Wastewater treating agent and application thereof in livestock breeding wastewater treatment

Abstract

The invention discloses a wastewater treatment agent and application thereof in livestock breeding wastewater treatment, and belongs to the technical field of sewage treatment. The wastewater treatment agent comprises a component A and a component B, the component A is a Zn-Fe-Al ternary metal oxide / biochar composite material, the component B is a complex microbial inoculant composed of Acinetobacter johnsonii CGMCC 1.5310, Pseudomonas pinnatifida CGMCC 1.12668 and Burkholderia bidirectionally CGMCC 1.10511, and the mass ratio of the component A to the component B is 2: 1. The treatment agent can efficiently remove various pollutants such as COD, ammonia nitrogen, total phosphorus and heavy metal ions in livestock breeding wastewater through the synergistic effect of physical adsorption, photocatalytic oxidation and biodegradation, the removal rate of all the pollutants can reach 94% or above, nitrate accumulation and pathogenic bacteria reproduction can be effectively controlled, and secondary pollution is avoided. According to the invention, resource utilization of pig manure waste is realized, the treatment process is green and economical, and an efficient solution is provided for up-to-standard discharge and resource utilization of livestock breeding wastewater.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, specifically relating to a wastewater treatment agent and its application in the treatment of livestock breeding wastewater. Background Technology

[0002] my country's livestock industry has developed rapidly, with significant increases in both the output and average yield of livestock and poultry products. The proportion of livestock industry value in my country's total agricultural output has also increased considerably. Livestock and poultry farming has gradually evolved from traditional small-scale individual farming to intensive large-scale farming, and farming areas have gradually shifted from rural areas to urban suburbs. While intensive large-scale farming has brought us abundant livestock and poultry products, the resulting environmental pollution problems cannot be ignored.

[0003] Livestock and poultry breeding wastewater is a type of high-concentration organic wastewater containing a variety of pollutants, and has become one of the main causes of agricultural non-point source pollution in my country. Livestock manure wastewater mainly includes animal excrement and flushing water, containing large amounts of organic pollutants, pathogens, various heavy metal ions from animal feed additives, and pollutants such as ammonia nitrogen and phosphorus. The organic pollutant indicators COD and ammonia nitrogen (NH3-N) are hundreds of times higher than those in domestic sewage, making treatment extremely difficult and achieving discharge standards challenging.

[0004] Currently, wastewater treatment methods for aquaculture can be categorized into three types based on their treatment principles: physical methods, chemical methods, and biological methods. Physical methods primarily remove suspended solids and harmful gases from water through mechanical and physical means. Common methods include sedimentation, filtration, foam separation, reverse osmosis, and adsorption. However, these methods have limited effectiveness in treating high-concentration organic wastewater, making it difficult to meet discharge standards. Chemical methods mainly include oxidation treatment, flocculant neutralization and coagulation, and electrochemical methods. While these can remove pollutants from wastewater to some extent, they may cause secondary pollution. For example, harmful byproducts may be generated during oxidation, and the use of flocculants may increase the chemical oxygen demand (COD) of the wastewater. Furthermore, the treatment cost is relatively high. Biological methods, such as biofilters, are effective at removing ammonia nitrogen and organic matter, but they increase nitrate levels in the water. Excessive nitrate accumulation can affect biological growth, and wastewater with high nitrogen content discharged into the environment can cause secondary pollution, such as eutrophication. Therefore, existing methods for treating livestock wastewater have certain limitations and cannot simultaneously meet the requirements of efficiently removing multiple pollutants, avoiding secondary pollution, and reducing treatment costs. Thus, it is necessary to develop a more efficient, environmentally friendly, and economical wastewater treatment agent and method to effectively solve the problem of livestock wastewater treatment and achieve the standard discharge and resource utilization of livestock wastewater. Summary of the Invention

[0005] The purpose of this invention is to provide a wastewater treatment agent that, through the rational design of its composition and preparation method, can fully exert multiple functions such as physical adsorption, chemical catalysis, and biodegradation, effectively removing various pollutants such as organic pollutants, ammonia nitrogen, and heavy metal ions from livestock breeding wastewater. At the same time, it avoids the generation of new harmful substances during the treatment process, reduces treatment costs, improves wastewater treatment efficiency and quality, and provides strong support for the sustainable development of the livestock breeding industry.

[0006] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows: A wastewater treatment agent comprises component A and component B. Component A is a Zn-Fe-Al ternary metal oxide / biochar composite material, and component B is a composite microbial agent comprising Acinetobacter johnsonii, Pseudomonas sonicans, and Burkholderia difficile. The Acinetobacter johnsonii strain is numbered CGMCC 1.5310; the Pseudomonas sonicans strain is numbered CGMCC 1.12668; and the Burkholderia difficile strain is numbered CGMCC 1.10511.

[0007] Preferably, the mass ratio of component A to component B is 2:1.

[0008] Preferably, the Zn-Fe-Al ternary metal oxide / biochar composite material is prepared by the following method: (1) Take the dried pig manure in a tube furnace, heat it to 600℃ under N2 atmosphere at a heating rate of 10℃ / min and keep it at that temperature for 2 hours. Cool it to room temperature and grind it. Pass it through a 200-mesh sieve to obtain biochar. (2) Dissolve 0.75g of ferrous sulfate heptahydrate and 14.5g of zinc nitrate hexahydrate in 50mL of methanol, add 2g of biochar, stir magnetically for 2h, then add 1.65g of 2-methylimidazole, continue stirring for 4h, centrifuge the mixture after the reaction is complete, wash the precipitate with deionized water several times and dry it, then transfer it into a tube furnace and calcine it at 400℃ for 2h under an inert atmosphere to obtain modified biochar; (3) The obtained modified biochar was added to a silane coupling agent KH550 ethanol solution with a mass fraction of 1-3%, and stirred at 45-50℃ for 2h. After filtration, it was dried to obtain pretreated modified biochar. (4) The pretreated modified biochar was dispersed in a Zn(NO3)2-FeCl3-AlCl3 mixed solution, and NaOH solution was added dropwise to adjust the pH to 10.0. Then, disodium EDTA was added and stirred at room temperature until the mixture was homogeneous. The mixture was allowed to stand at room temperature for 24 hours to precipitate. Then, it was centrifuged and the precipitate was washed with anhydrous ethanol until neutral. The precipitate was then dried in a drying oven and calcined in air at 500°C for 3 hours to obtain the Zn-Fe-Al ternary metal oxide / biochar composite material.

[0009] Preferably, the ethanol solution in step (3) is composed of anhydrous ethanol and water in a volume ratio of 9:1 and has a pH of 4.5.

[0010] Preferably, in step (4), the solid-liquid ratio of the pretreated modified biochar to the Zn(NO3)2-FeCl3-AlCl3 mixed solution is 1g:30mL; and the concentration of the NaOH solution is 1mol / L.

[0011] Preferably, the Zn / Fe / Al molar ratio in the Zn(NO3)2-FeCl3-AlCl3 mixed solution is 2:1:0.2-0.3; and the molar ratio of disodium EDTA to Zn(NO3)2 is 0.8-1:1.

[0012] Preferably, the compound microbial agent is prepared by the following method: Acinetobacter johnsonii, Pseudomonas sinenegatus, and Burkholderia bifidum are activated in PDA solid medium, and then single colonies are picked and inoculated into test tubes of LB liquid medium. The culture is carried out at 30°C and 200 r / min until OD600≈2.0. The seed liquid is inoculated into 200 mL of fermentation liquid medium at a volume of 10%, and fermented at 30°C and 200 r / min for 72 h. The fermentation is stopped to obtain three fermentation broths. Then, they are mixed in a volume ratio of 1:1:1 to obtain a compound microbial liquid. The compound microbial agent is obtained by vacuum freeze-drying.

[0013] Preferably, the fermentation liquid culture medium has the following composition: glucose 20 g / L, peptone 10 g / L, yeast extract 5 g / L, beef extract 3 g / L, sodium chloride 5.0 g / L, potassium dihydrogen phosphate 1 g / L, dipotassium hydrogen phosphate 2 g / L, magnesium sulfate 0.2 g / L, pH 7.0 ± 0.2.

[0014] Preferably, in use, the wastewater after preliminary filtration enters the aerated photocatalytic reactor, A component is added first, and after continuous aeration and treatment with 380-780nm LED light for 8-12 hours, B component is added to the effluent, and after incubation at 28-30℃ for 2-3 days, solid-liquid separation is achieved.

[0015] This invention also provides an application of the above-mentioned wastewater treatment agent in the treatment of livestock breeding wastewater. When treating wastewater generated from poultry and livestock farming, it is recommended to use 2-3 kg of the wastewater treatment agent of this invention per ton of wastewater.

[0016] Compared with the prior art, the beneficial effects of the present invention are: (1) This invention achieves an organic combination of physical adsorption, chemical catalytic oxidation, and biodegradation through the synergistic effect of component A (Zn-Fe-Al ternary metal oxide / biochar composite material) and component B (composite microbial agent). Component A has abundant pore structure and surface active sites, which can efficiently adsorb heavy metal ions, organic pollutants, and phosphorus in wastewater. At the same time, under visible light irradiation, Zn-Fe-Al ternary metal oxide can generate photogenerated electron-hole pairs, catalyze the degradation of organic pollutants, and promote the conversion of ammonia nitrogen. The composite microbial agent in component B (Acinetobacter johnsonii, Pseudomonas sinenephritis, and Burkholderia diffusa) can specifically degrade recalcitrant organic matter (such as residual antibiotics and dyes) in wastewater and effectively remove ammonia nitrogen and nitrates, avoiding secondary pollution. Experimental results show that the wastewater treatment agent of this invention can achieve a removal rate of more than 94% for COD, NH3-N, total phosphorus, and heavy metals in livestock breeding wastewater, which is significantly better than single physical, chemical, or biological treatment methods.

[0017] (2) This invention uses pig manure to prepare biochar, realizing the resource utilization of waste and reducing costs; at the same time, the entire treatment process does not introduce harmful chemicals, avoiding secondary pollution problems that may be caused by flocculants or oxidants; Component B uses specific strains that do not produce toxic intermediate products during the degradation of pollutants and can effectively inhibit the reproduction of pathogens, improving the safety of effluent. In addition, the photocatalytic process is carried out under mild conditions, without the need to add additional oxidants, reducing the generation of treatment by-products.

[0018] (3) This invention addresses the high concentration and high toxicity characteristics of livestock farming wastewater by optimizing the ratio of components A and B and the preparation process, ensuring the stability and adaptability of the treatment agent under complex water quality conditions. Even when the wastewater composition fluctuates significantly, it can still maintain a high pollutant removal efficiency, and the treated wastewater can meet national discharge standards or reuse requirements, providing a feasible approach for the resource utilization of livestock farming wastewater. Attached Figure Description

[0019] Figure 1 The microstructures of the Zn-Fe-Al ternary metal oxide / biochar composite material used in this invention after different modification steps during the preparation process are shown, where a is pig manure biochar, b is modified biochar, and c is the Zn-Fe-Al ternary metal oxide / biochar composite material. Figure 2This is a comparison chart of pig farm wastewater before and after treatment with the wastewater treatment agent of this invention. Detailed Implementation

[0020] The technical solution of the present invention will be further described below with reference to specific embodiments, but is not limited thereto. All strains used in the present invention were purchased through publicly available channels and do not require repeated preservation; the Acinetobacter johnsonii strain numbered CGMCC1.5310, with a preservation date of October 18, 2005, was purchased from the China General Microbiological Culture Collection Center; the Songnen Plain Pseudomonas aeruginosa strain numbered CGMCC1.12668, with a preservation date of August 12, 2013, was purchased from the China General Microbiological Culture Collection Center; the Burkholderia bifidum strain numbered CGMCC1.10511, with a preservation date of March 29, 2010, was purchased from the China General Microbiological Culture Collection Center.

[0021] Example 1 A wastewater treatment agent comprises component A and component B. Component A is a Zn-Fe-Al ternary metal oxide / biochar composite material, and component B is a composite microbial agent comprising Acinetobacter johnsonii, Pseudomonas sonicans, and Burkholderia difficile. The Acinetobacter johnsonii strain is numbered CGMCC 1.5310; the Pseudomonas sonicans strain is numbered CGMCC 1.12668; and the Burkholderia difficile strain is numbered CGMCC 1.10511.

[0022] The mass ratio of component A to component B is 2:1.

[0023] The Zn-Fe-Al ternary metal oxide / biochar composite material was prepared using the following method: (1) Take the dried pig manure in a tube furnace, heat it to 600℃ under N2 atmosphere at a heating rate of 10℃ / min and keep it at that temperature for 2 hours. Cool it to room temperature and grind it. Pass it through a 200-mesh sieve to obtain biochar. (2) Dissolve 0.75g of ferrous sulfate heptahydrate and 14.5g of zinc nitrate hexahydrate in 50mL of methanol, add 2g of biochar, stir magnetically for 2h, then add 1.65g of 2-methylimidazole, continue stirring for 4h, centrifuge the mixture after the reaction is complete, wash the precipitate with deionized water several times and dry it, then transfer it into a tube furnace and calcine it at 400℃ for 2h under an inert atmosphere to obtain modified biochar; (3) The obtained modified biochar was added to a 1% (w / w) silane coupling agent KH550 ethanol solution, stirred at 45°C for 2 h, filtered and dried to obtain pretreated modified biochar; the ethanol solution was composed of anhydrous ethanol and water in a volume ratio of 9:1 and a pH of 4.5. (4) The pretreated modified biochar was dispersed in a Zn(NO3)2-FeCl3-AlCl3 mixed solution at a solid-liquid ratio of 1g:30mL. The pH was adjusted to 10.0 by adding 1mol / L NaOH solution. Then, disodium EDTA was added and stirred at room temperature until the mixture was homogeneous. The mixture was allowed to stand at room temperature for 24h to co-precipitate. Then, it was centrifuged and the precipitate was washed with anhydrous ethanol until neutral. The precipitate was then dried in a drying oven and calcined in air at 500℃ for 3h to obtain the Zn-Fe-Al ternary metal oxide / biochar composite material. The Zn / Fe / Al molar ratio in the Zn(NO3)2-FeCl3-AlCl3 mixed solution was 2:1:0.2. The molar ratio of disodium EDTA to Zn(NO3)2 was 0.8:1.

[0024] The compound bacterial agent is prepared by the following method: Acinetobacter johnsonii, Pseudomonas sinenegaiensis, and Burkholderia buergeriana are activated separately in PDA solid medium, and then single colonies are picked and inoculated into test tubes of LB liquid medium and cultured at 30°C and 200 r / min until OD. 600 ≈2.0, the seed liquid was inoculated into 200 mL of fermentation liquid culture medium at a rate of 10%, and fermented at 30℃ and 200 r / min for 72 h. After stopping the fermentation, three fermentation liquids were obtained. Then, they were mixed in a volume ratio of 1:1:1 to obtain a compound microbial liquid. The compound microbial agent was obtained by vacuum freeze drying.

[0025] The fermentation liquid culture medium is composed of the following: glucose 20 g / L, peptone 10 g / L, yeast extract 5 g / L, beef extract 3 g / L, sodium chloride 5.0 g / L, potassium dihydrogen phosphate 1 g / L, dipotassium hydrogen phosphate 2 g / L, magnesium sulfate 0.2 g / L, pH 7.0 ± 0.2.

[0026] In use, the wastewater after preliminary filtration enters the aerated photocatalytic reactor. First, add component A, continue aeration, and treat with 380-780nm LED light for 8-12 hours. Then, add component B to the effluent and incubate at 28-30℃ for 2-3 days. After solid-liquid separation, the wastewater can be separated.

[0027] Example 2 A wastewater treatment agent comprises component A and component B. Component A is a Zn-Fe-Al ternary metal oxide / biochar composite material, and component B is a composite microbial agent comprising Acinetobacter johnsonii, Pseudomonas sonicans, and Burkholderia difficile. The Acinetobacter johnsonii strain is numbered CGMCC 1.5310; the Pseudomonas sonicans strain is numbered CGMCC 1.12668; and the Burkholderia difficile strain is numbered CGMCC 1.10511.

[0028] The mass ratio of component A to component B is 2:1.

[0029] The Zn-Fe-Al ternary metal oxide / biochar composite material was prepared using the following method: (1) Take the dried pig manure in a tube furnace, heat it to 600℃ under N2 atmosphere at a heating rate of 10℃ / min and keep it at that temperature for 2 hours. Cool it to room temperature and grind it. Pass it through a 200-mesh sieve to obtain biochar. (2) Dissolve 0.75g of ferrous sulfate heptahydrate and 14.5g of zinc nitrate hexahydrate in 50mL of methanol, add 2g of biochar, stir magnetically for 2h, then add 1.65g of 2-methylimidazole, continue stirring for 4h, centrifuge the mixture after the reaction is complete, wash the precipitate with deionized water several times and dry it, then transfer it into a tube furnace and calcine it at 400℃ for 2h under an inert atmosphere to obtain modified biochar; (3) The obtained modified biochar was added to a 2% (w / w) silane coupling agent KH550 ethanol solution, stirred at 50°C for 2 h, filtered and dried to obtain pretreated modified biochar; the ethanol solution was composed of anhydrous ethanol and water in a volume ratio of 9:1 and a pH of 4.5. (4) The pretreated modified biochar was dispersed in a Zn(NO3)2-FeCl3-AlCl3 mixed solution at a solid-liquid ratio of 1g:30mL. The pH was adjusted to 10.0 by adding 1mol / L NaOH solution. Then, disodium EDTA was added and stirred at room temperature until the mixture was homogeneous. The mixture was allowed to stand at room temperature for 24h to co-precipitate. Then, it was centrifuged and the precipitate was washed with anhydrous ethanol until neutral. The precipitate was then dried in a drying oven and calcined in air at 500℃ for 3h to obtain the Zn-Fe-Al ternary metal oxide / biochar composite material. The Zn / Fe / Al molar ratio in the Zn(NO3)2-FeCl3-AlCl3 mixed solution was 2:1:0.3. The molar ratio of disodium EDTA to Zn(NO3)2 was 0.9:1.

[0030] The compound bacterial agent is prepared by the following method: Acinetobacter johnsonii, Pseudomonas sinenegaiensis, and Burkholderia buergeriana are activated separately in PDA solid medium, and then single colonies are picked and inoculated into test tubes of LB liquid medium and cultured at 30°C and 200 r / min until OD. 600 ≈2.0, the seed liquid was inoculated into 200 mL of fermentation liquid culture medium at a rate of 10%, and fermented at 30℃ and 200 r / min for 72 h. After stopping the fermentation, three fermentation liquids were obtained. Then, they were mixed in a volume ratio of 1:1:1 to obtain a compound microbial liquid. The compound microbial agent was obtained by vacuum freeze drying.

[0031] The fermentation liquid culture medium is composed of the following: glucose 20 g / L, peptone 10 g / L, yeast extract 5 g / L, beef extract 3 g / L, sodium chloride 5.0 g / L, potassium dihydrogen phosphate 1 g / L, dipotassium hydrogen phosphate 2 g / L, magnesium sulfate 0.2 g / L, pH 7.0 ± 0.2.

[0032] In use, the wastewater after preliminary filtration enters the aerated photocatalytic reactor. First, add component A, continue aeration, and treat with 380-780nm LED light for 8-12 hours. Then, add component B to the effluent and incubate at 28-30℃ for 2-3 days. After solid-liquid separation, the wastewater can be separated.

[0033] Example 3 A wastewater treatment agent comprises component A and component B. Component A is a Zn-Fe-Al ternary metal oxide / biochar composite material, and component B is a composite microbial agent comprising Acinetobacter johnsonii, Pseudomonas sonicans, and Burkholderia difficile. The Acinetobacter johnsonii strain is numbered CGMCC 1.5310; the Pseudomonas sonicans strain is numbered CGMCC 1.12668; and the Burkholderia difficile strain is numbered CGMCC 1.10511.

[0034] The mass ratio of component A to component B is 2:1.

[0035] The Zn-Fe-Al ternary metal oxide / biochar composite material was prepared using the following method: (1) Take the dried pig manure in a tube furnace, heat it to 600℃ under N2 atmosphere at a heating rate of 10℃ / min and keep it at that temperature for 2 hours. Cool it to room temperature and grind it. Pass it through a 200-mesh sieve to obtain biochar. (2) Dissolve 0.75g of ferrous sulfate heptahydrate and 14.5g of zinc nitrate hexahydrate in 50mL of methanol, add 2g of biochar, stir magnetically for 2h, then add 1.65g of 2-methylimidazole, continue stirring for 4h, centrifuge the mixture after the reaction is complete, wash the precipitate with deionized water several times and dry it, then transfer it into a tube furnace and calcine it at 400℃ for 2h under an inert atmosphere to obtain modified biochar; (3) The obtained modified biochar was added to a 3% (w / w) silane coupling agent KH550 ethanol solution, stirred at 48°C for 2 h, filtered and dried to obtain pretreated modified biochar; the ethanol solution was composed of anhydrous ethanol and water in a volume ratio of 9:1 and a pH of 4.5. (4) The pretreated modified biochar was dispersed in a Zn(NO3)2-FeCl3-AlCl3 mixed solution at a solid-liquid ratio of 1g:30mL. The pH was adjusted to 10.0 by adding 1mol / L NaOH solution. Then, disodium EDTA was added and stirred at room temperature until the mixture was homogeneous. The mixture was allowed to stand at room temperature for 24h to co-precipitate. Then, it was centrifuged and the precipitate was washed with anhydrous ethanol until neutral. The precipitate was then dried in a drying oven and calcined in air at 500℃ for 3h to obtain the Zn-Fe-Al ternary metal oxide / biochar composite material. The Zn / Fe / Al molar ratio in the Zn(NO3)2-FeCl3-AlCl3 mixed solution was 2:1:0.3. The molar ratio of disodium EDTA to Zn(NO3)2 was 1:1.

[0036] The compound bacterial agent is prepared by the following method: Acinetobacter johnsonii, Pseudomonas sinenegaiensis, and Burkholderia buergeriana are activated separately in PDA solid medium, and then single colonies are picked and inoculated into test tubes of LB liquid medium and cultured at 30°C and 200 r / min until OD. 600 ≈2.0, the seed liquid was inoculated into 200 mL of fermentation liquid culture medium at a rate of 10%, and fermented at 30℃ and 200 r / min for 72 h. After stopping the fermentation, three fermentation liquids were obtained. Then, they were mixed in a volume ratio of 1:1:1 to obtain a compound microbial liquid. The compound microbial agent was obtained by vacuum freeze drying.

[0037] The fermentation liquid culture medium is composed of the following: glucose 20 g / L, peptone 10 g / L, yeast extract 5 g / L, beef extract 3 g / L, sodium chloride 5.0 g / L, potassium dihydrogen phosphate 1 g / L, dipotassium hydrogen phosphate 2 g / L, magnesium sulfate 0.2 g / L, pH 7.0 ± 0.2.

[0038] In use, the wastewater after preliminary filtration enters the aerated photocatalytic reactor. First, add component A, continue aeration, and treat with 380-780nm LED light for 8-12 hours. Then, add component B to the effluent and incubate at 28-30℃ for 2-3 days. After solid-liquid separation, the wastewater can be separated.

[0039] Comparative Example 1 A wastewater treatment agent, basically the same as in Example 1, except that component A is biochar material prepared from pig manure, without any modification treatment. The specific preparation method of biochar is as follows: dried pig manure is placed in a tube furnace and calcined at 600°C for 2 hours under N2 atmosphere at a heating rate of 10°C / min. After cooling to room temperature, it is ground and passed through a 200-mesh sieve to obtain biochar.

[0040] Comparative Example 2 A wastewater treatment agent, basically the same as in Example 1, except that component A is only modified biochar, and the specific method for preparing the modified biochar is as follows: (1) Take the dried pig manure in a tube furnace, heat it to 600℃ under N2 atmosphere at a heating rate of 10℃ / min and keep it at that temperature for 2 hours. Cool it to room temperature and grind it. Pass it through a 200-mesh sieve to obtain biochar. (2) Dissolve 0.75g of ferrous sulfate heptahydrate and 14.5g of zinc nitrate hexahydrate in 50mL of methanol, add 2g of biochar, stir magnetically for 2h, then add 1.65g of 2-methylimidazole, continue stirring for 4h, centrifuge the mixture after the reaction is complete, wash the precipitate with deionized water several times and dry it, then transfer it to a tube furnace and calcine it at 400℃ for 2h under an inert atmosphere to obtain modified biochar.

[0041] Comparative Example 3 A wastewater treatment agent, basically the same as in Example 1, except that component A is a Zn-Fe metal oxide / biochar composite material; the specific preparation method of the Zn-Fe metal oxide / biochar composite material is as follows: (1) Take the dried pig manure in a tube furnace, heat it to 600℃ under N2 atmosphere at a heating rate of 10℃ / min and keep it at that temperature for 2 hours. Cool it to room temperature and grind it. Pass it through a 200-mesh sieve to obtain biochar. (2) Dissolve 0.75g of ferrous sulfate heptahydrate and 14.5g of zinc nitrate hexahydrate in 50mL of methanol, add 2g of biochar, stir magnetically for 2h, then add 1.65g of 2-methylimidazole, continue stirring for 4h, centrifuge the mixture after the reaction is complete, wash the precipitate with deionized water several times and dry it, then transfer it into a tube furnace and calcine it at 400℃ for 2h under an inert atmosphere to obtain modified biochar; (3) The obtained modified biochar was added to a 1% (w / w) silane coupling agent KH550 ethanol solution, stirred at 45°C for 2 h, filtered and dried to obtain pretreated modified biochar; the ethanol solution was composed of anhydrous ethanol and water in a volume ratio of 9:1 and a pH of 4.5. (4) The pretreated modified biochar was dispersed in a Zn(NO3)2-FeCl3 mixed solution at a solid-liquid ratio of 1g:30mL. 1mol / L NaOH solution was added dropwise to adjust the pH to 10.0. Then, disodium EDTA was added and stirred at room temperature until the mixture was homogeneous. The mixture was allowed to stand at room temperature for 24h to co-precipitate. Then, it was centrifuged and the precipitate was washed with anhydrous ethanol until neutral. The precipitate was then dried in a drying oven and calcined in air at 500℃ for 3h to obtain the Zn-Fe metal oxide / biochar composite material. The Zn / Fe molar ratio in the Zn(NO3)2-FeCl3 mixed solution was 2:1. The molar ratio of disodium EDTA to Zn(NO3)2 was 0.8:1.

[0042] Comparative Example 4 A wastewater treatment agent includes component A and component B. Its principle, composition and preparation method are basically the same as those in Example 1. The only difference is that component B does not contain Acinetobacter johnsonii.

[0043] Comparative Example 5 A wastewater treatment agent includes component A and component B. Its principle, composition and preparation method are basically the same as those in Example 1. The only difference is that component B does not contain Pseudomonas sinenegatus.

[0044] Comparative Example 6 A wastewater treatment agent includes component A and component B. Its principle, composition and preparation method are basically the same as those in Example 1. The only difference is that component B does not contain Burkholderia bifidum.

[0045] Performance testing To visually characterize the microstructure evolution of the Zn-Fe-Al ternary metal oxide / biochar composite material prepared and used in this invention, scanning electron microscopy (SEM) was used to observe the morphology of key intermediates and final products in the preparation process. The results are as follows: Figure 1 As shown. Figure 1 a represents the original biochar obtained through direct pyrolysis of pig manure. It can be observed that its surface is relatively smooth and dense, with only a few particles. The pore structure is mainly composed of macropores, and the specific surface area is relatively low. This structure results in limited adsorption capacity and a lack of sufficient active sites to load metal oxides or carry out catalytic reactions. Figure 1 b represents the modified biochar obtained after modification with ZIF-8 precursor and calcination, and... Figure 1 Compared to the previous method, its morphology has changed significantly. The original smooth surface is now covered with a large number of nanoscale particles of varying sizes. These particles are ZnO nanoparticles derived from the pyrolysis of ZIF-8. This step greatly increases the specific surface area and the number of micropores / mesopores in the material, providing an ideal substrate and a huge loading space for the subsequent loading of ternary metal oxides. Figure 1 c represents the Zn-Fe-Al ternary metal oxide / biochar composite material finally prepared in this invention, whose microstructure is compared to... Figure 1 b represents a further leap forward. It can be clearly observed that a large number of relatively uniform nanoparticles are tightly packed and attached to the biochar substrate. These particles are relatively uniform in size, forming abundant interparticle pores within the nanoscale range. This structure can provide a huge specific surface area and abundant mesopores, providing a large number of sites for pollutant adsorption and catalytic reactions.

[0046] Wastewater (including manure flushing water) from a large-scale pig farm in Bancheng Town, Linyi City, Shandong Province was selected as the test water sample after preliminary filtration (removing suspended solids with a particle size >1mm). The initial indicators are shown in Table 1.

[0047] Table 1 Initial Indicators of Wastewater from Pig Farms The wastewater from the above-mentioned aquaculture farm was treated using the wastewater treatment agents described in Examples 1-3 and Comparative Examples 1-6, respectively. The specific application method was as follows: 3 kg of the wastewater treatment agent of this invention was used per ton of wastewater. The pre-filtered wastewater was introduced into an aerated photocatalytic reactor. Component A was added first, followed by continuous aeration and irradiation with a 380-780 nm LED lamp for 8-12 hours. Component B was then added to the effluent, and the mixture was incubated at 28-30℃ for 2-3 days, followed by solid-liquid separation. After treatment, the following core indicators were measured in the effluent. Each test was repeated three times, and the average value was taken. The test results are shown in Tables 2-3.

[0048] Test metrics: Pollutant removal rate: including COD, NH3-N, total phosphorus, and Zn 2+ Cu 2+ The removal rate is calculated as follows: Removal rate (%) = (Initial concentration - Effluent concentration) / Initial concentration × 100%; Secondary pollution risk: Detection of nitrate concentration in effluent (ultraviolet spectrophotometry HJ / T 346-2007) and nitrite concentration (N-(1-naphthyl)-ethylenediamine spectrophotometry GB / T 7493-1987); Biosafety: Detection of E. coli count in effluent (plate count method).

[0049] Table 2 Test Results As can be seen from the results in Table 2 above, Examples 1-3 of the present invention have effects on COD, NH3-N, TP and heavy metals (Zn). 2+ Cu 2 + The removal rates of all samples remained stable above 94%, demonstrating excellent and comprehensive pollutant removal capabilities. This indicates that the optimized A / B group ratio and preparation process of this invention can fully leverage the synergistic effect of "adsorption-photocatalysis-biodegradation," meeting the removal requirements of high-concentration pollutants in livestock wastewater. In contrast, Comparative Example 1 showed the lowest removal rates across all categories, indicating that the unmodified biochar has a simple pore structure and few surface active sites (e.g., ...). Figure 1As shown in (a), photocatalytic reactions could not be achieved, and the adsorption capacity for organic pollutants was limited, especially the adsorption capacity for heavy metals. The removal rate of Comparative Example 2 was better than that of Comparative Example 1 but significantly lower than that of the Example, indicating that the loading of Zn-Fe-Al ternary metal oxides is crucial for improving the photocatalytic oxidation performance and overall treatment effect of the material. The removal rate of Comparative Example 3 was also significantly lower than that of the Example, indicating that the introduction of Al further optimized the structure and performance of the material, increased the number of surface hydroxyl groups of the metal oxide, enhanced the chemical adsorption and catalytic conversion of ammonia nitrogen, and improved the material's complexation capacity for phosphate, forming a more efficient ternary synergistic catalytic system. The treatment effects of Comparative Examples 4-6 showed that Acinetobacter johnsonii, Pseudomonas sonicans, and Burkholderia bifidum have irreplaceable synergistic effects in degrading complex organic matter and removing nitrogen and phosphorus. The absence of any one of these species would lead to a decrease in the overall biological treatment efficiency.

[0050] The test results for secondary pollution risk (concentration of nitrate and nitrite in effluent) and biosafety (number of E. coli in effluent) are shown in Table 3 below. The environmental friendliness of the treatment process is verified by comparing the results with the limits of the "Emission Standard of Pollutants for Livestock and Poultry Farming" (GB 18596-2001).

[0051] Table 3 Test Results The results in Table 3 show that the effluent nitrate concentrations in Examples 1-3 were ≤12.3 mg / L and nitrite concentrations were ≤0.8 mg / L, both lower than the national standard limits; the Escherichia coli count was <100 CFU / mL, far below the national standard requirement of ≤1000 CFU / mL. This indicates that the compound bacterial agent of component B can convert ammonia nitrogen into harmless N2 through a complete denitrification chain, avoiding the accumulation of nitrate / nitrite; at the same time, the antibacterial substances produced during the metabolism of the strains can inhibit the reproduction of pathogenic bacteria such as Escherichia coli, ensuring the biological safety of the effluent. However, in Comparative Examples 1-3, due to incomplete modification of component A, the effluent nitrate and nitrite concentrations significantly exceeded the standards; although the Escherichia coli count in Comparative Examples 4-6 met the standards, the nitrate / nitrite concentrations exceeded the standards. This is because Burkholderia spp. is a key strain for denitrification; its absence caused ammonia nitrogen conversion to stagnate at the nitrate stage, and some even converted into nitrite, resulting in secondary pollution.

[0052] The COD concentration of the simulated wastewater fluctuated by ±20% (initial concentration 7250 mg / L, followed by fluctuations of 8700 mg / L and 5800 mg / L respectively). The COD removal rate of Example 2 and Comparative Examples 1-3 was tested to evaluate the adaptability of the treatment agent to water quality fluctuations. The specific results are shown in Table 4 below.

[0053] Table 4. Results of Wastewater Treatment Stability Test As can be seen from the results in Table 4 above, under the condition of a simulated wastewater COD concentration fluctuation of ±20%, the maximum variation in COD removal rate of Example 2 was only 1.3%, demonstrating excellent stability. This indicates that the complete A and B component synergistic system of the present invention has a strong adaptability to water quality fluctuations and can maintain stable treatment effects in practical applications. In contrast, the removal rate variations of Comparative Examples 1-3 were significantly larger, indicating that their treatment effects were more significantly affected by water quality fluctuations. In particular, Comparative Example 1, using unmodified biochar, showed the largest variation in removal rate of 7.1%, further illustrating the importance of the complete preparation process of the present invention for improving the stability and adaptability of the materials.

[0054] It should be noted that the above embodiments are merely some preferred embodiments of the present invention, and not all embodiments. Obviously, based on the above embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

Claims

1. A wastewater treatment agent comprising a component A and a component B, characterized in that, The A component is a Zn-Fe-Al ternary metal oxide / biochar composite material, the B component is a composite microbial agent, and the composite microbial agent includes Acinetobacter junii, Pseudomonas soli, and Burkholderia bilum.

2. The wastewater treatment agent according to claim 1, characterized by, The mass ratio of the A component to the B component is 2:

1.

3. The wastewater treatment of claim 1, wherein, The Zn-Fe-Al ternary metal oxide / biochar composite material is prepared by the following method: (1) After drying, the pig manure is placed in a tube furnace, and is heated to 600°C at a heating rate of 10°C / min under N2 atmosphere, and is kept at 600°C for 2h, and is cooled to room temperature and ground, and is passed through a 200 mesh screen to obtain biochar; (2) 0.75g of ferrous sulfate heptahydrate and 14.5g of zinc nitrate hexahydrate are dissolved in 50mL of methanol, 2g of biochar is added, and is stirred magnetically for 2h, and then 1.65g of 2-methylimidazole is added, and is continuously stirred for 4h, and after the reaction is completed, the mixture is centrifuged, and the obtained precipitate is washed with deionized water for multiple times and dried, and is then placed in a tube furnace, and is calcined at 400°C under inert atmosphere for 2h to obtain modified biochar; (3) The obtained modified biochar is added to a silane coupling agent KH550 ethanol solution with a mass fraction of 1-3%, and is stirred at 45-50°C for 2h, and is filtered and dried to obtain pretreated modified biochar; (4) The pretreated modified biochar is dispersed in a Zn(NO3)2-FeCl3-AlCl3 mixed solution, NaOH solution is added dropwise to adjust the pH to 10.0, and then disodium EDTA is added, and is stirred at room temperature until the mixture is uniform, and is placed at room temperature for 24h, and is then centrifuged, and the precipitate is washed with anhydrous ethanol until neutral, and the precipitate is placed in a drying oven for drying, and is then calcined at 500°C in air atmosphere for 3h to obtain a Zn-Fe-Al ternary metal oxide / biochar composite material.

4. The wastewater treatment of claim 3, wherein, In step (3), the ethanol solution is anhydrous ethanol:water in a volume ratio of 9:1, and the pH is 4.

5.

5. The wastewater treatment of claim 3, wherein, In step (4), the solid-liquid ratio of the pretreated modified biochar to the Zn(NO3)2-FeCl3-AlCl3 mixed solution is 1g:30mL; and the concentration of the NaOH solution is 1mol / L.

6. The wastewater treatment of claim 3, wherein, In the Zn(NO3)2-FeCl3-AlCl3 mixed solution, the molar ratio of Zn / Fe / Al is 2:1:0.2-0.3; and the molar ratio of disodium EDTA to Zn(NO3)2 is 0.8-1:

1.

7. The wastewater treatment of claim 1, wherein, The complex microbial agent is prepared by the following method: Acinetobacter johnsonii, Pseudomonas nigrificans and Burkholderia bipapillosa are activated in PDA solid culture medium respectively, then single colonies are inoculated into test tubes of LB liquid culture medium, and cultured at 30 DEG C, 200 r / min until OD 600 ≈2.0, the seed liquid is inoculated into 200 mL fermentation liquid culture medium at an amount of 10%, and fermented at 30 DEG C, 200 r / min for 72h, the fermentation is stopped to obtain three kinds of fermentation liquid, then the complex microbial agent is obtained by mixing the three kinds of fermentation liquid at a volume ratio of 1:1:1, and vacuum freeze-drying.

8. The wastewater treatment of claim 7, wherein, The fermentation liquid medium is composed of the following components: glucose 20g / L, proteose peptone 10g / L, yeast extract powder 5g / L, beef extract 3g / L, sodium chloride 5.0g / L, potassium dihydrogen phosphate 1g / L, dipotassium hydrogen phosphate 2g / L, magnesium sulfate 0.2g / L, and the pH is 7.0±0.

2.

9. The wastewater treatment of claim 7, wherein, In use, the preliminary filtered wastewater enters the aeration photocatalytic reactor, first adds A component, continuously aerates and irradiates under 380-780nm LED lamp for 8-12h, then adds B component in the effluent, and after culturing at 28-30℃ for 2-3 days, solid-liquid separation can be carried out.

10. The use of the wastewater treatment agent according to any one of claims 1-9 in the treatment of livestock breeding wastewater.

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