A method for the synergistic application of algae and bacteria in the treatment of livestock and poultry breeding wastewater

Abstract

This application discloses a method for the synergistic application of algae and bacteria in the treatment of livestock and poultry wastewater, relating to the field of livestock and poultry wastewater treatment technology. The application method includes the following steps: wastewater pretreatment; bacterial strain compounding: Enterococcus hesperidinus, Rhodococcus roseus, Pantotheca cumulus, and Acetobacter cocoa are fermented individually, and then the single fermented bacterial strains are compounded. The mass ratio of the fermentation liquid of Enterococcus hesperidinus, Rhodococcus roseus, Pantotheca cumulus, and Acetobacter cocoa is (1-3):1:(1-3):(3-5) to obtain a compound bacterial agent; microalgae compounding: Chlorella ellipsoides and Scenedesmus are cultured individually at a light intensity of 2500-4000 lux for 5-10 days at a temperature of 25-28℃, and then the single cultured microalgae are compounded to obtain a compound microalgae agent. The technical solution provided in this application can effectively degrade various pollutants in livestock and poultry wastewater, with significant treatment effects.

Description

Technical Field

[0001] This application relates to the field of livestock and poultry wastewater treatment technology, and in particular to a method for the application of algae and bacteria synergy in the treatment of livestock and poultry breeding wastewater. Background Technology

[0002] Animal husbandry has made a huge contribution to ensuring the supply of meat, eggs and milk for people. However, with the expansion of the scale of animal husbandry production and the increase in intensification, the harm caused by the stench produced by livestock and poultry farms has become more and more serious and has attracted widespread attention.

[0003] Due to the large volume of wastewater and high risk of diffusion during livestock waste treatment, coupled with cost constraints, its treatment is a key focus of livestock waste management. Livestock wastewater treatment differs from other wastewater treatment in several ways: it has a low carbon-to-nitrogen ratio, high organic matter content, and a strong odor, particularly characteristic of livestock excrement. Therefore, simply using other wastewater treatment processes is insufficient to effectively address its pollutant problems. In particular, odorous substances spread rapidly, travel long distances, and have complex compositions, making removal extremely difficult. Furthermore, compared to the degradation processes for COD, BOD, and ammonia nitrogen, odorous substances have received relatively less attention, and treatment technologies are still immature. The lower acceptable cost of treating livestock manure compared to industrial and domestic wastewater further restricts the research and application of deodorization technologies. Therefore, exploring methods for treating odorous substances from livestock wastewater that require less investment, have lower operating costs, and are highly efficient has become a crucial aspect of solving livestock pollution.

[0004] Odor components in livestock and poultry manure are diverse, and removal mechanisms are complex. The removal of these compounds mainly falls into three categories: physical methods, chemical methods, and biotransformation methods. Physical methods, such as plasma methods and ozone oxidation, primarily utilize physical equipment to generate oxidants to degrade complex compounds. Physical methods offer good odor removal efficiency, but they are costly to operate and energy-intensive, increasing treatment expenses. Chemical methods mainly use acids to absorb ammonia or strong oxidants to break down odor molecules. However, while these methods treat odorous substances, the treatment of their residues can also generate more toxic and persistent pollutants. For example, the use of chlorine-containing oxidants can produce recalcitrant dichloroacetonitrile and induce the proliferation of drug-resistant bacteria in the environment. Microbial transformation is highly efficient, inexpensive, and environmentally friendly in the systemic remediation of indole pollution and is widely used in the treatment of environmental pollutants. However, current research on deodorizing microorganisms is mostly limited to the degradation and transformation of a single odorous substance, and there is a lack of research on the specific deodorization mechanism. The developed deodorizing microbial agents often only have a removal effect on specific odorous substances, and the removal efficiency varies, which cannot meet the high-efficiency and comprehensive deodorization needs of the livestock and poultry farming industry.

[0005] Microalgae-bacteria symbiotic coupling systems for wastewater treatment are currently a global research hotspot. Symbiotic systems formed by composite microbial agents and microalgae are more stable than single-bacteria or microalgae systems; however, many problems remain to be solved in their implementation. For example, different algae often exhibit significant differences in treatment results for different aquaculture wastewaters; how to select suitable microalgae? How to better achieve the formation and maintenance of the algae-bacteria symbiotic microenvironment? Further improvements to novel reactors suitable for algae-bacteria symbiosis, etc. Summary of the Invention

[0006] The purpose of this application is to provide a method for the synergistic application of algae and bacteria in the treatment of livestock and poultry breeding wastewater, so as to solve at least one of the above-mentioned technical problems.

[0007] To address the aforementioned technical problems, this application provides a method for the synergistic application of algae and bacteria in the treatment of livestock and poultry breeding wastewater, the method comprising the following steps:

[0008] S1. Wastewater pretreatment: The livestock and poultry wastewater is filtered, then diluted with water, and the diluted livestock and poultry wastewater is introduced into a primary treatment tank. The primary treatment tank is equipped with a stirring mechanism and multiple irradiation ports. Quartz glass is installed at each irradiation port, and an ultraviolet lamp is installed on one side of the irradiation port. The ultraviolet lamp is turned on to sterilize the wastewater in the primary treatment tank.

[0009] S2. Microbial strain compounding: Enterococcus haematobacterium, Rhodococcus roseus, Pantotheca cumulus, and Acetobacter cocoa bean were fermented individually, and then the single-strain fermented were compounded. The mass ratio of the fermentation broth of Enterococcus haematobacterium, Rhodococcus roseus, Pantotheca cumulus, and Acetobacter cocoa bean was (1-3):1:(1-3):(3-5) to obtain a compound microbial agent;

[0010] S3. Microalgae compounding: Chlorella ovalis and Scenedesmus were cultured separately under a light intensity of 2500-4000 lux for 5-10 days at a temperature of 25-28℃. Then, the single microalgae were compounded with a culture medium mass ratio of Chlorella ovalis and Scenedesmus of (1-3):(2-5) to obtain a compound microalgae agent.

[0011] S4. Transfer the water from the primary treatment tank to the secondary treatment tank. Add the compound bacterial agent and compound microalgae agent to the secondary treatment tank. The mass ratio of the compound bacterial agent and compound microalgae agent is (8-12):1. The total amount of compound bacterial agent and compound microalgae agent added accounts for 0.05%-0.3% of the mass of wastewater in the secondary treatment tank. Under a light intensity of 2500-4000 lux, the light intensity is 9-12 hours per day, and the treatment lasts for 5-8 days.

[0012] S5. After filtering the water in the secondary treatment tank, the water is introduced into the tertiary treatment tank. The tertiary treatment tank is filled with an attachment medium suitable for algae and bacteria to attach to. The water in the tertiary treatment tank is filtered and discharged after 5-8 days of treatment.

[0013] Preferably, the Latin name of the *Enterococcus hirae* is CGMCC1.100; the Latin name of the *Rhodococcus rhodochrous* is CGMCC1.15298; the Latin name of the *Pantoae agglomerans* is CGMCC1.12475; and the Latin name of the *Acetobacter fabarum* is CICC10883.

[0014] Preferably, the Latin name of the elliptical Chlorella is Chlorella ellipsoidea, and the accession number is FACHB-42; the Latin name of the Scenedesmus sp. is Scenedesmus sp., and the accession number is FACHB-1420.

[0015] Preferably, in step S2, the mass ratio of the fermentation broth of Enterococcus haematobacterium, Rhodococcus roseum, Pantotheca cumulus, and Acetobacter cocoa is 2:1:2:4.

[0016] Preferably, in step S3, the mass ratio of the culture medium of Chlorella ellipsoides and Scenedesmus is 2:3.

[0017] Preferably, in step S4, the mass ratio of the compound bacterial agent to the compound microalgae preparation is 10:1.

[0018] Preferably, the attachment comprises a block-shaped or spherical filler made of polyurethane material and having multiple identical channels.

[0019] Preferably, the secondary treatment tank includes a first barrel with a accommodating space. A light-emitting component is provided inside the first barrel. The light-emitting component includes a columnar main body connected to the bottom of the first barrel and a branched portion extending radially along the main body. The branched portion is arranged in multiple layers along the length direction of the main body, and each layer has a plurality of the branched portions. A power supply component is provided at the bottom of the first barrel and is electrically connected to the light-emitting component. A first water inlet is provided on the side wall near the upper end of the first barrel, a first water outlet is provided on the side wall near the lower end, and a first air outlet is provided at the top of the first barrel.

[0020] The three-stage treatment tank includes a second barrel with a accommodating space; the packing material is placed in the second barrel, a second water inlet is provided above the second barrel, a second water outlet is provided below the second barrel, and the first water outlet and the second water inlet are connected; a second air outlet is provided above the second barrel.

[0021] Preferably, the main body and the branched portion are, from the outside to the inside, an attachment layer, a diffused light layer and a light source layer; the light source layer is provided with a light-emitting element electrically connected to the power supply component, and the attachment layer is suitable for algae to attach to;

[0022] The adhesion layer is made of transparent polyurethane material.

[0023] Preferably, a branch is formed on the bifurcation portion extending in a direction away from the bifurcation portion, the branch portion including the adhesion layer and the light-scattering layer;

[0024] The diffuser layer is made of transparent epoxy resin, and several glass beads are embedded in the diffuser layer.

[0025] Compared with the prior art, the beneficial effects of this application are as follows:

[0026] (1) Preliminary filtration during wastewater pretreatment can effectively filter out most of the large particles and impurities, which facilitates further treatment of livestock and poultry wastewater. Furthermore, dilution with water can effectively avoid the problem of high turbidity in livestock and poultry wastewater, which makes it difficult for light to pass through. After dilution with water, the concentration of livestock and poultry wastewater is reduced to a certain extent, the clarity is improved, and light can pass through better. This is beneficial for the subsequent cultivation of microalgae and also beneficial for the effect of ultraviolet light during sterilization.

[0027] (2) A stirring mechanism is used in the wastewater pretreatment process, which makes the wastewater in the primary treatment tank more uniform in texture. Combined with the sterilization effect of the ultraviolet lamp, the sterilization effect can be better.

[0028] (3) Using ultraviolet lamps in conjunction with quartz glass for sterilization is less likely to cause secondary pollution compared to the traditional disinfection method of hypochlorous acid; at the same time, the ozone generated can further enhance the sterilization effect.

[0029] (4) The facultative anaerobic characteristics of the strains are cleverly utilized. Enterococcus helix and Pantotheca aggregata are selected, which are very suitable for application in the micro-aerobic conditions of aquaculture wastewater. This allows them to adapt to the micro-aerobic environment and ensure excellent pollutant treatment effect.

[0030] (5) The selection of bacterial strains and microalgae is strategic. Among them, the clustered bacteria can generate a certain charge, which can effectively promote the microalgae to achieve better adsorption. In this way, it is not necessary to cooperate with some power generation mechanism to promote the concentrated attachment of microalgae. Instead, the synergistic effect between organisms can promote a more stable symbiosis between algae and bacteria, which can effectively reduce the loss rate of algae-bacterial symbiosis.

[0031] (6) Selecting appropriate bacterial strain ratios, i.e. microalgae ratio compound bacterial agents and microalgae preparations, and selecting appropriate algae-bacteria ratios can ultimately promote algae-bacteria balance in wastewater treatment and achieve a more comprehensive and thorough purification effect.

[0032] (7) Further improvements are made to the corresponding treatment tanks, including the installation of light-emitting components in the secondary treatment tanks. The light emission from the inside can make the light source more uniform. Uniform light emission is conducive to promoting the growth of algae, improving their cultivation efficiency, thereby alleviating the problem of imbalance between algae and bacteria, effectively promoting algae growth, increasing the dissolved oxygen rate of sewage in the tank, and thus promoting the aerobic decomposition bacteria to fully decompose pollutants.

[0033] (8) Further structures are set in the treatment tank for algae-bacterial symbionts to attach, providing good attachment sites for algae-bacterial symbionts, reducing the loss rate, improving the purification effect and the number of recycling times. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the overall structure of one embodiment of this application;

[0036] Figure 2 This is a partial structural schematic diagram of one embodiment of this application;

[0037] Figure 3 This is a partial structural schematic diagram of one embodiment of this application;

[0038] Figure 4 This is a schematic diagram showing the connection of the processing tanks at each stage according to one embodiment of this application;

[0039] Figure 5 These are the test results diagrams for each embodiment and comparative example;

[0040] Wherein: 11. First tank body; 12. First air outlet; 13. First water inlet; 14. First water outlet; 15. Power supply component; 20. Light-emitting component; 21. Main body; 22. Forked part; 23. Branch part; 24. Adhesive layer; 25. Diffusing layer; 26. Light-emitting element; 31. Second tank body; 32. Second air outlet; 33. Second water inlet; 34. Second water outlet; 35. Block packing; 40. Second filter screen; 51. Quartz glass; 52. Ultraviolet lamp; 53. First filter screen; 62. Secondary treatment tank; 63. Tertiary treatment tank. Detailed Implementation

[0041] The technical solution of the present invention will be clearly and completely described below with reference to embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] This application provides a method for the application of algae-bacteria synergy in the treatment of livestock and poultry breeding wastewater, which includes the following steps:

[0043] S1. Wastewater Pretreatment: The livestock and poultry wastewater is filtered, then diluted with water, and the diluted wastewater is introduced into a primary treatment tank. The primary treatment tank is equipped with a stirring mechanism and multiple irradiation ports. Quartz glass 51 is installed at each irradiation port, and an ultraviolet lamp is located on one side of each port. The ultraviolet lamp is turned on to sterilize the wastewater in the primary treatment tank. This initial filtration of the livestock and poultry wastewater effectively removes most large particles and impurities, facilitating further treatment. After filtration, the wastewater is further diluted with clean water to improve water transparency, facilitating subsequent light irradiation. The treatment includes ultraviolet sterilization and light treatment of microalgae. In addition, removing most impurities and large particles improves the clarity of the wastewater, thus increasing the light transmittance of the subsequent water and facilitating the cultivation of microalgae. This solution further incorporates ultraviolet lamps and quartz glass 51. Ultraviolet sterilization removes complex bacterial communities in the wastewater, providing a more stable growth environment for the subsequently introduced algae-bacterial symbiotic organisms and improving growth efficiency. Furthermore, this solution includes a stirring mechanism in the treatment tank, which makes the wastewater in the primary treatment tank more uniform, thus achieving uniform sterilization.

[0044] Understandably, a first filter screen is installed at the inlet of the primary treatment tank. Here, the first filter screen does not refer to a single filter screen, but is a shorthand term. In practical applications, it can be a filter system formed by multiple filter screens working together.

[0045] S2. Microbial strain compounding: Enterococcus haematobacterium, Rhodococcus roseum, Pantotheca acuminata, and Acetobacter cocoa are fermented individually, and then the single-strain fermented products are compounded. The mass ratio of the fermentation broth of Enterococcus haematobacterium, Rhodococcus roseum, Pantotheca acuminata, and Acetobacter cocoa is (1-3):1:(1-3):(3-5) to obtain a compound microbial agent. This scheme selected four strains with excellent compound treatment effects through multiple compounding experiments, and further experiments were conducted on their respective compounding ratios to finally obtain a suitable compounding ratio. Among them, taking Pantotheca acuminata as an example, the Pantotheca acuminata selected in this scheme has facultative anaerobic characteristics and can decompose corresponding pollutants in both aerobic and anaerobic environments. It showed excellent pollutant decomposition ability in the experiment. In addition, it can use acetic acid as the only carbon source and generate electricity during the decomposition process. Some of the products generated after its decomposition The electric charge effectively promotes better adsorption of microalgae, eliminating the need for electrostatic mechanisms to facilitate concentrated attachment. Instead, the synergistic effect between organisms fosters a more stable symbiosis between algae and bacteria. Furthermore, this solution incorporates *Acetobacter chrysogenum*, which has not been previously reported in livestock wastewater treatment. Experiments show that its synergistic effect with *Pantothecinus* effectively enhances pollutant treatment depth and purification efficiency. *Enterococcus helixeri*, a facultative anaerobic bacterium, effectively decomposes indole under both aerobic and anaerobic conditions. Experimental analysis reveals its superior decomposition effect under anaerobic conditions, making it highly suitable for application in the microaerobic environment of livestock wastewater. *Rhodococcus roseum*, rarely used in wastewater treatment, shows good synergistic effects with the aforementioned three bacteria through synergistic compounding experiments; therefore, this bacterium is added for further compounding.

[0046] S3. Microalgae compounding: *Chlorella ellipsoides* and *Scenedesmus* were cultured individually at a light intensity of 2500-4000 lux for 5-10 days at a temperature of 25-28℃. The resulting microalgae were then compounded at a culture medium mass ratio of (1-3):(2-5) to obtain a compound microalgae agent. This scheme, through multiple compounding experiments, selected *Chlorella ellipsoides* and *Scenedesmus*, which demonstrated excellent growth efficiency and good removal of N and P in livestock and poultry wastewater treatment experiments. Further experiments yielded the optimal ratio between the two. Cultivation at 2500-4000 lux was chosen because lower light intensities resulted in slower growth and reduced cultivation efficiency. Higher light intensities did not significantly improve cultivation efficiency but increased electricity costs, leading to higher treatment costs. Therefore, this light intensity range was ultimately selected.

[0047] S4. The water from the primary treatment tank is transferred to the secondary treatment tank. Compound bacterial agents and compound microalgae agents are added to the secondary treatment tank at a mass ratio of (8-12):1. The total dosage of the compound bacterial agents and compound microalgae agents accounts for 0.05%-0.3% of the wastewater mass in the secondary treatment tank. The treatment is carried out under a light intensity of 2500-4000 lux for 9-12 hours per day for 5-8 days. After sterilization, the livestock wastewater from the primary treatment tank is transferred to the secondary treatment tank. At this point, most of the complex bacterial communities in the wastewater have been eliminated, providing a better growth environment for the subsequent compound bacterial agents and compound microalgae agents, allowing them to quickly grow into dominant species and effectively improve growth efficiency. Cultivation is carried out at 2500-4000 lux. When the light intensity is below 500 lux, the growth efficiency of microalgae is slow, affecting the cultivation efficiency. When the light intensity is too high, the cultivation efficiency is not significantly improved, but the electricity cost increases, resulting in a higher treatment cost. Therefore, the light intensity range was ultimately selected. Through multiple experiments, the algae-to-bacteria ratio of (8-12):1 was selected. At this ratio, algae and bacteria can achieve balanced growth, and the removal effect of pollutants is significantly improved. When the proportion of bacteria is too high and the proportion of microalgae is too low, the dissolved oxygen in the wastewater is significantly reduced, causing most bacteria to undergo decomposition reactions under anaerobic conditions, resulting in incomplete and incomplete decomposition of pollutants. When the proportion of microalgae is too high, the algae-to-bacteria ratio is unbalanced, and both microalgae and bacteria experience increased loss rates, and the problem of incomplete and incomplete decomposition of pollutants also occurs.

[0048] S5. After filtering the water in the secondary treatment tank, it is introduced into the tertiary treatment tank. The tertiary treatment tank is filled with attachment bodies suitable for algae and bacteria to attach to. The water in the tertiary treatment tank is filtered and discharged after 5-8 days of treatment. The tertiary treatment tank is filled with a large number of attachment bodies, which can facilitate the attachment of algae and bacteria symbionts. In the tertiary treatment tank, the algae and bacteria symbionts have a large number of attachment sites, which can further and fully purify the water.

[0049] In one embodiment, the Latin name of the *Enterococcus hirae* is CGMCC1.100; the Latin name of the *Rhodococcus rhodochrous* is CGMCC1.15298; the Latin name of the *Pantoae agglomerans* is CGMCC1.12475; and the Latin name of the *Acetobacter fabarum* is CICC10883.

[0050] In one embodiment, the Latin name of the elliptical Chlorella is Chlorella ellipsoidea, and its accession number is FACHB-42; the Latin name of the Scenedesmus sp. is Scenedesmus sp., and its accession number is FACHB-1420.

[0051] It should be noted that Enterococcus haematobacterium, Rhodococcus roseus, and Pantotheca cumulus were all purchased from the China General Microbiological Culture Collection Center; Acetobacter cocoa bean was purchased from the China Industrial Microbiological Culture Collection Center; and Chlorella ellipsoides and Scenedesmus were purchased from the Freshwater Algae Culture Bank of the Chinese Academy of Sciences.

[0052] Furthermore, *Chlorella ellipsoides* and *Scenedesmus* were cultured individually using standard BG11 medium.

[0053] Furthermore, *Enterococcus haematobacterium*, *Rhodococcus roseum*, *Pantotheca cumulus*, and *Acetobacter cocoa* were cultured individually using standard LB medium until the concentration of each single strain reached 10. 8 -10 9 cfu / ml.

[0054] In one embodiment, in step S2, the mass ratio of the fermentation broth of Enterococcus haematobacterium, Rhodococcus roseum, Pantothecinus clumps, and Acetobacter cocoa is 2:1:2:4.

[0055] In one embodiment, in step S3, the mass ratio of the culture medium of Chlorella ellipsoides and Scenedesmus is 2:3.

[0056] In one embodiment, in step S4, the mass ratio of the compound bacterial agent to the compound microalgae preparation is 10:1.

[0057] In one embodiment, the attachment body includes a block-shaped or spherical filler made of polyurethane material and having multiple identical channels. The polyurethane material provides good attachment sites for algae and bacteria, and its strong corrosion resistance ensures a certain service life. In addition, the filler in this solution has multiple identical channels, which can effectively increase the surface area per unit volume, thereby providing more attachment sites and reducing the loss rate of the algae-bacterial symbiosis.

[0058] In one embodiment, see Figure 1-4The secondary treatment tank 62 includes a first barrel 11 forming a accommodating space. A light-emitting component 20 is provided inside the first barrel 11. The light-emitting component 20 includes a main body 21 connected to the bottom of the first barrel 11 and in the shape of a column, and a branched part 22 extending radially along the main body 21. The branched part 22 is arranged in multiple layers along the length direction of the main body 21, and each layer is provided with a plurality of branched parts 22. A power supply component 15 is provided at the bottom outside the first barrel 11. The power supply component 15 is electrically connected to the light-emitting component 20. A first water inlet 13 is provided on the side wall near the upper end of the first barrel 11, a first water outlet 14 is provided on the side wall near the lower end, and a first air outlet 12 is provided at the top of the first barrel 11.

[0059] The tertiary treatment tank 63 includes a second tank 31 forming a accommodating space; packing material is placed inside the second tank 31; a second inlet 33 is provided above the second tank 31, and a second outlet 34 is provided below the second tank 31; the first outlet 14 and the second inlet 33 are connected; a second vent 32 is provided above the second tank 31; wastewater passes sequentially through the first tank 11 and the second tank 31; in the first tank 11, a light-emitting component 20 is used to achieve algae-bacteria symbiosis and a relatively good balance, and after preliminary treatment, various pollution indicators of the wastewater are also improved to a certain extent. After entering the second tank 31, further treatment is not required. Instead of using the added light-emitting component 20, a large number of spherical or block-shaped packing materials 35 provide numerous attachment sites for algae and bacteria, preserving the algae-bacteria symbiosis as much as possible and preparing for subsequent recycling. This effectively ensures a balance between algae and bacteria, while improving wastewater treatment efficiency and the number of subsequent recycling cycles. In addition, this solution uses internal light emission, which makes the light source more uniform. Uniform light emission promotes algae growth, improves its cultivation efficiency, and alleviates the problem of algae-bacteria imbalance. It effectively promotes algae growth, increases the dissolved oxygen rate of wastewater in the tank, and thus promotes the aerobic decomposition bacteria to fully decompose pollutants.

[0060] In one embodiment, the main body 21 and the branched part 22 are, from the outside to the inside, an attachment layer 24, a diffused light layer 25 and a light source layer; the light source layer is provided with a light-emitting element 26 electrically connected to the power supply assembly 15, and the attachment layer 24 is suitable for algae to attach to; the attachment layer 24 is made of transparent polyurethane material.

[0061] It should be noted that the connection method of the power supply component 15 to the built-in light-emitting body is a relatively mature technology in the prior art, and the related waterproofing measures are also easily obtained by those skilled in the art from the prior art. Therefore, this solution will not elaborate further on the specific structure of this part.

[0062] Specifically, the main body 21 and the branched part 22 are, from the outside to the inside, an adhesion layer 24, a light diffusion layer 25 and a light source layer, respectively;

[0063] Furthermore, the light source layer is provided with a light-emitting element 26 electrically connected to the power supply component 15, and the attachment layer 24 is suitable for algae to attach to.

[0064] In the above scheme, the attachment layer 24 can provide attachment sites for algae and bacteria, thereby improving the adhesion strength of the algae-bacterial symbiosis, reducing its loss rate, and promoting recycling; while the light emitted by the light source layer can improve the uniformity of light illumination through the scattering effect of the scattering layer 25, which is conducive to improving the growth efficiency of algae and alleviating the problem of algae-bacterial imbalance.

[0065] Understandably, in some implementations, the wastewater treatment process may not only use internal light sources, but also install corresponding light sources on the outside of the first tank 11, which can be adjusted according to actual needs.

[0066] In one embodiment, a branch portion 23 is formed on the bifurcation portion 22 extending in a direction away from the bifurcation portion 22, and the branch portion 23 includes an adhesion layer 24 and a light-diffusing layer 25.

[0067] Furthermore, branch sections 23 are further provided on the bifurcation section 22, which can further increase the attachment points of algae and bacteria. At the same time, it does not need to set a light source layer, but can achieve light scattering through interconnected diffuser layers 25. The diffuser layer 25 is made of transparent epoxy resin, and several glass beads are embedded in the diffuser layer 25. The epoxy resin has good waterproof performance, and the glass beads embedded in it can promote light scattering.

[0068] For details, please see Figure 1 It also includes a first filter assembly, which is disposed at the connection to the first water inlet 13;

[0069] Specifically, the first filter assembly includes a first housing, with a third inlet and a third outlet at each end of the first housing, and a plurality of first filter screens 53 arranged in the first housing along the direction of water flow.

[0070] In the above scheme, when the sewage enters the first tank 11, it first passes through the filtration of the first filter component to remove some large particulate impurities. This not only effectively improves the quality of subsequent sewage treatment, but also avoids excessive impurities affecting the light diffusion inside the first tank 11.

[0071] Specifically, a second filter screen 40 is provided at the second outlet 34;

[0072] In the above scheme, by further installing a second filter screen 40 at the second outlet 34, the water discharged from the second treatment device can be filtered again, further improving the purification effect.

[0073] The primary treatment tank, secondary treatment tank 62, and tertiary treatment tank 63 have similar structures, as detailed in [reference needed]. Figure 1 It has an inlet, outlet and vent similar to the first tank 11 and the second tank 31, so the structure of the primary treatment tank will not be described in detail.

[0074] The following are some specific embodiments. It should be noted that the following embodiments do not exhaust all possible situations, and the materials used in the following embodiments are commercially available unless otherwise specified.

[0075] Example 1

[0076] This embodiment provides a method for the synergistic application of algae and bacteria in the treatment of livestock and poultry breeding wastewater, which includes the following steps:

[0077] S1. Wastewater pretreatment: The livestock and poultry wastewater is filtered, then diluted with water, and the diluted livestock and poultry wastewater is introduced into a primary treatment tank. The primary treatment tank is equipped with a stirring mechanism and multiple irradiation ports. Quartz glass 51 is installed at each irradiation port, and an ultraviolet lamp is installed on one side of the irradiation port. The ultraviolet lamp is turned on to sterilize the wastewater in the primary treatment tank.

[0078] S2. Microbial strain compounding: Enterococcus haematobacterium, Rhodococcus roseus, Pantotheca cumulus, and Acetobacter cocoa bean were fermented separately, and then the single fermented strains were compounded. The mass ratio of the fermentation liquid of Enterococcus haematobacterium, Rhodococcus roseus, Pantotheca cumulus, and Acetobacter cocoa bean was 2:1:2:4 to obtain a compound microbial agent.

[0079] S3. Microalgae compounding: Chlorella ovalis and Scenedesmus were cultured separately under a light intensity of 3500 lux for 8 days at a temperature of 25-28℃. Then, the single microalgae were compounded with a culture medium mass ratio of Chlorella ovalis to Scenedesmus of 2:3 to obtain a compound microalgae agent.

[0080] S4. The water in the primary treatment tank is transferred to the secondary treatment tank. The compound bacterial agent and compound microalgae agent are added to the secondary treatment tank. The mass ratio of the compound bacterial agent and compound microalgae agent is 10:1. The total amount of compound bacterial agent and compound microalgae agent added accounts for 0.15% of the mass of wastewater in the secondary treatment tank. The treatment is carried out under a light intensity of 3500 lux for 12 hours per day for 7 days.

[0081] S5. After filtering the water in the secondary treatment tank, the water is introduced into the tertiary treatment tank. The tertiary treatment tank is filled with an attachment medium suitable for algae and bacteria to attach to. The water in the tertiary treatment tank is filtered and discharged after 7 days of treatment.

[0082] Example 2

[0083] This embodiment provides a method for the application of algae-bacteria synergy in the treatment of livestock and poultry breeding wastewater. The specific application method can be referred to in Embodiment 1, wherein the fermentation broth of Enterococcus haematobacterium, Rhodococcus roseus, Pantothecinus clumps, and Acetobacter cocoa bean has a different mass ratio, specifically 1:1:3:5.

[0084] Example 3

[0085] This embodiment provides a method for the synergistic application of algae and bacteria in the treatment of livestock and poultry breeding wastewater. The specific application method can be referred to in Embodiment 1, wherein the mass ratio of fermentation broth of Enterococcus haematobacterium, Rhodococcus roseus, Pantothecinus clumps, and Acetobacter cocoa bean is different, specifically 3:1:1:3.

[0086] Example 4

[0087] This embodiment provides a method for the synergistic application of algae and bacteria in the treatment of livestock and poultry breeding wastewater. The specific application method can be referred to in Embodiment 1, wherein the mass ratio of the culture medium of Chlorella ellipsoides and Scenedesmus is different, specifically 1:5.

[0088] Example 5

[0089] This embodiment provides a method for the synergistic application of algae and bacteria in the treatment of livestock and poultry breeding wastewater. The specific application method can be referred to in Embodiment 1, wherein the mass ratio of the culture medium of Chlorella ellipsoides and Scenedesmus is different, specifically 3:2.

[0090] Example 6

[0091] This embodiment provides a method for the application of algae-bacteria synergy in the treatment of livestock and poultry breeding wastewater. The specific application method can be referred to in Embodiment 1, wherein the mass ratio of compound bacterial agent and compound microalgae preparation is different, specifically 8:1.

[0092] Example 7

[0093] This embodiment provides a method for the application of algae-bacteria synergy in the treatment of livestock and poultry breeding wastewater. The specific application method can be referred to in Embodiment 1, wherein the mass ratio of compound bacterial agent and compound microalgae preparation is different, specifically 12:1.

[0094] Comparative Example 1

[0095] The treatment process of Comparative Example 1 was basically the same as that of Example 1, except that no clump-forming pantothenia was added to Comparative Example 1.

[0096] Comparative Example 2

[0097] The processing procedure for Comparative Example 2 was basically the same as that for Example 1, except that Comparative Example 2 did not add Acetobacter cocoa bean.

[0098] Comparative Example 3

[0099] The treatment process of Comparative Example 3 was basically the same as that of Example 1, except that Enterococcus heisenbergi was not added to Comparative Example 3.

[0100] Comparative Example 4

[0101] The treatment process of Comparative Example 4 was basically the same as that of Example 1, wherein the mass ratio of the compound bacterial agent and the compound microalgae preparation in Comparative Example 4 was 5:1.

[0102] Comparative Example 5

[0103] The processing procedure of Comparative Example 5 is basically the same as that of Example 1. In Comparative Example 5, no light-emitting component is installed in the secondary processing tank, but a corresponding light source is installed externally for irradiation.

[0104] Comparative Example 6

[0105] The processing procedure of Comparative Example 6 is basically the same as that of Example 1. In Comparative Example 6, no adhering body is placed in the three-stage treatment tank.

[0106] Comparative Example 7

[0107] The processing procedure of Comparative Example 7 is basically the same as that of Example 1. In Comparative Example 7, the ultraviolet lamp is not turned on.

[0108] Livestock and poultry breeding wastewater was treated according to the application methods in Examples 1-7 and Comparative Examples 1-7. The concentrations of pollutants in the biogas slurry before and after treatment were measured, and the removal rates of each pollutant were calculated. Specific results can be found in [reference needed]. Figure 5 .

[0109] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0110] The above description is merely a preferred embodiment of this application and is not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application shall fall within the scope of the technical solution of this application.

Claims

1. A method for the synergistic application of algae and bacteria in the treatment of livestock and poultry breeding wastewater, characterized in that: The application method includes the following steps: S1. Wastewater pretreatment: The livestock and poultry wastewater is filtered, then diluted with water, and the diluted livestock and poultry wastewater is introduced into a primary treatment tank. The primary treatment tank is equipped with a stirring mechanism and multiple irradiation ports. Quartz glass is installed at each irradiation port, and an ultraviolet lamp is installed on one side of the irradiation port. The ultraviolet lamp is turned on to sterilize the wastewater in the primary treatment tank. S2. Microbial strain compounding: Enterococcus haematobacterium, Rhodococcus roseus, Pantotheca cumulus, and Acetobacter cocoa bean were fermented individually, and then the single-strains after single fermentation were compounded. The mass ratio of the fermentation broth of Enterococcus haematobacterium, Rhodococcus roseus, Pantotheca cumulus, and Acetobacter cocoa bean was (1-3):1:(1-3):(3-5) to obtain a compound microbial agent; S3. Microalgae compounding: Chlorella ovalis and Scenedesmus were cultured separately under a light intensity of 2500-4000 lux for 5-10 days at a temperature of 25-28℃. Then, the single microalgae were compounded with a culture medium mass ratio of Chlorella ovalis and Scenedesmus of (1-3):(2-5) to obtain a compound microalgae agent. S4. Transfer the water from the primary treatment tank to the secondary treatment tank. Add the compound bacterial agent and compound microalgae agent to the secondary treatment tank. The mass ratio of the compound bacterial agent and compound microalgae agent is (8-12):

1. The total amount of compound bacterial agent and compound microalgae agent added accounts for 0.05%-0.3% of the mass of wastewater in the secondary treatment tank. Under a light intensity of 2500-4000 lux, the light intensity is 9-12 hours per day, and the treatment lasts for 5-8 days. S5. After filtering the water in the secondary treatment tank, the water is introduced into the tertiary treatment tank. The tertiary treatment tank is filled with an attachment medium suitable for algae and bacteria to attach to. The water in the tertiary treatment tank is filtered and discharged after 5-8 days of treatment.

2. The application method according to claim 1, characterized in that: The Latin name of the Enterococcus haematobacterium is Enterococcus hirae The accession number is CGMCC1.100; the Latin name of the *Rhodococcus roseum* is... Rhodococcus rhodochrous The accession number is CGMCC1.15298; the Latin name of the *Panthera solani* clumps is... Pantoae agglomerans The accession number is CGMCC1.12475; the Latin name of the Acetobacter cocoa bean is... Acetobacter fabarum The accession number is CICC10883.

3. The application method according to claim 1, characterized in that: The Latin name of the oval-shaped Chlorella is Chlorella ellipsoidea The accession number is FACHB-42; the Latin name of the described Scenedesmus is Scenedesmus sp. The accession number is FACHB-1420.

4. The application method according to claim 1, characterized in that: In step S2, the mass ratio of the fermentation broth of Enterococcus haematobacterium, Rhodococcus roseum, Pantotheca cumulus, and Acetobacter cocoa is 2:1:2:

4.

5. The application method according to claim 1, characterized in that: In step S3, the mass ratio of the culture medium for Chlorella vulgaris and Scenedesmus is 2:

3.

6. The application method according to claim 1, characterized in that: In step S4, the mass ratio of the compound bacterial agent to the compound microalgae preparation is 10:

1.

7. The application method according to claim 1, characterized in that: The attachment includes a block or spherical filler made of polyurethane material and having multiple identical channels.

8. The application method according to claim 7, characterized in that: The secondary treatment tank includes a first barrel with a accommodating space. A light-emitting component is provided inside the first barrel. The light-emitting component includes a columnar main body connected to the bottom of the first barrel and a branched portion extending radially along the main body. The branched portion is arranged in multiple layers along the length direction of the main body, and each layer has a plurality of the branched portions. A power supply component is provided at the bottom of the first barrel and is electrically connected to the light-emitting component. A first water inlet is provided on the side wall near the upper end of the first barrel, a first water outlet is provided on the side wall near the lower end, and a first air outlet is provided at the top of the first barrel. The three-stage treatment tank includes a second barrel with a accommodating space; the packing material is placed in the second barrel, a second water inlet is provided above the second barrel, a second water outlet is provided below the second barrel, and the first water outlet and the second water inlet are connected; a second air outlet is provided above the second barrel.

9. The application method according to claim 8, characterized in that: The main body and the branched part are, from the outside to the inside, an attachment layer, a diffused light layer and a light source layer; the light source layer is provided with a light-emitting element electrically connected to the power supply component, and the attachment layer is suitable for algae to attach to; The adhesion layer is made of transparent polyurethane material.

10. The application method according to claim 9, characterized in that: A branch portion is formed on the bifurcation portion extending in a direction away from the bifurcation portion, and the branch portion includes the adhesion layer and the light-scattering layer; The diffuser layer is made of transparent epoxy resin, and several glass beads are embedded in the diffuser layer.

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