary sedimentation algae breeding tank (2). After the seawater has been allowed to stand for 7 days in the secondary sedimentation algae breeding tank (2), the pump is turned on to pump the seawater into the multi-stage dark sedimentation tank (3) through the pumping pipeline for further treatment, or the seawater is introduced into the intermediate breeding tank (9) for tidal flat shellfish juveniles, and the algae that have been reproduced in large quantities in the secondary sedimentation algae breeding tank (2) are used as bait for shellfish juveniles.

3. The seawater treatment system for aquatic organism seedling and seedling cultivation based on natural ecological cycle according to claim 2 is characterized in that: The steep gate (12) is located between the natural sedimentation tank (1) and the secondary sedimentation algae breeding tank (2), and the steep gate (12) opens a waterway from top to bottom to allow seawater to flow gradually downward from the upper layer of the natural sedimentation tank (1) to the secondary sedimentation algae breeding tank (2). The natural sedimentation tank (1) and the secondary sedimentation algae breeding tank (2) are used to perform two long-term sedimentation of silt in the seawater, and after a certain period of sedimentation due to sunlight, the native algae in the relatively clear seawater multiply in large quantities to reduce the large amount of organic matter in the seawater in the natural sea area.

4. The seawater treatment system for aquatic organism seedling and seedling cultivation based on natural ecological cycle according to claim 1 is characterized in that: Based on the arrangement of an overflow wall (35) and a bottom seepage wall (37) in the multi-stage dark sedimentation tank (3), the dark sedimentation sub-tank (31) is further divided into an overflow sub-tank (311) and a bottom seepage sub-tank (312). Both the overflow sub-tank (311) and the bottom seepage sub-tank (312) are provided with a water seepage board (38) and a pebble layer (39) arranged on the water seepage board (38). A cavity (381) is also arranged at the bottom of the water seepage board (38). The seawater in the overflow sub-tank (311) and the bottom seepage sub-tank (312) is subjected to Z-shaped deflection relative to the overflow sub-tank (311) and the bottom seepage sub-tank (312). The sunshade net (32) is used to reduce or eliminate the large-scale death and precipitation of algae caused by sunlight.

5. The seawater treatment system for aquatic organism seedling and seedling cultivation based on natural ecological cycle according to claim 1 is characterized in that: The second branch pipe (414) and the high-pressure air pump (436) provided in the primary sand filter (4) are used to start the backwashing function after closing the outlet pipe (431), and to flush water in the outlet chamber (432) through the second branch pipe (414). The backwashing water flows back through the permeable plate (433) and flows up the multi-layer filter material (434). The high-pressure air pump (436) forms a water-gas mixture and simultaneously breaks up the compacted multi-layer filter material (434) for thorough cleaning.

6. The seawater treatment system for aquatic organism seedling and seedling cultivation based on natural ecological cycle according to claim 5 is characterized in that: The sewage pipe (435) comprises a drainage pipe fixed on the wall of the multi-layer filter tank (43) and a pipe blocking member (4351), wherein the pipe blocking member (4351) comprises a hollow pipe matching the drainage pipe opening upward, and the hollow pipe is plugged into the drainage pipe to form a blocked sewage pipe (435).

7. The seawater treatment system for aquatic organism seedling and seedling cultivation based on natural ecological cycle according to claim 6 is characterized in that: The high-pressure air pump (436) is provided with an air guide pipe, the opening of which is arranged relatively to the lower side of the permeable plate (433), and a plurality of rows of air jet pipes are arranged on a side of the air guide pipe relatively to the sewage pipe (435) away from the wall of the multi-layer filter tank (43), and the air jet pipes are controlled by air valves arranged outside the multi-layer filter tank (43) to spray air.

8. The seawater treatment system for aquatic organism seedling and seedling cultivation based on natural ecological cycle according to claim 1 is characterized in that: The fine sand particle size of the fine sand layer (4341) is 1-2 mm, the sand and gravel particle size of the sand and gravel layer (4342) is 3-5 mm, the pebble particle size of the pebble layer (4343) is 5-6 cm, the thickness of the fine sand layer (4341) is 50 cm, the thickness of the sand and gravel layer (4342) is 40 cm, and the thickness of the pebble layer (4343) is 30 cm.

Images