Composite sewage treatment agent, sewage treatment method and application thereof

Abstract

The application provides a composite sewage treatment agent, a sewage treatment method and application, and belongs to the technical field of water treatment agents.The composite sewage treatment agent comprises an A agent, a B agent and a C agent, the A agent comprises the following raw materials in a mass fraction: modified silicon-calcium-based mineral material 40-60 parts, organic flocculant 10-20 parts, structure regulator 5-10 parts, inorganic flocculant 5-10 parts and filler 20-30 parts; the B agent comprises the following raw materials in a mass fraction: tea seed meal extract microcapsule 30-50 parts, carbon source 20-40 parts, trace element mixture 10-20 parts, nitrification accelerator 5-15 parts and binder 3-8 parts; and the C agent comprises the following raw materials in a mass fraction: coated sodium bicarbonate 70-80 parts and nanoscale crystal seed 20-30 parts.The joint action of the A agent, the B agent and the C agent improves the sewage treatment effect and ensures that the effluent meets the discharge standard.

Description

Technical Field

[0001] This application relates to the field of water treatment agent technology, and in particular to a composite wastewater treatment agent, wastewater treatment method and application. Background Technology

[0002] Industrial wastewater mainly refers to intermediate products, by-products, cleaning solutions, and extraction solvents generated during industrial production. The vast majority of discharged industrial wastewater consists of organic chemical raw materials or intermediates in various forms. Typical industries such as electronics, coking, steel, and printing and dyeing are consistently major emitters of organic pollutants. In addition, there are pesticides, fertilizers, herbicides, and other chemicals and related additives, as well as heavy metal pollutants. These substances enter the environment through various pathways and are ultimately discharged into rivers and lakes as wastewater. On the one hand, due to the limited self-purification capacity of natural water bodies, if the pollutants discharged into the water bodies exceed the ecological carrying capacity of the natural water bodies or cause irreversible pollution, the wastewater will be discharging into them. On the other hand, these pollutants discharged into the environment have certain biological activity, which can cause toxic reactions or carcinogenic effects on aquatic plants and animals, and may even directly endanger human health.

[0003] Patent application CN202311647122.5 discloses a wastewater treatment agent that uses oxidants, non-oxidants, and flocculants as raw materials. The iron-based substances in the non-oxidants can catalyze the oxidation of percarbonate to generate hydroxyl radicals, which greatly improves the oxidizing power and oxidation rate of percarbonate. Sulfamic acid, as a preservative and stabilizer, can further enhance the effect of the wastewater treatment agent in treating black and odorous water bodies and extend the treatment time. However, the above-mentioned prior art is not very efficient in removing organic pollutants from wastewater. Patent application CN201911307611.X discloses a papermaking wastewater treatment agent, including a flocculant. The flocculant, by weight, comprises: 5-10 parts polyferric sulfate, 10-15 parts polyferric silicate, 10-15 parts chitosan, 20-30 parts sodium alginate, 5-10 parts slaked lime, 5-10 parts polyacrylamide, and 1-2 parts acetic acid. It also includes 5-10 parts of a coagulant aid, which comprises one or more of activated silica, activated water glass, and sodium silicate. However, the acrylamide prepared in the above patent has a relatively small molecular weight, resulting in poor flocculation performance.

[0004] Existing wastewater treatment agents have limited effectiveness and are difficult to handle complex water qualities: Traditional flocculants (such as PAC and PAM) mainly target suspended solids and colloids, and have limited effectiveness in removing soluble recalcitrant organic matter, heavy metal ions, high ammonia nitrogen and other pollutants. They often require multiple processes in series, resulting in lengthy processes and high costs. Summary of the Invention

[0005] This application is made in view of the above-mentioned problems, and its purpose is to provide a composite wastewater treatment agent, a wastewater treatment method and application, which can comprehensively treat wastewater and has a good treatment effect.

[0006] Specifically, the first aspect of this application provides a composite wastewater treatment agent, including agent A, agent B, and agent C.

[0007] The A agent comprises the following raw materials by mass fraction: 40-60 parts of modified silicon-calcium based mineral material, 10-20 parts of organic flocculant, 5-10 parts of structure regulator, 5-10 parts of inorganic flocculant, and 20-30 parts of filler.

[0008] The B agent comprises the following raw materials by mass fraction: 30-50 parts of tea seed meal extract microcapsules, 20-40 parts of carbon source, 10-20 parts of trace element mixture, 5-15 parts of nitration accelerator, and 3-8 parts of binder.

[0009] The C agent comprises the following raw materials in mass fractions: 70-80 parts of coated sodium bicarbonate and 20-30 parts of nano-sized seed crystals.

[0010] Furthermore, the modified silicon-calcium based mineral material in agent A is sepiolite or diatomaceous earth loaded with nano-calcium oxide and iron salts; and / or

[0011] The structure modifier is disodium hydrogen phosphate or sodium dihydrogen phosphate; and / or

[0012] The organic flocculant is amphoteric polyacrylamide; and / or

[0013] The inorganic flocculant is ferric polysilicate sulfate.

[0014] Furthermore, the preparation method of the tea seed meal extract microcapsules in Agent B is as follows: using the sharp-hole coagulation bath method, a core material solution containing sodium alginate and tea seed meal extract is dripped into a coagulation bath containing calcium ions and chitosan to form gel microcapsules.

[0015] Further, the trace element mixture in agent B comprises 1-3% CuSO4·5H2O, 2-4% ZnSO4·7H2O, 1-2% Na2MoO4·2H2O, 0.3-0.8% CoCl2·6H2O, and 90-95% zeolite powder carrier; and / or

[0016] The nitration accelerator is a mixture of ammonium chloride and urea in a mass ratio of 1:0.8-1.2; and / or

[0017] The binder is sodium carboxymethyl cellulose.

[0018] Furthermore, the preparation method of the coated sodium bicarbonate in Agent C is as follows: using a solution of biodegradable polymer material as the coating liquid, the sodium bicarbonate particles are coated, and the coating weight gain is controlled to be 10%-20%.

[0019] A second aspect of the present invention provides a wastewater treatment method using the aforementioned composite wastewater treatment agent, comprising the following steps:

[0020] (1) Add agent A to the industrial wastewater to be treated to carry out coagulation and sedimentation reaction and complete the primary treatment;

[0021] (2) Introduce the effluent from step (1) into the biochemical treatment unit and add agent B to it for bio-enhanced treatment;

[0022] (3) Add agent C to the effluent from step (2), stir and react, and precipitate to complete the deep treatment.

[0023] Furthermore, in step (1), after adding agent A, the reaction time is sequentially 250-350 s. -1 70-90 s -1 and 20-40 s -1 The stirring intensity G value is used to carry out a three-stage reaction.

[0024] Furthermore, agent B is added to the anoxic zone or inlet of the biochemical treatment unit at a mass ratio of agent B to inlet COD of 1:50-200.

[0025] Furthermore, the dosage of agent C is controlled according to the molar ratio of bicarbonate ions to residual calcium ions and heavy metal ions in the wastewater (1.0-1.5:1), and the reaction stirring intensity G is 15-25 s. -1 .

[0026] A third aspect of this application provides the application of the aforementioned composite wastewater treatment agent in wastewater treatment.

[0027] The present invention has the following beneficial effects:

[0028] This invention, through the rational combination and synergistic effect of agents A, B, and C, not only achieves highly efficient removal of various pollutants but also demonstrates unique advantages in sludge treatment and cost control. Agent A primarily functions as a flocculator and mineralizer. Modified silica-calcium-based mineral materials possess a large specific surface area and abundant pore structure, enabling them to adsorb suspended solids, colloids, and some organic matter in wastewater. The synergistic effect of organic and inorganic flocculants allows fine particles in wastewater to aggregate into larger flocs, facilitating subsequent sedimentation and separation. Structure regulators help adjust the structure of the flocs, making them more compact and improving sedimentation efficiency. The filler increases the weight of the flocs, accelerating the sedimentation rate. In primary treatment, the addition of agent A effectively removes most of the suspended solids and some organic matter from wastewater, reducing turbidity and COD. By precisely controlling the dosage of agent A and the stirring intensity, the coagulation and sedimentation reaction can achieve optimal results. Wastewater treated with agent A shows initial improvement in water quality, laying a good foundation for subsequent biological and advanced treatment.

[0029] Agent B primarily functions as a bioactivator. The microcapsules of tea seed meal extract provide a suitable growth environment and nutrients for microorganisms, optimizing their microbial community structure and enhancing their activity and metabolic capacity. The trace element mixture provides essential trace elements for microbial growth and metabolism, helping to maintain normal physiological functions. The nitrification promoter accelerates nitrification, improving the removal efficiency of ammonia nitrogen in wastewater. During the bio-enhanced treatment stage, Agent B is added to the anoxic zone or inlet of the biochemical treatment unit, rapidly activating microbial activity and improving the system's ability to remove organic matter and ammonia nitrogen. The microencapsulated tea seed meal extract specifically inhibits filamentous bulking, preventing sludge bulking and ensuring stable operation of the biochemical system. Simultaneously, the microbial community in Agent B can adapt to fluctuations in toxic substances and loads in the wastewater, enhancing the system's resilience to shock loads. After treatment with Agent B, the content of organic matter and ammonia nitrogen in the wastewater is further reduced, resulting in significant water quality improvement. Moreover, the use of Agent B helps improve the treatment efficiency of the biochemical system, reduces the residence time of the biochemical treatment unit, and lowers treatment costs. In addition, the microbial community in Agent B can convert some organic matter into carbon dioxide and water, thus achieving the harmless treatment of organic matter.

[0030] Agent C plays a crucial role in deep mineralization. The coated sodium bicarbonate slowly releases bicarbonate ions into water, which react with residual calcium and heavy metal ions in the wastewater to form insoluble carbonate precipitates, thus achieving deep removal of heavy metal ions. Nanoscale seed crystals provide crystallization nuclei for the precipitation reaction, promoting precipitate formation and growth, and improving precipitation efficiency. During the deep treatment stage, the dosage of Agent C is controlled according to the molar ratio of bicarbonate ions to residual calcium and heavy metal ions in the wastewater (1.0-1.5:1), and the reaction stirring intensity G value is 15-25 s. -1 This ensures the precipitation reaction proceeds fully. Agent C further transforms the remaining pollutants into stable solids, achieving deep removal of heavy metal ions and other pollutants from the wastewater. Wastewater treated with Agent C shows a significant reduction in the content of heavy metal ions, color, and other pollutants, with effluent quality comprehensively exceeding the Class A standard. Simultaneously, the use of Agent C further reduces sludge volume and lowers the leaching toxicity of the sludge, making it easier to handle and utilize. The entire composite wastewater treatment agent, through the synergistic effect of Agents A, B, and C, achieves comprehensive and in-depth treatment of wastewater, demonstrating broad application prospects in the wastewater treatment field. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this application clearer, the following description and illustration are provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0032] Obviously, the following description is merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios without any inventive effort. Furthermore, it is understood that although the effort involved in such development may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, any changes to design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as insufficient disclosure of the content of this application.

[0033] The first aspect of this application provides a composite wastewater treatment agent, comprising agent A, agent B, and agent C.

[0034] The A agent comprises the following raw materials by mass fraction: 40-60 parts of modified silicon-calcium based mineral material, 10-20 parts of organic flocculant, 5-10 parts of structure regulator, 5-10 parts of inorganic flocculant, and 20-30 parts of filler.

[0035] The B agent comprises the following raw materials by mass fraction: 30-50 parts of tea seed meal extract microcapsules, 20-40 parts of carbon source, 10-20 parts of trace element mixture, 5-15 parts of nitration accelerator, and 3-8 parts of binder.

[0036] The C agent comprises the following raw materials in mass fractions: 70-80 parts of coated sodium bicarbonate and 20-30 parts of nano-sized seed crystals.

[0037] This invention, through the rational combination and synergistic effect of agents A, B, and C, not only achieves highly efficient removal of various pollutants but also demonstrates unique advantages in sludge treatment and cost control. Agent A primarily functions as a flocculator and mineralizer. Modified silica-calcium-based mineral materials possess a large specific surface area and abundant pore structure, enabling them to adsorb suspended solids, colloids, and some organic matter in wastewater. The synergistic effect of organic and inorganic flocculants allows fine particles in wastewater to aggregate into larger flocs, facilitating subsequent sedimentation and separation. Structure regulators help adjust the structure of the flocs, making them more compact and improving sedimentation efficiency. The filler increases the weight of the flocs, accelerating the sedimentation rate. In primary treatment, the addition of agent A effectively removes most of the suspended solids and some organic matter from wastewater, reducing turbidity and COD. By precisely controlling the dosage of agent A and the stirring intensity, the coagulation and sedimentation reaction can achieve optimal results. Wastewater treated with agent A shows initial improvement in water quality, laying a good foundation for subsequent biological and advanced treatment.

[0038] Agent B primarily functions as a bioactivator. The microcapsules of tea seed meal extract provide a suitable growth environment and nutrients for microorganisms, optimizing their microbial community structure and enhancing their activity and metabolic capacity. The trace element mixture provides essential trace elements for microbial growth and metabolism, helping to maintain normal physiological functions. The nitrification promoter accelerates nitrification, improving the removal efficiency of ammonia nitrogen in wastewater. During the bio-enhanced treatment stage, Agent B is added to the anoxic zone or inlet of the biochemical treatment unit, rapidly activating microbial activity and improving the system's ability to remove organic matter and ammonia nitrogen. The microencapsulated tea seed meal extract specifically inhibits filamentous bulking, preventing sludge bulking and ensuring stable operation of the biochemical system. Simultaneously, the microbial community in Agent B can adapt to fluctuations in toxic substances and loads in the wastewater, enhancing the system's resilience to shock loads. After treatment with Agent B, the content of organic matter and ammonia nitrogen in the wastewater is further reduced, resulting in significant water quality improvement. Moreover, the use of Agent B helps improve the treatment efficiency of the biochemical system, reduces the residence time of the biochemical treatment unit, and lowers treatment costs. In addition, the microbial community in Agent B can convert some organic matter into carbon dioxide and water, thus achieving the harmless treatment of organic matter.

[0039] Agent C plays a crucial role in deep mineralization. The coated sodium bicarbonate slowly releases bicarbonate ions into water, which react with residual calcium and heavy metal ions in the wastewater to form insoluble carbonate precipitates, thus achieving deep removal of heavy metal ions. Nanoscale seed crystals provide crystallization nuclei for the precipitation reaction, promoting precipitate formation and growth, and improving precipitation efficiency. During the deep treatment stage, the dosage of Agent C is controlled according to the molar ratio of bicarbonate ions to residual calcium and heavy metal ions in the wastewater (1.0-1.5:1), and the reaction stirring intensity G value is 15-25 s. -1 This ensures the precipitation reaction proceeds fully. Agent C further transforms the remaining pollutants into stable solids, achieving deep removal of heavy metal ions and other pollutants from the wastewater. Wastewater treated with Agent C shows a significant reduction in the content of heavy metal ions, color, and other pollutants, with effluent quality comprehensively exceeding the Class A standard. Simultaneously, the use of Agent C further reduces sludge volume and lowers the leaching toxicity of the sludge, making it easier to handle and utilize. The entire composite wastewater treatment agent, through the synergistic effect of Agents A, B, and C, achieves comprehensive and in-depth treatment of wastewater, demonstrating broad application prospects in the wastewater treatment field.

[0040] In this embodiment, the mass fraction of the modified calcium silicate-based mineral material in Agent A is any value or combination of 40, 45, 50, 55, and 60 parts. When the mass fraction of the modified calcium silicate-based mineral material is less than 40 parts, its adsorption capacity is insufficient, making it difficult to effectively remove suspended solids, colloids, and some organic matter from wastewater. This results in an insignificant reduction in turbidity and COD of the wastewater after primary treatment, failing to lay a good foundation for subsequent treatment. When the mass fraction is greater than 60 parts, it increases the cost of Agent A and may cause material waste. At the same time, excessive material may affect the formation and sedimentation of flocs.

[0041] The modified silicon-calcium based mineral material comprises 70% 100-mesh sepiolite powder, 20% nano-calcium oxide (CaO), and 10% ferric chloride hexahydrate (FeCl3·6H2O).

[0042] The organic flocculant can be present in any number or combination of 10, 12, 15, 18, or 20 parts by mass. If the organic flocculant is less than 10 parts by mass, it will be difficult to coagulate fine particles in wastewater into larger flocs when working synergistically with inorganic flocculants, which is not conducive to sedimentation and separation. If the organic flocculant is more than 20 parts by mass, the flocs may be too loose, making them difficult to settle and increasing treatment costs. The organic flocculant is amphoteric polyacrylamide with a molecular weight of 8-10 million and an ionicity of 20%.

[0043] The structure regulator is disodium hydrogen phosphate, and its mass fraction is any value or combination of 5, 6, 8, 9, and 10 parts. When the mass fraction is less than 5 parts, the regulating effect on the floc structure is not significant, the flocs are not dense enough, and the precipitation effect is poor. When the mass fraction is greater than 10 parts, it may change the properties of the flocs and affect the precipitation process.

[0044] The inorganic flocculant is ferric polysilicate, and its mass fraction is any value or combination of 5, 6, 8, 9, and 10 parts. When it is less than 5 parts, the synergistic effect with the organic flocculant is poor and it cannot effectively remove particles from the wastewater. When it is more than 10 parts, it may lead to excessively high ion concentration in the wastewater, which will affect subsequent treatment.

[0045] The filler is anhydrous sodium sulfate, and its mass fraction is any value or combination of 20, 22, 25, 28, and 30 parts. When it is less than 20 parts, the increase in floc weight is not obvious and the sedimentation rate is slow. When it is more than 30 parts, it will increase the volume and cost of agent A and may affect the effectiveness of other components.

[0046] The preparation method of agent A is as follows:

[0047] Place 100-mesh sepiolite powder in a high-efficiency mixer, heat to 80-90℃, slowly add metered ferric chloride hexahydrate (dissolved in a small amount of deionized water), stir and react for 40 minutes, then add nano CaO powder, continue stirring for 60 minutes to ensure full loading and mixing, remove and dry at 105℃ to constant weight for later use.

[0048] The modified sepiolite, zwitterionic polyacrylamide, disodium hydrogen phosphate, ferric polysilicate sulfate, and anhydrous sodium sulfate prepared above are added into a three-dimensional motion mixer in proportion. The mixer is run at a speed of 15-20 rpm for 45-60 minutes to ensure that the components are evenly distributed. The mixture is then discharged and sealed in a moisture-proof packaging bag to obtain Agent A.

[0049] The mass fraction of the tea seed meal extract microcapsules in Agent B is any value or combination of 30, 35, 40, 45, and 50 parts. When the mass fraction is less than 30 parts, the growth environment and nutrients provided for the microorganisms are insufficient, making it difficult to effectively optimize the microbial community structure and enhance microbial activity. When the mass fraction is greater than 50 parts, it may lead to excessive microbial growth, consuming too much carbon source and other substances, thus affecting the treatment effect. The core component of the tea seed meal extract microcapsules is tea saponin extract, and the wall material is sodium alginate-chitosan.

[0050] The carbon source can be any number or combination of 20, 25, 30, 35, or 40 parts by mass. Below 20 parts, microorganisms lack sufficient energy, limiting their metabolic capacity and affecting the removal of organic matter and ammonia nitrogen. Above 40 parts, carbon source waste may occur, and excessive microbial growth may lead to other problems. The carbon source should consist of 60% soluble starch and 40% glucose.

[0051] The mass fractions of the trace element mixture are any number or combination of 10, 12, 15, 18, and 20 parts. If the mass fraction is less than 10 parts, it will not be able to provide enough trace elements for the microorganisms, affecting their normal physiological functions. If the mass fraction is more than 20 parts, it may cause an imbalance of trace elements in the microorganisms, affecting their growth and metabolism.

[0052] The mass fraction of the nitrification accelerator is any value or combination of 5, 8, 10, 12, or 15 parts. When the fraction is less than 5 parts, the promoting effect on the nitrification reaction is not obvious, and the ammonia nitrogen removal efficiency is low; when the fraction is more than 15 parts, it may change the environment of the biochemical system and affect the growth of microorganisms. Ammonium chloride and urea are mixed in a 1:1 mass ratio in the nitrification accelerator.

[0053] The binder is sodium carboxymethyl cellulose, and its mass fraction is any value or combination of 3, 4, 5, 6, and 8 parts. When it is less than 3 parts, it cannot effectively bind other components, affecting the molding and use effect of agent B; when it is more than 8 parts, it may affect the release and function of other components in agent B.

[0054] Agent B is used to precisely regulate the colony structure of biochemical systems, inhibit filamentous bacteria, provide slow-release carbon sources and trace elements, and enhance system stability. The preparation method of Agent B is as follows:

[0055] Tea seed meal powder was mixed with 60% ethanol solution at a solid-liquid ratio of 1:10 and extracted by reflux at 60℃ for 2 hours. The crude extract of tea saponin was obtained by filtration and concentration. A core material was prepared by mixing 2% sodium alginate solution with tea saponin extract at a volume ratio of 4:1 using a sharp-pore coagulation bath method. The core material was slowly dripped into a coagulation bath containing 1.5% calcium chloride and 0.5% chitosan (dissolved in 1% acetic acid solution) using a peristaltic pump. Water droplets instantly formed gel beads (microcapsules) in the coagulation bath. After solidification and cross-linking for 30 minutes, the microcapsules were removed, washed with deionized water, and vacuum dried at 40℃ to obtain tea saponin microcapsules.

[0056] The microcapsules, composite carbon source, trace element mixture, nitration accelerator, and sodium carboxymethyl cellulose were added together into a trough mixer. A small amount of deionized water was sprayed to make the material moisture content moderate. The mixture was then granulated using a swing granulator through a 20-mesh sieve. The wet granules were then fluidized bed dried at 50°C until the moisture content was <5%, yielding agent B.

[0057] Agent B microencapsulates tea saponins for gut microbiota regulation, achieving sustained release and targeted effects while avoiding the impact of instantaneous high concentrations on the microbiome.

[0058] The mass fraction of the coated sodium bicarbonate in Agent C is any value or combination of 70, 72, 75, 78, and 80 parts. When the mass fraction is less than 70 parts, the released bicarbonate ions are insufficient, making it difficult to effectively remove calcium and heavy metal ions from wastewater; when the mass fraction is greater than 80 parts, it may lead to excessively high concentrations of bicarbonate ions in the water, affecting water quality. The core of the coated sodium bicarbonate is NaHCO3, the coating material is polylactic acid (PLA), and the coating weight gain is 15%.

[0059] The mass fraction of nano-sized seed crystals can be any value or combination of 20, 22, 25, 28, or 30 parts. Below 20 parts, there are insufficient crystallization nuclei provided for the precipitation reaction, resulting in low precipitation efficiency; above 30 parts, it may increase costs without significantly improving the precipitation effect. The nano-sized seed crystals are nano-calcite seed crystals with an average particle size of 50 nm.

[0060] The C agent induces crystallization by slowly releasing carbonate ions at the end, deeply stabilizing heavy metals and removing hardness to ensure that the effluent meets standards. The preparation method of the C agent is as follows:

[0061] NaHCO3 powder was placed in a fluidized bed granulation and coating machine. Polylactic acid (PLA) was dissolved in dichloromethane to prepare a 5% coating solution. The inlet air temperature was controlled at 40°C and the atomization pressure at 0.3 MPa. The fluidized NaHCO3 was bottom-sprayed for coating until the coating layer achieved a 15% weight gain. This process ensured that the PLA film completely encapsulated the NaHCO3. The coated NaHCO3 particles were then mixed with nano-calcite seed crystals in a gentle mixer for 5 minutes to prevent the coating layer from breaking, yielding agent C.

[0062] Precise coating of NaHCO3 with biodegradable PLA film achieves CO3... 2- The delayed release allows its release curve to match the pollutant concentration and pH environment.

[0063] In this embodiment, the modified silica-calcium based mineral material in Agent A is sepiolite or diatomaceous earth loaded with nano-calcium oxide and iron salts; the structure regulator is disodium hydrogen phosphate or sodium dihydrogen phosphate; the organic flocculant is zwitterionic polyacrylamide; and the inorganic flocculant is ferric sulfate polysilicate. Among these, sepiolite or diatomaceous earth loaded with nano-calcium oxide and iron salts, due to their unique microstructure and chemical properties, forms an important basis for adsorbing and removing pollutants from wastewater. Nano-calcium oxide has strong alkalinity, which can neutralize some acidic substances in wastewater and promote the precipitation of some metal ions. During hydrolysis, iron salts form ferric hydroxide colloids with adsorption and coagulation effects, further enhancing the capture capacity of fine particles and organic matter in wastewater. Zwitterionic polyacrylamide, as an organic flocculant, has both positive and negative ionic groups on its molecular chain. In wastewater, it can neutralize, bridge, and adsorb pollutant particles with different charges, causing them to approach each other and aggregate into larger flocs. This flocculation effect is unaffected by the pH value of the wastewater, operating within a wide pH range and exhibiting strong adaptability. Ferric polysilicate sulfate, as an inorganic flocculant, has hydrolysis products with high polymerization degree and positive charge density. On one hand, it can neutralize the charge on colloidal particles in wastewater, reducing the surface charge repulsion and promoting particle collision and aggregation. On the other hand, the polymers formed can connect multiple particles together through adsorption bridging, forming larger flocs. When used in conjunction with organic flocculants, the advantages of both can be fully utilized, improving flocculation efficiency and effectiveness. Disodium hydrogen phosphate or sodium dihydrogen phosphate, as structure modifiers, plays a role in regulating floc structure during floc formation. They can form complexes with metal ions, altering the surface properties and internal structure of the flocs, making them denser and more stable. Dense flocs have better settling performance during sedimentation, separating from wastewater more quickly, thereby improving sedimentation efficiency and effluent quality. These components work synergistically, enabling Agent A to efficiently remove suspended solids, colloids, and some organic matter from wastewater in primary treatment. The adsorption effect of modified calcium silicate-based mineral materials provides the foundation for the subsequent flocculation process. The synergistic effect of organic and inorganic flocculants enables pollutant particles to rapidly aggregate into flocs, while the structure regulator ensures that the flocs have good sedimentation properties. Through this comprehensive effect, Agent A can significantly reduce the turbidity and COD of wastewater, creating favorable conditions for subsequent biological and advanced treatment. Moreover, this combined formulation of Agent A exhibits good adaptability and stability under different water qualities and treatment conditions, meeting the needs of various wastewater treatment scenarios.

[0064] In this embodiment, the trace element mixture in Agent B includes 1-3% CuSO4·5H2O, 2-4% ZnSO4·7H2O, 1-2% Na2MoO4·2H2O, 0.3-0.8% CoCl2·6H2O, and 90-95% zeolite powder carrier; the nitrification promoter is a mixture of ammonium chloride and urea in a mass ratio of 1:0.8-1.2; and the binder is sodium carboxymethyl cellulose. Trace elements such as CuSO4·5H2O, ZnSO4·7H2O, Na2MoO4·2H2O, and CoCl2·6H2O are components or activators of various enzymes in microorganisms, participating in various physiological processes such as energy metabolism and substance synthesis. The zeolite powder carrier can not only load these trace elements but also has a large specific surface area and ion exchange capacity, enabling it to adsorb and exchange some harmful substances in wastewater while providing a site for microbial attachment and growth. A nitrification accelerator, a mixture of ammonium chloride and urea at a mass ratio of 1:0.8-1.2, provides a suitable nitrogen source for nitrifying bacteria, promoting the nitrification reaction. In biological systems, nitrifying bacteria convert ammonia nitrogen into nitrite and nitrate, a process crucial for removing ammonia nitrogen from wastewater. Appropriate ratios of ammonium chloride and urea can meet the nitrogen source requirements of nitrifying bacteria at different growth stages, improving ammonia nitrogen removal efficiency. Sodium carboxymethyl cellulose, acting as a binder, binds tea seed meal extract microcapsules, carbon sources, trace element mixtures, and nitrification accelerators together, forming granular B-agent with a certain strength and stability. This not only facilitates the storage, transportation, and use of B-agent but also allows control over the release rate of its components. In biological systems, B-agent slowly releases its components, enabling precise control over the bacterial colony structure of the system.

[0065] Agent B, through the synergistic effect of its components, precisely regulates the microbial community structure of the biological system, inhibiting the growth of filamentous bacteria. Excessive growth of filamentous bacteria in the biological system leads to sludge bulking, affecting system stability and treatment efficiency. The tea saponins in the tea seed meal extract microcapsules can regulate the microbial growth environment, inhibiting the growth of filamentous bacteria while providing suitable growth conditions for beneficial microorganisms. Furthermore, Agent B provides a slow-release carbon source and trace elements, ensuring a stable nutrient supply for microorganisms throughout the treatment process, enhancing system stability and shock resistance. Under different water qualities and treatment loads, Agent B plays a unique role in improving the removal efficiency of organic matter and ammonia nitrogen in the biological system, further enhancing the quality of wastewater treatment.

[0066] Agent C plays a crucial role in the final stage of wastewater treatment. Sodium bicarbonate coating, one of the main components of Agent C, uses polylactic acid (PLA) as its coating material, which is biodegradable. This not only aligns with environmental protection principles but also helps achieve CO3 reduction. 2-The delayed release. When agent C is added to wastewater, over time, the polylactic acid (PLA) coating is gradually decomposed by microorganisms in the environment, causing the core NaHCO3 to begin releasing bicarbonate ions (HCO3-). - These bicarbonate ions will react with calcium ions (Ca) in the wastewater. 2+ A reaction occurs, producing calcium carbonate (CaCO3) precipitate. The specific reaction formula is: Ca... 2+ + 2HCO3 - The reaction ⇌CaCO3↓ + H2O + CO2↑ effectively reduces the concentration of calcium ions in wastewater, thereby lowering water hardness.

[0067] Meanwhile, for heavy metal ions in wastewater, such as lead ions (Pb) 2+ ), copper ions (Cu) 2+ Bicarbonate ions react with these substances in a series of chemical reactions, forming corresponding carbonate precipitates. Nanoscale seed crystals, specifically nano-calcite seed crystals, consist of fine particles with an average diameter of 50 nm. Their unique particle size and crystal structure provide numerous crystallization nuclei for the precipitation reaction. When the tiny particles generated in the precipitation reaction encounter nanoscale seed crystals, they rapidly adhere to the seed crystal surface and grow according to the seed crystal structure, forming larger and more stable precipitate particles. These precipitate particles exhibit better settling performance and can be separated from wastewater more quickly, thus achieving deep and stable removal of heavy metal ions.

[0068] Moreover, the polylactic acid (PLA) coating enables CO3 production. 2- The delayed release of bicarbonate ions allows the release curve to match the pollutant concentration and pH environment. When the pollutant concentration in wastewater is high and the pH value is suitable for the reaction, bicarbonate ions can be released continuously and stably, ensuring the efficient progress of the precipitation reaction. Simultaneously, this delayed release avoids a large, one-time release of bicarbonate ions, preventing excessively high bicarbonate ion concentrations in the water from affecting water quality. Agent C, at the end of the treatment process, slowly releases carbonate ions, induces crystallization, deeply stabilizes heavy metals, and removes hardness, ensuring that the effluent meets relevant water quality standards, thus providing a perfect conclusion to the entire wastewater treatment process. In wastewater of different types and concentrations, Agent C, with its unique mechanism of action, demonstrates excellent treatment effects, providing a reliable guarantee for wastewater treatment.

[0069] A second aspect of the present invention provides a wastewater treatment method using the aforementioned composite wastewater treatment agent, comprising the following steps:

[0070] (1) Add agent A to the industrial wastewater to be treated to carry out coagulation and sedimentation reaction and complete the primary treatment;

[0071] (2) Introduce the effluent from step (1) into the biochemical treatment unit and add agent B to it for bio-enhanced treatment;

[0072] (3) Add agent C to the effluent from step (2), stir and react, and precipitate to complete the deep treatment.

[0073] In this embodiment, the wastewater treatment equipment includes an equalization tank, an intelligent dosing system, a primary flocculation sedimentation tank, an A / O biological treatment tank, a secondary sedimentation tank, and a clear water tank. An online UV-VIS spectral sensor and an ion-selective electrode are installed at the inlet of the equalization tank to monitor the concentration of COD, TOC, color, and specific heavy metals (such as Cu and Cr) in real time.

[0074] In step (1), wastewater is pumped from the equalization tank into the primary reaction tank (divided into three compartments: fast mixing, medium speed, and slow mixing).

[0075] Quick mixing: Add agent A, and control the stirring intensity (G value) at 250-350 s. -1 The hydraulic residence time (HRT) is 2 minutes.

[0076] Mid-speed mode: G-force drops to 70-90 s -1 HRT is 5 minutes.

[0077] Slow blending: G value drops to 20-40 s -1 HRT is 10 minutes.

[0078] It then enters an inclined plate sedimentation tank, with a surface loading of 1.0 m. 3 / m 2 • h. The settled sludge is discharged into the sludge storage tank, and the supernatant from the primary sedimentation tank enters the A / O biological treatment tank.

[0079] In this embodiment, the A / O biochemical tank includes an anoxic tank (A tank) and an aerobic tank (O tank).

[0080] Anoxic tank (tank A): HRT=2h, dissolved oxygen (DO)<0.5 mg / L. At the beginning of this tank, agent B is continuously added via a dry powder dosing machine at a ratio of agent B to influent COD of 1:50-200 (mass ratio).

[0081] Aerobic tank (O tank): HRT=6h, DO controlled at 2-3 mg / L.

[0082] Mixed liquor reflux ratio: 100%-200%. The biochemical effluent enters the secondary reaction tank (slow mixing tank).

[0083] In this embodiment, based on the online monitoring values ​​of effluent pH (typically 7.0-7.5) and hardness, the ratio of agent C to residual calcium is determined. 2+Add agent C in a ratio of (1.0 - 1.5) : 1 in terms of the molar ratio of heavy metal ions, and the G value of the reaction stirring intensity is 15 - 25 s -1 , and the HRT is 20 minutes.

[0084] Subsequently, it enters the final sedimentation tank (surface loading of 0.8 m 3 / m 2 ·h) to completely separate the generated microcrystalline particles. The clear and up-to-standard supernatant overflows to the clear water tank for discharge or reuse.

[0085] Merge the sludge from the first and second sedimentation tanks and enter the sludge thickening tank.

[0086] The third aspect of this application provides an application of the composite sewage treatment agent in sewage treatment.

[0087] When treating industrial wastewater containing high concentrations of suspended solids, colloids, and organic matter, the use of agent A can quickly reduce the turbidity and COD of the wastewater, reducing the burden on subsequent treatment. Agent B plays a key role in the biochemical treatment unit. Taking the treatment of printing and dyeing wastewater as an example, the composition of printing and dyeing wastewater is complex, containing a large amount of organic matter and chromaticity substances, and the biochemical treatment is difficult. Components such as the tea seed meal extract microcapsule, carbon source, trace element mixture, and nitrification promoter in agent B act synergistically to precisely regulate the colony structure of the biochemical system, inhibit the growth of filamentous bacteria, and avoid sludge bulking. At the same time, it provides a stable nutrient supply for microorganisms, enhances the stability and shock resistance of the system, and improves the removal effect of the biochemical system on organic matter and ammonia nitrogen. Agent C is indispensable in the advanced treatment stage. For mine wastewater containing high hardness and heavy metal ions, the coated sodium bicarbonate in agent C slowly releases carbonate ions, which react with calcium ions and heavy metal ions to form precipitates. The nanoscale crystal seeds provide a crystallization core for the precipitation reaction, making the precipitate particles larger and more stable, effectively reducing the water hardness and removing heavy metal ions, ensuring that the effluent meets the standards. The composite sewage treatment agent and the sewage treatment method are applicable to the treatment of various types of industrial wastewater and have broad application prospects.

[0088] Examples

[0089] The following examples more specifically describe the content disclosed in the present invention. These examples are only for illustrative purposes, because various modifications and changes within the scope of the present invention are obvious to those skilled in the art. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are based on weight. Unless otherwise stated, all reagents used in the examples can be obtained through conventional commercial channels or synthesized according to conventional methods and can be directly used without further treatment. Unless otherwise stated, the instruments used in the examples can be obtained through conventional commercial channels.

[0090] Preparation Example 1

[0091] A composite wastewater treatment agent includes agent A, agent B, and agent C, wherein...

[0092] Agent A comprises the following raw materials in mass fraction: 50 parts modified silicon-calcium based mineral material, 15 parts zwitterionic polyacrylamide, 8 parts disodium hydrogen phosphate, 7 parts polysilicic acid ferric sulfate, and 25 parts anhydrous sodium sulfate.

[0093] The B agent comprises the following raw materials by mass fraction: 40 parts of tea seed meal extract microcapsules, 30 parts of carbon source (starch and glucose), 15 parts of trace element mixture, 12 parts of nitration accelerator, and 5 parts of sodium carboxymethyl cellulose.

[0094] The C agent comprises the following raw materials in mass fractions: 75 parts coated sodium bicarbonate and 25 parts nano calcite seed crystals.

[0095] Preparation Example 2

[0096] A composite wastewater treatment agent includes agent A, agent B, and agent C, wherein...

[0097] Agent A comprises the following raw materials by mass fraction: 42 parts modified silicon-calcium based mineral material, 13 parts zwitterionic polyacrylamide, 6 parts disodium hydrogen phosphate, 9 parts polysilicic acid ferric sulfate, and 30 parts anhydrous sodium sulfate.

[0098] The B agent comprises the following raw materials by mass fraction: 32 parts of tea seed meal extract microcapsules, 23 parts of carbon source (starch and glucose), 11 parts of trace element mixture, 14 parts of nitration accelerator, and 7 parts of sodium carboxymethyl cellulose.

[0099] The C agent comprises the following raw materials in mass fractions: 70 parts coated sodium bicarbonate and 30 parts nano calcite seed crystals.

[0100] Preparation Example 3

[0101] A composite wastewater treatment agent includes agent A, agent B, and agent C, wherein...

[0102] Agent A comprises the following raw materials by mass fraction: 60 parts modified silicon-calcium based mineral material, 18 parts zwitterionic polyacrylamide, 8 parts disodium hydrogen phosphate, 5 parts polysilicic acid ferric sulfate, and 22 parts anhydrous sodium sulfate.

[0103] The B agent comprises the following raw materials by mass fraction: 50 parts of tea seed meal extract microcapsules, 38 parts of carbon source (starch and glucose), 18 parts of trace element mixture, 5 parts of nitration accelerator, and 3 parts of sodium carboxymethyl cellulose.

[0104] The C agent comprises the following raw materials in mass fractions: 80 parts coated sodium bicarbonate and 20 parts nano calcite seed crystals.

[0105] The following examples all used actual combined wastewater collected from an industrial park in Changsha as the raw water for the experiments. The main water quality indicators were: COD: 850-900 mg / L, NH3-N: 65-70 mg / L, color: 350-400 times, Cr... 3+ 2.5-2.8 mg / L, Cd 2+ : 0.7-0.9mg / L, pH: 7.5-8.5.

[0106] Example 1

[0107] Take five 1L portions of raw water and add 100, 200, 300, 400, and 500 mg / L of reagent A from Preparation Example 1, respectively. Stir rapidly (300 rpm / 2 min), moderately (80 rpm / 5 min), and slowly (40 rpm / 10 min), then allow to settle for 30 min. Collect the supernatant and measure COD, color, and heavy metal concentration. The results are shown in Table 1.

[0108]

[0109] As shown in Table 1, the removal rate curve reached a plateau when the dosage of agent A was 300 mg / L, and further increasing the dosage was not cost-effective. Therefore, the optimal dosage was 300 mg / L.

[0110] Example 2

[0111] Five portions of the supernatant treated with Example 1 (300 mg / L of agent A) were inoculated with an equal volume of activated sludge, and agent B (based on agent B dry weight / influent COD) was added at concentrations of 0, 5, 10, 15, and 20 mg / L, respectively. After reacting in the A / O system for 8 hours, the COD and NH3-N of the effluent were measured, and the results are shown in Table 2.

[0112]

[0113] Table 2 shows that agent B effectively improved biochemical efficiency and sludge properties. The optimal dosage was 10 mg / L.

[0114] Example 3

[0115] Take 5 portions of the effluent treated in Example 2 (Agent B 10 mg / L), and mix them according to n(HCO3) 3- ):n(Ca 2+ +M 2+ Add agent C at ratios of 0.8:1, 1.0:1, 1.2:1, 1.5:1, and 2.0:1, stir slowly (25 rpm / 20 min), and allow to settle. Measure the residual hardness, heavy metal content, and turbidity of the supernatant. The results are shown in Table 3.

[0116]

[0117] Table 3 shows that pollutants are thoroughly removed at a molar ratio of 1.2:1. The optimal molar ratio is 1.2:1.

[0118] Example 4

[0119] Take 1L of raw water and process it as follows: A agent (300mg / L) → sedimentation → B agent (10mg / L) + A / O biochemical treatment (8h) → C agent (n(HCO3) - (n(ions) = 1.2:1) → Complete precipitation process. The final effluent parameters were tested, and the results are shown in Table 4.

[0120]

[0121] Comparative Example 1

[0122] Take 1L of raw water, add 300mg / L PAC + 5mg / L PAM, after flocculation and sedimentation, the supernatant is put into the A / O system for treatment for 8h (without adding agent B), and the supernatant is taken for testing after sedimentation. The results are shown in Table 5.

[0123]

[0124] Comparative Example 2

[0125] Take 1L of raw water and process it according to the following process: A agent (300mg / L) → sedimentation → C agent (1.2:1) → sedimentation (skipping the biochemical unit).

[0126] Results: COD in effluent was 105 mg / L, and NH3-N in effluent was 55 mg / L.

[0127] Analysis: NH3-N was almost entirely not removed, demonstrating that Agent B and its driven biochemical process are essential for removing biodegradable pollutants (such as ammonia nitrogen). This is likely because the tea seed meal extract microcapsules, carbon source, trace element mixture, and nitrification promoter in Agent B provide a suitable growth environment and abundant nutrients for microorganisms, promoting their metabolic activity and thus effectively removing biodegradable pollutants such as ammonia nitrogen. In Comparative Example 2, because the biochemical treatment unit with Agent B was skipped, the lack of microbial activity meant that pollutants such as ammonia nitrogen could not be fully decomposed and removed.

[0128] The overall experimental results of the composite wastewater treatment agent and method of this invention demonstrate significant advantages in treating industrial wastewater. Compared with traditional treatment agents (such as PAC and PAM in Comparative Example 1), the composite wastewater treatment agent of this invention can more efficiently remove various pollutants from wastewater, including COD, ammonia nitrogen, color, and heavy metals, and the treated effluent quality better meets national standards. Simultaneously, each agent plays a unique and crucial role in different treatment stages: agent A's coagulation and sedimentation reduces the load on subsequent treatments; agent B's bio-enhanced treatment improves biochemical efficiency and sludge properties; and agent C's advanced treatment ensures that the effluent meets discharge standards.

[0129] Comparative Example 3

[0130] The process is as follows: Agent A (300 mg / L) → Precipitation → Agent B (10 mg / L) + A / O Biochemical (8 h).

[0131] Result: Cd in effluent 2+ The concentration was 0.09 mg / L, and the total hardness was relatively high.

[0132] Analysis: Cd in the effluent 2+ The concentration exceeded the standard, and hardness was not effectively removed. This proves that Agent C is crucial for the deep removal of heavy metals and hardness. The reason may be that the coated sodium bicarbonate in Agent C can slowly release carbonate ions, reacting with calcium ions and heavy metal ions such as cadmium ions in the wastewater to form precipitates. The nano-calcite seed crystals provide crystallization nuclei for the precipitation reaction, making the resulting precipitate particles larger and more stable, thus effectively reducing water hardness and removing heavy metal ions. In Comparative Example 3, because Agent C was not used for deep treatment, cadmium ions and hardness in the wastewater could not be fully removed, resulting in an excessive cadmium ion concentration and high total hardness in the effluent.

[0133] The results from the above embodiments and comparative examples further demonstrate that the composite wastewater treatment agent A, B, and C of the present invention are indispensable. They work together at different stages of wastewater treatment to form a complete and efficient wastewater treatment system.

[0134] Comparative Example 4

[0135] Take 1L of raw water and add agent A (300mg / L), agent B (10mg / L), and agent C (1.2:1) simultaneously at the start of rapid mixing. The subsequent process is the same as in Example 4.

[0136] Results: Treatment efficiency decreased across the board, with COD in the effluent reaching 85 mg / L, NH3-N in the effluent reaching 22 mg / L, and Cd... 2+ The effluent concentration is 0.15 mg / L.

[0137] Analysis: Simultaneous administration leads to mutual interference of drug effects (e.g., agent C releases CO3 prematurely). 2- (Encapsulated by flocculation; Agent B is removed by flocculation).

[0138] Comparative Example 5

[0139] Replace the microcapsules (Agent B) in Example 4 with an equal amount of ordinary tea seed meal powder, and follow the same steps.

[0140] Results: The COD removal rate of the biochemical system was acceptable in the early stage, but after 24 hours of operation, the microbial activity was significantly inhibited and the NH3-N removal rate dropped to below 60%.

[0141] Analysis: Unencapsulated tea seed meal powder releases high concentrations of saponins instantaneously, impacting and even toxicizing the microbial community. This demonstrates that microencapsulation technology is crucial for achieving sustained release and biocompatibility.

[0142] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A composite wastewater treatment agent, characterized in that, Including Agent A, Agent B, and Agent C, Agent A comprises the following raw materials in mass fraction: 40-60 parts of sepiolite loaded with nano-calcium oxide and iron salts, 10-20 parts of organic flocculant, 5-10 parts of structure regulator, 5-10 parts of inorganic flocculant, and 20-30 parts of filler. The B agent comprises the following raw materials by mass fraction: 30-50 parts of tea seed meal extract microcapsules, 20-40 parts of carbon source, 10-20 parts of trace element mixture, 5-15 parts of nitration accelerator, and 3-8 parts of binder. The preparation method of tea seed meal extract microcapsules is as follows: using the sharp-hole coagulation bath method, a core material solution containing sodium alginate and tea seed meal extract is dropped into a coagulation bath containing calcium ions and chitosan to form gel microcapsules. The C agent comprises the following raw materials in mass fractions: 70-80 parts of coated sodium bicarbonate and 20-30 parts of nano-sized seed crystals.

2. The composite wastewater treatment agent according to claim 1, characterized in that, The structure modifier mentioned in Agent A is disodium hydrogen phosphate or sodium dihydrogen phosphate; and / or The organic flocculant is amphoteric polyacrylamide; and / or The inorganic flocculant is ferric polysilicate sulfate.

3. The composite wastewater treatment agent according to claim 1, characterized in that, The trace element mixture in Agent B includes 1-3% CuSO4·5H2O, 2-4% ZnSO4·7H2O, 1-2% Na2MoO4·2H2O, 0.3-0.8% CoCl2·6H2O, and 90-95% zeolite powder carrier; and / or The nitration accelerator is a mixture of ammonium chloride and urea in a mass ratio of 1:0.8-1.2; and / or The binder is sodium carboxymethyl cellulose.

4. The composite wastewater treatment agent according to claim 1, characterized in that, The preparation method of the coated sodium bicarbonate in Agent C is as follows: using a solution of biodegradable polymer material as the coating liquid, the sodium bicarbonate particles are coated, and the weight gain of the coating is controlled to be 10%-20%.

5. A wastewater treatment method using the composite wastewater treatment agent as described in any one of claims 1-4, characterized in that, Includes the following steps: (1) Add agent A to the industrial wastewater to be treated to carry out coagulation and sedimentation reaction and complete the primary treatment; (2) Introduce the effluent from step (1) into the biochemical treatment unit and add agent B to it for bio-enhanced treatment; (3) Add agent C to the effluent from step (2), stir and react, and precipitate to complete the deep treatment.

6. The wastewater treatment method using the composite wastewater treatment agent according to claim 5, characterized in that, In step (1), after adding agent A, the reaction time is sequentially 250-350 s. -1 70-90 s -1 and 20-40 s -1 The stirring intensity G value is used to carry out a three-stage reaction.

7. The wastewater treatment method using the composite wastewater treatment agent according to claim 5, characterized in that, Agent B is added to the anoxic zone or inlet of the biochemical treatment unit at a mass ratio of Agent B to COD of the inlet water of 1:50-200.

8. The wastewater treatment method using the composite wastewater treatment agent according to claim 5, characterized in that, The dosage of agent C is controlled according to the molar ratio of bicarbonate ions to residual calcium ions and heavy metal ions in the wastewater (1.0-1.5:1), and the reaction stirring intensity G value is 15-25 s. -1 .

9. The application of the composite wastewater treatment agent as described in any one of claims 1-4 in wastewater treatment.

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