Grazing type fish culture and tail water treatment system

Abstract

The utility model discloses a grazing type fish culture and tail water treatment system which comprises a fish culture system and a culture tail water treatment system, the fish culture system comprises a culture working platform, an area partition part, an automatic feeding device, an underwater monitoring device, a fish collecting device, a pollutant monitoring device and a pollutant collecting device, the area partition component is arranged in a culture water area in a surrounding mode to form a culture area to limit a fish activity area, the underwater monitoring device is used for detecting the fish feeding condition of the culture area, the fish collecting device is used for collecting fishes, the pollutant monitoring device is used for detecting the water pollution index of the culture area, and the pollutant collecting device is used for collecting pollutants formed by culture; the culture tail water treatment system comprises a primary sedimentation tank, an AO tank, a secondary sedimentation tank, a plant absorption tank, a discharge tank and a tail water treatment monitoring system which are connected in sequence. According to the invention, fresh water grazing type fish culture and effective treatment of culture tail water can be realized.

Description

Technical Field

[0001] This application relates to the fields of aquaculture and water treatment technology, and in particular to a grazing-style fish farming and wastewater treatment system. Background Technology

[0002] Free-range fish farming technology refers to the practice of using large-scale fishery facilities and a systematic management system within a large open water area. It leverages the natural aquatic ecosystem, such as the fluidity of open water and the presence of zooplankton and phytoplankton, to simulate the natural wild environment for fish under artificial rearing conditions. This farming model ensures water quality while allowing the reared fish to achieve a "near-wild" state, thus improving fish quality. Free-range fish farming technology is applied in both freshwater and marine aquaculture, and is currently most commonly used in open water areas in the form of cage culture. Taking marine free-range fish farming as an example, with the increasing demand for seafood in my country, and the fact that marine fishing can no longer meet the growing demand, high-density, high-feeding marine cage culture has emerged. With the development of technology, cage culture has become more mature and environmentally friendly, leading to the development of circular rubber-lined cages. However, as a high-density, high-feeding artificial aquaculture ecosystem, marine cage aquaculture systems generate waste, uneaten feed, metabolic and excretory waste, which are the main sources of pollution causing environmental problems. In addition, the unreasonable layout of cage aquaculture areas, which are usually located in inner bays with low water exchange rates, will cause a series of ecological and environmental problems when the aquaculture capacity exceeds the environmental capacity of the sea area.

[0003] Freshwater free-range aquaculture technology is mainly used in fisheries operations on large bodies of water such as rivers, lakes, and reservoirs. Because freshwater aquaculture areas do not need to cope with complex and variable climates, such as wind, waves, and tides, the structure of freshwater aquaculture cages is simpler than that of marine aquaculture cages. However, due to the lower climate influence and poorer water flow in freshwater compared to marine aquaculture, the dispersion of pollutants in cage aquaculture is lower. With the same amount of pollutants, pollutants remain in the area for a longer period, resulting in more severe ecological problems and greater pressure on the surrounding aquatic environment. This not only fails to promote fish growth but also introduces pathogenic microorganisms, deteriorating water quality and causing mass mortality, thus defeating the original purpose of free-range aquaculture. Utility Model Content

[0004] Therefore, it is necessary to provide a grazing-style fish farming and wastewater treatment system. This utility model's grazing-style fish farming and wastewater treatment system can be used for freshwater grazing-style fish farming and the effective treatment of aquaculture wastewater, reducing or avoiding a series of ecological problems such as eutrophication and red tides in the aquaculture area, and reducing or avoiding environmental pollution.

[0005] One embodiment of this application provides a grazing-style fish farming and wastewater treatment system.

[0006] A free-range fish farming and wastewater treatment system includes a fish farming system and a wastewater treatment system set in a farming area. The fish farming system includes a farming platform, a zone partition, an automatic feeding device, an underwater monitoring device, a fish collection device, a pollutant monitoring device, and a pollutant collection device. The zone partition encloses a farming area in the farming area to restrict the fish's activity space. The automatic feeding device automatically feeds the farming area. The underwater monitoring device detects the feeding behavior of the fish in the farming area. The fish collection device collects the fish. The pollutant monitoring device detects water pollution indicators in the farming area. The pollutant collection device collects pollutants generated during the farming process.

[0007] The aquaculture wastewater treatment system includes a primary sedimentation tank, an AO tank, a secondary sedimentation tank, a plant absorption tank, a discharge tank, and a wastewater treatment monitoring system connected in sequence. The aquaculture wastewater treatment system is used to treat the aquaculture wastewater from the fish farming system.

[0008] In some embodiments, the area partition component includes a plurality of area partition nets and a plurality of uprights, the area partition nets being connected to the uprights to form the aquaculture area.

[0009] In some embodiments, the automatic feeding device includes several automatic fish feeders installed in the aquaculture area.

[0010] In some embodiments, the underwater monitoring device includes a camera capable of operating underwater.

[0011] In some embodiments, the fish collection device includes a net deployment and retrieval device, a connecting rope, a fishing net, a net positioning device, and a net fixing device. The net deployment and retrieval device is installed on the aquaculture platform. One end of the connecting rope is connected to the fishing net, and the other end of the connecting rope is connected to the net positioning device located at the top of the aquaculture area and near the edge of the aquaculture area. One end of the fishing net is connected to the net positioning device, and the other end of the fishing net is connected to the net fixing device located on the bottom of the aquaculture area. The portion of the fishing net in contact with the bottom of the aquaculture area is connected to multiple counterweights to ensure that the portion of the fishing net on the bottom of the aquaculture area does not float with the water flow due to gravity. The net deployment and retrieval device can bend the connecting rope under external power to move the net positioning device toward the aquaculture platform and to retract the fishing net.

[0012] In some embodiments, the pollutant monitoring device includes at least a COD index detection sensor, a TP index detection sensor, an ammonia nitrogen index detection sensor, a TN index detection sensor, and a pH index detection sensor.

[0013] In some embodiments, the pollutant collection device includes a pollutant collection platform, a scraper, a collection funnel, and a wastewater lift pump. The pollutant collection platform is a reinforced concrete platform, flush with the bottom surface of the aquaculture area. The scraper is movably mounted on the pollutant collection platform for periodically cleaning up leftover fish food and fish feces. The collection funnel is located below and at the end of the pollutant collection platform, and is used to collect pollutants scraped off the platform by the scraper. The wastewater lift pump is connected to the collection funnel via a pipe for periodically transferring the pollutants in the collection funnel to the aquaculture wastewater treatment system.

[0014] In some embodiments, the AO tank includes an aeration device, and the AO tank is used to remove COD and ammonia nitrogen from aquaculture wastewater.

[0015] In some embodiments, the plant absorption pond includes lettuce, water spinach, watercress, and sweet potato, which are capable of removing total nitrogen and total phosphorus from freshwater, and / or eelgrass and sea calamus, which are capable of removing total phosphorus and total nitrogen from seawater.

[0016] In some embodiments, the wastewater treatment monitoring system includes at least a COD sensor, a TP sensor, an ammonia nitrogen sensor, a TN sensor, and a pH sensor.

[0017] The aforementioned free-range fish farming and wastewater treatment system aims to maintain environmental sustainability and achieve an environmentally friendly free-range aquaculture model. It includes a novel free-range farming method and a wastewater treatment system. Borrowing from terrestrial "grazing," a fish ranch is established as the farming area in a near-shore open water area. Based on the feeding, excretion, and growth patterns of fish, technical means are used to concentrate the fish in fixed locations within the farming area for feeding and excretion. After feeding and excretion, the fish are released to other locations within the farming area, providing them with more space and promoting a more "wild" growth environment. Remaining food and excrement in the fixed locations are collected and treated by the integrated wastewater treatment system before being discharged in compliance with standards, minimizing the environmental pollution of surrounding waters caused by high-density aquaculture. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings. In the following description, the same reference numerals denote the same parts.

[0020] Figure 1 This is a schematic diagram of a grazing-style fish farming and wastewater treatment system according to an embodiment of the present invention.

[0021] Explanation of reference numerals in the attached figures

[0022] 10. Grazing-style fish farming and wastewater treatment system; 100. Fish farming system; 110. Aquaculture work platform; 120. Area partition components; 121. Area partition net; 122. Upright pole; 131. Fishing net retrieval device; 132. Connecting rope; 133. Fishing net; 134. Fishing net positioning device; 135. Fishing net fixing device; 140. Pollutant collection device; 141. Pollutant collection platform; 142. Sludge scraper; 143. Collection funnel; 144. Wastewater lifting pump; 200. Aquaculture wastewater treatment system; 210. Primary sedimentation tank; 220. AO tank; 221. Aeration device; 230. Secondary sedimentation tank; 240. Plant absorption tank; 250. Discharge tank. Detailed Implementation

[0023] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0024] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0025] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0026] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0027] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0028] In this document, "optionally," "optionally," and "optional" mean that something is optional, that is, it is selected from either "with" or "without." If multiple "options" appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "option" is independent. In this application, descriptions such as "optionally contains" and "optionally includes" indicate "contains or does not contain."

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0030] This application provides a free-range fish farming and tailwater treatment system 10 to solve at least one of the following technical problems in existing fish farming technology: (1) At present, almost all free-range farming technologies are aimed at seawater free-range farming, and there is almost no field of freshwater free-range farming; (2) Regarding the farming method, existing free-range farming and traditional net cage farming are similar, both using net cages to be placed in fixed positions in a fixed enclosure manner. In freshwater with relatively poor water flow, it is easier to cause pollutants to accumulate in the farming area, which is not conducive to the survival and growth of fish, and is more likely to cause eutrophication of the water body in the area, causing a series of ecological problems such as red tides; (3) Pollutants generated during the farming process, such as undigested fish feed and fish feces, release nitrogen, phosphorus, COD, etc., which cannot be effectively treated in a unified manner and are directly discharged into the water body, causing a certain degree of pollution to the environment; (4) Free-range farming is prone to polluting the surrounding water bodies, so in recent years, free-range farming sites have been set up in remote coastal areas, transported by boat, which is inconvenient for farming personnel to operate. The following description, in conjunction with the accompanying drawings, will explain the grazing-style fish farming and wastewater treatment system 10.

[0031] The grazing-style fish farming and wastewater treatment system 10 provided in this application embodiment is exemplary; please refer to [link to example]. Figure 1 As shown, Figure 1 This is a schematic diagram of the structure of the free-range fish farming and wastewater treatment system 10 provided in this application embodiment. The free-range fish farming and wastewater treatment system 10 of this application can be used for freshwater free-range fish farming and effective treatment of aquaculture wastewater, reducing or avoiding a series of ecological problems such as eutrophication and red tides in the aquaculture area, and reducing or avoiding environmental pollution.

[0032] To more clearly illustrate the structure of the grazing-style fish farming and wastewater treatment system 10, the following description, in conjunction with the accompanying drawings, will be provided. For an example, please refer to... Figure 1 As shown, Figure 1 This is a schematic diagram of the structure of the grazing-style fish farming and wastewater treatment system 10 provided in the embodiments of this application.

[0033] A free-range fish farming and wastewater treatment system 10 includes a fish farming system 100 and a wastewater treatment system 200, both located in aquaculture areas. The fish farming system 100 includes a farming work platform 110, a zone partition component 120, an automatic feeding device, an underwater monitoring device, a fish collection device, a pollutant monitoring device, and a pollutant collection device 140. The zone partition component 120 encloses a farming area within the aquaculture area to restrict fish activity. The automatic feeding device automatically feeds the fish in the farming area. The underwater monitoring device detects the feeding activity of the fish in the farming area. The fish collection device collects the fish. The pollutant monitoring device detects water pollution indicators in the farming area, and the pollutant collection device 140 collects pollutants generated during the farming process.

[0034] The aquaculture wastewater treatment system 200 includes a primary sedimentation tank 210, an AO tank 220, a secondary sedimentation tank 230, a plant absorption tank 240, a discharge tank 250, and a wastewater treatment monitoring system connected in sequence. The aquaculture wastewater treatment system 200 is used to treat the aquaculture wastewater from the fish farming system 100.

[0035] In some embodiments, the area partition component 120 includes a plurality of area partition nets 121 and a plurality of uprights 122. The area partition nets 121 are connected to the uprights 122 to form the aquaculture area.

[0036] In some embodiments, the automatic feeding device includes several automatic fish feeders disposed in the aquaculture area. The automatic feeding device is not shown in the accompanying drawings.

[0037] In some embodiments, the underwater monitoring device includes a camera capable of operating underwater. The underwater monitoring device is not shown in the accompanying drawings.

[0038] In some embodiments, the fish collection device includes a net deployment / retraction device 131, a connecting rope 132, a fishing net 133, a fishing net positioning device 134, and a fishing net fixing device 135. The net deployment / retraction device 131 is installed on the aquaculture platform 110. One end of the connecting rope 132 is connected to the fishing net 133. The fishing net 133 is made of polyethylene material, and the other end of the connecting rope 132 is connected to the fishing net positioning device 134, located at the top of the aquaculture area and near its edge. One end of the fishing net 133 is connected to the fishing net positioning device 134. The other end of the fishing net 133 is connected to the fishing net fixing device 135, located on the bottom surface of the aquaculture area. Multiple counterweights are connected to the portion of the fishing net 133 in contact with the bottom surface of the aquaculture area to prevent the portion of the fishing net 133 on the bottom surface from floating with the water flow due to gravity. The fishing net launching and retracting device 131 can bend the connecting rope 132 under the action of external power to move the fishing net positioning device 134 toward the aquaculture work platform 110 and realize the gathering of the fishing net 133.

[0039] The fish collection device operates as follows: When the fishing net retrieval device 131 operates, performing the "retrieval" action, its electric rope retractor begins to retract the connecting rope 132 on the fishing net 133, and the fishing net positioning device 134 begins to move horizontally towards the aquaculture platform 110. The space inside the fishing net 133 shrinks, and the fish are concentrated in the space under the aquaculture platform 110. This fixed space serves as a fixed location for feeding and excretion. When the "release" action is performed, the electric rope retractor begins to release the connecting rope 132, and the fishing net positioning device 134 begins to move outward away from the aquaculture platform 110 and pulls the fishing net 133 to ensure that the fishing net 133 opens smoothly. The fish's activity space increases, and the fish move outward within the aquaculture area. At this time, the larger space serves as a free-range area for the fish. The core component of the fishing net retrieval and release device 131 is an electric rope retractor, which is connected to the connecting rope 132 at one end of the fishing net 133 and serves to retract and release the connecting rope 132. The fishing net positioning device 134 is used to keep the fishing net 133 from drifting and collapsing at will, ensuring the fish's activity space. Its structure is a two-way translation device, which is linked with the fishing net retrieval and release device 131. When the fishing net retrieval and release device 131 performs a "retrieval" action, the fishing net positioning device 134 translates in the direction of retracting the fishing net 133. When the fishing net retrieval and release device 131 performs a "release" action, the fishing net positioning device 134 translates in the direction of releasing the fishing net 133 and has a certain pulling and driving effect, ensuring that the fishing net 133 is correctly placed and preventing it from piling up in the same place due to the gravity of the bottom counterweight, which would affect the fish's activity range.

[0040] In some of these embodiments, see Figure 1As shown, when the fishing net 133 is in the fully "released" state, the fishing net positioning device 134 is close to the pole 122 furthest away from the aquaculture work platform 110. When the fishing net 133 is in the fully "retrieved" state, the fishing net positioning device 134 is close to the aquaculture work platform 110.

[0041] In some embodiments, the fishing net 133 is a polyethylene fishing net 133.

[0042] In some embodiments, the connecting rope 132 may be a nylon rope.

[0043] In some embodiments, the pollutant monitoring device includes at least a COD sensor, a TP sensor, an ammonia nitrogen sensor, a TN sensor, and a pH sensor. The pollutant monitoring device is not shown in the accompanying drawings.

[0044] In some embodiments, the pollutant collection device 140 includes a pollutant collection platform 141, a scraper 142, a collection funnel 143, and a wastewater lift pump 144. The pollutant collection platform 141 is a reinforced concrete platform, flush with the bottom surface of the aquaculture area. The scraper 142 is movably mounted on the pollutant collection platform 141 for periodically cleaning leftover fish food and fish feces. The collection funnel 143 is located below and at the end of the pollutant collection platform 141. The collection funnel 143 collects the pollutants scraped off the pollutant collection platform 141 by the scraper 142. The wastewater lift pump 144 is connected to the collection funnel 143 via a pipe for periodically transferring the pollutants in the collection funnel 143 to the aquaculture wastewater treatment system 200.

[0045] In some embodiments, the primary sedimentation tank 210 in this application performs primary sedimentation to remove most of the suspended solids in the aquaculture effluent.

[0046] In some embodiments, the AO tank 220 contains activated sludge. Preferably, the activated sludge can be replaced with algae, and the propagated algae can be collected for the cultivation of algae-eating fish, thus achieving material recycling.

[0047] In some embodiments, the AO tank 220 includes an aeration device 221, and the AO tank 220 is used to remove COD and ammonia nitrogen from aquaculture wastewater.

[0048] In some embodiments, the plant absorption pool 240 includes lettuce, water spinach, watercress, and sweet potato, which are capable of removing total nitrogen and total phosphorus from freshwater, and / or eelgrass and sea calamus, which are capable of removing total phosphorus and total nitrogen from seawater.

[0049] In some embodiments, the effluent treatment monitoring system includes at least a COD sensor, a TP sensor, an ammonia nitrogen sensor, a TN sensor, and a pH sensor. The effluent treatment monitoring system is not shown in the accompanying drawings.

[0050] The aforementioned free-range fish farming and wastewater treatment system 10 aims to maintain sustainable environmental development and achieve an environmentally friendly free-range aquaculture model. It includes a novel free-range aquaculture method and a wastewater treatment system 200. Drawing inspiration from terrestrial "grazing," a fish ranch is established as the aquaculture area in a near-shore open water area. Based on the feeding, excretion, and growth patterns of fish, technical means are used to concentrate the fish in fixed locations within the aquaculture area for feeding and excretion. After feeding and excretion, the fish are released to other locations within the aquaculture area, providing them with more space and promoting a more "wild" growth environment. Remaining fish food and excrement in the fixed locations are collected and treated by the supporting wastewater treatment system 200 before being discharged in compliance with standards, minimizing the environmental pollution of the surrounding waters caused by high-density aquaculture.

[0051] In summary, the grazing-style fish farming and wastewater treatment system 10 of this application has the following beneficial effects:

[0052] (1) It fills the technological gap in the development of freshwater cage aquaculture in the existing technology.

[0053] (2) It solves the problem that pollutants are easily accumulated in aquaculture areas in waters with relatively poor water flow.

[0054] (3) It solved the problem of pollution caused by untreated pollutants from grazing aquaculture being directly discharged into the water.

[0055] (4) Fish have more space to move around and a better living environment, which effectively improves the quality of fish.

[0056] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0057] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0058] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A grazing-style fish farming and wastewater treatment system, characterized in that, The system includes a fish farming system and a fish farming wastewater treatment system installed in aquaculture waters. The fish farming system includes a farming work platform, a zone partition component, an automatic feeding device, an underwater monitoring device, a fish collection device, a pollutant monitoring device, and a pollutant collection device. The zone partition component encloses a farming area in the aquaculture waters to restrict the activity area of ​​the fish. The automatic feeding device is used to automatically feed the farming area. The underwater monitoring device is used to detect the feeding status of the fish in the farming area. The fish collection device is used to collect the fish. The pollutant monitoring device is used to detect water pollution indicators in the farming area. The pollutant collection device is used to collect pollutants generated during the farming process. The aquaculture wastewater treatment system includes a primary sedimentation tank, an AO tank, a secondary sedimentation tank, a plant absorption tank, a discharge tank, and a wastewater treatment monitoring system connected in sequence. The aquaculture wastewater treatment system is used to treat the aquaculture wastewater from the fish farming system.

2. The grazing-style fish farming and wastewater treatment system according to claim 1, characterized in that, The area partition component includes several area partition nets and several uprights, with the area partition nets connected to the uprights to form the breeding area.

3. The grazing-style fish farming and wastewater treatment system according to claim 1, characterized in that, The automatic feeding device includes several automatic fish feeders installed in the aquaculture area.

4. The grazing-style fish farming and wastewater treatment system according to any one of claims 1 to 3, characterized in that, The underwater monitoring device includes cameras capable of operating underwater.

5. The grazing-style fish farming and wastewater treatment system according to any one of claims 1 to 3, characterized in that, The fish collection device includes a net deployment and retrieval device, a connecting rope, a fishing net, a net positioning device, and a net fixing device. The net deployment and retrieval device is installed on the aquaculture platform. One end of the connecting rope is connected to the fishing net, and the other end of the connecting rope is connected to the net positioning device located at the top of the aquaculture area and near its edge. One end of the fishing net is connected to the net positioning device, and the other end of the fishing net is connected to the net fixing device located on the bottom of the aquaculture area. Multiple counterweights are connected to the portion of the fishing net in contact with the bottom of the aquaculture area to prevent the portion of the fishing net on the bottom of the aquaculture area from floating with the water flow due to gravity. The net deployment and retrieval device can bend the connecting rope under external power to move the net positioning device toward the aquaculture platform and to retract the fishing net.

6. The grazing-style fish farming and wastewater treatment system according to any one of claims 1 to 3, characterized in that, The pollutant monitoring device includes at least a COD index detection sensor, a TP index detection sensor, an ammonia nitrogen index detection sensor, a TN index detection sensor, and a pH index detection sensor.

7. The grazing-style fish farming and wastewater treatment system according to any one of claims 1 to 3, characterized in that, The pollutant collection device includes a pollutant collection platform, a scraper, a collection funnel, and a wastewater lift pump. The pollutant collection platform is a reinforced concrete platform, flush with the bottom surface of the aquaculture area. The scraper is movably mounted on the pollutant collection platform for periodically cleaning up leftover fish food and fish feces. The collection funnel is located below and at the end of the pollutant collection platform, and is used to collect pollutants scraped off the platform by the scraper. The wastewater lift pump is connected to the collection funnel via a pipe for periodically transferring the pollutants in the collection funnel to the aquaculture wastewater treatment system.

8. The grazing-style fish farming and wastewater treatment system according to any one of claims 1 to 3, characterized in that, The AO tank contains an aeration device and is used to remove COD and ammonia nitrogen from aquaculture wastewater.

9. The grazing-style fish farming and wastewater treatment system according to any one of claims 1 to 3, characterized in that, The plant absorption pond includes lettuce, water spinach, watercress, and sweet potato, which can remove total nitrogen and total phosphorus from freshwater, and / or eelgrass and sea calamus, which can remove total phosphorus and total nitrogen from seawater.

10. The grazing-style fish farming and wastewater treatment system according to any one of claims 1 to 3, characterized in that, The wastewater treatment monitoring system includes at least a COD sensor, a TP sensor, an ammonia nitrogen sensor, a TN sensor, and a pH sensor.

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