An algae-bacteria whole-process regulation and tail water treatment system and method in aquaculture

Abstract

The present application provides an algae and bacteria whole-process regulation and tail water treatment system and method in aquaculture, which comprises an ecological breeding area (1), a sedimentation area (2), a filtration area (3), a tail water treatment area (4) and a deep purification area (5). The ecological breeding area (1) comprises a first breeding pond (1-1) and a second breeding pond (1-2), the first breeding pond (1-1) and the second breeding pond (1-2) are communicated through a first water pump (12-1), the water outlet of the second breeding pond (1-2) is communicated with the water inlet of the sedimentation area (2), the water outlet of the sedimentation area (2) is communicated with the water inlet of the filtration area (3), the water outlet of the filtration area (3) is communicated with the first water inlet of the tail water treatment area (4), the first water outlet of the tail water treatment area (4) is communicated with the water inlet of the deep purification area (5), and the second water outlet of the tail water treatment area (4) is communicated with the first water supplement inlet of the first breeding pond (1-1).

Description

Technical Field

[0001] This invention relates to a whole-process regulation system and method for algae and bacteria in aquaculture and wastewater treatment, belonging to the field of green agriculture and non-point source pollution control. Background Technology

[0002] The existing problems, such as the mismatch between technology supply and demand, serious agricultural non-point source pollution, and the high investment, low returns, and high technological risks of green agriculture, make it difficult to break through the traditional agricultural development mode.

[0003] There is a lack of effective technical solutions for green pond aquaculture and green wastewater treatment in the agricultural and rural aquaculture industry. A green and stable pond ecological environment is the foundation for sustainable and healthy aquaculture. Furthermore, aquaculture wastewater that is discharged in stages or on a large scale needs to be treated quickly and effectively to reduce non-point source pollution and prevent serious impacts on the water quality of the receiving water bodies.

[0004] To address pollution issues in aquaculture water and wastewater, algae have garnered significant attention as an energy-efficient, green, and sustainable material. Algae require substantial amounts of nitrogen and phosphorus for growth and possess high adaptability, ease of survival, and low cost. Adding algae to aquaculture water effectively maintains water stability, restores water quality, and increases aquaculture yields, proving to be a promising green method for maintaining pond ecosystems. Furthermore, algae and bacteria can be used to treat aquaculture wastewater. Laboratory simulations of aquaculture wastewater by adding algae such as *Chlorella vulgaris*, *Cyclophora spp.*, and *Cryptocybea* have shown that total nitrogen (TN), total phosphorus (TP), and chemical oxygen demand (COD) in the wastewater can be significantly reduced. The removal rates of oxygen demand (COD) can reach 80%. In addition, algae can effectively promote the growth of bacteria. Through nitrification, denitrification and bioaccumulation of phosphorus, bacteria can remove nutrients from aquaculture water and aquaculture wastewater. Under long-term operation, an algae-bacterial symbiotic system can be formed, which further enhances the system's ability to remove pollutants such as nitrogen, phosphorus and organic matter. Using algae as a medium can simultaneously achieve green pond aquaculture and green wastewater treatment, and can also promote the recycling and reuse of resources within the system.

[0005] In the existing patent application CN116439191A, an aquaculture zone, sedimentation zone, electrochemical reaction device, effluent treatment zone, and water quality improvement zone are constructed. This system uses traditional electrochemical methods to degrade pollutants, which is costly, requires professional personnel for management and maintenance, and does not conform to the concept of ecological and environmental protection in terms of water treatment technology. The existing patent application CN116491459A discloses a recirculating aquaculture system including an aquaculture zone, a filtration zone, and a regulation zone arranged in sequence. This system uses ecological bacteria and algae to purify aquaculture effluent for reuse, but it lacks a comprehensive and multi-level integrated control approach for ecological bacteria and algae. It cannot simultaneously achieve the recycling of aquaculture effluent, the discharge of aquaculture effluent in compliance with standards, and the resource recovery and reuse of algae. Furthermore, it does not fully consider the relationship between pollutant removal and the growth and reproduction of bacteria and algae, nor does it fully explore the potential of multiple uses of bacteria and algae to improve the efficiency of each part of the system and the overall operation.

[0006] Addressing the shortcomings of existing pond aquaculture and wastewater treatment systems in green aquaculture, ecological governance, energy conservation and carbon reduction, and sustainable recycling in the agricultural and rural aquaculture industry, it is of great significance to promote the reduction of pollutants at the source, interception during the process, end-of-pipe treatment and resource recycling, as well as to maintain the ecological environment of ponds and purify and reuse aquaculture wastewater. Summary of the Invention

[0007] This invention proposes a whole-process regulation system and method for algae and bacteria in aquaculture and wastewater treatment, which aims to maintain the ecological environment of ponds in aquaculture and purify aquaculture wastewater.

[0008] The technical solution of this invention is a whole-process control system for algae and bacteria in aquaculture and a wastewater treatment system. The system includes an ecological aquaculture zone 1, a sedimentation zone 2, a filtration zone 3, a wastewater treatment zone 4, and a deep purification zone 5. The ecological aquaculture zone 1 includes a first aquaculture pond 1-1 and a second aquaculture pond 1-2. The first aquaculture pond 1-1 and the second aquaculture pond 1-2 are connected by a first water pump 12-1. The outlet of the second aquaculture pond 1-2 is connected to the inlet of the sedimentation zone 2. The outlet of the sedimentation zone 2 is connected to the inlet of the filtration zone 3. The outlet of the filtration zone 3 is connected to the first inlet of the wastewater treatment zone 4. The first outlet of the wastewater treatment zone 4 is connected to the inlet of the deep purification zone 5. The second outlet of the wastewater treatment zone 4 is connected to the first water supply outlet of the first aquaculture pond 1-1.

[0009] Furthermore, the aforementioned system for the whole-process regulation and wastewater treatment of algae and bacteria in aquaculture also includes an algae sludge fermentation tank 6, an algae-bacteria co-culture expansion tank 8, and a residual algae recycling tank 9. The algae sludge fermentation tank 6 is connected to the sedimentation zone 2 via a sludge vacuum pump 19. A fertilizer transport vehicle 20 is installed at the outlet of the algae sludge fermentation tank 6. The algae-bacteria co-culture expansion tank 8 is connected to the deep purification zone 5 via a second water pump 12-2. The first outlet of the algae-bacteria co-culture expansion tank 8 is connected to the second water inlet of the first aquaculture pond 1-1. The second outlet of the algae-bacteria co-culture expansion tank 8 is connected to the second inlet of the wastewater treatment zone 4. The third outlet of the algae-bacteria co-culture expansion tank 8 is connected to the inlet of the residual algae recycling tank 9.

[0010] Furthermore, the aforementioned system for the whole-process regulation and tailwater treatment of algae and bacteria in aquaculture also includes a photobioreactor 7. The third outlet of the tailwater treatment zone 4 is connected to the inlet of the photobioreactor 7. During operation, part of the algae- and bacteria-containing water purified in the tailwater treatment zone 4 enters the ecological aquaculture zone 1 for recycling, part enters the photobioreactor 7 as a supplementary material for algae and bacteria cultivation, and part is discharged into the deep purification zone 5 for deep treatment using the algae and bacteria biofilm. After reaching the standard, it is transported to the algae and bacteria co-culture expansion pond 8 as expansion water or discharged to a nearby receiving water body.

[0011] Furthermore, the ecological aquaculture zone 1, sedimentation zone 2, filtration zone 3, effluent treatment zone 4, and deep purification zone 5 are sequentially connected to form a five-stage treatment system: "ecological aquaculture - high-efficiency sedimentation - rapid filtration - purification and reuse - compliant discharge." Within this system, ecological aquaculture zone 1 is divided into two aquaculture areas: a first aquaculture pond 1-1 and a second aquaculture pond 1-2, separated by an artificial walkway 23. During operation, one-third of the water from the first aquaculture pond 1-1 is periodically discharged into the second aquaculture pond 1-2. Then, based on the water volume of sedimentation zone 2, wastewater is discharged from the second aquaculture pond 1-2 into sedimentation zone 2 for tailwater treatment. When the water volume of the second aquaculture pond 1-2 is only 2 / 3 of the initial volume, 1 / 3 of the water in the first aquaculture pond 1-1 is discharged into the second aquaculture pond 1-2 again. The tailwater from the second aquaculture pond 1-2 is discharged into sedimentation zone 2, where tannins are added to cause insoluble solids and suspended matter to settle. After flowing through filtration zone 3 to further remove suspended solids, it enters tailwater treatment zone 4. In tailwater treatment zone 4, the assimilation and absorption of algae and the heterotrophic metabolism of epiphytic bacteria are used to synergistically purify pollutants in the water.

[0012] Furthermore, the algae sludge fermentation tank 6, the algae-bacterial co-culture expansion tank 8, and the residual algae recovery tank 9 form a three-stage supplementary system of "algae sludge fermentation - algae-bacterial co-culture - recycling". In the three-stage supplementary system, the algae sludge fermentation tank 6 composts the algae-containing bottom mud in the sedimentation zone 2 to produce bio-fertilizer. The bio-fertilizer produced by composting is used to expand algae and bacteria in the photobioreactor 7 and the algae-bacterial co-culture expansion tank 8. The photobioreactor 7 initially obtains algae- and bacteria-containing water from the ecological aquaculture zone 1, and expands beneficial algae and epiphytic bacteria by controlling temperature, light, and aeration. After the system is running, the photobioreactor 7 obtains algae- and bacteria-containing water from the effluent treatment zone 4 to expand beneficial algae and bacteria. The beneficial algae epiphytes are expanded in the photobioreactor 7, and the water containing algae and bacteria is transported to the algae-bacteria co-culture expansion pond 8 for further expansion. The algae-bacteria co-culture expansion pond 8 obtains water from the deep purification zone 5 after disinfection and insecticidal treatment with calcium oxide. The water is regulated with bio-fertilizer obtained from the algae mud fermentation pond 6. After algae liquid is introduced into the algae-bacteria co-culture expansion pond 8, algae and algae epiphytes are expanded under natural light. Part of the algae expanded in the algae-bacteria co-culture expansion pond 8 is used to supplement the ecological aquaculture zone 1 to maintain the pond's ecological environment and provide feed. Part of it is provided to the wastewater treatment zone 4 to treat aquaculture wastewater. The remaining part is recycled in the residual algae recycling pond 9 and used to produce biomass materials.

[0013] Furthermore, during operation, fresh water is introduced into the ecological aquaculture zone 1 through the first pipe 11-1; the effluent from the ecological aquaculture zone 1 is discharged into the sedimentation zone 2 through the second pipe 11-2 located at 1 / 2 depth of the second aquaculture pond 1-2 in the ecological aquaculture zone 1. The bottom of the sedimentation zone 2 is set as a slope, and the side of the bottom of the sedimentation zone 2 closest to the ecological aquaculture zone 1 is higher than the side of the bottom of the sedimentation zone 2 closest to the filtration zone 3. The settled water flows from the sedimentation zone 2 into the filtration zone 3 through the third pipe 11-3. A filter dam 13 is set in the middle of the filtration zone 3; the filter dam 13 divides the filtration zone 3 into a front half and a rear half. The area between the filter dam 13 and the sedimentation zone 2 is the front half, and the area between the filter dam 13 and the effluent treatment zone 4 is the rear half. The bottom of the front half of the filtration zone 3 is sloped to promote the flow of water towards the effluent treatment zone 4.

[0014] Furthermore, the tailwater treatment zone 4 is designed in a racetrack shape, with a first flow barrier 14-1 in the middle. A first flow promoter 15-1 is installed between the first flow barrier 14-1 and the pool wall of the tailwater treatment zone 4. The first flow promoter 15-1 drives the water flow to circulate within the tailwater treatment zone 4. The tailwater treatment zone 4 obtains high-density algae-containing water from the algae-bacteria co-culture expansion pond 8 and mixes it thoroughly with the tailwater to treat pollutants. After treatment, a portion of the algae-containing water that meets the aquaculture standards is transported to the first aquaculture pond 1-1 in the ecological aquaculture zone 1 by the third water pump 12-3, a portion is discharged to the deep purification zone 5 through the fifth pipe 11-5, and another portion enters the photobioreactor 7 through the fourth water pump 12-4 as a supplementary source for algae-bacteria expansion.

[0015] Furthermore, the interior of the deep purification zone 5 is arranged in a racetrack shape, with a second baffle wall 14-2 in the middle of the deep purification zone 5. A second flow promoter 15-2 is installed between the second baffle wall 14-2 and the pool wall of the deep purification zone 5. Several sets of algae-bacterial biofilm rotating discs 16 are installed on both sides of the second baffle wall 14-2 and between the pool wall of the deep purification zone 5. After the water is deeply purified in the deep purification zone 5, it is discharged into a natural water body through the sixth pipe 11-6 or transported to the algae-bacterial mixed culture expansion tank 8 as culture water through the second water pump 12-2.

[0016] Furthermore, the tannins mentioned are plant tannins.

[0017] A method for the whole-process regulation of algae and bacteria and the treatment of wastewater in aquaculture, the method comprising:

[0018] 1) Within the ecological aquaculture zone 1, aquaculture is carried out after setting algae density and various water quality indicators according to the aquaculture targets;

[0019] 2) The ecological aquaculture area 1 regularly discharges aquaculture water containing algae and bacteria as tailwater into sedimentation area 2. Plant tannins are added to sedimentation area 2 to precipitate insoluble solids and suspended matter in the tailwater.

[0020] 3) The effluent after sedimentation in sedimentation zone 2 is further filtered in filtration zone 3 to remove floating impurities;

[0021] 4) Tailwater treatment zone 4 obtains tailwater from filtration zone 3 and algae-bacterial mixed culture expansion tank 8. The algae-bacterial water is diluted by the tailwater and fully mixed with the tailwater for post-treatment. Algae and bacteria are used to remove N, P and organic matter contained in the tailwater, and water treatment and algae-bacterial expansion are achieved simultaneously. Algae and bacteria are generated while pollutants are reduced.

[0022] 5) After treatment in the tailwater treatment zone 4, part of the tailwater is introduced into the ecological aquaculture zone 1 through the third water pump 12-3, part of the tailwater is introduced into the photobioreactor 7 through the fourth water pump 12-4 as a supplementary source for algae and bacteria expansion, and part of the tailwater enters the deep purification zone 5 for treatment using the algae and bacteria biofilm formed on the algae-bacteria biofilm turntable 16. After treatment in the deep purification zone 5, the water that meets the pond aquaculture discharge standards is transported to the algae and bacteria mixed culture expansion pond 8 for reuse or discharged into natural water bodies.

[0023] Furthermore, the method for the whole-process regulation of algae and bacteria and the treatment of wastewater in aquaculture further includes:

[0024] 6) The algae fermentation tank 6 collects algae-containing sediment in the sedimentation zone 2 through the sludge vacuum pump 19, and composts it with straw, weeds and plant debris around the breeding area to produce biogas and bio-fertilizer. The bio-fertilizer is provided to the algae and fungi co-culture expansion tank 8 for the expansion of algae and fungi.

[0025] 7) The algae-bacterial mixed culture expansion tank 8 is equipped with several photobioreactors 7. The photobioreactors 7 initially obtain algae-bacterial water from the ecological aquaculture area 1, use the bio-fertilizer obtained from the algae mud fermentation tank 6 and control the external conditions to screen and expand algae, and then introduce it into the algae-bacterial mixed culture expansion tank 8 through the hose 18. The algae-bacterial mixed culture expansion tank 8 combines the bio-fertilizer obtained from the algae mud fermentation tank 6 to expand algae and bacteria to form a high-density algae-bacterial water body.

[0026] 8) After the algae and bacteria are expanded in the algae and bacteria co-culture expansion pond 8 to form a high-density algae and bacteria-containing water body, a portion of the high-density algae and bacteria-containing water body is supplemented to the ecological aquaculture area 1 and the tailwater treatment area 4 as needed. The remaining high-density algae and bacteria-containing water body is introduced into the remaining algae recycling pond 9 and used for the production of biomass materials after being recovered by air flotation.

[0027] The beneficial effects of this invention are:

[0028] 1) This invention facilitates the control and management of algae and bacteria in aquaculture ponds, eliminating or greatly reducing the need for continuous external replenishment of algae and bacteria. It is a low-cost, non-powered, and ecologically-oriented rural pollution control technology that can promote the recycling of nutrients, improve the quality of aquatic animals, and achieve green and ecological aquaculture.

[0029] 2) This invention utilizes the synergistic effect of algae and bacteria to determine the technical route for comprehensive prevention and control based on the basic paths of pollutant generation, migration and destination, thereby strengthening pollutant removal, improving the quality of aquaculture water environment, and ensuring that aquaculture wastewater meets discharge standards.

[0030] 3) This invention is adapted to local conditions and can carry out comprehensive prevention and control measures based on small watersheds or catchment areas. It can be carried out by modifying existing aquaculture ponds without occupying other land resources. It has a simple structure and is easy to operate and manage.

[0031] 4) This system is ecological and environmentally friendly, reducing the addition of feed and disease prevention drugs during the breeding process. It is conducive to the implementation of rural pollutant resource recycling and the operation and maintenance model of strengthening the follow-up management of the project. It can generate high-value biological resources and has significant economic and ecological benefits.

[0032] 5) This invention enables the continuous and multi-level application of algae and bacteria within the system. On the one hand, it improves the utilization rate of algae and bacteria, and can simultaneously achieve water treatment and algae and bacteria expansion. On the other hand, it increases the proportion of beneficial algae and bacteria within the system, improves the efficiency of water treatment, fermentation and expansion, and further improves the operating efficiency of the system.

[0033] 6) The engineering materials required for this invention include pebbles, gravel, ceramsite, etc., which are inexpensive and readily available, and do not cause secondary pollution; straw, weeds and other waste materials, which are one of the raw materials for composting, are readily available, which can improve system operation and promote the green treatment of waste. Attached Figure Description

[0034] Appendix Figure 1 This is a schematic diagram of a whole-process control system for algae and bacteria and a wastewater treatment system in aquaculture.

[0035] Appendix Figure 2 This is a schematic diagram of a whole-process control system for algae and bacteria and a wastewater treatment system in aquaculture.

[0036] Appendix Figure 3 This is a schematic cross-sectional view of a five-stage main system for the whole-process regulation of algae and bacteria and the treatment of tailwater in aquaculture.

[0037] Appendix Figure 4 This is a schematic cross-sectional view of a three-stage auxiliary system for the whole-process regulation of algae and bacteria and the treatment of tailwater in aquaculture.

[0038] Appendix Figure 5 This is a schematic diagram of the process of the tailwater treatment area in this invention.

[0039] Appendix Figure 6 This is a schematic diagram of the deep purification zone process in this invention.

[0040] In the attached diagram, 1 is the ecological aquaculture area, 1-1 is the first aquaculture pond, 1-2 is the second aquaculture pond, 2 is the sedimentation area, 3 is the filtration area, 4 is the effluent treatment area, 5 is the deep purification area, 6 is the algae fermentation tank, 7 is the photobioreactor (including light source, gas supply, temperature control, etc.), 8 is the algae-bacteria co-culture expansion tank, 9 is the residual algae recycling tank, 10 is the spray dryer, 11-1 is the first pipeline, 11-2 is the second pipeline, 11-3 is the third pipeline, 11-4 is the fourth pipeline, 11-5 is the fifth pipeline, 11-6 is the sixth pipeline, 11-7 is the seventh pipeline, and 11-8 is... The eighth pipeline, 12-1 is the first water pump, 12-2 is the second water pump, 12-3 is the third water pump, 12-4 is the fourth water pump, 13 is the filter dam, 14-1 is the first flow barrier, 15-1 is the first flow booster, 14-2 is the second flow barrier, 15-2 is the second flow booster, 16 is the algae-bacterial biofilm rotating disc, 17 is the aeration device, 18 is the flexible hose, 19 is the sludge vacuum pump, 20 is the fertilizer transport vehicle, 21 is the chain scraper, 22 is the algae collection tank, and 23 is the artificial walkway. Detailed Implementation

[0041] A system for the whole-process regulation of algae and bacteria and the treatment of wastewater in aquaculture is disclosed. The system includes an ecological aquaculture zone 1, a sedimentation zone 2, a filtration zone 3, a wastewater treatment zone 4, and a deep purification zone 5. The ecological aquaculture zone 1 includes a first aquaculture pond 1-1 and a second aquaculture pond 1-2. The first aquaculture pond 1-1 and the second aquaculture pond 1-2 are connected by a first water pump 12-1. The outlet of the second aquaculture pond 1-2 serves as the outlet of the ecological aquaculture zone 1 and is connected to the inlet of the sedimentation zone 2. The outlet of the ecological aquaculture zone 1 is connected to the inlet of the sedimentation zone 2. The outlet of the sedimentation zone 2 is connected to the inlet of the filtration zone 3. The outlet of the filtration zone 3 is connected to the first inlet of the wastewater treatment zone 4. The first outlet of the wastewater treatment zone 4 is connected to the inlet of the deep purification zone 5. The second outlet of the wastewater treatment zone 4 is connected to the first water supply outlet of the first aquaculture pond 1-1.

[0042] The aforementioned system for the whole-process regulation and tailwater treatment of algae and bacteria in aquaculture includes an algae sludge fermentation tank 6, an algae-bacteria co-culture expansion tank 8, and a residual algae recovery tank 9. The algae sludge fermentation tank 6 is connected to a sedimentation zone 2 via a sludge vacuum pump 19. A fertilizer transport vehicle 20 is installed at the outlet of the algae sludge fermentation tank 6 to transport fertilizer to the algae-bacteria co-culture expansion tank 8. The algae-bacteria co-culture expansion tank 8 is connected to a deep purification zone 5 via a second water pump 12-2. The first outlet of the algae-bacteria co-culture expansion tank 8 is connected to the second water inlet of the first aquaculture pond 1-1. The second outlet of the algae-bacteria co-culture expansion tank 8 is connected to the second inlet of the tailwater treatment zone 4. The third outlet of the algae-bacteria co-culture expansion tank 8 is connected to the inlet of the residual algae recovery tank 9.

[0043] The aforementioned system for the whole-process regulation and tailwater treatment of algae and bacteria in aquaculture includes a photobioreactor 7. The third outlet of the tailwater treatment zone 4 is connected to the inlet of the photobioreactor 7. During operation, part of the algae- and bacteria-containing water purified in the tailwater treatment zone 4 enters the ecological aquaculture zone 1 for recycling, part enters the photobioreactor 7 as a supplementary material for algae and bacteria cultivation, and part is discharged into the deep purification zone 5 for deep treatment using algae and bacteria biofilm. After reaching the standard, it is transported to the algae and bacteria co-culture expansion pond 8 as expansion water or discharged to a nearby receiving water body.

[0044] This invention proposes a five-stage main treatment system for the whole-process regulation and wastewater treatment of algae and bacteria in aquaculture. The system comprises an ecological aquaculture zone 1, a sedimentation zone 2, a filtration zone 3, a wastewater treatment zone 4, and a deep purification zone 5, which are sequentially connected to form a system of "ecological aquaculture - high-efficiency sedimentation - rapid filtration - purification and reuse - compliant discharge." An algae sludge fermentation tank 6, an algae-bacteria co-culture expansion tank 8, and a residual algae recovery tank 9 form a three-stage supplementary system of "algae sludge fermentation - algae-bacteria co-culture - recycling." Within the five-stage main treatment system, the ecological aquaculture zone 1 is divided into two aquaculture areas: a first aquaculture pond 1-1 and a second aquaculture pond 1-2, separated by an artificial walkway 23. During operation... The first aquaculture pond 1-1 periodically discharges 1 / 3 of its water into the second aquaculture pond 1-2. Then, based on the water volume of the sedimentation zone 2, wastewater is continuously discharged from the second aquaculture pond 1-2 into the sedimentation zone 2 for tailwater treatment. This process is repeated when the water volume in the second aquaculture pond 1-2 is reduced to only 2 / 3 of its initial volume. The first aquaculture pond 1-1 then discharges another 1 / 3 of its water into the second aquaculture pond 1-2. This eliminates the need for a storage tank and facilitates drainage control. It also allows for more flexible layout of the five-stage treatment main system and the three-stage auxiliary system, enabling the appropriate system area to be set according to needs and the available space in the aquaculture area without affecting the system's operational performance. The effluent from aquaculture ponds 1-2 is discharged into sedimentation zone 2, where tannins are added to cause insoluble solids and suspended matter to settle. The effluent then flows through filtration zone 3 for further removal of suspended solids before entering effluent treatment zone 4. In treatment zone 4, algae assimilate and absorb pollutants, along with epiphytic bacteria undergo heterotrophic metabolism, to synergistically purify the water. A portion of the purified algae- and bacteria-containing water from treatment zone 4 is recycled into ecological aquaculture zone 1, another portion enters photobioreactor 7 as a supplement for algae and bacteria cultivation, and the remaining portion is discharged into deep purification zone 5 for further treatment using algae and bacteria biofilm. After reaching the required standards, the treated water is then transported to algae and bacteria co-culture expansion pond 8 as expansion water or discharged into nearby receiving water bodies. This is part of the three-stage auxiliary system. The algae fermentation tank 6 composts the algae-containing bottom mud in the sedimentation zone 2 with other wastes around the aquaculture area. The bio-fertilizer produced by composting is used to cultivate algae and bacteria in the photobioreactor 7 and the algae-bacterial co-culture expansion tank 8. The photobioreactor 7 initially obtains algae-bacterial water from the ecological aquaculture zone 1 and cultivates beneficial algae and their epiphytic bacteria by controlling temperature, light, and aeration. After the system is running, the photobioreactor 7 obtains algae-bacterial water from the tailwater treatment zone 4 to cultivate beneficial algae and their epiphytic bacteria. After the water quality of the algae-bacterial co-culture expansion tank 8 is adjusted, under sufficient natural light, the algae-bacterial water cultivated in the photobioreactor 7 is transported to the algae-bacterial co-culture expansion tank 8 for large-scale cultivation.The algae-bacterial co-culture expansion pond 8 uses calcium oxide for disinfection and insect control, and obtains water from the deep purification zone 5. Bio-fertilizer obtained from the algae sludge fermentation tank 6 is used to regulate the water. Algae solution is introduced into the algae-bacterial co-culture expansion pond 8, and algae and their epiphytic bacteria are cultivated on a large scale under natural light. Part of the algae cultivated in the algae-bacterial co-culture expansion pond 8 can be used to supplement the ecological aquaculture zone 1 to maintain the pond's ecological environment and provide feed; part is provided to the wastewater treatment zone 4 to treat aquaculture wastewater; and the remainder is recycled in the residual algae recycling pond 9 and can be used to produce biomass materials. This invention achieves the goals of synergistic and efficient algae-bacterial purification, algae-water recycling for carbon reduction and efficiency improvement, and algae-sludge recycling for greening and cost reduction.

[0045] This invention fully considers the shortcomings of existing pond aquaculture and wastewater treatment systems in agricultural and rural aquaculture in terms of green aquaculture, ecological governance, energy conservation and carbon reduction, and sustainable recycling. It innovatively proposes using independent or contiguous pond aquaculture areas as basic units, adapting or redesigning existing aquaculture areas according to local conditions. It only requires regulating algae and bacteria, which are already considered in the aquaculture process, to promote source reduction, process interception, end-of-pipe disposal, and resource recycling of pollutants throughout the aquaculture and wastewater exchange process. Furthermore, it reduces the artificial addition of algae and bacteria during the aquaculture process, eliminating the need for other traditional water treatment devices, significantly reducing energy consumption and potential toxic byproducts. By setting up a five-stage main treatment system and a three-stage auxiliary system, combined with the basic pathways of pollutant generation, migration, and destination, it utilizes the assimilation and absorption of algae and the heterotrophic metabolism of epiphytic bacteria to synergistically purify pollutants in the water. Based on the actual aquaculture model, it comprehensively considers the layout of aquaculture ponds and wastewater treatment processes in terms of flow and space, achieving the goals of maintaining the ecological environment of aquaculture ponds, purifying and reusing aquaculture wastewater, ensuring wastewater meets discharge standards, and recycling resources.

[0046] This invention overcomes the problems of traditional pond aquaculture, such as the difficulty in maintaining a stable and healthy ecological environment, the high energy consumption and easy generation of toxic byproducts in removing pollutants from aquaculture wastewater, the discharge of substandard aquaculture wastewater into the natural environment, and the serious waste of resources within the aquaculture system. This invention is a comprehensive regulation system that conforms to the characteristics of the aquaculture cycle, effectively promotes the reuse of water, algae, and bacteria, maintains a good aquaculture ecological environment, and promotes the ecological treatment of wastewater. The entire process of this invention fully considers the characteristics of high organic load in aquaculture water and drainage, intermittent water exchange during aquaculture, and concentrated drainage at the end of aquaculture. It only needs to amplify the algae and bacteria functions that originally needed to be managed in aquaculture and use them as the main regulation targets to achieve the effects that previously required a combination of multiple water treatment processes.

[0047] As attached Figure 1 Appendix Figure 2 Appendix Figure 3As shown, during operation, fresh water (fresh water refers to natural water source or water retained from the previous cycle and treated in situ) is input into the ecological aquaculture area 1 through the first pipe 11-1; the effluent from the ecological aquaculture area 1 is discharged into the sedimentation area 2 through the second pipe 11-2, which is located at 1 / 2 depth of the second aquaculture pond 1-2 in the ecological aquaculture area 1. The bottom of the sedimentation area 2 is set as an incline, and the side of the bottom of the sedimentation area 2 closest to the ecological aquaculture area 1 is higher than the side of the bottom of the sedimentation area 2 closest to the filtration area 3. The settled water is discharged from the third pipe 11-3 from the... The sedimentation zone 2 flows into the filtration zone 3, and a filter dam 13 is set in the middle of the filtration zone 3. The filter dam 13 divides the filtration zone 3 into a front half and a rear half. The area between the filter dam 13 and the sedimentation zone 2 is the front half, and the area between the filter dam 13 and the effluent treatment zone 4 is the rear half. The bottom of the front half of the filtration zone 3, near the sedimentation zone 2, is higher than the bottom of the front half of the filtration zone 3, near the filter dam 13. The bottom of the front half of the filtration zone 3 (the end near the sedimentation zone 2) is sloped so that the water can flow quickly towards the effluent treatment zone 4.

[0048] The tannin is preferably plant tannin, which can efficiently precipitate algae and suspended solids and improve the service life of the filtration zone 3; the photobioreactor is preferably a columnar photobioreactor, which can be a columnar microalgae photobioreactor with a diameter of 0.6 m and a height of 2 m produced by Guangyu Biotechnology Co., Ltd.

[0049] The filter dam 13 is made of pebbles, gravel, ceramsite, etc., which are filled from bottom to top layer by layer under the fixation of stainless steel wire mesh. During operation, the water in the first half of the filter zone 3 reaches the second half of the filter zone 3 through the filter dam 13, and then the water is discharged into the tailwater treatment zone 4 through the fourth pipe 11-4.

[0050] As attached Figure 5 As shown, the tailwater treatment zone 4 is designed in a racetrack shape. A first baffle wall 14-1 is set in the middle of the tailwater treatment zone 4. A first flow promoter 15-1 is set between the first baffle wall 14-1 and the pool wall of the tailwater treatment zone 4. The first flow promoter 15-1 promotes the water flow to circulate in the tailwater treatment zone 4. The tailwater treatment zone 4 obtains high-density algae-containing water from the algae-bacteria co-culture expansion pond 8 and mixes it thoroughly with the tailwater to treat pollutants. After treatment, part of the algae-containing water that meets the aquaculture standards is transported to the first aquaculture pond 1-1 in the ecological aquaculture zone 1 through the third water pump 12-3 to maintain the pond's ecological environment and provide feed for the aquaculture products, realizing the secondary utilization of algae. Part of it is discharged to the deep purification zone 5 through the fifth pipe 11-5 for further treatment and discharge after meeting the standards. Another part enters the photobioreactor 7 through the fourth water pump 12-4 as a supplementary source for algae-bacteria expansion, reducing the addition of external algae and bacteria and improving the utilization rate of algae and bacteria.

[0051] As attached Figure 6As shown, the interior of the deep purification zone 5 is designed in the shape of a racetrack. A second baffle wall 14-2 is set in the middle of the deep purification zone 5. A second flow promoter 15-2 is set between the second baffle wall 14-2 and the pool wall of the deep purification zone 5. Several sets of algae-bacterial biofilm rotating discs 16 are set on both sides of the second baffle wall 14-2 and between the pool wall of the deep purification zone 5. After the water is deeply purified in the deep purification zone 5, it is discharged into the natural water body through the sixth pipe 11-6 or transported to the algae-bacterial mixed culture expansion tank 8 as the culture water body through the second water pump 12-2.

[0052] As attached Figure 4 As shown, for the three-stage auxiliary system, the algae fermentation tank 6 uses a sludge vacuum pump 19 to obtain algae-containing bottom sludge from the sedimentation zone 2, and combines it with other waste in the aquaculture area for composting and gas production. The gas is used for the operation of mechanical devices, and the fertilizer is used for the cultivation of algae and bacteria in the photobioreactor 7 and the algae-bacterial co-culture expansion tank 8. The photobioreactor 7 preferably adopts a columnar microalgae photobioreactor with a diameter of 0.6 m and a height of 2 m produced by Guangyu Biotechnology Co., Ltd. It can control external conditions such as temperature, light, and aeration, and is used to centrally screen the algae required for expansion. After reaching a certain density, it is discharged into the algae-bacterial co-culture expansion tank 8 for scale-up expansion. After discharge, algae-bacterial-containing water is obtained from the tailwater treatment zone 4 to repeat the above process. The algae-bacterial co-culture expansion tank 8 adopts an open pond cultivation system with a pond depth not exceeding 0.6 m. m, to improve the algae's light utilization rate, after the expansion culture is completed, the remaining high-density algae-bacteria-containing water is discharged to the remaining algae recovery tank 9 through the seventh pipe 11-7 of the third outlet of the algae-bacteria mixed culture expansion tank 8; the remaining algae recovery tank 9 uses the traditional air flotation method to recover algae. The bottom of the remaining algae recovery tank 9 is equipped with an aeration device 17, and the algae are concentrated into the algae collection tank 22 by the scraping device 21 to recover the algae. The recovered algae is transported to the spray dryer 10 through the eighth pipe 11-8; the spray dryer 10 evaporates the water in the algae liquid recovered by air flotation to generate dry algae powder, which can be further processed into microalgae series products.

[0053] A method for aquaculture and wastewater treatment utilizing a whole-process control system for algae and bacteria in aquaculture and a wastewater treatment system, the method comprising:

[0054] 1) After setting algae density and various water quality indicators according to the aquaculture objects in ecological aquaculture zone 1, aquaculture can be carried out. This can achieve simultaneous management of algae and bacteria, joint regulation of water quality, fertile water without eutrophication, reduce the occurrence of diseases and pests, and at the same time improve the immunity of aquatic products, increase survival rate and product quality.

[0055] 2) Periodically discharge 1 / 3 of the water containing algae and bacteria into sedimentation zone 2 as effluent. Add plant tannins to sedimentation zone 2 to precipitate insoluble solids and suspended matter in the effluent, improve sedimentation speed and aggregation effect, reduce effluent turbidity, and thus significantly extend the service life of filtration zone 3. At the same time, rapid sedimentation and good aggregation can also reduce the operating efficiency of sludge vacuum pump 19 and reduce the system's effluent treatment time.

[0056] 3) In the sedimentation zone 2, insoluble solids and suspended matter in the effluent are precipitated. After sedimentation, the effluent is further filtered in the filtration zone 3 to remove floating impurities. At this time, the water mainly contains dissolved organic matter and contains little or no algae, which can effectively promote the formation of algal biofilm, thus performing preliminary treatment on the effluent. After that, it enters the effluent treatment zone 4.

[0057] 4) The wastewater treatment zone 4 obtains wastewater containing a large amount of dissolved pollutants from the filtration zone 3 and obtains high-density algae and bacteria-containing water from the algae and bacteria co-culture expansion tank 8. The wastewater is diluted and fully mixed with the wastewater for post-treatment. The algae and bacteria can be used to remove part of the N, P, organic matter, etc. contained in the wastewater. Water treatment and algae and bacteria expansion are achieved simultaneously. While pollutants are reduced, algae and bacteria that can maintain a good ecological environment of the aquaculture farm and promote the ecological treatment of wastewater are generated, which improves the utilization rate and yield of algae and bacteria.

[0058] 5) The treated effluent in the tailwater treatment zone 4 meets the aquaculture standards but may not meet the discharge standards. At this time, the water body is a low-density algae-bacteria-containing water body. A portion of the low-density algae-bacteria-containing water body is introduced into the ecological aquaculture zone 1 through the third water pump 12-3. The algae, bacteria and water can be recycled, improving the utilization rate and maintaining the pond ecological environment of the ecological aquaculture zone 1. The algae can also serve as food for aquaculture products and improve the immunity of aquatic products. A portion of the low-density algae-bacteria-containing water body enters the photobioreactor 7 through the fourth water pump 12-4 as a supplementary source for algae and bacteria expansion. Another portion of the low-density algae-bacteria-containing water body enters the deep purification zone 5. The algae and bacteria biofilm formed on the algae-bacteria biofilm turntable 16 is used to enhance the treatment of pollutants in the low-density algae-bacteria-containing water body. After treatment in the deep purification zone 5, the water body that meets the pond aquaculture discharge standards can be transported to the algae-bacteria co-culture expansion pond 8 for reuse or discharged into natural water bodies.

[0059] In the tailwater treatment zone 4, algae remove nitrate nitrogen, nitrite nitrogen, ammonia nitrogen, and free ammonia from the water through assimilation, ammonia volatilization, nitrification, and denitrification. Multiple phosphorylation pathways convert hydrogen phosphate, dihydrogen phosphate, and phosphate into adenosine triphosphate, phospholipids, and other organic matter to remove phosphorus. Organic matter is removed through rapid passive physicochemical adsorption and slow active absorption and degradation. Bacteria degrade nitrogen, phosphorus, and organic matter in the tailwater through respiration, nitrification, denitrification, and the excessive accumulation of phosphorus by microorganisms. Under long-term operation, an algae-bacteria symbiotic system can be formed, further promoting the system's ability to remove pollutants such as nitrogen, phosphorus, and organic matter.

[0060] The formation of the algae-bacterial biofilm in the deep purification zone 5 can greatly promote the synergistic effect between algae and bacteria through close material exchange, and the treatment effect is significantly higher than that of the suspended algae-bacterial treatment mode in the effluent treatment zone 4. The effluent entering the deep purification zone 5 provides nitrogen, phosphorus and other elements for the growth of microalgae, and bacteria can decompose organic matter to provide carbon sources for microalgae. The oxygen produced by the photosynthesis of microalgae can provide a guarantee for bacterial metabolism. After a breeding cycle, the algae-bacterial biofilm can also be recycled for resource utilization.

[0061] A method for aquaculture and wastewater treatment utilizing a whole-process control system for algae and bacteria in aquaculture and a wastewater treatment system, the method further comprising:

[0062] 6) The algae fermentation tank 6 collects algae-containing sediment in the sedimentation zone 2 through the sludge vacuum pump 19, and composts it with waste such as straw, weeds, and plant debris around the aquaculture area to produce biogas and bio-fertilizer. The biogas is used to maintain the daily operation of various mechanical equipment in the system, and the bio-fertilizer is provided to the algae and fungi co-culture expansion tank 8 for the expansion of algae and fungi. The multi-level utilization of algae and fungi can also promote the proportion of algae and fungi in the algae-containing sediment, promote the fermentation process and improve the nutritional indicators of the final fertilizer. The composition ratio of the bio-fertilizer is also more stable.

[0063] 7) The algae-bacteria co-culture expansion tank 8 is equipped with a set of photobioreactors 7 containing light sources, gas supply, temperature control and other devices. The photobioreactor 7 initially obtains algae-bacteria-containing water from the ecological aquaculture area 1, uses the bio-fertilizer obtained from the algae mud fermentation tank 6 and controls the external conditions to screen and expand algae, and then introduces it into the algae-bacteria co-culture expansion tank 8 through the hose 18. Combined with the bio-fertilizer obtained from the algae mud fermentation tank 6, a large number of algae and bacteria are expanded to form a high-density algae-bacteria-containing water body. The algae and bacteria participate in the entire process of the system. The algae and bacteria with better adaptability can reproduce and grow better, and there are fewer interfering substances in the expansion process. The algae and bacteria use bio-fertilizer more stably, which reduces the screening and expansion pressure of the photobioreactor 7 and the algae-bacteria co-culture expansion tank 8, forming a virtuous cycle.

[0064] 8) After a large number of algae and bacteria are cultivated in the algae and bacteria co-culture expansion pond 8 to form a high-density algae and bacteria-containing water body, a portion of the high-density algae and bacteria-containing water body is supplemented to the ecological aquaculture area 1 and the tailwater treatment area 4 as needed. The excess high-density algae and bacteria-containing water body is introduced into the remaining algae recycling pond 9 and used for the production of biomass materials after being recovered by air flotation.

[0065] The fertilizer produced by the algae fermentation tank 6 is transported to the photobioreactor 7 and the algae-bacterial co-culture expansion tank 8 by the fertilizer transport vehicle 20. The photobioreactor 7 is connected to the algae-bacterial co-culture expansion tank 8 through the hose 18. The algae-containing water in the algae-bacterial co-culture expansion tank 8 is connected to the remaining algae recovery tank 9 through the seventh pipe 11-7. The algae liquid in the remaining algae recovery tank 9 is collected into the algae collection tank 22 by the chain scraper 21. The algae collection tank 22 is transported to the spray dryer 10 through the eighth pipe 11-7 to produce algae powder.

[0066] The algae-bacterial co-culture expansion tank 8, photobioreactor 7, and tailwater treatment zone 4 form a circular system for algae-bacterial expansion, achieving pollutant removal and large-scale algae-bacterial expansion. This promotes the conversion of pollutants, mainly generated from excessive but poorly utilized aquaculture feed, into algae-bacteria, and further enhances the benefits of the aquaculture system and tailwater treatment system. It also promotes close integration between aquaculture and tailwater treatment, effectively achieving the goals of maintaining the ecological environment of the aquaculture pond, purifying and reusing aquaculture tailwater, ensuring tailwater meets discharge standards, and recycling resources within the entire system. Example 1

[0067] A system for the whole-process regulation of algae and bacteria and the treatment of wastewater in aquaculture, wherein the regulation of algae, bacteria and water includes the following steps:

[0068] 1) Five-stage main treatment system: In the initial stage of aquaculture, ecological aquaculture zone 1 draws water from external sources or utilizes retained water. Different water quality and algae density indicators are set according to the aquaculture species. After adjusting the indicators, aquaculture is carried out, and beneficial bacteria such as yeast, lactic acid bacteria, and nitrifying bacteria are added to promote the formation of epiphytic bacteria. Beneficial algae are selected and initially added externally. Subsequently, algae-bacterial mixed culture expansion tank 8 and tailwater treatment zone 4 are obtained as a supplement to the algae and bacteria. Based on the purification of the aquaculture water by algae and bacteria, in order to further maintain water quality, the aquaculture water is discharged into sedimentation zone 2 every 7-10 days or according to the actual situation. Plant tannins are added to sedimentation zone 2 to flocculate and precipitate the insoluble solids and suspended matter such as algae, feces, and feed contained in the discharged aquaculture water. The sedimented bottom sludge is transported to algae fermentation tank 6 by sludge vacuum pump. Then, the tailwater containing a small amount of incompletely settled matter flows from the front end of filtration zone 3 through filter dam 13 to the rear end. Filter dam 13 Locally available materials (such as pebbles, gravel, and ceramsite) are used as fillers to further remove suspended solids from the effluent and provide a habitat for microorganisms to form a biofilm. After preliminary removal of pollutants from the effluent, the biofilm flows into the effluent treatment zone 4. The effluent treatment zone 4 obtains effluent containing dissolved pollutants from the filtration zone 3 and high-density algae-bacterial mixed culture tank 8. Under the action of the first flow promoter 15-1, the algae-bacterial mixed culture tank flows in an "O" shape along the effluent treatment zone, allowing the algae and water to mix thoroughly. The algae partially remove N, P, and organic matter from the water. Afterward, part of the water enters the ecological aquaculture zone 1 for the algae and water to be recycled, and part of the water enters the deep purification zone 5. The deep purification zone 5 uses the algae-bacterial biofilm formed on several sets of algae-bacterial biofilm turntables 16 set at both ends of the second baffle wall 14 to deeply purify the effluent. The purified effluent is then transported to the algae-bacterial mixed culture tank 8 for reuse or discharged into natural water bodies.

[0069] 2) Tertiary Additional System: The photobioreactor 7 operates simultaneously with the initial water body regulation steps in the ecological aquaculture zone 1. Initially, the photobioreactor 7 obtains algae- and bacteria-containing water from the ecological aquaculture zone 1. After the system is operational, it obtains algae- and bacteria-containing water from the effluent treatment zone 4, regulating temperature, light, aeration, etc., and obtaining fertilizer from outside the system for efficient algae propagation. Once a certain density is reached, it is transported to the algae- and bacteria co-culture expansion tank 8 for large-scale propagation. In the early stages, the fertilizer for both the photobioreactor 7 and the algae- and bacteria co-culture expansion tank 8 is supplemented from outside the system. After the algae fermentation tank 6 starts operating, fertilizer is obtained from it; the algae fermentation tank 6 uses the sludge vacuum pump 19 to obtain algae-containing bottom mud from the sedimentation zone 2, and combines it with other waste in the aquaculture area for composting and biogas production. The biogas can be used as energy for mechanical devices, and the fertilizer is used to expand algae and bacteria in the photobioreactor 7 and the algae-bacteria co-culture expansion tank 8; the remaining algae recovery tank 9 obtains excess algae-containing water from the algae-bacteria co-culture expansion tank 8, uses the air flotation method to recover algae, and uses the spray dryer 10 to produce biomass materials and energy, etc. Example 2

[0070] This invention was applied to the standardized renovation and wastewater treatment of a contiguous freshwater aquaculture pond in Jiangsu Province. The total area of ​​this ecological aquaculture system is approximately 12.1 mu (approximately 8.7 hectares), with the ecological aquaculture area occupying approximately 9.7 mu (approximately 6.5 hectares), the high-efficiency sedimentation area approximately 0.27 mu (approximately 0.6 hectares), the wastewater treatment area approximately 1.16 mu (approximately 0.8 hectares), the deep purification area approximately 0.39 mu (approximately 0.6 hectares), and the filtration area, algae fermentation tank, algae-bacteria co-culture expansion tank, residual algae recovery tank, and other facilities occupying approximately 0.55 mu (approximately 0.06 hectares). The specific implementation process is shown in the attached figure. Figure 1 , attached Figure 2 , attached Figure 3 As shown, the ecological aquaculture area is divided into two zones, each measuring 80 × 40 × 1.8 m³ (length × width × height). The average water level is maintained at 1.2 m. Every 15-20 days, one-third of the water from one zone is pumped to the other. The first zone then discharges 13-18 cm of wastewater through pipes laid at the bottom of the pond into a sedimentation zone. This process replenishes the first zone with water from external sources or through system circulation. The process is repeated when the second zone has approximately two-thirds of its original water volume. The sedimentation zone, designed to take advantage of the low-lying terrain, measures 15 × 12 × 2.7 m³. The filter chamber has a volume of m³, with a bottom slope of 0.1. After the aquaculture wastewater enters, plant tannins are added to flocculate and settle suspended solids such as feed, feces, and algae. A scraper collects the settled sludge at the bottom of the slope and transports it to the algae fermentation tank via a sludge vacuum pump. The settled wastewater then enters the filtration zone through pipes. The filtration zone has a 0.2 slope at the front bottom and a filter dam in the middle. From bottom to top, it consists of a 20-50 mm pebble layer (approximately 80 cm), a 10-20 mm gravel layer (approximately 50 cm), and a 5-10 mm expanded clay layer (approximately 20 cm), all secured with stainless steel mesh cages. This further removes any remaining suspended solids in the wastewater. Over time, a biofilm forms on the filter media, treating some dissolved pollutants. The wastewater flows through the filter dam and then through pipes from the rear of the filtration zone to the wastewater treatment zone. The wastewater treatment zone consists of five racetrack-type reactors, each with dimensions of 30 × 6 × 0.8 m (length × width × height). 3The main flow path is 24 m long, with semi-circular bends at both ends, each 6 m in diameter. A flow-blocking wall, 20 m long, 0.4 m wide, and 0.6 m high, is located in the center of the pool. The system is equipped with a flow propulsion device. After the effluent is collected in the effluent treatment area, it is fully mixed with the algae-containing water obtained from the algae-bacteria co-culture expansion pond for 3-4 days. During this time, algae undergo assimilation and absorption, ammonia volatilization, multiple phosphorylation pathways, and assimilation and absorption, while bacteria undergo nitrification, denitrification, and excessive phosphorus accumulation to remove pollutants from the water. Part of the algae-bacteria-containing water is then used to replenish the ecological aquaculture area, part is used to supplement the airlift columnar photoreactor for screening and expanding algae and bacteria, and part flows to the deep purification area. The deep purification area consists of two racetrack-type reactors. Based on the same specifications as the deep purification area pond, four sets of rotating disc biofilm reactors are set at both ends of the baffle wall. Utilizing the algae assimilation and absorption and epiphytic bacteria heterotrophic metabolism functions on the formed algae-bacteria biofilm, the monitoring indicators are enhanced after 2-3 days of treatment. Referring to the Jiangsu Province "Pond Aquaculture Wastewater Discharge Standard" (DB32 / 4043-2021), the effluent is discharged to a nearby collection water body or reused after meeting the standards.

[0071] Simultaneously, two algae sludge fermentation tanks were set up, each measuring 6 × 4 × 1.5 m³ (length × width × height). Algae-containing bottom sludge was obtained from the high-efficiency sedimentation zone and combined with compost from straw, weeds, and livestock manure in the aquaculture area. Gas was generated to power water pumps and aeration devices. The resulting fertilizer was manually added to airlift columnar photobioreactors and algae-bacterial co-culture expansion tanks to cultivate the algae and bacteria. Four algae-bacterial co-culture expansion tanks were set up, covering approximately 0.45 acres, with a depth of 0.6 m. Each tank was equipped with four columnar photobioreactors, each 0.6 m in diameter and 2 m high. The columnar photobioreactor initially obtains algae-containing water from the ecological aquaculture area, controls the temperature, light, and aeration to screen and cultivate beneficial algae, and then uses a hose to transport it to the algae-bacteria co-culture expansion tank for large-scale cultivation. At the same time, algae-bacteria-containing water is obtained from the tailwater treatment area and the above steps are repeated. The high-density algae-bacteria-containing water after expansion is used to supplement the ecological aquaculture area and the tailwater treatment area. The remaining algae-containing water is transported to the remaining algae recycling tank. The remaining algae recycling tank has dimensions of length × width × height = 10 × 3 × 3 m³. Combined with an aeration device, algae are recovered by air flotation, and a small spray dryer is set up to dry the collected algae liquid into algae powder, which is used as nutrients for aquatic products.

[0072] Three sampling tests were conducted at different times on the effluent from the ecological aquaculture zone and the effluent from the deep purification zone of the system. The results show that the system has a very good removal effect on pollutants in aquaculture effluent, as shown in Table 1.

[0073] Table 1. Water quality test results, removal rates, and effluent standards of Jiangsu Province's "Pond Aquaculture Wastewater Discharge Standard" (DB32 / 4043-2021) for effluent from the ecological aquaculture area and the deep purification area at three different time periods.

[0074] As can be seen from Table 1, with the assistance of the three-stage auxiliary system consisting of the algae sludge fermentation tank, the algae-bacteria co-culture expansion tank, and the residual algae recycling tank, the removal rate is relatively stable after the treatment of the five-stage main system of "ecological aquaculture-high-efficiency sedimentation-rapid filtration-purification and reuse-standard discharge". The effluent quality can meet the first-level effluent standard of Jiangsu Province's "Pond Aquaculture Wastewater Discharge Standard" (DB32 / 4043-2021). The final effluent meets the discharge standard, and the algae in the system and effluent are beneficial algae such as green algae and diatoms after laboratory microscopic examination.

Claims

1. A system for the whole-process regulation of algae and bacteria and treatment of wastewater in aquaculture, characterized by: The system includes an ecological aquaculture area (1), a sedimentation area (2), a filtration area (3), a wastewater treatment area (4), a deep purification area (5), an algae fermentation tank (6), a photobioreactor (7), an algae-bacteria co-culture expansion tank (8), and a residual algae recycling tank (9). The ecological aquaculture area (1) includes a first aquaculture pond (1-1) and a second aquaculture pond (1-2). The first aquaculture pond (1-1) and the second aquaculture pond (1-2) are connected by a first water pump (12-1). The outlet of the second aquaculture pond (1-2) is connected to the inlet of the sedimentation area (2). The outlet of zone (2) is connected to the inlet of filtration zone (3), the outlet of filtration zone (3) is connected to the first inlet of tailwater treatment zone (4), the first outlet of tailwater treatment zone (4) is connected to the inlet of deep purification zone (5), and the second outlet of tailwater treatment zone (4) is connected to the first water supply outlet of the first aquaculture pond (1-1); the algae fermentation tank (6) is connected to sedimentation zone (2) through sludge vacuum pump (19), the outlet of algae fermentation tank (6) is equipped with fertilizer transport vehicle (20), and the algae-bacteria mixed culture expansion tank (8) is connected to the second water pump (12-2) through the second water pump (12-2). The deep purification zone (5) is connected, the first outlet of the algae-bacterial mixed culture expansion pond (8) is connected to the second water inlet of the first aquaculture pond (1-1), the second outlet of the algae-bacterial mixed culture expansion pond (8) is connected to the second inlet of the tailwater treatment zone (4), and the third outlet of the algae-bacterial mixed culture expansion pond (8) is connected to the inlet of the remaining algae recycling pond (9); the third outlet of the tailwater treatment zone (4) is connected to the inlet of the photobioreactor (7); during operation, part of the algae-bacterial water purified by the tailwater treatment zone (4) enters the ecological aquaculture zone (1) for recycling, and part of the algae-bacterial water is recycled. The algae enter the photobioreactor (7) as a supplementary material for algae and bacteria cultivation. A portion of the algae is discharged into the deep purification zone (5) and then transported to the algae and bacteria co-culture expansion tank (8) after deep treatment using the algae and bacteria biofilm to meet the standards. The algae fermentation tank (6) composts the algae-containing bottom mud in the sedimentation zone (2) to produce bio-fertilizer. The bio-fertilizer produced by composting is used in the photobioreactor (7) and the algae and bacteria co-culture expansion tank (8) to expand algae and bacteria. The algae-containing water body that has been expanded in the photobioreactor (7) is transported to the algae and bacteria co-culture expansion tank (8) for further expansion.

2. The whole-process regulation system for algae and bacteria in aquaculture and the wastewater treatment system according to claim 1, characterized in that: The ecological aquaculture area (1), sedimentation area (2), filtration area (3), effluent treatment area (4), and deep purification area (5) are sequentially connected to form a five-stage treatment system of "ecological aquaculture - high-efficiency sedimentation - rapid filtration - purification and reuse - compliant discharge". In the five-stage treatment system, the ecological aquaculture area (1) is divided into two aquaculture areas: the first aquaculture pond (1-1) and the second aquaculture pond (1-2). The first aquaculture pond (1-1) and the second aquaculture pond (1-2) are separated by an artificial walkway (23). During operation, the first aquaculture pond (1-1) regularly discharges 1 / 3 of the water in the first aquaculture pond (1-1) into the second aquaculture pond (1-2). Then, based on the water volume of the sedimentation zone (2), water is discharged from the second aquaculture pond (1-2) to the sedimentation zone (2) for tailwater treatment. When the water volume of the second aquaculture pond (1-2) is only 2 / 3 of the initial volume, 1 / 3 of the water in the first aquaculture pond (1-1) is discharged into the second aquaculture pond (1-2). The tailwater of the second aquaculture pond (1-2) is discharged into the sedimentation zone (2). Tannins are added in the sedimentation zone (2) to cause insoluble solids and suspended matter to settle. Then, it flows through the filtration zone (3) to further remove suspended solids before entering the tailwater treatment zone (4). In the tailwater treatment zone (4), the assimilation and absorption of algae and the heterotrophic metabolism of epiphytic bacteria are used to synergistically purify pollutants in the water.

3. The whole-process regulation and effluent treatment system for algae and bacteria in aquaculture according to claim 1, characterized in that: The algae fermentation tank (6), the algae-bacterial co-culture expansion tank (8), and the residual algae recycling tank (9) form a three-level supplementary system of "algae fermentation - algae-bacterial co-culture - recycling"; the photobioreactor (7) initially obtains algae-bacterial water from the ecological aquaculture area (1), and expands beneficial algae and beneficial algae epiphytes by controlling temperature, light, and aeration. After the system is running, the photobioreactor (7) obtains algae-bacterial water from the tailwater treatment area (4) to expand beneficial algae and beneficial algae epiphytes; the algae-bacterial co-culture expansion tank ( 8) After disinfecting and killing insects with calcium oxide, water is obtained from the deep purification zone (5). The water is regulated by the bio-fertilizer obtained from the algae fermentation tank (6). Algae liquid is introduced into the algae and bacteria co-culture expansion tank (8) and combined with natural light to expand algae and the epiphytic bacteria of algae. Part of the algae expanded in the algae and bacteria co-culture expansion tank (8) is used to supplement the ecological aquaculture zone (1) to maintain the ecological environment of the pond and provide feed. Part of it is provided to the tailwater treatment zone (4) to treat the aquaculture tailwater. The rest is recycled by the remaining algae recycling tank (9) and used to produce biomass materials.

4. A system for the whole-process regulation of algae and bacteria and treatment of wastewater in aquaculture according to any one of claims 1-3, characterized in that its operation... Fresh water is fed into the ecological aquaculture area (1) through the first pipe (11-1); the effluent from the ecological aquaculture area (1) is discharged into the sedimentation area (2) through the second pipe (11-2) located at 1 / 2 depth of the second aquaculture pond (1-2) in the ecological aquaculture area (1). The bottom of the sedimentation area (2) is set as a slope, and the side of the bottom of the sedimentation area (2) near the ecological aquaculture area (1) is higher than the side of the bottom of the sedimentation area (2) near the filtration area (3). The settled water flows from the sedimentation area (2) into the filtration area (3) through the third pipe (11-3). A filter dam (13) is set in the middle of the filtration area (3). The filter dam (13) divides the filtration area (3) into a front half and a back half. The area between the filter dam (13) and the sedimentation area (2) is the front half, and the area between the filter dam (13) and the tailwater treatment area (4) is the back half. The bottom of the front half of the filtration area (3) is set with a slope to make the water flow towards the tailwater treatment area (4).

5. A system for the whole-process regulation of algae and bacteria and treatment of effluent in aquaculture according to any one of claims 1-3, characterized in that: The tailwater treatment area (4) is set up in a racetrack shape. A first baffle wall (14-1) is set in the middle of the tailwater treatment area (4). A first flow promoter (15-1) is set between the first baffle wall (14-1) and the pool wall of the tailwater treatment area (4). The first flow promoter (15-1) pushes the water flow to circulate in the tailwater treatment area (4). The tailwater treatment area (4) obtains high-density algae-containing water from the algae-bacteria co-culture expansion pond (8) and mixes it with the tailwater to treat pollutants. After treatment, part of the algae-containing water that meets the aquaculture standards is transported to the first aquaculture pond (1-1) in the ecological aquaculture area (1) through the third water pump (12-3). Part of it is discharged to the deep purification area (5) through the fifth pipe (11-5). Another part enters the photobioreactor (7) through the fourth water pump (12-4) as a supplementary source for algae-bacteria expansion. The deep purification zone (5) is set up in a racetrack shape. A second flow barrier (14-2) is set in the middle of the deep purification zone (5). A second flow pusher (15-2) is set between the second flow barrier (14-2) and the pool wall of the deep purification zone (5). Several sets of algae-bacterial biofilm turntables (16) are set between the second flow barrier (14-2) and the pool wall of the deep purification zone (5) on both sides. After the water is deeply purified in the deep purification zone (5), it is discharged into the natural water body through the sixth pipe (11-6) or transported to the algae-bacterial mixed culture expansion tank (8) as the culture water body through the second water pump (12-2).

6. The whole-process regulation and effluent treatment system for algae and bacteria in aquaculture according to claim 2, characterized in that: The tannins mentioned are plant tannins.

7. A method for the whole-process regulation of algae and bacteria and treatment of wastewater in aquaculture, characterized by: The method includes: 1) Aquaculture is carried out in the ecological aquaculture area (1) after setting algae density indicators and various water quality indicators according to the aquaculture objects; 2) In the ecological aquaculture area (1), algae-containing aquaculture water is regularly discharged as tailwater into the sedimentation area (2). Plant tannins are added to the sedimentation area (2) to precipitate insoluble solids and suspended matter in the tailwater. 3) The tailwater after sedimentation in the sedimentation zone (2) is further filtered in the filtration zone (3) to remove floating impurities; 4) Tailwater treatment area (4) obtains tailwater from filtration area (3) and algae-bacterial mixed culture expansion tank (8). The algae-bacterial water is diluted by tailwater and fully mixed with the tailwater for post-treatment. Algae and bacteria are used to remove N, P and organic matter contained in tailwater, and water treatment and algae-bacterial expansion are achieved simultaneously. Algae and bacteria are generated while pollutants are reduced. 5) After treatment in the tailwater treatment area (4), part of the tailwater is introduced into the ecological aquaculture area (1) through the third water pump (12-3), part of the tailwater is introduced into the photobioreactor (7) through the fourth water pump (12-4) as a supplementary source for algae and bacteria expansion, and part of the tailwater enters the deep purification area (5) to be treated by the algae and bacteria biofilm formed on the algae-bacteria biofilm turntable (16). After treatment in the deep purification area (5), the water that meets the pond aquaculture discharge standards is transported to the algae and bacteria mixed culture expansion pond (8) for reuse or discharge into natural water bodies.

8. The method for whole-process regulation of algae and bacteria and treatment of effluent in aquaculture according to claim 7, characterized in that: The method also includes: 6) The algae fermentation tank (6) collects algae-containing sediment in the sedimentation zone (2) through the sludge vacuum pump (19), and composts the straw, weeds and plant debris around the breeding area to produce biogas and bio-fertilizer. The bio-fertilizer is provided to the algae and fungi co-culture expansion tank (8) for the expansion of algae and fungi. 7) The algae-bacterial mixed culture expansion pond (8) is equipped with several photobioreactors (7). The photobioreactors (7) initially obtain algae-bacterial water from the ecological aquaculture area (1), use the bio-fertilizer obtained from the algae mud fermentation pond (6) and control the external conditions to screen and expand algae, and then introduce it into the algae-bacterial mixed culture expansion pond (8) through the hose (18). The algae-bacterial mixed culture expansion pond (8) combines the bio-fertilizer obtained from the algae mud fermentation pond (6) to expand algae and bacteria to form a high-density algae-bacterial water body; 8) After the algae and bacteria are expanded in the algae and bacteria co-culture expansion pond (8) to form a high-density algae and bacteria-containing water body, a portion of the high-density algae and bacteria-containing water body is supplemented to the ecological aquaculture area (1) and the tailwater treatment area (4) as needed. The remaining high-density algae and bacteria-containing water body is introduced into the remaining algae recycling pond (9) and used for the production of biomass materials after being recovered by air flotation.

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