Wastewater treatment system and method for enhancing biochemical coupling phycomycete fixed bed

Abstract

The invention discloses a wastewater treatment system and method for strengthening a biochemical coupling phycomycete fixed bed. According to the invention, the phycomycete immobilized rubber balls are combined with the multi-stage biological rope reactor, so that staged directional removal of pollutants is realized. The system comprises adsorption-embedding co-immobilization phycomycete gel balls, an active fiber biological rope carrier and a multi-stage baffling reaction unit. According to the rubber ball, a MgAl-LDO and zeolite composite material is used for embedding bacteria and algae, and a biological rope carrier is used for fixing microorganisms to form an anoxic-aerobic dynamic environment. According to the system, the removal effects of NH4 < + >-N, TP, COD and NO3-N are improved to different degrees, and the system is high in anti-interference performance and particularly suitable for aquaculture wastewater, low-C / N-ratio wastewater and decentralized sewage treatment scenes.

Description

Technical Field

[0001] This invention relates to wastewater biological treatment technology, specifically an enhanced treatment system combining adsorption-embedding co-fixation and algae-bacteria fixed bed, suitable for treating wastewater from high-nitrogen and high-phosphorus aquaculture. Background Technology

[0002] With the rapid development of aquaculture, the discharge of high concentrations of nitrogen and phosphorus pollutants in aquaculture wastewater has become a major challenge for treatment. Traditional activated sludge processes rely on nitrification-denitrification for nitrogen removal, requiring a large amount of organic carbon to maintain a high C / N ratio. However, aquaculture wastewater generally exhibits a low C / N ratio, leading to intense competition for carbon sources, low denitrification efficiency, and severely limited nitrogen removal capacity. For wastewater with low C / N ratios, algal-microbe symbiotic systems have attracted significant attention due to their unique carbon-nitrogen synergistic metabolic mechanism. Algae fix CO2 and release O2 through photosynthesis, providing an aerobic environment for heterotrophic bacteria, while simultaneously absorbing nitrogen and phosphorus to synthesize biomass, thus alleviating the carbon source shortage problem. However, existing algal-microbe symbiotic systems still face multiple challenges: algae are prone to over-proliferation under nitrogen and phosphorus enrichment conditions, leading to uncontrollable free algal cell biomass and secondary pollution caused by their escape from the effluent (Kim et al., Biological and Chemical Approaches for Controlling Harmful Microcystis Blooms. Journal of Microbiology, 62(3), 249-260); in addition, traditional immobilized carriers (such as bio-ropes, alginate balls, etc.) have limited adsorption capacity and lack a protective mechanism for microorganisms under high pollution loads or water quality fluctuations, while algal and microbial microorganisms have poor tolerance to sudden pollutant loads, making the system susceptible to environmental stress and resulting in a sharp drop in treatment efficiency. Therefore, it is difficult for a single carrier material to simultaneously achieve nitrogen and phosphorus removal and microbial protection.

[0003] In recent years, layered bimetallic hydroxides (LDHs) and their calcined products (LDOs) have been used for phosphate adsorption due to their anion exchange properties. However, their practical applications are limited by their small particle size and difficulties in recovery after dispersion. While zeolites exhibit excellent adsorption performance for ammonia nitrogen, they are less effective at capturing phosphates. Existing research has largely focused on the modification of single materials, while studies combining LDH / zeolite composite systems with microbial immobilization technology remain largely unexplored.

[0004] To address the above-mentioned situation, this invention proposes an innovative solution: by loading MgAl-LDH onto the surface of zeolite and calcining it to form a MgAl-LDO@zeolite composite material, which possesses both ammonia nitrogen adsorption and phosphate adsorption-slow release functions, it can simultaneously regulate nitrogen and phosphorus supply. Combined with alginate encapsulation technology, bacteria and algae are co-immobilized with the composite material within the gel beads, utilizing the material's adsorption properties to mitigate pollutant load shocks and maintain microbial physiological activity. Simultaneously, by encapsulating and immobilizing bacteria and algae within the gel beads and intermittently discharging them from the bio-rope cells, a multi-stage treatment structure is formed, dynamically regulating dissolved oxygen to achieve synergistic effects of anoxic denitrification and aerobic nitrification. This overcomes the competitive inhibition and mass transfer bottlenecks of traditional algae-bacteria fixed beds, achieving a simultaneous leap in COD, TN, and TP removal rates. It has significant potential, especially in mitigating hydraulic load shocks in microbial treatment systems. This technology is suitable for treating aquaculture wastewater with large fluctuations in nitrogen and phosphorus concentrations and low C / N ratios, providing a new approach for the efficient treatment of low C / N ratio wastewater. Summary of the Invention

[0005] Based on this, the present invention provides a wastewater treatment system and method for enhanced biochemical coupling algae-bacterial fixed beds. The system employs a multi-stage treatment structure formed by intermittent discharge of wastewater treatment gel balls encapsulating microorganisms in MgAl-LDO@zeolite composite materials and bio-rope cells. Compared with traditional algae-bacterial fixed beds, this system achieves zoned synergy between the gel balls and bio-ropes, enabling efficient staged removal of pollutants. Specifically, when water flows through the bio-ropes, the large-scale reproduction of microorganisms causes a decrease in dissolved oxygen (DO), creating anoxic conditions for denitrification. Conversely, when water flows through the microbial-encapsulated gel balls, algal cells utilize water for photolysis, releasing oxygen and converting H₂O into hydrogen sulfide. + It is used for the synthesis of organic matter, which realizes the generation of oxygen and the increase of DO, thereby driving nitrification. At the same time, phosphorus is removed through the dual pathway of EPS adsorption and P assimilation. The content of N and P pollutants in water is gradually reduced through the degradation of bio-rope and rubber balls, which leads to the increase of C / N ratio and the oxygen-rich environment promotes the rapid reproduction of microorganisms, ultimately achieving efficient removal of COD.

[0006] The objective of this invention is achieved by at least one of the following technical solutions.

[0007] A wastewater treatment method for enhanced biochemical coupling algae-bacteria fixed bed includes the following steps:

[0008] (1) Filling: Active fiber bio-rope is filled into the reactor as a carrier for algae-bacteria symbiotic biological bed, with a bio-rope filling rate of 20-25%.

[0009] (2) Biofilm formation stage: Add algae and bacteria solution with a mass ratio of Chlorella and activated sludge of (0.5-1):1 to form a biofilm. Aerate for 10-12 hours per day to maintain the DO concentration of the water body at 3-4 mg / L. The biofilm formation is considered successful when a dense yellow-green biofilm forms on the surface of the activated fiber biological rope.

[0010] (3) Adding microbial balls: Place the microbial-encapsulated microbial balls into the isolation net and alternate them with the bio-rope cells in the manner of microbial ball-bio-rope cell-microbial ball-bio-rope cell;

[0011] (4) Operation: Control the hydraulic retention time to 24-48h; adopt an air-water ratio of (3-4):1 and aerate intermittently for 10-12h; place the device outdoors in a sunny place for operation.

[0012] Furthermore, the preparation of the glue balls in step (3) includes the following steps:

[0013] (3.1) Pretreatment and activation of zeolite:

[0014] Select clinoptilolite with a particle size of 0.5-1.0 mm, then soak the clinoptilolite in 1-2 mol / L HCl solution for 2-4 hours. After soaking, rinse the clinoptilolite with deionized water until neutral and then dry it for later use.

[0015] Prepare a NaHCO3 solution with a mass concentration of 60-200 g / L, add the pretreated clinoptilolite and stir at 80-95℃ for 1-3 h, drain and calcine at 300-500℃ for 2-4 h to obtain Na-type porous activated zeolite.

[0016] (3.2) Synthesis of composite materials:

[0017] MgCl2 and AlCl3·6H2O were dissolved in deionized water to prepare metal salt solutions with different molar ratios. The Na-type porous activated zeolite described in step (3.1) was added, and the pH was adjusted to 10-12 with NaOH and Na2CO3 solution. The mixture was then hydrothermally aged at 60-80℃ for 12-24 hours with continuous stirring. After filtration, the mixture was washed with deionized water until the pH was neutral and dried at 60-80℃ for 12-24 hours. Finally, the obtained material was calcined at 350-500℃ for 3-5 hours to obtain the MgAl-LDO@zeolite composite material.

[0018] (3.3) Preparation of bacterial and algal suspension:

[0019] Activated sludge and Chlorella were mixed in a certain proportion, centrifuged, and then resuspended in deionized water to form a bacterial-algae suspension with a mass concentration of 2-3 g / L.

[0020] (3.4) Preparation of rubber balls:

[0021] The bacterial and algal suspension from step (3.3) is mixed with sodium alginate solution with a mass concentration of 20-40 g / L at a volume ratio of 1:2-2:1. The MgAl-LDO@zeolite composite material from step (3.2) is added, and after stirring, it is injected into a CaCl2 solution with a mass concentration of 20-30 g / L for cross-linking to form wastewater treatment granules with a diameter of 3-5 mm encapsulating microorganisms.

[0022] Furthermore, the molar ratio of magnesium salt to aluminum salt in the metal salt solution is (1-3):1; the solid-liquid ratio of the Na-type porous activated zeolite to the metal salt solution is (1-2):10g / mL.

[0023] Furthermore, the dry weight mixing ratio of the activated sludge and Chlorella is (1-2):1.

[0024] Furthermore, the amount of the MgAl-LDO@zeolite composite material added is (2-2.5) g / 50 ml.

[0025] Furthermore, the activated sludge described in step (3.3) is screened twice before use to remove particulate impurities. The treated activated sludge is placed in an environment of 25-28℃ and acclimatized and cultured with wastewater for 12-15 days.

[0026] Furthermore, in the wastewater, NH4 + -N concentration is 5-15 mg / L, NO3 - -N concentration is 15-25 mg / L, TP concentration is 3-5 mg / L, and COD concentration is 40-50 mg / L.

[0027] Further, the Chlorella described in step (3.3) is inoculated into sterile BG11 medium and cultured for 6-8 days under the conditions of a temperature of 25±1℃, a light intensity of 5000±500 lux, and a light / dark cycle of 12 / 12h.

[0028] Further, the dry weight mixing ratio of activated sludge and Chlorella in step (3.3) is (1-2):1.

[0029] The present invention also provides a system for enhancing the wastewater treatment method of biochemically coupled algae-bacteria fixed bed, which includes: an influent pump, active fiber bio-rope, immobilized gel balls, and baffles. The length-to-width ratio of the device is (3.75-4):1, and the length-to-height ratio is (1-1.25):1. Three baffles are set in the reactor, so that the wastewater flows in the reactor in the form of up-and-down baffles, forming four cells with the same volume. The ratio of the height of the baffle to the height of the reactor is (1-1.25):1. The bio-rope filling rate is 20-25%, and the length is consistent with the height of the reactor.

[0030] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0031] The microbial gel balls used in this invention solve the problem of easy loss of algal cells in general algae-fixed beds and reduce the impact of environmental fluctuations (such as insufficient light) on the system.

[0032] The enhanced biochemical coupling algae-bacterial fixed bed used in this invention achieves functional zoning, namely, the bio-rope cell is mainly for bacterial-dominated organic matter degradation and nitrification, while the gel ball cell is mainly for algal assimilation and denitrification, and multi-stage reactions are promoted through up-and-down flow.

[0033] Compared with ordinary algae-bacteria fixed beds, the enhanced biochemical coupling algae-bacteria fixed bed used in this invention has a significantly improved pollutant removal efficiency.

[0034] The enhanced biochemical coupling algae-bacteria fixed bed used in this invention has strong resistance to shock loads and achieves dynamic control of DO and C / N ratios through the synergistic effect of microorganisms. It is particularly suitable for aquaculture wastewater, low C / N ratio wastewater and decentralized sewage treatment scenarios, and has significant technical and economic competitiveness. Attached Figure Description

[0035] Figure 1 In the example, NH4 + -N removal rate dynamic change curve.

[0036] Figure 2 This is a dynamic change curve of TP removal rate in the embodiment.

[0037] Figure 3 This is a dynamic change curve of COD removal rate in the embodiment.

[0038] Figure 4 NO3 in the embodiment - Dynamic curve of nitrogen concentration.

[0039] Figure 5 A schematic diagram of a device for enhancing the biochemical coupling of algae and bacteria in a fixed bed. Detailed Implementation

[0040] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described in detail below. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0042] Unless otherwise stated or in case of contradiction, the terms or phrases used in this invention shall have the following meanings:

[0043] In this invention, numerical ranges are involved. Unless otherwise specified, the numerical ranges are considered continuous and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe features or characteristics, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are included.

[0044] Unless otherwise specified, the percentage content involved in this invention refers to mass percentage for solid-liquid mixtures and solid-phase-solid mixtures, and volume percentage for liquid-phase-liquid mixtures.

[0045] Unless otherwise specified, all percentage concentrations mentioned in this invention refer to the final concentration. The final concentration refers to the proportion of the added component in the system after the addition of that component.

[0046] The following description, in conjunction with specific embodiments, provides further details.

[0047] Example 1

[0048] The specific steps to enhance the operation of the wastewater treatment system with biochemical coupling of algae and bacteria in a fixed bed are as follows:

[0049] 1. Preparation of immobilized gel balls

[0050] (1) Pretreatment and activation of zeolite: Select clinoptilolite with a particle size of 0.5-1.0 mm, then soak the zeolite in 1 mol / L HCl solution for 4 h, rinse the zeolite raw material with deionized water until neutral, and then dry it for later use; prepare 60 g / L NaHCO3 solution, add the pretreated zeolite and stir at 80 °C for 2 h, drain and calcine at 450 °C for 4 h to obtain Na-type porous activated zeolite;

[0051] (2) Synthesis of composite material: MgCl2 (0.1 mol) and AlCl3·6H2O (0.05 mol) were weighed according to the Mg:Al = 2:1 molar ratio and dissolved in 200 mL of deionized water; 2 mol / L NaOH solution and 1 mol / L NaCO3 solution were added to adjust the pH to 10.5 and stirred for 3 h to form a homogeneous precursor solution; 5 g of activated zeolite was added to the precursor solution with a solid-liquid ratio of 1:10 g / mL, the temperature was raised to 80 °C and stirred for 12 h, then filtered and washed with deionized water until neutral pH was reached, and dried at 80 °C for 12 h; finally, the obtained material was calcined at 350 °C for 3 h to obtain MgAl-LDO@zeolite composite material;

[0052] (3) Preparation of gel beads: 0.0325 g of microorganisms were resuspended in deionized water (the mass ratio of bacteria to algae in the mixed solution was 1:1) to form 50 mL of suspension. This suspension was then mixed with a sodium alginate solution with a mass concentration of 40 g / L at a volume ratio of 1:1. The MgAl-LDO@zeolite composite material from step (2) was added, and after stirring, it was injected into a CaCl2 solution with a mass concentration of 30 g / L to crosslink and form gel beads with a diameter of 3-5 mm. The algae used in this experiment was Chlorella vulgaris, and the activated sludge used came from the aerobic section of a domestic sewage treatment plant in Guangzhou.

[0053] 2. System Operation

[0054] (1) Equipment preparation: The reactor consists of an inlet pump, active fiber biological rope, immobilized gel balls, etc. The length, width and height of the device are 60cm, 15cm and 50cm respectively. Three baffles with a height of 40cm are set in the reactor so that the wastewater flows in the reactor in the form of up and down baffles, and is isolated to form 4 cells, each cell with a water depth of 40cm.

[0055] (2) Filling: Active fiber bio-rope is filled into the reactor as a carrier for algae-bacteria symbiotic bio-bed, with a bio-rope filling rate of 20% and a length consistent with the height of the reactor.

[0056] (3) Biofilm formation stage: Add algae and bacteria concentrated solution with an algae-to-bacteria ratio of 1:2 to form biofilm, aerate for 8 hours a day, and maintain the DO concentration of the water body at 3-4 mg / L; the biofilm formation is successful when a dense yellow-green biofilm forms on the surface of the active fiber bio-rope.

[0057] (4) Adding gel balls: Place the gel balls containing microorganisms into the isolation net with a filling rate of 20%, and release them intermittently with the biological rope cells;

[0058] (5) System operation: The hydraulic retention time was controlled at 24 hours; an air-to-water ratio of 3:1 was used, with intermittent aeration for 10-12 hours; the device was placed outdoors in a sunny location, and the influent concentration was changed every 6 days for a total of 24 days. The system's effects on COD and NO3 were evaluated. - -N, TP, NH4 + -N removes the effect.

[0059] Comparative Example 1

[0060] The specific steps for operating the wastewater treatment system of the biological rope algae fixed bed are as follows:

[0061] 1. Equipment preparation: The reactor consists of an inlet pump, active fiber biological rope, immobilized gel balls, etc. The length, width and height of the device are 60cm, 15cm and 50cm respectively. Three baffles with a height of 40cm are set in the reactor to make the wastewater flow in the reactor in the form of up and down baffles, and isolate it to form 4 cells, each cell with a water depth of 40cm.

[0062] 2. Filler material placement: Active fiber bio-ropes are used as carriers for the algae-bacteria symbiotic bio-bed and filled into the four cells of the reactor, with a bio-rope filling rate of 20% and a length consistent with the reactor height;

[0063] 3. Biofilm formation stage: Add an algae-to-bacterial concentrate with an algae-to-bacterial ratio of 1:2 to form a biofilm. Aerate for 8 hours daily and maintain the DO concentration of the input solution at 3-4 mg / L. Successful biofilm formation is indicated when a dense yellow-green biofilm forms on the surface of the active fiber bio-rope.

[0064] 4. System Operation: The hydraulic retention time was controlled at 24 hours; an air-to-water ratio of 3:1 was used, with intermittent aeration for 10-12 hours; the device was placed outdoors in a sunny location, and the influent concentration was changed every 6 days for a total of 24 days. The system's effects on COD and NO3 were evaluated. - -N, TP, NH4 + -N removes the effect.

[0065] In Example 1, the enhanced biochemical coupling algae-bacteria fixed bed system for NH4 + -N, TP, COD, NO3 - -N removal efficiency and the effect of bio-rope algae fixed bed on NH4 in Comparative Example 1 + -N, TP, COD, NO3 - The removal effect of -N is shown below. Figure 1-4 As shown, NH4 +-N, TP, and COD are expressed as removal rates, while NO3... - The removal effect of -N is expressed as concentration. Figure 5 A schematic diagram of a device for enhancing the biochemical coupling of algae and bacteria in a fixed bed.

[0066] In the diagram, days 1-6 represent the first stage of system operation, days 7-12 represent the second stage, days 13-18 represent the third stage, and days 19-24 represent the fourth stage. The influent concentration for each stage is shown in Table 1 below.

[0067] Table 1. Influent concentration at each operating stage

[0068]

[0069] It can be seen that the addition of immobilized algal balls enhances the biochemical coupling of the algae-bacteria fixed bed system, thus improving the NH4+ effect. + -N, TP, COD, NO3 - The removal efficiency of nitrogen (N) was improved to varying degrees. The improved COD removal efficiency was mainly due to the increased number of microorganisms and the decreased algae-to-bacteria ratio in the bio-rope cells at the end of the reactor. This is because N and P pollutants in the water undergo stepwise degradation, resulting in a gradual decrease in their concentration within the device. The increased C / N ratio and the oxygen-rich environment promote rapid microbial reproduction, thus enhancing the COD degradation effect. The improved TN and TP removal rates were mainly due to the synergistic effect of the bio-rope and the gel balls. This is because the large-scale reproduction of microorganisms and the decrease in dissolved oxygen (DO) when the water flows through the bio-rope create anoxic conditions for denitrification; while the photosynthetic oxygen production by algal cells when the water flows through the microbial gel balls increases DO, driving nitrification. Simultaneously, phosphorus is removed through a dual pathway of EPS adsorption and phosphorus assimilation. The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0070] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims, and the specification can be used to interpret the content of the claims.

Claims

1. A wastewater treatment method for enhanced biochemical coupling algae-bacteria fixed bed, characterized in that... The following steps are involved: (1) Filling: Active fiber bio-rope is filled into the reactor as a carrier for algae-bacteria symbiotic biological bed, with a bio-rope filling rate of 20-25%. (2) Biofilm formation stage: Add algae and bacteria solution with a mass ratio of Chlorella and activated sludge of (0.5-1):1 to form a biofilm. Aerate for 10-12 hours per day to maintain the DO concentration of the water body at 3-4 mg / L. The biofilm formation is considered successful when a dense yellow-green biofilm forms on the surface of the activated fiber biological rope. (3) Adding microbial balls: Place the microbial-encapsulated microbial balls into the isolation net and alternate them with the bio-rope cells in the manner of microbial ball-bio-rope cell-microbial ball-bio-rope cell; (4) Operation: Control the hydraulic retention time to 24-48h; adopt an air-water ratio of (3-4):1 and aerate intermittently for 10-12h; place the device outdoors in a sunny place for operation.

2. The wastewater treatment method of enhanced biochemical coupling algae-bacteria fixed bed according to claim 1, characterized in that... The preparation of the rubber balls in step (3) includes the following steps: (3.1) Pretreatment and activation of zeolite: Select clinoptilolite with a particle size of 0.5-1.0 mm, then soak the clinoptilolite in 1-2 mol / L HCl solution for 2-4 hours. After soaking, rinse the clinoptilolite with deionized water until neutral and then dry it for later use. Prepare a NaHCO3 solution with a mass concentration of 60-200 g / L, add the pretreated clinoptilolite and stir at 80-95℃ for 1-3 h, drain and calcine at 300-500℃ for 2-4 h to obtain Na-type porous activated zeolite. (3.2) Synthesis of composite materials: MgCl2 and AlCl3·6H2O were dissolved in deionized water to prepare metal salt solutions with different molar ratios. The Na-type porous activated zeolite described in step (3.1) was added, and the pH was adjusted to 10-12 with NaOH and Na2CO3 solution. The mixture was then hydrothermally aged at 60-80℃ for 12-24 hours with continuous stirring. After filtration, the mixture was washed with deionized water until the pH was neutral and dried at 60-80℃ for 12-24 hours. Finally, the obtained material was calcined at 350-500℃ for 3-5 hours to obtain the MgAl-LDO@zeolite composite material. (3.3) Preparation of bacterial and algal suspension: Activated sludge and Chlorella were mixed in a certain proportion, centrifuged, and then resuspended in deionized water to form a bacterial-algae suspension with a mass concentration of 2-3 g / L. (3.4) Preparation of rubber balls: The bacterial and algal suspension from step (3.3) is mixed with a sodium alginate solution with a mass concentration of 20-40 g / L at a volume ratio of 1:2-2:

1. The MgAl-LDO@zeolite composite material from step (3.2) is added, and after stirring, it is injected into a CaCl2 solution with a mass concentration of 20-30 g / L for cross-linking to form wastewater treatment granules with a diameter of 3-5 mm encapsulating microorganisms.

3. The wastewater treatment method for enhanced biochemical coupling algae-bacteria fixed bed according to claim 2, characterized in that, The molar ratio of magnesium salt to aluminum salt in the metal salt solution is (1-3):1; the solid-liquid ratio of the Na-type porous activated zeolite to the metal salt solution is (1-2):10g / mL.

4. The wastewater treatment method for enhanced biochemical coupling algae-bacteria fixed bed according to claim 2, characterized in that, The dry weight mixing ratio of the activated sludge and Chlorella is (1-2):

1.

5. The wastewater treatment method for enhanced biochemical coupling algae-bacteria fixed bed according to claim 2, characterized in that, The amount of the MgAl-LDO@zeolite composite material added is (2-2.5) g / 50 ml.

6. The wastewater treatment method for an enhanced biochemical coupled algae-bacteria fixed bed according to claim 2, characterized in that, The activated sludge described in step (3.3) is screened twice before use to remove particulate impurities. The treated activated sludge is placed in an environment of 25-28℃ and acclimatized and cultured with wastewater for 12-15 days.

7. A wastewater treatment method for an enhanced biochemical coupled algae-bacteria fixed bed according to claim 6, characterized in that... The wastewater contains NH4 + -N concentration is 5-15 mg / L, NO3 - -N concentration is 15-25 mg / L, TP concentration is 3-5 mg / L, and COD concentration is 40-50 mg / L.

8. The wastewater treatment method of enhanced biochemical coupling algae-bacteria fixed bed according to claim 1, characterized in that... The Chlorella described in step (3) is inoculated into sterile BG11 medium and cultured for 6-8 days at a temperature of 25±1℃, a light intensity of 5000±500 lux, and a light / dark cycle of 12 / 12h.

9. A wastewater treatment method for an enhanced biochemical coupled algae-bacteria fixed bed according to claim 1, characterized in that... The dry weight mixing ratio of activated sludge and Chlorella in step (3) is (1-2):

1.

10. A system for implementing the wastewater treatment method of the enhanced biochemical coupling algae-bacteria fixed bed as described in claim 1, characterized in that... include: The device consists of an inlet pump, active fiber bio-ropes, immobilized gel balls, and baffles. The length-to-width ratio of the device is (3.75-4):1, and the length-to-height ratio is (1-1.25):

1. Three baffles are installed in the reactor to allow the wastewater to flow in the reactor in an up-and-down baffle manner, forming four cells with the same volume. The ratio of the height of the baffles to the height of the reactor is (1-1.25):

1. The bio-rope filling rate is 20-25%, and its length is consistent with the height of the reactor.

Images