Alcomycete symbiotic culture tail water treatment system based on 3D printing carrier

Abstract

The invention discloses a phycomycete symbiotic culture tail water treatment system based on a 3D printing carrier. The phycomycete symbiotic culture tail water treatment system comprises a reaction container, a 3D printing gyandroid model carrier, a light source, an aeration mechanism and a stirring mechanism, the reaction container is provided with a water inlet and a water outlet which are communicated with the interior of the reaction container, and the water inlet and the water outlet are of opening and closing controllable structures; a plurality of 3D printing gyandroid model carriers are filled in a reaction container; the light source is used for providing illumination for the interior of the reaction container; the aeration mechanism is used for carrying out aeration treatment on the interior of the reaction container; the stirring mechanism is used for stirring the interior of the reaction container; according to the scheme, a stable attachment environment is provided for algae and microorganisms through the high specific surface area and the optimized pore structure of the 3D printing gyandroid model carrier, biological membrane formation and stability are enhanced, meanwhile, through the synergistic effect of the light source, the aeration mechanism and the stirring mechanism, the mass transfer efficiency and the pollutant removal effect are improved, and the effect of removing pollutants is achieved. The efficient removal of nutrient salts such as nitrogen and phosphorus in the culture tail water is realized.

Description

Technical Field

[0001] This invention relates to the technical field of wastewater treatment, and in particular to a wastewater treatment system for algae-bacteria symbiotic culture based on a 3D-printed carrier. Background Technology

[0002] With the continuous expansion of high-density aquaculture, the demand for aquaculture wastewater treatment is increasing daily. During the aquaculture process, uneaten feed, medications, aquatic organism excrement, and the decomposition of carcasses result in wastewater rich in nutrients such as nitrogen and phosphorus, as well as suspended solids, impacting the aquatic environment. Existing wastewater treatment technologies mainly include physical, chemical, and biological methods. Physical methods, such as mechanical filtration and foam separation, remove suspended solids through physical interception; chemical methods, such as ozone oxidation and coagulation sedimentation, transform pollutants through chemical reactions; traditional biological methods, such as activated sludge and biofilm processes, utilize microbial metabolism to remove organic matter and nutrients. Algae-microbe symbiotic systems achieve the removal of nutrients such as nitrogen and phosphorus through the synergistic effect of algae and microorganisms. Biofilm carriers, as an important component of algae-microbe symbiotic systems, provide an environment for algae and microorganisms to attach and grow; their structure and materials directly affect the system's operational performance. 3D printing technology can precisely control the geometry, porosity, and material properties of carriers, providing new possibilities for biofilm carrier design.

[0003] However, in existing technologies, algae-bacteria symbiotic systems face challenges in practical applications, such as an unsatisfactory biofilm attachment environment and insufficient system operational stability, which affect the system's ability to operate continuously. Summary of the Invention

[0004] The purpose of this invention is to provide a wastewater treatment system for algae-bacteria symbiotic aquaculture based on a 3D-printed carrier, in order to solve the technical problems in existing aquaculture wastewater treatment, such as low specific surface area of ​​biofilm carriers, unreasonable pore structure, poor mass transfer efficiency, easy clogging, insufficient biocompatibility, and severe light shading, poor settling properties, and low pollutant degradation rate in algae-bacteria symbiotic systems.

[0005] To address the aforementioned technical problems, this invention provides a wastewater treatment system for algae-bacteria symbiotic aquaculture based on a 3D-printed carrier, comprising a reaction container, a 3D-printed gyroid model carrier, a light source, an aeration mechanism, and a stirring mechanism. The reaction container has an inlet and an outlet communicating with its interior, both of which are controllable opening and closing structures. Multiple 3D-printed gyroid model carriers are filled inside the reaction container. The light source provides illumination to the interior of the reaction container. The aeration mechanism aerates the interior of the reaction container. The stirring mechanism stirs the interior of the reaction container.

[0006] In one embodiment, the reaction vessel is made of a transparent material.

[0007] In one embodiment, the reaction vessel is made of transparent plexiglass.

[0008] In one embodiment, the water inlet is connected to a water inlet tank, and a water inlet pump is provided on the passage connecting the water inlet and the water inlet tank; the water outlet is connected to a water outlet tank, and a water outlet pump is provided on the passage connecting the water outlet and the water outlet tank.

[0009] In one embodiment, the reaction vessel is provided with a removable top cover.

[0010] In one embodiment, the 3D-printed gyroid model carrier is spherical.

[0011] In one embodiment, the 3D printed gyroid model carrier is made of PEEK or PEKK material.

[0012] In one embodiment, the diameter of the 3D-printed gyroid model carrier is 15-25 mm, the wall thickness is 450-550 μm, and the specific surface area is 900-1200 m². 2 / m³, the pore size of the 3D printed gyroid model carrier is greater than or equal to 1.5mm.

[0013] In one embodiment, the aeration mechanism includes an air pump and an aeration stone unit, the air pump being connected to the aeration stone unit, which is located at the bottom of the reaction vessel.

[0014] In one embodiment, the algae-bacteria symbiotic aquaculture wastewater treatment system further includes a support frame, on which the stirring mechanism is provided, and the stirring part of the stirring mechanism is suspended inside the reaction vessel.

[0015] The beneficial effects of this invention are as follows: 1. This scheme uses a 3D-printed gyroid model carrier to fill the inside of the reaction vessel. Its triple-period minimum surface design provides a high specific surface area and optimized pore structure, providing a stable attachment environment for algae and microorganisms, thereby enhancing the formation and stability of biofilm.

[0016] 2. The reaction vessel is equipped with a controllable inlet and outlet that are connected to its interior, enabling precise control of the hydraulic residence time, supporting sequential batch operation mode, and improving the system's adaptability to different water quality conditions.

[0017] 3. The use of a light source to illuminate the interior of the reaction vessel promotes algal photosynthesis, achieving oxygen self-sufficiency and reducing the system's dependence on aeration. The aeration system further supplements the dissolved oxygen required by the system, while also promoting nitrification and water mixing.

[0018] 4. The stirring mechanism inside the reaction vessel enhances water disturbance and nutrient diffusion, improves the coupling between the algae and bacteria microenvironment, and increases mass transfer efficiency. This design not only solves the problems of low specific surface area and unreasonable pore structure in traditional biofilm carriers, but also effectively alleviates the light shading effect in algae-bacteria symbiotic systems, improving the system's load resistance and operational stability. Ultimately, this system achieves highly efficient removal of nutrients such as nitrogen and phosphorus from aquaculture wastewater, providing a sustainable solution for aquaculture wastewater treatment. Attached Figure Description

[0019] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure provided in an embodiment of the present invention; Figure 2 yes Figure 1 A schematic diagram of the 3D printed gyroid model carrier structure; Figure 3 This is a graph showing the change in dry weight of the carrier during the biofilm attachment stage provided in an embodiment of the present invention; Figure 4 This is a graph showing the PN and PS content in biofilms of different carrier materials provided in the embodiments of the present invention; Figure 5 The different material carrier reactors provided in this embodiment of the invention demonstrate different pollutant removal effects. Figure 6 This is the second aspect of the pollutant removal effect of the different material carrier reactors provided in the embodiments of the present invention; Figure 7 The different material carrier reactors provided in this embodiment of the invention demonstrate the pollutant removal effects.

[0021] The attached figures are labeled as follows: 100. Reaction vessel; 110. Inlet; 120. Outlet; 130. Inlet water tank; 140. Inlet water pump; 150. Outlet water tank; 160. Outlet water pump; 170. Top cover; 200. 3D printed gyroid model carrier; 300. Light source; 400. Aeration mechanism; 410. Air pump; 420. Aeration stone unit; 500. Stirring mechanism; 600. Support frame. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0023] This invention provides a wastewater treatment system for algae-bacteria symbiotic aquaculture based on a 3D-printed carrier, such as... Figure 1 and Figure 2 As shown, it includes a reaction container 100, a 3D-printed gyroid model carrier 200, a light source 300, an aeration mechanism 400, and a stirring mechanism 500. The reaction container 100 is provided with an inlet 110 and an outlet 120 that are connected to its interior. Both the inlet 110 and the outlet 120 are controllable structures for opening and closing. Multiple 3D-printed gyroid model carriers 200 are filled inside the reaction container 100. The light source 300 is used to provide illumination to the interior of the reaction container 100. The aeration mechanism 400 is used to aerate the interior of the reaction container 100. The stirring mechanism 500 is used to stir the interior of the reaction container 100.

[0024] The reaction vessel 100 is a closed or semi-closed cavity structure that accommodates the algae-bacteria symbiotic reaction system. Its shape is cylindrical, cubic, or frustum-shaped, and its size can be set according to the treatment scale. The material of the reaction vessel 100 can be selected as transparent or opaque material according to actual needs. When it is necessary to cooperate with the light source 300 to achieve light-driven algae growth, a material with good light transmittance can be selected. The inlet 110 and outlet 120 of the reaction vessel 100 are equipped with controllable valves or solenoid valves to realize the periodic water intake and drainage control in the SBR (Sequencing Batch Reactor) operation mode. The opening and closing sequence is matched with the HRT (Hydraulic Retention Time) gradient change. 72 h HRT is used in the biofilm formation stage, and it is gradually shortened to 6 h in the stable operation stage.

[0025] The 3D printed gyroid model carrier 200 is the core of this invention, and the material selection of the 3D printed gyroid model carrier 200 has a particularly important impact on its performance. Therefore, this embodiment has made a specific choice of material for the 3D printed gyroid model carrier 200, and the specific reasons will be explained in detail below.

[0026] Based on the optimized gyroid model, the material selection problem suitable for this model was further investigated. In recent years, with the development of 3D printing technology, high-performance materials (such as PEEK, PEKK, PPSU, etc.) have gradually become potential choices for new carriers due to their excellent high temperature resistance, high pressure resistance, chemical shock resistance, and biocompatibility. Among them, PEEK, PEKK, ABS, and PETG were selected as the four materials for this study to be used as biofilm carriers for algae-bacteria symbiotic systems due to their better density range and chemical shock resistance.

[0027] Because PEEK, PEKK, ABS, and PETG (specific properties are shown in Table 1 below) can be modified to carry a positive charge on their surface, this will improve their biocompatibility. Materials with good biocompatibility can often withstand long-term chemical shocks and do not produce harmful microbial components under long-term conditions. For example, PC material will hydrolyze and produce substances harmful to microorganisms when immersed in water for a long time, thus PC material is considered to have poor biocompatibility and chemical shock resistance. At the same time, the low density (1.1-1.3 mg / L) and extremely high chemical shock resistance of these materials have been widely used in the field of aerospace medicine because these materials have maintained performance stability for decades.

[0028] Table 1 Common Materials for 3D Printing Technology To compare the performance of the aforementioned materials, after the cultivation of activated sludge and the enrichment and cultivation of Chlorella, the present invention added Chlorella and activated sludge at a weight ratio of 1:3, along with 3D-printed gyroid model carriers 200 made of the four materials, to four sets of algae-bacterial symbiotic aquaculture wastewater treatment systems. The stirring mechanism was set to a speed of 500 rpm, and the light intensity and light ratio of the light source were set to 300 ppm. Simulated aquaculture wastewater was also provided, and the algae-bacterial symbiotic aquaculture wastewater treatment system was operated according to a certain hydraulic retention time (HRT) to perform biofilm formation and pollutant removal. The algae-bacterial symbiotic aquaculture wastewater treatment system operated for a total of 65 days. The first 28 days were the biofilm formation stage, during which biofilm formation performance indicators were tested periodically, and pollutant water quality indicators were measured daily throughout the entire operation period.

[0029] Carrier dry weight is the most direct indicator for evaluating the carrier's biofilm adhesion ability and biocompatibility, such as... Figure 3As shown, the dry weight of all carriers at 28 days showed an upward trend compared to the initial stage. The dry weight increases of PEEK, PEKK, ABS, and PETG after the film formation stage were 198.4±9.33mg, 192.1±37.47mg, 68.85±6.86mg, and 11.8±1.70mg, respectively. During the biofilm attachment stage, the dry weight of the PEEK carrier increased significantly over time, showing the highest increase from day 0 to day 28, rising from an initial value of 1139.45±1.20 mg to 1337.85±8.13 mg at day 28. The main biofilm attachment and growth stages were distributed between days 0-7 and 14-28. The dry weight of the PEKK carrier also increased over time, with a slightly smaller increase than PEKK but still higher than ABS and PETG, rising from an initial value of 1064.6±1.56 mg to 1256.7±35.92 mg at day 28. The main biofilm attachment and growth stages were mainly between days 14-28. The dry weight of the ABS carrier showed a relatively gradual increase over time, rising from an initial value of 1094.6±4.10 mg to 1160.45±2.76 mg at day 28, with a relatively even distribution of biofilm attachment and growth stages. The dry weight of the PETG carrier remained basically unchanged throughout the experimental period, consistently around 830 mg. It is evident that there are significant differences in the biofilm adhesion ability of the four materials. PEEK and PEKK carriers exhibit strong biofilm adhesion and growth capabilities with a significant increase in dry weight. ABS shows a lower biofilm adhesion and growth trend, while PETG biofilms are difficult to adhere and grow on the surface of this type of carrier.

[0030] Extracellular polymeric substances (EPS) are important indicators of biofilm growth. By measuring the protein (PN) and sugar (PS) content in EPS, the adaptability and growth status of microorganisms to environmental changes can be assessed. This study measured the protein (PN) and sugar (PS) content in the EPS of biofilms on different carrier surfaces at days 14 and 28. Figure 4 As shown, the PN and PS contents of PEEK and PEKK carriers were significantly higher than those of ABS and PETG, and showed a significant increasing trend over time, indicating that these two carrier materials have a strong promoting effect on biofilm growth and adhesion. The PN and PS contents of the ABS carrier were relatively small, and the increase over time was also smaller, indicating poor biofilm adhesion ability. The PN and PS contents of the PETG carrier remained the lowest throughout the entire experimental period, suggesting that this type of carrier may have a certain inhibitory effect on biofilm growth and adhesion.

[0031] By comparing the removal of nutrient pollutants by different carrier materials during the operation of the algae-bacterial symbiotic aquaculture effluent treatment system, the effects of biofilm adhesion, growth, and activity on the carrier surface are indirectly reflected. During the operation of the algae-bacterial symbiotic aquaculture effluent treatment system, the removal efficiency of pollutants by the four carrier materials showed a gradual increasing trend. After 37 days of operation, the effluent from the algae-bacterial symbiotic aquaculture effluent treatment system basically reached a stable state. Under the same influent water quality, such as... Figures 5 to 7 As shown, the PEEK carrier significantly outperformed the other three carriers in removing nutrient pollutants from the effluent, with average removal rates of 82.65±7.51% for COD, 72.94±6.63% for TP, and 82.32±7.48% for NH4-N. The PETG carrier exhibited the worst removal performance, with average removal rates of 32.28±2.93% for COD, 31.50±2.86% for TP, and 39.06±3.55% for NH4-N. The PEKK and ABS carriers showed similar removal efficiency, but were slightly lower than the PEEK carrier. Therefore, the PEEK carrier performed best in pollutant removal, while PEKK and ABS carriers were slightly less effective, and the PETG carrier showed the worst performance.

[0032] Experimental results demonstrate the feasibility of using the 3D-printed gyroid model carrier 200 for treating aquaculture wastewater in an algae-bacteria symbiotic system. During the biofilm attachment stage, the biofilm growth of PEEK and PEKK materials was significantly better than that of ABS and PETG, indicating their superior biocompatibility and attachment performance. Furthermore, throughout the entire operation phase, the PEEK carrier showed the highest removal efficiency for COD, TP, and NH4-N, demonstrating excellent operational performance.

[0033] The above experimental procedure can be carried out in the following manner: 1. Activated sludge acclimatization Take activated sludge from the aeration tank of the wastewater treatment plant and transfer it to a sludge culture medium (283 mg / L glucose, 47 mg / L (NH4)SO4, 9.06 mg / L KH2PO4) with a COD:N:P ratio of 150:5:1 for cultivation. Use a magnetic stirrer to maintain the temperature at 30℃ and 120 rpm / min, adjust the pH to 7-8 using NaHCO3 or NaOH, and use an ACO-9602 aeration pump to control the dissolved oxygen (DO) concentration to maintain 3-4 mg / L. Cultivate for 72 hours, changing the sludge culture medium every 24 hours during this period, and monitor the changes in pollutant concentration and sludge settling ratio to ensure sludge activity. To enrich the sludge to adapt to the simulated aquaculture wastewater quality, the culture medium composition was gradually replaced over 14 days. Specifically, the proportion of aquaculture wastewater (29.2 mg / L NH4Cl, 9.6 mg / L NaNO3, 15.4 mg / L KH2PO4, 1.5 mg / L NaNO2, 140.6 mg / L glucose) in the culture medium was gradually increased. Each 1 L of simulated aquaculture wastewater contained 3 mL of trace element culture medium (3 g / L ZnSO4, 3 g / L MnSO4, 0.6 g / L CaCl2, 0.3 g / L FeSO4), with the increase ratios being 10%, 30%, 50%, 70%, 90%, and 100% of the simulated aquaculture wastewater. The pollutant concentration and half-hour settling ratio were measured every two days until the activated sludge showed good pollutant removal effect, the half-hour settling ratio reached 1:3, and there was no obvious odor, indicating that the activated sludge had been successfully acclimatized.

[0034] 2. Chlorella culture Chlorella vulgaris (AGA30007) purchased from the Freshwater Algae Culture Bank of the Wuhan Institute of Hydrobiology, Chinese Academy of Sciences, was used. 5 mL of bacterial culture was placed in 300 mL of autoclaved (120℃, 30 min) BG-11 medium and cultured. The pH of the medium was maintained within the range of 6-8. After shaking well, samples were taken to measure the initial OD of the algal culture. 435 For the first 24 hours after incubation, the light intensity was 1000 lux, then increased to 4000 lux; the light / dark cycle was 12 / 12 hours. The flasks were shaken twice daily. The OD of the algal solution was continuously measured. 435 The value continues until Chlorella enters the logarithmic growth phase.

[0035] 3. Operation of the algae-bacteria symbiotic aquaculture wastewater treatment system The acclimatized activated sludge and Chlorella vulgaris in the logarithmic growth phase were collected. The algal cells were separated from the BG-11 medium (centrifuged at 3000 rpm for 5 minutes), and the supernatant was carefully discarded. The cells were washed three times with a sterile solution of 0.85% sodium chloride (w / v), and the Chlorella vulgaris was resuspended in the same sodium chloride solution. Similarly, the activated sludge was separated from the medium (centrifuged at 3500 rpm for 10 minutes). At a mass ratio of 1:3, 15 3D-printed gyroid model carriers of four different materials (the 3D-printed gyroid model carriers 200 were sterilized by irradiation under ultraviolet light for 30 minutes before use) were placed into four algae-bacterial symbiotic aquaculture wastewater treatment systems. The water level in the algae-bacterial symbiotic aquaculture wastewater treatment systems was controlled at 1L using simulated aquaculture wastewater, and the carrier filling rate was approximately 20%. The operating parameters of the algae-bacterial symbiotic aquaculture wastewater treatment systems are set as shown in Table 2. The pH in the reactor was adjusted to be between 6 and 8 every 12 hours using NaHCO3. The DO concentration was controlled to be maintained at 3-4 mg / L using an ACO-9602 aeration pump. The reactor was continuously operated for 68 days with a light intensity of 4000 lux and a light-dark ratio of 12h / 12h using a light source 300. The pollutant index of the reactor influent and effluent was measured daily, and the biofilm adhesion index was measured periodically.

[0036] Table 2. Parameter Settings for the Algae-Bacteria Symbiotic Aquaculture Wastewater Treatment System It should also be noted that the 3D-printed gyroid model carrier 200 is a three-dimensional porous structure constructed based on the gyroid triple-period minimum surface mathematical model. Its overall shape is spherical or approximately spherical, with a diameter of 15–25 mm, a wall thickness of 450–550 μm, a specific surface area of ​​900–1200 m² / m³, and internal interconnecting pores with a diameter greater than or equal to 1.5 mm. This structure features a highly uniform pore distribution and isotropic flow channel characteristics, which can significantly reduce fluid resistance and clogging risk while ensuring sufficient adhesion area. The 3D-printed gyroid model carrier 200 is made of PEEK or PEKK material with a density of 1.30–1.32. The material has a surface charge of g / cm³, which is positively charged after charge modification, which is conducive to the initial attachment of microorganisms. The material has excellent resistance to chemical impact and long-term immersion stability, and does not release harmful components that inhibit the growth of algae or microorganisms. In practical applications, multiple 3D printed gyroid model carriers 200 are arranged inside the reaction vessel 100 with a filling rate of 5-30‰. The filling rate can be dynamically adjusted according to the target treatment load and biofilm stage. A filling rate of 15‰ is used in the early stage of biofilm formation, and it is increased to 20-25‰ during the stable operation period.

[0037] The light source 300 is an illumination device that can provide stable visible spectrum output and can be configured with adjustable light intensity. The light source 300 is arranged on the outer top of the reaction vessel 100 or embedded in the inner side of the top cover 170 to ensure that the light penetrates the wall of the reaction vessel 100 uniformly and illuminates the surface of the internal carrier. The light source 300 can be an LED array, and its spectral composition can be optimized according to the absorption peak of Chlorella photosynthetic pigments, such as enhancing the ratio of blue light (450 nm) and red light (660 nm) components. The working mode of the light source 300 can be continuous illumination or light-dark alternation, with a typical light-dark cycle of 12 h / 12 ​​h.

[0038] The aeration unit 400 not only provides the oxygen required for the nitrification reaction, but also works with the stirring unit 500 to improve the gas-liquid-solid three-phase mass transfer efficiency and alleviate the problems of algal sedimentation and biofilm hypoxia on the carrier surface.

[0039] The stirring mechanism 500 is a mechanical stirring device placed outside the reaction vessel 100 and extending into its interior. It includes a motor, a drive shaft, and a stirring impeller. The stirring impeller is suspended in the lower middle position of the reaction vessel 100, and its rotation direction and speed are adjustable, with a typical speed range of 300–600 rpm. The stirring action can break up water stratification, promote nutrient diffusion, prevent algae aggregation and sedimentation, and enhance the exchange of substances between algae and the biofilm on the carrier surface. The stirring mechanism 500 works in conjunction with the light source 300 and the aeration mechanism 400 to ensure that the algae receive sufficient light while avoiding excessive shear force that could damage the biofilm structure.

[0040] Through the above technical solutions, this invention achieves the following: utilizing the high specific surface area structure of the 3D-printed gyroid model carrier 200 to provide stable attachment sites for algae and microorganisms and alleviate clogging; supporting the intermittent operation mode of the SBR through the controllable opening / closing inlet / outlet 120, enabling the system to flexibly adapt to different HRTs; driving oxygen production through photosynthesis of Chlorella via the top light source 300, reducing dependence on external aeration; supplementing dissolved oxygen required for nitrification through the aeration mechanism 400, and enhancing three-phase mass transfer together with the stirring mechanism 500; and ultimately, significantly improving COD and NH4 under the synergistic effect of algae and bacteria symbiosis. + – The efficiency of simultaneous removal of N and TP.

[0041] Example 2: In existing technologies, reaction vessels 100 are mostly made of materials such as stainless steel, ceramic, or opaque plastic. Although they have structural strength and corrosion resistance, they severely hinder the penetration of external light sources 300, resulting in a significant increase in the light intensity gradient inside the reactor—the light intensity is sufficient in the top area but rapidly decreases in the middle and lower parts, thus limiting the photosynthetic efficiency of algae. At the same time, the light shading effect exacerbates the uneven distribution of biofilm on the carrier, with dense attachment on the upper layer and sparse attachment on the lower layer, weakening the overall nitrification / denitrification synergy, thereby reducing the stability of nitrogen and phosphorus removal and the treatment load capacity.

[0042] In one alternative embodiment, the reaction vessel 100 is made of a transparent material.

[0043] The reaction vessel 100 is made of a transparent material, meaning that all structural components constituting the body of the reaction vessel 100 (including side walls, bottom plate, and top plate) are integrally formed or spliced ​​from a material with visible light transmittance. This transparent material can be acrylic glass (polymethyl methacrylate, PMMA), quartz glass, borosilicate glass, or high-transmittance polycarbonate (PC), etc. Acrylic glass is a suitable choice due to its excellent light transmittance (≥92%), good mechanical strength, ease of 3D processing and customized molding, good weather resistance, and moderate cost. Quartz glass can also be used, with a light transmittance of up to 99.5% and a low coefficient of thermal expansion, suitable for high-temperature or strong ultraviolet radiation conditions, but it is more difficult and costly to process. This embodiment of the invention does not impose specific limitations on the type of material; the choice can be made based on the actual operating environment's light intensity requirements, temperature range, chemical compatibility, and economic considerations.

[0044] The reaction vessel 100 is made of a transparent material, which allows it to form an optical coupling relationship with the "light source 300" in this invention. When the light source 300 (such as an LED array, cool white light lamp, or halogen lamp) is arranged directly above the reaction vessel 100 or installed around it from the side, the light can be incident vertically or obliquely into the interior of the reaction vessel 100 without significant attenuation. The penetration path covers the entire liquid phase area and the carrier filling area, ensuring that each micro-area on the surface of the 3D printed gyroid model carrier 200 (especially the convex surface facing the light source 300 and the concave surface facing away from the light) obtains an effective photon flux. This supports Chlorella to complete light capture, electron transfer, and carbon assimilation at different curvature positions on the carrier, while maintaining the metabolic activity of the attached microorganisms, thus achieving spatial symbiosis and functional complementarity between algae and bacteria.

[0045] Through the above technical solution, the present invention achieves the following: because the reaction vessel 100 is made entirely of a highly transparent material with high light transmittance, the optical barrier caused by traditional non-transparent containers is eliminated, allowing the external light source 300 to efficiently and uniformly reach the depth region of the reaction system; thereby increasing the photosynthetic rate of algae per unit area and the biofilm space coverage, and enhancing COD and NH4 levels. + – Synchronous removal dynamics of N and TP; and extended effective light utilization depth under the same illumination power, reducing the need for additional supplementary lighting units to compensate for light decay, and reducing the overall energy consumption and equipment complexity of the system.

[0046] Example 3: In one alternative embodiment, the reaction vessel 100 is made of transparent plexiglass.

[0047] The reaction vessel 100 is made of transparent plexiglass, which is integrally molded from polymethyl methacrylate (PMMA) material. It has moderate mechanical strength and impact resistance and can withstand the dynamic loads caused by stirring, aeration and carrier filling inside the reactor.

[0048] The transparent plexiglass reaction vessel 100 is formed by methods including but not limited to casting, extrusion, or CNC machining. The surface roughness Ra of its inner wall is controlled within the range of 0.8–3.2 μm, which avoids the difficulty of algae attachment due to excessive smoothness and prevents local accumulation of biofilm or difficulty in cleaning due to excessively rough surface.

[0049] Through the above technical solutions, this invention achieves improved tolerance and structural reliability of the reaction vessel 100 to the chemical environment of aquaculture wastewater while ensuring high light transmittance. By using PMMA material instead of ordinary glass or unmodified acrylic, the problems of yellowing, embrittlement or precipitation that occur in conventional transparent materials under conditions of alternating weak acid and alkali, organic matter adsorption and long-term light exposure are avoided. This maintains the light energy utilization efficiency of algae and the stability of the microenvironment for microbial attachment, supporting the formation of algal-microbe symbiotic biofilm on the carrier surface and continuously performing synchronous nitrification, denitrification and phosphorus absorption functions.

[0050] Example 4: In one alternative embodiment, such as Figure 1 As shown, the inlet 110 is connected to the inlet water tank 130, and the inlet pump 140 is provided on the passage connecting the inlet 110 and the inlet water tank 130; the outlet 120 is connected to the outlet water tank 150, and the outlet pump 160 is provided on the passage connecting the outlet 120 and the outlet water tank 150.

[0051] The inlet tank 130 is used to store the aquaculture wastewater to be treated and to provide a stable, continuous and homogeneous source of inlet water for the system. The inlet pump 140 is located in the passage between the inlet tank 130 and the inlet 110 of the reaction vessel 100 and is used to quantitatively and periodically deliver the wastewater into the reaction vessel 100. The flow rate of the inlet pump 140 can be adjusted according to the preset hydraulic retention time (HRT). The inlet pump 140 can be a peristaltic pump, a diaphragm pump or a centrifugal pump. Its model, head and flow rate parameters can be adapted according to the actual volume of the reaction vessel 100, the total pipeline resistance of the system and the HRT control accuracy requirements. This embodiment of the invention does not impose any special limitations on this.

[0052] The effluent tank 150 is used to temporarily store the effluent after treatment by the reaction vessel 100, and plays a role in buffering and stabilizing the flow, reducing the impact of instantaneous fluctuations in the effluent on subsequent testing or reuse processes. The effluent pump 160 is located in the passage between the outlet 120 of the reaction vessel 100 and the effluent tank 150, and is used to quantitatively discharge the supernatant after the settling stage. The working sequence of the effluent pump 160 is coordinated with the inlet pump 140 to jointly realize the four stages of "inlet → reaction → settling → drainage" in the SBR sequential batch reactor cycle. The effluent pump 160 can be the same type or different type of pump as the inlet pump 140. Its start and stop are uniformly scheduled by a timing controller or PLC module to ensure that the duration of each stage strictly meets the preset HRT gradient requirements. The start and stop logic of the effluent pump 160 can be based on the feedback signal of the liquid level sensor in the reaction vessel 100 or a fixed-time program trigger. The specific implementation method can be flexibly selected according to the configuration of the control system. This embodiment of the invention does not impose any special limitations on this.

[0053] Both the inlet 110 and the outlet 120 are controllable opening and closing structures, and their opening and closing actions are linked and coordinated with the inlet pump 140 and the outlet pump 160: during the water intake stage, the inlet 110 is opened, the outlet 120 is closed, and the inlet pump 140 is started; during the reaction and sedimentation stage, both the inlet 110 and the outlet 120 are closed; during the drainage stage, the inlet 110 is closed, the outlet 120 is opened, and the outlet pump 160 is started; the controllable opening and closing structure can be a solenoid valve, a pneumatic valve, or an electric ball valve, and its response time, sealing performance, and corrosion resistance need to be adapted to the characteristics of the aquaculture tailwater medium. This embodiment of the invention does not impose any special limitations on this.

[0054] Through the above technical solution, this invention achieves automated and precise control of the SBR (Sequencing Batch Reactor) operation process of the algae-bacteria symbiotic aquaculture wastewater treatment system: the inlet pump 140 and the inlet tank 130 work together to ensure that the inlet flow rate is consistent with the HRT (Hydrogen Temperature Regulator) set value; the outlet pump 160 and the outlet tank 150 work together to achieve a dynamic balance between the discharge volume and the inlet volume; the controllable opening and closing structure of the inlet 110 and the outlet 120 forms a closed-loop fluid regulation mechanism with the pump group, supporting the HRT gradient reduction operation strategy (72 h → 6 h) recorded in the invention, thereby providing sufficient biological attachment time in the early stage of biofilm formation, increasing the unit volume treatment load and pollutant removal efficiency in the stable period, and ultimately improving the system's repeatability, data reliability, and engineering scale-up feasibility.

[0055] Example 5: In one alternative embodiment, such as Figure 1 As shown, the top of the reaction vessel 100 is provided with a removable top cover 170.

[0056] A detachable top cover 170 is located on the top of the reaction vessel 100 and can be repeatedly assembled and sealed with the top plate of the reaction vessel 100 through threaded connection, snap-fit ​​structure or magnetic attraction structure. The top cover 170 is made of transparent material with a light transmittance of not less than 85% to ensure that the light flux loss when the light source 300 shines into the interior of the reaction vessel 100 is controllable. The size of the top cover 170 matches the opening of the top plate of the reaction vessel 100, and a silicone sealing ring is provided on the edge to maintain a slightly positive or negative pressure environment inside the reaction vessel 100 in the closed state to prevent light leakage and the entry of external contaminants. The top cover 170 can be provided with reserved holes for the drive shaft of the stirring mechanism 500, the fixing parts of the light source 300 bracket or the sampling pipeline. Each reserved hole is equipped with a detachable rubber plug to maintain the sealing integrity when not in use.

[0057] The above technical solution enables convenient periodic water quality sampling, biofilm dry weight determination, EPS extraction, carrier replacement, agitator blade cleaning, and light source 300° angle calibration without compromising the overall sealing and lighting conditions of the reaction vessel 100. Because the top cover 170 can be quickly opened / closed, the time required for each maintenance operation is significantly shortened, ensuring the daily measurement of influent and effluent COD, TP, and NH4. + The experiment ensures the continuity and data reliability of "-N concentration" and "stage-by-stage determination of biofilm dry weight and PN / PS content in EPS"; at the same time, it avoids the risk of structural fatigue and sealing failure caused by frequent disassembly of sidewall interfaces, and improves the long-term operational stability and user-friendliness of the system.

[0058] Example 6: In one alternative embodiment, such as Figure 1 and Figure 2 As shown, the 3D printed gyroid model carrier 200 is set to be spherical.

[0059] The 3D printed gyroid model carrier 200 is spherical, meaning its overall shape is a geometric sphere with no sharp edges or abrupt changes in planar planes, and a smooth, continuous surface. This spherical structure optimizes the macroscopic geometry of the carrier while maintaining the internal gyroid triple-period minimum surface topology.

[0060] Among them, "spherical" means that the overall shape of the carrier conforms to the basic geometric definition of a sphere, and the dimensional deviation in the diameter direction does not exceed ±5%, which can achieve uniform force in the flow field and stable rotational posture. This shape can effectively reduce the collision frequency and impact intensity between the carrier and the reaction vessel wall 100 and between carriers during the stirring process, and reduce the risk of structural damage caused by local stress concentration. At the same time, the spherical shape allows the water to flow around more fully, enhances the uniformity of shear force distribution on the carrier surface, and is conducive to the multidirectional attachment of algae and microorganisms on the gyroid surface and the balanced growth of biofilm thickness.

[0061] The diameter of the spherical 3D printed gyroid model carrier 200 is 15–25 mm, for example, it can be 19 mm, or 15 mm, 20 mm or 25 mm; its specific value can be adaptively set according to the actual operating parameters such as the volume of the reaction vessel 100, the filling rate, the stirring speed and the hydraulic residence time, and the embodiments of the present invention do not make special limitations in this regard.

[0062] The spherical 3D printed gyroid model carrier 200 has a wall thickness of 450–550 μm, for example, it can be 500 μm, 450 μm or 550 μm; this wall thickness range takes into account both structural stiffness and mass transfer efficiency, ensuring the mechanical strength of the carrier while ensuring the connectivity of internal channels and the diffusion rate of nutrients; the specific value of the wall thickness can be adjusted according to the mechanical properties of the selected material (such as PEEK, PEKK) and the precision of the 3D printing process, and the embodiments of the present invention do not impose special limitations on this.

[0063] The spherical 3D printed gyroid model carrier 200 has a specific surface area of ​​900–1200 m² / m³, for example, it can be 1072 m² / m³, or it can be 900 m² / m³ or 1200 m² / m³. This specific surface area is determined by the internal gyroid curved surface structure, which works in conjunction with the spherical shape to maximize the density of microbial attachment sites within a limited volume. The specific value of the specific surface area can be adjusted according to the gyroid unit period length, surface curvature and printing resolution. This embodiment of the invention does not impose any special limitations on this.

[0064] The spherical 3D printed gyroid model carrier 200 has a pore size greater than or equal to 1.5 mm, for example, it can be 1.5 mm, 2.0 mm or 2.5 mm; this pore size ensures that water flow can freely penetrate the internal channels of the carrier, avoiding clogging problems caused by excessive biofilm growth; the pore size can be adapted according to the molecular size of the target pollutants, the biofilm maturation cycle and backwashing requirements, and the embodiments of the present invention do not impose special limitations on this.

[0065] Through the above technical solution, the present invention achieves the following: while maintaining the functional advantages of the gyroid micro-topology, by limiting the macroscopic shape of the carrier to a spherical shape, the fluidization stability and suspension uniformity under stirring conditions are significantly improved; the spherical shape causes the carrier to spontaneously flip and rotate isotropically under the drive of the stirring mechanism 500, causing different regions of the gyroid surface to be alternately exposed to the light zone and the mainstream water flow zone, thereby improving the light energy utilization efficiency and the nutrient mass transfer rate.

[0066] Example 7: In one optional embodiment, the 3D printed gyroid model carrier 200 is made of PEEK or PEKK material.

[0067] The 3D-printed gyroid model carrier 200 is made of polyether ether ketone (PEEK), a semi-crystalline thermoplastic polymer material with excellent chemical corrosion resistance, high temperature stability, mechanical strength, and biocompatibility. It does not undergo hydrolysis, swelling, or release of antibacterial molecules during long-term immersion in aquaculture wastewater environments with pH 5–9, maintaining structural integrity and surface functional stability for more than 6 months. After plasma or acid-base oxidation modification, its surface exhibits a stable positive charge, which is beneficial for the initial electrostatic adsorption of negatively charged bacteria and algae cells, accelerating the biofilm formation process.

[0068] The 3D-printed Gyroid model carrier 200 is made of polyether ketone ketone (PEKK), a structural derivative of PEEK. Its main chain contains more ketone bonds, and while its crystallinity is slightly lower than PEEK, it is chemically more inert, especially against highly oxidizing wastewater components (such as NO2). - It exhibits better tolerance to residual H2O2 and weakly acidic environments (pH 5.5–6.5).

[0069] The choice of PEEK or PEKK materials does not preclude other alternative materials that meet equivalent performance indicators, such as those with a density in the range of 1.0–1.3 g / cm³, surfaces that can be modified to carry a positive charge, which do not release inhibitory substances in aquaculture wastewater with pH 5–9 and in the coexistence of COD / N / P, and which possess ≥10 6 High molecular weight polymers with tensile strength of Pa and impact toughness of ≥100 kJ / m²; however, the present invention may select PEEK and PEKK, as they achieve the optimal balance between chemical shock resistance, biocompatibility and long-term operational stability.

[0070] Through the above technical solution, this invention achieves the following in an algae-bacterial symbiotic aquaculture wastewater treatment system: by limiting the 3D-printed gyroid model carrier 200 to PEEK or PEKK material, and utilizing their high crystallinity, strong molecular chain rigidity, and controllable surface charge characteristics, the carrier structure remains stable and the microbial affinity interface activity is maintained in complex wastewater environments containing weak acids and alkalis, nitrogen and phosphorus organic matter. This improves the initial biofilm attachment rate, extends the carrier's service life, and enhances COD, TP, and NH4 levels. + –N synchronous removal efficiency avoids system performance degradation due to material deterioration.

[0071] Example 8: In one optional embodiment, the diameter of the 3D printed gyroid model carrier 200 is set to 15–25 mm. This diameter range is determined based on the synergistic effect of structural stability, filling density, and light penetration depth. If the diameter is too small, the mechanical strength of a single carrier will be insufficient, making it easily broken under stirring and aeration shearing. If the diameter is too large, the number of carriers per unit volume will be reduced, weakening the overall specific surface area contribution and exacerbating internal light attenuation, thus affecting the photosynthetic efficiency of attached algae. In this embodiment of the invention, a diameter of 19 mm can be selected, which is consistent with the carrier size corresponding to the best performance measured in the experiment. However, this embodiment of the invention does not impose a special limitation on the specific value of the diameter. For example, it can be 15 mm, 17 mm, 20 mm, 22 mm, or 25 mm, which can be flexibly set according to the volume of the reaction vessel 100, the hydraulic residence time, and the target biofilm load.

[0072] The wall thickness of the 3D-printed gyroid model carrier 200 is 450–550 μm. This wall thickness range balances the carrier's rigid support capacity with the proportion of internal fluid channel space: when the wall thickness is less than 450 μm, the carrier is prone to deformation or local collapse under long-term immersion and fluid disturbance, affecting the integrity of the gyroid surface topology; when the wall thickness is greater than 550 μm, the internal pore volume is compressed, the effective mass transfer cross section is reduced, and the spatial partitioning and coexistence ability of nitrifying / denitrifying bacteria is weakened. In this embodiment of the invention, the wall thickness can be selected as 500 μm; however, this embodiment of the invention does not impose a special limitation on the specific value of the wall thickness, for example, it can be 450 μm, 480 μm, 500 μm, 520 μm or 550 μm, and can be adaptively adjusted according to the accuracy of the selected printing equipment, the melt flowability of the material and the post-processing conditions.

[0073] The specific surface area of ​​the 3D-printed gyroid model carrier 200 is 900–1200 m² / m³. This specific surface area range meets the requirements for simultaneous attachment of algae and various functional microorganisms (such as ammonia-oxidizing bacteria, nitrite-oxidizing bacteria, denitrifying bacteria, and polyphosphate-accumulating bacteria) and microecological zoning. When the specific surface area is below 900 m² / m³, the biomass that a unit volume of carrier can carry is limited, making it difficult to support the total metabolic activity required for high-load effluent treatment. Although a specific surface area above 1200 m² / m³ is theoretically beneficial for attachment, it easily leads to surface densification and increased tortuosity of internal pores, which inhibits the diffusion of nutrients and dissolved oxygen to the deep biofilm, causing the expansion of the endogenous anaerobic zone and nitrate accumulation. The measured SSA of the PEEK carrier is 1072 m² / m³, which is in the middle of this range, verifying its feasibility. The specific value of the specific surface area in the embodiments of this invention is not specifically limited, for example, it can be 900 m² / m³, 980 m² / m³, 1072 m² / m³, 1120 m² / m³, etc. The thickness can be adjusted to m² / m³ or 1200 m² / m³, depending on the actual printing layer thickness, surface subdivision accuracy, and post-processing polishing degree.

[0074] The pore size of the 3D-printed gyroid model carrier 200 is greater than or equal to 1.5 mm. This lower limit of pore size is set to prevent internal flow channel blockage caused by excessive biofilm proliferation: when the pore size is less than 1.5 mm, mature biofilm can easily completely block the pores within a few days, causing the dead zone inside the carrier to expand, mass transfer resistance to increase dramatically, and denitrification efficiency to decrease; while through-holes of ≥1.5 mm can maintain the macroscopic penetration ability of water flow inside the carrier while ensuring sufficient specific surface area, so that dissolved oxygen and carbon, nitrogen and phosphorus nutrients can be continuously transported to different depth microenvironments to support the spatial coupling metabolism of algae and bacteria. It is clearly stated that "internal pore size >1.5 mm effectively avoids biofilm blockage", and all experimental groups adopted this pore size threshold; the specific value of pore size in the embodiments of this invention is not specifically limited, for example, it can be 1.5 mm, 1.8 mm, 2.0 mm, 2.2 mm or 2.5 mm, and can be differentiated according to the target aquaculture tailwater suspended solids concentration, expected operating cycle and whether a pre-filtration unit is set.

[0075] Through the above technical solution, this invention achieves synergistic constraints on the key geometric parameters of the 3D-printed gyroid model carrier 200: under the constraints of a diameter of 15–25 mm and a wall thickness of 450–550 μm, it ensures both the overall structural reliability and lightweight level of the carrier, while providing a stable configuration basis for the gyroid's minimum surface topology; within a specific surface area range of 900–1200 m² / m³, it ensures sufficient biofilm attachment sites to support a highly active algae-bacteria symbiotic system; and under the condition of a pore size ≥1.5 mm, it maintains the internal fluid permeability and material exchange efficiency of the carrier. These four factors together constitute a multi-dimensional parameter window, enabling the carrier to maintain stable biofilm proliferation without significant clogging during continuous operation, and supporting COD, TP, and NH4. + –N synchronous and efficient removal.

[0076] Example 9: In one alternative embodiment, such as Figure 1 As shown, the aeration mechanism 400 includes an air pump 410 and an aeration stone unit 420. The air pump 410 is connected to the aeration stone unit 420, which is located at the bottom of the reaction vessel 100.

[0077] Air pump 410 is used to provide stable and controllable compressed air to aeration stone unit 420; the rated flow rate of air pump 410 can be set according to the volume of reaction vessel 100, hydraulic residence time and target dissolved oxygen concentration, and its output pressure is sufficient to drive gas through aeration stone and form uniform microbubbles.

[0078] The aeration stone unit 420 is located inside the reaction vessel 100 near the bottom and downstream of the inlet 110. The aeration stone unit 420 includes porous ceramic aeration stone, sintered stainless steel aeration stone or microporous silica gel aeration stone, which can break compressed air into micron-sized bubbles.

[0079] The aeration mechanism 400, together with the light source 300, the stirring mechanism 500, and the 3D-printed gyroid model carrier 200, works together to maintain the dissolved oxygen (DO) concentration in the reaction vessel 100 stably within the range of 3–4 mg / L. This DO concentration range coincides with the symbiotic aerobic window of nitrifying bacteria (optimal DO ≥ 2 mg / L) and Chlorella (optimal DO ≤ 5 mg / L), ensuring that the nitrification reaction proceeds fully while avoiding the enhancement of algal photorespiration or the accumulation of reactive oxygen species (ROS) caused by high DO. The DO concentration can be monitored in real time by an online dissolved oxygen probe, and the start / stop or frequency conversion output of the air pump 410 can be adjusted accordingly to achieve closed-loop control.

[0080] Through the above technical solution, the present invention achieves the following: by utilizing the combined structure of the air pump 410 and the aeration stone unit 420, and with their specific connection relationship between the inlet 110 and the aeration stone unit 420, a directional microbubble air supply path is formed. This ensures a stable supply of dissolved oxygen while significantly improving gas-liquid mass transfer efficiency and mitigating the physical impact of bubbles on algal cells and biofilms. This, in turn, supports the algae-bacteria symbiotic system in maintaining COD, TP, and NH4 levels during continuous operation. + –N High-efficiency synchronous removal performance.

[0081] Example 10: In one alternative embodiment, such as Figure 1 As shown, the algae-bacteria symbiotic aquaculture wastewater treatment system also includes a support frame 600, on which a stirring mechanism 500 is provided. The stirring part of the stirring mechanism 500 is suspended inside the reaction vessel 100.

[0082] The support frame 600 is a rigid metal structure, such as a three-dimensional frame welded from stainless steel square tubes. It has adjustable feet at the bottom to adjust the overall height and ensure horizontal stability. The top of the support frame 600 is equipped with a mounting plate or guide rail structure to fix the stirring motor and drive shaft assembly.

[0083] Through the above technical solution, the present invention achieves rigid constraints on the installation benchmark and spatial attitude of the stirring mechanism 500, stabilizes the flow field distribution, and avoids hard contact with the spherical 3D printed gyroid model carrier 200, thereby improving the processing stability and shock load resistance of the algae-bacteria symbiotic system.

[0084] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A wastewater treatment system for algae-bacteria symbiotic aquaculture based on a 3D-printed carrier, characterized in that, Includes reaction vessel, 3D printed gyroid model carrier, light source, aeration mechanism and stirring mechanism; The reaction vessel is provided with an inlet and an outlet that are connected to its interior, and both the inlet and the outlet are controllable opening and closing structures. Multiple 3D-printed gyroid model carriers are filled inside the reaction vessel; The light source is used to provide illumination to the interior of the reaction vessel; The aeration mechanism is used to aerate the interior of the reaction vessel. The stirring mechanism is used to stir the interior of the reaction vessel.

2. The algae-bacterial symbiotic aquaculture wastewater treatment system according to claim 1, characterized in that, The reaction vessel is made of a transparent material.

3. The algae-bacterial symbiotic aquaculture wastewater treatment system according to claim 2, characterized in that, The reaction vessel is made of transparent plexiglass.

4. The algae-bacterial symbiotic aquaculture wastewater treatment system according to claim 1, characterized in that, The water inlet is connected to a water tank, and a water pump is installed on the passage connecting the water inlet and the water tank. The outlet is connected to a water tank, and a water pump is installed on the passage connecting the outlet and the water tank.

5. The algae-bacterial symbiotic aquaculture wastewater treatment system according to claim 1, characterized in that, The reaction vessel is equipped with a removable top cover.

6. The algae-bacterial symbiotic aquaculture wastewater treatment system according to claim 1, characterized in that, The 3D printed gyroid model carrier is spherical.

7. The algae-bacterial symbiotic aquaculture wastewater treatment system according to claim 1, characterized in that, The 3D printed gyroid model carrier is made of PEEK or PEKK material.

8. The algae-bacterial symbiotic aquaculture wastewater treatment system according to claim 1, characterized in that, The 3D-printed gyroid model carrier has a diameter of 15-25mm, a wall thickness of 450-550μm, and a specific surface area of ​​900-1200m². 2 / m³, the pore size of the 3D printed gyroid model carrier is greater than or equal to 1.5mm.

9. The algae-bacterial symbiotic aquaculture wastewater treatment system according to claim 1, characterized in that, The aeration mechanism includes an air pump and an aeration stone unit. The air pump is connected to the aeration stone unit, which is located at the bottom of the reaction vessel.

10. The algae-bacterial symbiotic aquaculture wastewater treatment system according to claim 1, characterized in that, The algae-bacteria symbiotic aquaculture wastewater treatment system also includes a support frame, on which the stirring mechanism is mounted, and the stirring part of the stirring mechanism is suspended inside the reaction vessel.

Images