Construction method of a coastal cofferdam oyster fattening and breeding sewage purification system

Abstract

The application provides a construction method of a coastal cofferdam oyster breeding and fattening sewage purification system, and relates to the technical field of sewage purification systems. The method comprises the following steps: constructing a breeding pond; initially hardening the breeding pond; laying a sewage pipeline; reinforcing the hardening of the breeding pond; and laying a seepage-proof membrane. The system constructed by the method comprises a breeding pond, a sewage pipeline and a sewage pump. The construction of a breeding ridge and a sewage ditch structure at the bottom of the breeding pond, the hardening and seepage-proof treatment, the laying of the sewage pipeline at the bottom of the sewage ditch and the installation of the sewage pump make it possible to breed and fatten oysters in the coastal cofferdam, effectively solve the technical problems of sediment accumulation and water quality deterioration in the breeding pond, the unique floating ball type sewage valve design completely isolates the residual pollutants in the sewage pipeline from the clean breeding water body, completely eliminates secondary pollution and guarantees the growth and cultivation environment of oysters.

Description

Technical Field

[0001] This invention relates to the field of sewage purification systems, and in particular to a method for constructing a sewage purification system for oyster fattening and aquaculture in coastal dikes. Background Technology

[0002] Oyster farming and fattening are generally carried out in sea areas or estuaries with suitable salinity, abundant food (phytoplankton), and good water exchange, rather than in enclosed ponds. This is because oyster growth is greatly affected by the environment, such as the supply of food, water flow rate, and sediment accumulation in their growth environment. These factors are crucial to the growth rate, quality, and survival rate of oysters.

[0003] If oysters are cultured in enclosed ponds, their metabolic products, fecal matter, and organic particles that are not replaced in time will accumulate at the bottom of the pond. Under stagnant or low-oxygen conditions, the bottom mud is prone to turning black and producing toxic substances such as hydrogen sulfide. At the same time, excessive accumulation of sediment can easily breed bacteria, affecting the health of oysters and even causing them to die. Summary of the Invention

[0004] This invention addresses the problem that oyster fattening cannot be carried out using enclosed aquaculture technology, and provides a coastal enclosed oyster fattening and aquaculture sewage purification system and construction method. The system constructed by this method includes aquaculture ponds, sewage pipes, and sewage pumps. By constructing aquaculture ridges and sewage ditches at the bottom of the aquaculture ponds and hardening and preventing seepage, and laying sewage pipes at the bottom of the sewage ditches and installing sewage pumps, coastal enclosed oyster fattening becomes possible, effectively solving the technical problems of sediment accumulation and water quality deterioration in aquaculture ponds.

[0005] Therefore, the technical solution of the present invention is a method for constructing a wastewater purification system for oyster fattening and aquaculture in coastal areas, comprising the following steps:

[0006] Step S1. Constructing aquaculture ponds: Construct a dike in a selected coastal area to form aquaculture ponds, construct multiple parallel aquaculture ridges at the bottom of the ponds, and construct drainage ditches between adjacent aquaculture ridges.

[0007] Step S2. Initial hardening of the aquaculture pond: Mix cement, quicklime and sludge to form a hardening material, spread it on the bottom of the entire aquaculture pond, and compact it to maintain the shape of the aquaculture ridges and drainage ditches. Let it stand and dry to form an initial hardened layer.

[0008] Step S3. Laying sewage pipes: Lay sewage pipes with multiple sewage outlets at the bottom of the sewage ditch. Sewage valves are installed in the sewage outlets. One end of each sewage pipe is sealed, and the other end is connected to a sewage collection pipe. A sewage pump is installed at the end of the sewage collection pipe.

[0009] Step S4. Strengthening and hardening the aquaculture pond: Lay a cement blanket on the initial hardened layer, and make through holes in the cement blanket corresponding to the position of the sewage outlet. Water the cement blanket to cure and form a strengthened and hardened layer.

[0010] Step S5. Laying the geomembrane: Lay the geomembrane on the reinforced and hardened layer, and make geomembrane through holes on the geomembrane at the positions corresponding to the sewage outlets.

[0011] Furthermore, one end of each sewage pipe is sealed by an inlet valve, and the other end is connected to a sewage collection pipe, which is also equipped with an outlet valve.

[0012] Furthermore, the drain valve includes an upper cover with a valve hole, a bottom cover, a mesh cylinder, and a float ball located in the mesh cylinder chamber. The float ball can rise and fall with the water level to open or close the valve hole.

[0013] Furthermore, the valve orifice is tapered, and the float is made of an elastic material.

[0014] Furthermore, the upper end of the drain valve's mesh cylinder is equipped with a sealing cylinder, and the lower end of the sealing cylinder is equipped with a sealing ring; when the aquaculture pond is filled with water, the float rises under the action of buoyancy, and at the same time seals the valve hole and fits with the sealing ring to form a double sealing structure.

[0015] Furthermore, the cross-section of the sewage ditch is V-shaped.

[0016] Furthermore, the width of the aquaculture ridges is 2m-6m.

[0017] Furthermore, there are two breeding ridges, and a drainage ditch is located between the two breeding ridges. The breeding ridges are inclined at an angle that is conducive to drainage towards the drainage ditch.

[0018] Furthermore, the outermost aquaculture ridges are constructed as a single unit with the inner wall of the embankment, or a drainage ditch is set between the two.

[0019] Furthermore, in step S2, the mixing ratio of cement, quicklime, and sludge is as follows: for every 5-10 square meters of pool bottom, use 40-60 kg of cement, 20-30 kg of quicklime, and 0.5-1 cubic meters of sludge.

[0020] Furthermore, the mixing ratio of the hardening materials is as follows: for every 5 square meters of pool bottom, use 50 kg of cement, 25 kg of quicklime, and 0.5 cubic meters of sludge.

[0021] Furthermore, in step S2, the initial hardened layer is left to dry for 3-7 days; in step S4, the cement blanket is watered and cured for 3-7 days.

[0022] The beneficial effects of this invention are that by constructing a culture ridge and drainage ditch structure at the bottom of the culture pond, laying two layers of hardened layer and seepage-proof layer, and laying drainage pipes and installing drainage pumps at the bottom of the culture pond, it is possible to carry out oyster fattening in coastal enclosures. This effectively solves the technical problems of sediment accumulation and water quality deterioration in culture ponds, and makes efficient and high-density oyster fattening in enclosure environments a reality.

[0023] A unique pool bottom structure is constructed through a preliminary hardening layer of mixed materials, a reinforcing layer of cement blanket, and a seepage-proof membrane layer. The preliminary hardening layer utilizes sludge, achieving resource utilization and facilitating future dismantling, thus meeting environmental protection requirements. The cement blanket layer provides a high-strength, integral, and robust base. The surface seepage-proof membrane forms a smooth, impermeable working surface, preventing pollutants from seeping down and greatly facilitating rapid and thorough cleaning of the pool bottom using high-pressure water jets, significantly reducing the difficulty and cost of daily maintenance.

[0024] Adopting a unique float-type drain valve design, it automatically opens during the drainage and cleaning stage to ensure the smooth discharge of sewage and sediment; it automatically closes during the aquaculture water filling stage. In particular, the double sealing structure of the valve hole and the internal sealing cylinder completely isolates residual pollutants in the drain pipe from the clean aquaculture water, preventing secondary pollution and protecting the oyster growth and cultivation environment. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the purification system of the present invention;

[0026] Figure 2 This is a structural diagram of the sewage pipes and sewage pumps;

[0027] Figure 3 yes Figure 2 Top view;

[0028] Figure 4 This is a structural diagram of the sewage pipe;

[0029] Figure 5 This is a schematic diagram of the drain valve.

[0030] Figure 6 yes Figure 5 A sectional view;

[0031] Figure 7 This is a schematic diagram of the structure after the float ball is removed from the drain valve;

[0032] Figure 8 yes Figure 7 A sectional view.

[0033] Figure 9 This is a schematic diagram of the purification system according to another embodiment.

[0034] Figure 10 This is a schematic diagram of the sewage pipe and sewage pump in another embodiment.

[0035] Explanation of symbols in the diagram:

[0036] 1. Aquaculture pond; 11. Enclosure; 12. Aquaculture ridge; 13. Drainage ditch; 2. Sewage pipe; 21. Sewage pipe; 211. Sewage outlet; 22. Sewage collection pipe; 23. Sewage valve; 231. Top cover; 2311. Valve hole; 232. Bottom cover; 233. Net cylinder; 234. Float ball; 235. Sealing cylinder; 2351. Sealing ring; 24. Inlet valve; 25. Outlet valve; 3. Sewage pump. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] Example 1

[0039] like Figures 1-8 As shown, the present invention provides a coastal oyster fattening and aquaculture sewage purification system. The system includes an aquaculture pond 1, a sewage pipe 2, and a sewage pump 3. The aquaculture pond 1 is located on the coast to facilitate seawater exchange. The aquaculture pond 1 is constructed by a dike 11, which is used to enclose water on the coast. The bottom of the aquaculture pond 1 is provided with multiple aquaculture ridges 12, which are arranged in rows or columns. Sewage ditches 13 are provided between the aquaculture ridges 12. The outermost aquaculture ridge 12 is connected to the dike 11, or the outermost aquaculture ridge 12 is connected to the dike 11 by a sewage ditch 13, so as to improve the sewage discharge effect.

[0040] The culture ridge 12 is used to place oysters. During the oyster fattening stage, the oysters are first placed in special fattening boxes to facilitate the arrangement and transportation of the oysters. The fattening boxes containing oysters are then placed on the culture ridge 12. The width of the culture ridge 12 is 2m-6m, and the length of the culture ridge 12 can be determined according to the size of the culture site.

[0041] The drainage ditch 13 is used for cleaning and removing sediment in the aquaculture pond 1. The drainage ditch 13 has a V-shaped cross-section. The bottom of the drainage ditch 13 is used to install the sewage pipe 2. During the oyster fattening stage, the aquaculture pond 1 can be cleaned once every 1-2 days. When cleaning, the seawater is first drained, and then the aquaculture ridge 12 is rinsed with a water gun to wash the sediment into the drainage ditch 13 and discharged through the sewage pipe 2 installed in the drainage ditch 13.

[0042] The sewage pipe 2 includes a sewage pipe 21 and a sewage collection pipe 22. The sewage pipe 21 has a diameter of 20-40 cm and multiple sewage outlets 211. The sewage pipe 21 is laid at the bottom of the sewage ditch 13. One end of the sewage pipe 21 is sealed with an end cap, and the other end of the sewage pipe 21 is collected through the sewage collection pipe 22. One end of the sewage collection pipe 22 is equipped with a sewage pump 3, which is a combination of a pump and a motor and has the characteristics of anti-clogging and wear-resistant.

[0043] In oyster fattening in culture pond 1, feed can be added regularly, such as concentrated algae slurry or artificially cultivated microalgae. To purify the oyster's growth environment, culture pond 1 can be cleaned regularly through sewage pipe 2 and sewage pump 3 to remove sediment.

[0044] To further purify the oyster fattening environment, a drain valve 23 is installed in the drain outlet 211 of the drain pipe 21. When the seawater is emptied and the sediment in the culture pond 1 is cleaned, the drain valve 23 is in the open state, and the sewage and sediment enter the drain pipe 21 through the drain valve 23 and are discharged. When the culture pond 1 is filled with seawater, the drain valve 23 is in the closed state. At this time, the drain valve 23 effectively isolates the drain pipe 2 from the seawater in the culture pond 1, and the sediment remaining in the drain pipe 2 will not pollute the seawater in the culture pond 1.

[0045] Specifically, the drain valve 23 includes an upper cover 231, a bottom cover 232, a mesh cylinder 233, and a float 234. The upper cover 231 is located at the upper end of the mesh cylinder 233, and the bottom cover 232 is located at the lower end of the mesh cylinder 233. The float 234 is located in the cavity formed by the mesh cylinder 233, the upper cover 231, and the bottom cover 232. The float 234 can float freely up and down in the drain valve 23. The inside of the float 234 is a sealed cavity. When the drain pipe 21 is filled with water, the float 234 floats upward under the action of buoyancy, and the float 234 will seal the upper cover 231. When the water level in the drain pipe 21 drops, the float 234 will also drop, and the float 234 will open the seal of the upper cover 231.

[0046] The top cover 231 is an arc-shaped panel, and its shape matches the outer wall of the drain valve 23. When the drain valve 23 is installed, the top cover 231 is sealed to the outer wall of the drain valve 23. A valve hole 2311 is provided in the middle of the top cover 231. The valve hole 2311 is the inlet for sewage and sediment. When the float 234 floats upward, it seals the valve hole 2311. When the float 234 descends, it opens the valve hole 2311. To ensure the sealing effect of the valve hole 2311, the float 234 is made of elastic material. The valve hole 2311 is designed with a conical opening that matches the outer contour of the float 234.

[0047] The bottom cover 232 is used for the installation and removal of the float 234. The bottom cover 232 and the mesh cylinder 233 are fixed by snap-fit ​​or thread. The mesh cylinder 233 is used to limit the float 234 and ensure that sewage and sediment can smoothly enter the sewage pipe 21.

[0048] To improve the sealing effect, a sealing cylinder 235 is provided at the upper end of the mesh cylinder 233, and a sealing ring 2351 is provided at the lower end of the sealing cylinder 235. When the float 234 floats upward to seal the valve hole 2311, the float 234 and the sealing ring 2351 fit together to seal the sealing cylinder 235. At this time, two seals are formed to isolate the sewage pipe 21 from the seawater in the aquaculture pond 1, ensuring that the sediment remaining in the sewage pipe 21 will not pollute the seawater in the aquaculture pond 1.

[0049] Example 2

[0050] like Figure 9 As shown, this embodiment provides a sewage purification system for oyster fattening and aquaculture in coastal dikes. The difference between the sewage purification system in this embodiment 2 and that in embodiment 1 is that there are two aquaculture ridges 12, and the sewage ditch 13 is located between the two aquaculture ridges 12. The aquaculture ridges 12 are provided with an inclined angle that is conducive to sewage discharge in the direction of the sewage ditch 13. That is, the aquaculture ridges 12 are provided with an inclined angle from the end away from the sewage ditch 13 to the end closer to the sewage ditch 13, such as an inclined angle of 1-10 degrees, so as to improve the sewage discharge effect.

[0051] Example 3

[0052] like Figure 10 As shown, this embodiment provides a sewage purification system for oyster fattening and aquaculture in coastal dikes. The difference between the sewage purification system of this embodiment 3 and that of embodiment 1 is that one end of the sewage pipe 21 is provided with an inlet valve 24, and the other end of the sewage pipe 21 is connected to the sewage collection pipe 22. One end of the sewage collection pipe 22 is sealed with an end cap 3, and the other end of the sewage collection pipe 22 is provided with an outlet valve 25 and / or a sewage pump 3. When the inlet valve 24 and the outlet valve 25 are in the closed state, the sewage purification system of this embodiment 3 is used in the same way as that of embodiment 1. The purpose of setting up inlet valve 24 and outlet valve 25 in this embodiment 3 is that when the cofferdam 11 is full of water, the inlet valve 24 and outlet valve 25 are opened at the same time. Under the pressure of the seawater, the seawater in the cofferdam 11 will enter the sewage pipe 21 through the inlet valve 24 and then be discharged through the outlet valve 25 (the outlet valve 25 is connected to the sewage ditch). The impact force of the seawater when it is discharged will wash the sewage pipe 21, clean the sewage and sediment in the sewage pipe 21, so as to improve the sewage discharge effect.

[0053] Example 4

[0054] This invention also provides a method for constructing a wastewater purification system for oyster fattening and aquaculture in coastal dikes, specifically including the following steps:

[0055] 1. Construct a breeding pond

[0056] A suitable coastal area is selected, and a dike is constructed to form an aquaculture pond 1. Multiple parallel and raised aquaculture ridges 12 are planned and constructed at the bottom of the pond, along with longitudinal drainage ditches 13 located between adjacent ridges 12. The drainage ditches 13 preferably have a V-shaped cross-section to facilitate sediment accumulation to the bottom. The outermost ridge 12 can be integrally constructed with the inner wall of the dike 11, or drainage ditches can also be installed between them.

[0057] Specifically, in the coastal area above the mean tide line, a soil-rock cofferdam 11, approximately 1.5-2 meters high and 1 meter wide at the top, is constructed to enclose a nearly rectangular aquaculture pond 1. At the bottom of the pond, multiple parallel aquaculture ridges 12 are built, each approximately 2-6 meters wide at the top and the same length as the pond. V-shaped drainage ditches 13, approximately 0.2-0.3 meters deep, are formed between adjacent ridges 12. The outermost ridges 12 on both sides are directly connected to the inner slope toe of the cofferdam 11, or a V-shaped drainage ditch 13 is formed between the ridge 12 and the cofferdam 11. The ridges 12 are used to systematically place oyster-filled fattening boxes, and the V-shaped drainage ditches 13 are used to collect sediment.

[0058] 2. Initial hardening of the aquaculture pond

[0059] Cement, quicklime, and sludge are mixed in a predetermined ratio to form a hardening material. This material is then evenly spread across the entire bottom of the aquaculture pond 1, including the surfaces of the aquaculture ridges 12 and the drainage ditch 13, and compacted to maintain the shape of the ridges 12 and ditch 13. The mixture is then left to dry and harden for 3-7 days, forming a preliminary hardened layer. This step, using a mixture of cement, quicklime, and sludge to create the hardening material, achieves the resource utilization of waste sludge. Furthermore, the hardened material facilitates subsequent removal, meeting national requirements prohibiting hardening in specific areas.

[0060] The mixing ratio of cement, quicklime, and sludge is as follows: for every 5-10 square meters of pool bottom, use 40-60 kg of cement, 20-30 kg of quicklime, and 0.5-1 cubic meter of sludge. As the optimal solution, for every 5 square meters of pool bottom, use 50 kg of cement, 25 kg of quicklime, and 0.5 cubic meter of sludge.

[0061] 3. Lay sewage pipes

[0062] Sewage pipe 2 is laid at the bottom of the breeding pond 1. At the bottom of the hardened sewage ditch 13, sewage pipe 21 with multiple sewage outlets 211 is laid. One end of each sewage pipe 12 is sealed and the other end is connected to the sewage collection pipe 22. Sewage pump 3 is installed at the end of the sewage collection pipe 22.

[0063] A drain valve 23 is installed in the drain outlet 211 of the drain pipe 21. The drain valve 23 includes an upper cover 231 with a conical valve hole 2311, a bottom cover 232, a mesh cylinder 233, a freely floating elastic float 234, and an internal sealing cylinder 235 with a sealing ring 2351. Its working principle is as follows: when the pool water needs to be drained for cleaning, as the water level drops, the float falls, the valve hole opens, and sewage and sediment enter the drain pipe through the mesh cylinder; when the aquaculture pond is filled with seawater for aquaculture, the drain pipe is filled with water, the float rises under the action of buoyancy, and at the same time seals the valve hole and the sealing cylinder, forming a double seal, thereby isolating the aquaculture water body from the drain pipe.

[0064] 4. Reinforce and harden the aquaculture ponds

[0065] A cement blanket is laid on the initial hardened layer at the bottom of the breeding pond 1. After the cement blanket is laid, a through hole is made above the sewage outlet 211 of the sewage pipe 21. The size of the through hole matches the sewage outlet 211. Water is poured onto the cement blanket to make it firmly bonded to the lower layer, and it is allowed to dry and harden for 3-7 days.

[0066] Specifically, a high-strength cement blanket is laid on the fully hardened preliminary hardened layer. The cement blankets overlap by approximately 10 centimeters. After laying, a cutting tool is used to precisely cut circular through holes in the cement blanket directly above each drain valve 23, fully exposing the valve hole 2311 of the drain valve 23 without affecting the normal operation of its float 234. Water is poured onto the cement blanket to fully hydrate it and ensure it bonds tightly to the underlying layer. It is then cured and hardened for 3-7 days to form a solid and flat reinforced hardened layer. Compared to traditional cofferdam ponds, this invention sets up culture ridges 12 at the bottom of the culture pond 1, and these ridges undergo preliminary and reinforced hardening before being used to place oyster fattening boxes.

[0067] 5. Laying the geomembrane

[0068] A geomembrane is laid on the reinforced and hardened layer at the bottom of the aquaculture pond 1. After the geomembrane is laid, a geomembrane through hole is opened above the sewage outlet 211 of the sewage pipe 21. The size of the geomembrane through hole matches the sewage outlet 211. The function of the geomembrane is to form a smooth, impermeable surface to prevent pollutants from seeping into the bottom structure of the pond and to facilitate the flushing of sediments to the sewage pipe by a water gun.

[0069] During fattening, filtered seawater is injected into the pond, and oyster fattening boxes are placed on the cultivation ridges 12. Appropriate amounts of feed can be provided. Regular (e.g., every 1-2 days) sludge removal is performed: the inlet is closed, and the sludge pump 3 is started to empty the pond. At this time, the sludge valve 23 automatically opens. Simultaneously, a high-pressure water gun is used to manually wash the bottom of the pond, especially the surface of the cultivation ridges 12, flushing the wastewater and sediment into the drainage ditch 13, which is then pumped out of the system via the sludge valve 23. After cleaning, the sludge pump 3 is turned off, fresh seawater is injected again, and the sludge valve 23 automatically closes under buoyancy, allowing the system to enter the next cultivation cycle.

[0070] This invention enables oyster fattening in coastal enclosures by constructing aquaculture ridges and drainage ditches at the bottom of the aquaculture pond, laying two layers of hardened and impermeable layers, laying drainage pipes at the bottom of the aquaculture pond, and installing drainage pumps. This effectively solves the technical problems of sediment accumulation and water quality deterioration in aquaculture ponds, making efficient and high-density oyster fattening in enclosure environments a reality.

[0071] A unique pool bottom structure is constructed through a preliminary hardening layer of mixed materials, a reinforcing layer of cement blanket, and a seepage-proof membrane layer. The preliminary hardening layer utilizes sludge, achieving resource utilization and facilitating future dismantling, thus meeting environmental protection requirements. The cement blanket layer provides a high-strength, integral, and robust base. The surface seepage-proof membrane forms a smooth, impermeable working surface, preventing pollutants from seeping down and greatly facilitating rapid and thorough cleaning of the pool bottom using high-pressure water jets, significantly reducing the difficulty and cost of daily maintenance.

[0072] Adopting a unique float-type drain valve design, it automatically opens during the drainage and cleaning stage to ensure the smooth discharge of sewage and sediment; it automatically closes during the aquaculture water filling stage. In particular, the double sealing structure of the valve hole and the internal sealing cylinder completely isolates residual pollutants in the drain pipe from the clean aquaculture water, preventing secondary pollution and protecting the oyster growth and cultivation environment.

[0073] However, the above description is merely a specific embodiment of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any substitution of equivalent components or equivalent changes and modifications made in accordance with the scope of protection of the present invention should still fall within the scope of the claims of the present invention.

Claims

1. A method for constructing a wastewater purification system for oyster fattening and aquaculture in coastal enclosures, characterized in that, Includes the following steps: Step S1. Constructing aquaculture ponds: Constructing a dike in a selected coastal area to form an aquaculture pond, constructing multiple parallel aquaculture ridges at the bottom of the pond, and constructing drainage ditches between adjacent aquaculture ridges; Step S2. Preliminary hardening of the aquaculture pond: Mix cement, quicklime and sludge to form a hardening material, spread it on the bottom of the entire aquaculture pond, and compact it to maintain the shape of the aquaculture ridges and drainage ditches. Let it stand and dry to form a preliminary hardening layer. Step S3. Laying sewage pipes: Laying sewage pipes with multiple sewage outlets at the bottom of the sewage ditch, with sewage valves installed in the sewage outlets, each sewage pipe sealed at one end and connected to a sewage collection pipe at the other end, and a sewage pump installed at the end of the sewage collection pipe; Step S4. Strengthening and hardening the aquaculture pond: Lay a cement blanket on the initial hardened layer, and make through holes in the cement blanket at the position corresponding to the sewage outlet. Water the cement blanket to cure and form a strengthened and hardened layer. Step S5. Laying the geomembrane: Laying the geomembrane on the reinforced and hardened layer, and opening geomembrane through holes on the geomembrane at the positions corresponding to the sewage outlets.

2. The construction method of a wastewater purification system for oyster fattening and aquaculture in coastal areas according to claim 1, characterized in that, One end of each of the sewage pipes is sealed by an inlet valve, and the other end is connected to a collection pipe, the end of which is also equipped with an outlet valve.

3. The construction method of a wastewater purification system for oyster fattening and aquaculture in coastal dikes according to claim 1, characterized in that, The drain valve includes an upper cover with a valve hole, a bottom cover, a mesh cylinder, and a float ball located in the mesh cylinder chamber. The float ball can rise and fall with the water level to open or close the valve hole.

4. The construction method of a wastewater purification system for oyster fattening and aquaculture in coastal areas according to claim 3, characterized in that, The valve orifice is tapered, and the float is made of elastic material.

5. The construction method of a wastewater purification system for oyster fattening and aquaculture in coastal dikes according to claim 4, characterized in that, The upper end of the drain valve's mesh cylinder is also equipped with a sealing cylinder, and the lower end of the sealing cylinder is equipped with a sealing ring. When the aquaculture pond is filled with water, the float rises under the action of buoyancy, simultaneously sealing the valve hole and fitting with the sealing ring to form a double sealing structure.

6. The construction method of a wastewater purification system for oyster fattening and aquaculture in coastal enclosures according to claim 1, characterized in that, The number of breeding ridges is two, and the drainage ditch is located between the two breeding ridges. The breeding ridges are inclined at an angle that is conducive to drainage towards the drainage ditch.

7. The construction method of a wastewater purification system for oyster fattening and aquaculture in coastal dikes according to claim 1, characterized in that, The width of the breeding ridges is 2m-6m.

8. The construction method of a wastewater purification system for oyster fattening and aquaculture in coastal enclosures according to claim 1, characterized in that, In step S2, the mixing ratio of cement, quicklime, and sludge is as follows: for every 5-10 square meters of pool bottom, use 40-60 kg of cement, 20-30 kg of quicklime, and 0.5-1 cubic meters of sludge.

9. A method for constructing a wastewater purification system for oyster fattening and aquaculture in coastal areas according to claim 8, characterized in that, The mixing ratio of the hardening material is as follows: for every 5 square meters of pool bottom, use 50 kg of cement, 25 kg of quicklime, and 0.5 cubic meters of sludge.

10. The method for constructing a wastewater purification system for oyster fattening and aquaculture in coastal areas according to claim 1, characterized in that, In step S2, the initial hardened layer is left to dry for 3-7 days; in step S4, the cement blanket is watered and cured for 3-7 days.

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