Medical wastewater treatment method for synergistic removal of new pollutants and pathogenic microorganisms

Abstract

This invention belongs to the field of wastewater treatment technology, specifically a method for treating medical wastewater by synergistically removing new pollutants and pathogenic microorganisms. The method includes the following steps: S1, Pretreatment: Inorganic flocculants are added to the medical wastewater to promote the aggregation and sedimentation of suspended particles and colloids; S2, Oxidation Treatment: A composite agent is added to the pretreated medical wastewater while a direct current electric field is applied. The composite agent includes potassium persulfate, aminosulfonic acid, sodium chloride, sodium bromide, surfactant, pH buffer, composite corrosion inhibitor, anti-caking agent, and anhydrous sodium sulfate. After dissolving, the composite agent generates a strong oxidizing component that mineralizes and decomposes organic matter while killing pathogens; S3, Biochemical Treatment: The oxidized medical wastewater is then subjected to biochemical treatment to remove ammonia nitrogen and small molecule organic matter. This invention can effectively decompose various new pollutants and inactivate pathogenic microorganisms, thus improving the treatment effect.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, and in particular to a medical wastewater treatment method for the synergistic removal of new pollutants and pathogenic microorganisms. Background Technology

[0002] Wastewater from medical institutions not only contains highly pathogenic microorganisms but also is rich in chemically stable new pollutants such as antibiotics and endocrine disruptors. For a long time, the treatment of medical wastewater has typically employed a combination of primary biological treatment followed by disinfection, or secondary biological treatment followed by disinfection. Biological treatment processes can effectively remove conventional organic pollutants (such as COD and ammonia nitrogen), and the final disinfection stage mainly relies on traditional chlorine-containing disinfectants such as sodium hypochlorite and liquid chlorine. However, this type of process is limited by the relatively low oxidation potential of available chlorine species, achieving only basic sterilization and disinfection, and is insufficient to effectively destroy the structure of new pollutants. When incompletely degraded new pollutants are discharged into natural water bodies, they can easily induce the generation and spread of drug-resistant bacteria and resistance genes, posing a potential ecological and environmental risk. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a medical wastewater treatment method that synergistically removes new pollutants and pathogenic microorganisms, which can effectively decompose various new pollutants and inactivate pathogenic microorganisms at the same time, thereby improving the treatment effect.

[0004] To address the above problems, the technical solution adopted in this invention is: a medical wastewater treatment method for the synergistic removal of new pollutants and pathogenic microorganisms, comprising the following steps:

[0005] S1. Pretreatment: Inorganic flocculants are added to medical wastewater to promote the aggregation and sedimentation of suspended particles and colloids in the medical wastewater;

[0006] S2. Oxidation treatment: A composite agent is added to the pretreated medical wastewater while a direct current electric field is applied. The composite agent comprises the following components in parts by weight:

[0007] Potassium persulfate compound salt: 45-55 parts;

[0008] Aminosulfonic acid: 5-10 parts;

[0009] Sodium chloride: 1-3 parts;

[0010] Sodium bromide: 2-4 parts;

[0011] Surfactant: 10-15 parts;

[0012] pH buffer: 5-10 parts;

[0013] Composite corrosion inhibitor: 8-12 parts;

[0014] Anti-caking agent: 2-4 parts;

[0015] Anhydrous sodium sulfate: 2-5 parts;

[0016] After the compound agent dissolves, it generates a strong oxidizing component that mineralizes and decomposes organic matter while killing pathogens.

[0017] S3. Biochemical treatment: The medical wastewater after oxidation is subjected to biochemical treatment to remove ammonia nitrogen and small molecule organic matter.

[0018] Further, in step S2, the pretreated medical wastewater is introduced into the adsorption chamber, and adsorption particles with surface-loaded nano-adsorption materials are placed in the adsorption chamber. The nano-adsorption materials selectively adsorb organic matter in the medical wastewater. Then, the adsorption particles and part of the medical wastewater are introduced into the first oxidation chamber, and the medical wastewater without adsorption particles is introduced into the second oxidation chamber. The amount of medical wastewater introduced into the first oxidation chamber is less than the amount introduced into the second oxidation chamber.

[0019] A composite reagent is introduced into the first oxidation chamber, while a direct current electric field is applied.

[0020] A composite agent is added to the second oxidation chamber, and the amount of composite agent added to the second oxidation chamber is lower than the amount of composite agent added to the first oxidation chamber.

[0021] The medical wastewater treated in the first and second oxidation chambers is then mixed before proceeding to step S3.

[0022] Furthermore, the adsorbent particles are hollow iron oxide particles, and the nano-adsorbent material is one or more of mesoporous silica, graphitic carbon nitride, metal-organic framework materials, covalent organic framework materials, and activated carbon.

[0023] Furthermore, a filter layer is provided in the adsorption chamber, the diameter of the filter pores of the filter layer is smaller than the particle size of the adsorbed particles, and a first outlet and a second outlet are respectively provided on both sides of the filter layer, the first outlet being connected to the first oxidation chamber and the second outlet being connected to the second oxidation chamber.

[0024] Furthermore, the outlet of the first oxidation chamber is equipped with an adsorption particle collection mechanism, which collects adsorption particles and then puts the adsorption particles back into the adsorption chamber.

[0025] Furthermore, in the first oxidation chamber, the dosage of the composite agent is 30-50 mg / L, and the current density is 5-15 mA / cm²; in the second oxidation chamber, the dosage of the composite agent is 5-10 mg / L.

[0026] Furthermore, the preparation method of the compound agent is as follows:

[0027] Weigh each component according to the parts by weight;

[0028] Sodium bromide, sodium chloride, surfactant, and anti-caking agent are put into a high-speed mixer. The mechanical force and frictional heat generated by high-speed shearing cause the surfactant and anti-caking agent to extend on the surface of sodium bromide and sodium chloride particles and form a dense physical coating layer, thus obtaining a mixture A with hydrophobic properties.

[0029] Mixture B is obtained by uniformly mixing potassium persulfate compound salt, aminosulfonic acid, pH buffer, composite corrosion inhibitor and anhydrous sodium sulfate by low-speed stirring.

[0030] Add mixture A slowly to mixture B and stir slowly until mixture A and mixture B are evenly mixed to obtain a compound agent.

[0031] Furthermore, when preparing mixture A, sodium bromide, sodium chloride, and half of the anti-caking agent are first added to a high-speed mixer and mixed for 2-3 minutes at a speed of 800-1000 r / min, so that the anti-caking agent initially adheres to the surface of the particles.

[0032] Add surfactant, increase rotation speed to 1500-1800 r / min, and simultaneously heat material to 50-65℃. Stir for 5-8 minutes, then rapidly cool material to below 35℃. Reduce rotation speed to 300-500 r / min, add remaining anti-caking agent, and stir for 2-3 minutes.

[0033] Furthermore, the surfactant is sodium dodecyl sulfonate; the pH buffer is a mixture of citric acid and sodium citrate in a mass ratio of 1:1 to 3:1; the composite corrosion inhibitor is a mixture of sodium silicate, disodium EDTA, sodium gluconate, and sodium hexametaphosphate; and the anti-caking agent is a mixture of fumed silica and magnesium chloride.

[0034] The beneficial effects of this invention are as follows: 1. This invention utilizes the synergistic effect of a composite agent and a DC electric field. Under the activation of the electric field, the potassium persulfate composite salt in the composite agent generates strong oxidizing components with higher oxidation potentials (such as sulfate free radicals, hydroxyl free radicals, and bromine-based active species). Compared with traditional chlorine-containing disinfectants, it can effectively destroy new pollutants with stable chemical structures, such as antibiotics and endocrine disruptors, achieving their mineralization and decomposition. This solves the problem that traditional processes can only perform basic sterilization and cannot deeply degrade new pollutants. At the same time, the synergistic effect of the strong oxidizing components and the electric field can significantly improve the killing efficiency of pathogenic microorganisms, achieving the dual goals of removing new pollutants and sterilization, and cutting off the source of the generation and spread of drug-resistant bacteria and resistance genes.

[0035] 2. This invention employs a rational process of "pretreatment-oxidation treatment-biochemical treatment." In the pretreatment stage, inorganic flocculants remove suspended particles and colloids, preventing them from interfering with subsequent oxidation reactions and biochemical treatment efficiency. After oxidation treatment, only small-molecule organic matter remains, which can be efficiently degraded by subsequent biochemical processes. This solves the problem of poor compatibility between oxidation and biochemical processes in traditional methods. Simultaneously, biochemical treatment further removes ammonia nitrogen, achieving deep water purification and ensuring that the effluent meets standards. Compared to traditional chlorine-containing disinfection processes, this invention eliminates the need for large amounts of disinfectant, reducing the total amount of chemicals used and lowering costs. It also avoids the generation of chlorine-containing disinfection byproducts, reducing the risk of secondary pollution.

[0036] 3. The aminosulfonic acid in the compound agent can stabilize the strong oxidizing components in the system, prevent its rapid decay, prolong the oxidation time, and ensure the complete degradation of new pollutants; the pH buffer can maintain the pH of the reaction system within a suitable range, ensure the activation efficiency of the electric field for potassium persulfate, and avoid water quality fluctuations affecting the treatment effect; the synergistic cooperation of each component makes the oxidation system highly stable and resistant to interference, adaptable to the complex water quality and diverse pollutant characteristics of medical wastewater. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the device used in Embodiment 1 of the present invention;

[0038] Figure 2 This is a schematic diagram of the device used in Embodiment 2 of the present invention;

[0039] Figure 3 This is a top view of the adsorption chamber in Example 2;

[0040] Reference numerals: 1—Adsorption chamber; 2—Adsorption particles; 3—First oxidation chamber; 4—Second oxidation chamber; 5—Filter layer; 6—First outlet; 7—Second outlet; 8—Adsorption particle collection mechanism; 100—Equalization tank; 110—Oxidation tank; 111—Cathode plate; 112—Anode plate; 113—Power supply; 120—Biochemical tank. Detailed Implementation

[0041] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0042] Example 1

[0043] The medical wastewater treatment method for synergistic removal of new pollutants and pathogenic microorganisms in this embodiment includes the following steps:

[0044] S1. Pretreatment: Inorganic flocculants are added to medical wastewater to promote the aggregation and sedimentation of suspended particles and colloids in the medical wastewater;

[0045] S2. Oxidation treatment: A composite agent is added to the pretreated medical wastewater while a direct current electric field is applied. The composite agent comprises the following components in parts by weight:

[0046] Potassium persulfate compound salt: 45-55 parts;

[0047] Aminosulfonic acid: 5-10 parts;

[0048] Sodium chloride: 1-3 parts;

[0049] Sodium bromide: 2-4 parts;

[0050] Surfactant: 10-15 parts;

[0051] pH buffer: 5-10 parts;

[0052] Composite corrosion inhibitor: 8-12 parts;

[0053] Anti-caking agent: 2-4 parts;

[0054] Anhydrous sodium sulfate: 2-5 parts;

[0055] After the compound agent dissolves, it generates a strong oxidizing component that mineralizes and decomposes organic matter while killing pathogens.

[0056] S3. Biochemical treatment: The medical wastewater after oxidation is subjected to biochemical treatment to remove ammonia nitrogen and small molecule organic matter.

[0057] Specifically, adopt Figure 1 The equipment shown is for treating medical wastewater. The equipment includes an equalization tank 100, an oxidation tank 110, and a biochemical tank 120.

[0058] The equalization tank 100 is connected to a medical wastewater supply pipe, which centrally transports the medical wastewater to be treated to the equalization tank 100. The equalization tank 100 is used to regulate the water quality and quantity, ensuring that the medical wastewater flows into the oxidation tank 110 and the biological treatment tank 120 at a stable flow rate. A pipe mixer can be installed on the medical wastewater supply pipe to add flocculants (such as polyaluminum chloride) to the medical wastewater and promote thorough mixing between the flocculants and the medical wastewater. In the equalization tank 100, suspended particles (SS) and colloidal substances in the medical wastewater aggregate into large particles and settle to the bottom of the equalization tank 100.

[0059] An overflow outlet is installed at the top of the equalization tank 100, away from the medical wastewater supply pipe. The overflow outlet is connected to an overflow pipe, which is connected to the oxidation tank 110. After flocculation and sedimentation, the supernatant of the medical wastewater in the equalization tank 100 enters the oxidation tank 110 through the overflow outlet and the overflow pipe. A pipe mixer can be installed on the overflow pipe to add a compound agent to the medical wastewater. The dosage of the compound agent is 30-50 mg / L, that is, 30-50 mg of compound agent is added per liter of medical wastewater.

[0060] The oxidation tank 110 is equipped with a cathode plate 111 and an anode plate 112, which can be conventional electrodes such as titanium-based ruthenium-iridium electrodes. Multiple cathode plates 111 and anode plates 112 can be used, and they are arranged alternately. A power supply 113 is connected to the cathode plates 111 and anode plates 112, which supplies power to the cathode plates 111 and anode plates 112, thereby applying a DC electric field with a specific current density of 5-15 mA / cm².

[0061] The composite agent used in this invention uses potassium persulfate complex salt as the core oxidant source to generate a strong oxidizing component. Specifically, the potassium persulfate complex salt is composed of potassium persulfate, potassium bisulfate, and potassium sulfate, with the molecular formula 2KHSO5·KHSO4·K2SO4. Upon dissolving in water, it dissociates into persulfate ions. Persulfate itself has strong oxidizing power, capable of directly killing some pathogenic microorganisms and disrupting their cell membranes and nucleic acid structures. Under the activation of a DC electric field, persulfate ions undergo electrochemical cleavage, generating strong oxidizing free radicals such as sulfate and hydroxyl radicals. These free radicals can rapidly attack the chemical bonds (such as benzene rings, amide bonds, and ether bonds) of new pollutants like antibiotics and endocrine disruptors, achieving ring-opening and chain-breaking of the pollutants until they are mineralized and decomposed into inorganic small molecules such as carbon dioxide and water. Simultaneously, persulfate reacts with chloride and bromide ions in the system to generate active hypobromous acid and hypochlorous acid, which can attack bacterial cell membrane proteins and electron-rich groups of antibiotics, enhancing the effectiveness.

[0062] Aminosulfonic acid molecules contain strongly electron-withdrawing sulfonic acid and amino groups, which can form stable complex structures with persulfate and sulfate radicals. This inhibits the hydrolysis of persulfate to sulfate in water, mitigating the ineffective loss of oxidizing components and extending the effective action time of strong oxidizing components. This ensures the complete degradation of trace new pollutants in medical wastewater and avoids incomplete degradation due to rapid decay of oxidizing components. Furthermore, aminosulfonic acid can complex with metal ion impurities in medical wastewater, preventing the ineffective decomposition of persulfate catalyzed by metal ions. This reduces the ineffective consumption of potassium persulfate complex salt, allowing for a lower dosage of core oxidizing components while saving reagent costs. Simultaneously, it enhances the system's resistance to impurity interference, making it suitable for the complex water quality of medical wastewater containing trace metal ions.

[0063] Sodium bromide and sodium chloride dissolve in water to produce chloride ions and bromide ions, which react with persulfate and sulfate free radicals to generate hypobromic acid and hypochlorous acid, or other active substances. These substances play a role in sterilization and synergistically degrading new pollutants such as quinolone antibiotics and phenolic endocrine disruptors.

[0064] Surfactants can improve the solubility of pharmaceutical agents and the mass transfer efficiency of the system, enhance the contact probability between oxidizing components and pollutants, and also have a solubilizing effect on new hydrophobic pollutants, solving the problem of difficulty in sufficient contact between hydrophobic pollutants and active ingredients. Sodium dodecyl sulfonate is the preferred surfactant.

[0065] pH buffers stabilize the pH value within a suitable range, ensuring the efficiency of electric field activation and the stability of oxidizing components, and preventing pH changes caused by fluctuations in the quality of medical wastewater from affecting the treatment effect. The pH buffer is composed of citric acid and sodium citrate mixed in a mass ratio of 1:1 to 3:1.

[0066] Composite corrosion inhibitors are used to suppress corrosion of electrodes, metal pipes, and other equipment under the influence of direct current electric fields, thereby extending the service life of the equipment. The composite corrosion inhibitor is composed of sodium silicate, disodium EDTA, sodium gluconate, and sodium hexametaphosphate, with a weight ratio of (40-50):(25-35):(15-20):(10-15). This composite corrosion inhibitor uses a small amount of sodium hexametaphosphate and has a low phosphorus content, effectively reducing the total phosphorus content of the composite agent and minimizing the potential load on the aquatic environment.

[0067] Anti-caking agents are used to prevent compound agents from caking during storage, transportation, and dosing, ensuring the dispersibility and uniformity of the agent, and avoiding inaccurate dosage and uneven distribution of oxidizing power caused by caking. The anti-caking agent is a mixture of fumed silica and magnesium chloride, with a weight ratio of fumed silica to magnesium chloride of 1:1, and both fumed silica and magnesium chloride have a particle size ≤20μm.

[0068] After pretreatment, medical wastewater has low conductivity, which leads to low current efficiency of the DC electric field and slow electrochemical decomposition rate of persulfate. Anhydrous sodium sulfate dissolves in water and dissociates into sodium ions and sulfate ions, which can significantly improve the conductivity of the water, reduce the internal resistance of the electric field, make the current more evenly distributed in the water, promote the electrochemical activation of persulfate on the electrode surface, and increase the amount of free radicals generated.

[0069] An overflow outlet can also be installed at the top of the oxidation tank 110. The overflow outlet is connected to the biological treatment tank 120 through an overflow pipe. The medical wastewater after oxidation treatment enters the biological treatment tank 120 through the overflow outlet and the overflow pipe. The biological treatment tank 120 is equipped with microbial packing material, which uses microorganisms to further decompose residual small molecule organic matter, ammonia nitrogen and other inorganic matter, so as to achieve full purification of medical wastewater.

[0070] Halogen salts such as sodium chloride and sodium bromide can act as activators to enhance the high-efficiency oxidation performance of potassium persulfate complex salts in aqueous phases. However, potassium persulfate complex salts have strong hygroscopicity and oxidizing activity. If they are directly mixed with components such as sodium chloride and sodium bromide under solid-phase conditions and coexist for a long time, a slow oxidation reaction is likely to occur, leading to the loss of effective components, premature release of irritating odors, product clumping, and decreased fluidity. This affects the treatment effect of medical wastewater, increases the dosage of the reagent, and raises the cost of treatment. Furthermore, the poor stability of the reagent also results in high storage costs.

[0071] To solve the above problems, the preparation method of the compound agent is as follows:

[0072] Weigh each component according to the specified weight proportions. Before weighing, pulverize each component and pass it through an 80-mesh sieve, then dry it at a low temperature (40-60℃) to ensure that the water activity is below 0.30.

[0073] Sodium bromide, sodium chloride, surfactant, and anti-caking agent are fed into a high-speed mixer. The mechanical force and frictional heat generated by high-speed shearing cause the surfactant and anti-caking agent to extend on the surface of sodium bromide and sodium chloride particles and form a dense physical coating layer, thus obtaining a mixture A with hydrophobic properties.

[0074] By coating sodium bromide and sodium chloride particles with surfactants and anti-caking agents, direct contact between the sodium bromide and sodium chloride particles and potassium persulfate composite salt can be avoided. This prevents the potassium persulfate composite salt from reacting with sodium bromide and sodium chloride, improves the stability of the entire composite agent, and prevents the loss of active ingredients.

[0075] Specifically, sodium bromide, sodium chloride, and half of the anti-caking agent are first added to a high-speed mixer and mixed for 2-3 minutes at 800-1000 rpm. This allows the anti-caking agent to initially adhere to the particle surface, providing a framework for subsequent coating. The anti-caking agent (such as fumed silica and magnesium chloride) is an ultrafine hydrophobic inorganic powder with a particle size much smaller than that of sodium bromide and sodium chloride particles. Under mechanical stirring, it adheres to the uneven surfaces of sodium bromide and sodium chloride particles through van der Waals forces and electrostatic adsorption, filling the surface voids and forming a porous framework layer. This framework layer provides a uniform substrate for subsequent surfactant coating, preventing localized accumulation of surfactants due to surface voids in the halide salts (sodium bromide and sodium chloride). Furthermore, it introduces hydrophobic sites on the surface of the halide salt particles in advance, laying the foundation for subsequent hydrophobic modification. Add only half of the anti-caking agent to avoid excessive anti-caking agent forming a thick layer of powder coating, which would hinder the subsequent contact between the surfactant and the surface of the brine particles, thus ensuring that the surfactant can be effectively adsorbed on the surface of the brine particles.

[0076] Next, add the surfactant, increase the rotation speed to 1500-1800 r / min, and simultaneously heat the material to 50-65℃, stirring for 5-8 minutes. At this temperature, the surfactant (such as sodium dodecyl sulfonate) softens to a state with good extensibility but not melted (after melting, it is easily lost under centrifugal force, or shrinks into droplets due to surface tension, making it unable to spread evenly). It has good extensibility and adhesion, and can spread evenly under shear force, slowly spreading on the surface of the halide particles, completely adhering to the skeleton layer, filling the porous gaps in the skeleton layer, and forming a continuous and dense coating film. If the temperature is below 50℃, the surfactant is hard and brittle, lacks extensibility, and is difficult to spread; if the temperature is above 65℃, the surfactant melts, is easily lost, and the coating layer is discontinuous. High rotation speed generates strong shear force and centrifugal force, which on the one hand can shear the surfactant aggregates into tiny flakes to ensure full contact with the halide salt particles; on the other hand, it can promote the softened surfactant to spread rapidly on the surface of the halide salt particles, overcome the resistance of surface tension, and achieve full coverage; at the same time, centrifugal force can make the coating layer adhere tightly to the surface of the halide salt particles, reduce the porosity of the coating layer, and improve the density.

[0077] Next, the material is rapidly cooled to below 35°C, then the rotation speed is reduced to 300-500 r / min, and the remaining anti-caking agent is added, followed by stirring for 2-3 minutes. The remaining anti-caking agent acts as an isolator and lubricant. At 35°C, below the glass transition temperature of the surfactant, rapid cooling (e.g., completing cooling within less than 30 seconds) allows the surfactant coating layer, which is in a highly elastic state, to quickly solidify and set, preventing the coating layer from cold flow and sticking due to excessive temperature, resulting in a dense, solidified coating film structure. Simultaneously, rapid cooling reduces moisture absorption and reabsorption by the halide particles (halides are hygroscopic, with a rapid moisture absorption rate at high temperatures), ensuring the hydrophobic effect of the coating layer. The preferred rapid cooling method is to circulate cooling water through the mixer jacket, achieving uniform cooling within the material and preventing cracking of the coating layer due to localized temperature differences. Reducing the rotation speed generates a slight stirring force, ensuring uniform mixing of the remaining anti-caking agent with the coated halide particles without damaging the solidified surfactant coating layer, thus preventing coating layer detachment and cracking. The remaining anti-caking agent will adhere to the surface of the solidified hydrophobic coating layer through physical adsorption, forming an ultrafine inorganic powder isolation and lubrication layer. This layer does not enter the inner coating structure, but only forms a physical isolation between the halide salt particles, preventing the particles from sticking together due to van der Waals forces and electrostatic effects. At the same time, the lubricity of the inorganic powder can reduce the friction between the particles, improve the dispersibility of mixture A, and ensure that there is no clumping during subsequent storage and that it is easy to disperse when added.

[0078] Sodium bromide and sodium chloride are strongly hydrophilic ionic crystals with high surface energy, easily adsorbing water molecules and causing deliquescence and clumping. By using the above process to form a coating layer on the surface, the hydrophilic lattice sites on the particle surface are completely covered by dense hydrophobic surfactant chains (such as alkyl chains), and an outer layer is coated with a hydrophobic anti-caking agent. This changes the surface wettability of sodium bromide and sodium chloride from strongly hydrophilic to hydrophobic, effectively inhibiting the adsorption of water molecules by the halide particles and solving the problem of moisture absorption and clumping at its source. When added to water, water molecules permeate through the micropores of the coating layer to the surface of the halide particles, causing the particles to dissolve rapidly. Bromine and chloride ions can be released into the water through the coating layer, reacting with persulfate ions and free radicals to generate active halogen substances, without affecting the release efficiency of halide ions or the oxidation reaction effect.

[0079] Potassium persulfate complex salt, aminosulfonic acid, pH buffer, composite corrosion inhibitor, and anhydrous sodium sulfate were added to a three-dimensional mixer and stirred at low speed (15 rpm) for approximately 25 minutes to ensure uniform mixing of the potassium persulfate complex salt, aminosulfonic acid, pH buffer, composite corrosion inhibitor, and anhydrous sodium sulfate, resulting in mixture B. Low-speed stirring avoids excessive friction leading to localized heating, thereby preventing the decomposition of the potassium persulfate complex salt.

[0080] Mixture A is slowly added to mixture B, specifically, mixture A is added to mixture B at a uniform rate over 5-8 minutes. The mixture is then slowly stirred (10 rpm) until mixture A and mixture B are uniformly mixed to obtain the composite agent. Slow stirring ensures uniform distribution of the two components and maximizes the protection of the micro-coating structures on the surfaces of sodium bromide and sodium chloride in mixture A, thereby preventing direct contact between the oxidant and the reducing agent.

[0081] After mixing thoroughly, immediately vacuum seal the mixture in an aluminum foil bag in a dry environment.

[0082] The composite agent prepared by this invention can effectively prevent the loss of active ingredients and ensure the efficacy of the agent.

[0083] Example 2

[0084] The medical wastewater treatment method for synergistic removal of new pollutants and pathogenic microorganisms in this embodiment includes the following steps:

[0085] S1. Pretreatment: Inorganic flocculants are added to medical wastewater to promote the aggregation and sedimentation of suspended particles and colloids in the medical wastewater;

[0086] S2. Oxidation treatment: A composite agent is added to the pretreated medical wastewater while a direct current electric field is applied. The composite agent comprises the following components in parts by weight:

[0087] Potassium persulfate compound salt: 45-55 parts;

[0088] Aminosulfonic acid: 5-10 parts;

[0089] Sodium chloride: 1-3 parts;

[0090] Sodium bromide: 2-4 parts;

[0091] Surfactant: 10-15 parts;

[0092] pH buffer: 5-10 parts;

[0093] Composite corrosion inhibitor: 8-12 parts;

[0094] Anti-caking agent: 2-4 parts;

[0095] Anhydrous sodium sulfate: 2-5 parts;

[0096] After the compound agent dissolves, it generates a strong oxidizing component that mineralizes and decomposes organic matter while killing pathogens.

[0097] S3. Biochemical treatment: The medical wastewater after oxidation is subjected to biochemical treatment to remove ammonia nitrogen and small molecule organic matter.

[0098] Specifically, adopt Figure 2 and Figure 3 The device shown is for treating medical wastewater. It includes an equalization tank 100, an oxidation treatment mechanism, and a biochemical tank 120. The equalization tank 100 and biochemical tank 120 are the same as in Embodiment 1. The oxidation treatment mechanism includes an adsorption chamber 1, a first oxidation chamber 3, and a second oxidation chamber 4. The adsorption chamber 1 can be a rectangular tank with multiple baffles inside, dividing the interior of the adsorption chamber 1 into a serpentine water flow channel to prolong the residence time of the medical wastewater in the adsorption chamber 1. One end of the adsorption chamber 1 is the inlet, and the other end is the outlet. The outlet is provided with a first discharge port 6 and a second discharge port 7. The first discharge port 6 communicates with the first oxidation chamber 3, and the second discharge port 7 communicates with the second oxidation chamber 4. A filter layer 5 is provided between the first discharge port 6 and the second discharge port 7.

[0099] In step S1, flocculation and sedimentation treatment is carried out in the equalization tank 100.

[0100] In step S2, the pretreated medical wastewater is introduced into the adsorption chamber 1, and adsorption particles 2 with surface-loaded nano-adsorption materials are placed at the inlet end of the adsorption chamber 1. The nano-adsorption materials selectively adsorb organic matter in the medical wastewater. Then, the adsorption particles 2 and part of the medical wastewater are introduced into the first oxidation chamber 3, and the medical wastewater without adsorption particles 2 is introduced into the second oxidation chamber 4. The amount of medical wastewater introduced into the first oxidation chamber 3 is less than the amount introduced into the second oxidation chamber 4.

[0101] Specifically, adsorbent particle 2 is a hollow iron oxide particle, or other commonly used hollow carrier particles can be used. The density of adsorbent particle 2 is ensured to be similar to that of the medical wastewater, allowing it to remain suspended in the wastewater and move slowly with it without sinking or floating. The nano-adsorbent material is one or more of the following: mesoporous silica, graphitic carbon nitride, metal-organic frameworks, covalent organic frameworks, and activated carbon. The specific choice depends on the type of new pollutant in the medical wastewater, ensuring that the nano-adsorbent material can selectively adsorb new pollutants. For example, fluoroquinolone antibiotics (FQs, such as ciprofloxacin, norfloxacin, and ofloxacin) have a conjugated quinolone core, carboxyl groups, and piperazine groups, carrying a charge. The nano-adsorbent material can be amino-functionalized mesoporous silica: its surface amino groups can form strong hydrogen bonds and electrostatic interactions with the carboxyl and carbonyl groups of the FQs, resulting in good selective adsorption of fluoroquinolone antibiotics. For example, sulfonamide antibiotics (SAs, such as sulfamethoxazole and sulfadiazine) contain benzene rings, sulfonamide groups and amino groups. Nanoparticle adsorbents can be made of magnetic covalent organic framework materials (Fe3O4@COF), which can achieve strong π-π stacking between their benzene rings and the benzene rings of SAs, while their channels can accommodate SAs molecules.

[0102] Adsorbed particles 2 flow slowly with the medical wastewater to the outlet of adsorption chamber 1 and absorb new pollutants from the wastewater. The pore diameter of the filter layer 5 is smaller than the particle size of the adsorbed particles 2. Therefore, the medical wastewater can pass through the filter layer 5 and reach the second outlet 7, then flow into the second oxidation chamber 4. The adsorbed particles 2, however, cannot pass through the filter layer 5 and can only enter the first oxidation chamber 3 through the first outlet 6 along with a portion of the medical wastewater. By using pumps or other equipment to increase the water flow rate at the second outlet 7, the amount of medical wastewater flowing into the first oxidation chamber 3 is reduced to less than that flowing into the second oxidation chamber 4. Specifically, 20%-30% of the total wastewater volume can be fed into the first oxidation chamber 3.

[0103] A composite reagent is introduced into the first oxidation chamber 3, and a direct current electric field is applied simultaneously. The first oxidation chamber 3 is equipped with a cathode plate 111 and an anode plate 112, which can be conventional electrodes such as titanium-based ruthenium-iridium electrodes. Multiple cathode plates 111 and anode plates 112 can be used, and they are arranged alternately. The cathode plates 111 and anode plates 112 are connected to a power supply 113. In the first oxidation chamber 3, the adsorbed particles 2 enrich new pollutants from the medical wastewater. The concentration of these new pollutants is high; therefore, the new pollutants are degraded by applying a direct current electric field in conjunction with the composite reagent, the principle of which is the same as in Example 1.

[0104] A composite reagent is added to the second oxidation chamber 4, with a lower dosage than that in the first oxidation chamber 3. Since most of the new pollutants in the medical wastewater are adsorbed by the adsorption particles 2, the concentration of new pollutants in the second oxidation chamber 4 is low, requiring only a small amount of composite reagent.

[0105] In the first oxidation chamber 3, the dosage of the composite agent is 30-50 mg / L, and the current density is 5-15 mA / cm²; in the second oxidation chamber 4, the dosage of the composite agent is 5-10 mg / L.

[0106] In this embodiment, the adsorption particles 2 selectively enrich new pollutants (antibiotics, endocrine disruptors, etc.) in medical wastewater through nano-adsorption materials. This concentrates the new pollutants, which were originally dispersed in trace amounts in large volumes of medical wastewater, into a tiny solid phase region on the surface of the adsorption particles 2. Under strong oxidation conditions activated by high-dose composite agents and DC electric fields, the strong oxidizing components (sulfate radicals, hydroxyl radicals, and active halogen species) can directly contact the high concentration of pollutants on the surface of the adsorption particles. This avoids the problems of oxidizing components being diluted by a large amount of aqueous phase and having a low probability of contact with trace pollutants in conventional processes, and the degradation rate is improved compared to the uniform oxidation process.

[0107] Adsorption particles 2 preferentially enrich recalcitrant, highly toxic, and hydrophobic organic matter, which is then strongly oxidized and decomposed in the first oxidation chamber 3. Meanwhile, easily degradable small-molecule organic matter in medical wastewater enters the second oxidation chamber 4 along with most of the wastewater, where it is initially decomposed under low-dose oxidation conditions. This avoids the consumption of strong oxidizing components generated by the combined compound reagent and DC electric field by easily degradable organic matter, while ensuring the effective removal of easily degradable organic matter.

[0108] In the first oxidation chamber 3, the organic matter enriched on the surface of the adsorbent particles 2 is oxidized and decomposed, simultaneously achieving in-situ regeneration of the adsorbent particles 2, allowing them to be reused and reducing the usage cost of the adsorbent particles 2. To achieve the reuse of the adsorbent particles 2, an adsorbent particle collection mechanism 8 is installed at the outlet of the first oxidation chamber 3. The adsorbent particle collection mechanism 8 can be a collection basket with filter holes to filter and collect the adsorbent particles 2. The adsorbent particles 2 are collected using the adsorbent particle collection mechanism 8 and then reintroduced into the adsorption chamber 1.

[0109] In addition, in this embodiment, a high dose of agent is added only to the first oxidation chamber 3 (small volume wastewater) and a low dose of agent is added to the second oxidation chamber 4 (large volume wastewater). The amount of agent added to the second oxidation chamber 4 is less than the amount of agent added to the first oxidation chamber 3. Compared with the first embodiment, the total amount of compound agent can be reduced by about 40%, which greatly saves the agent cost.

[0110] The medical wastewater treated in the first oxidation chamber 3 and the second oxidation chamber 4 is mixed and then fed into the biochemical tank 120 for step S3.

[0111] In this embodiment, the components, proportions, and preparation methods of the compound agent are the same as in Example 1.

[0112] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for the synergistic removal of new contaminants and pathogenic microorganisms from medical wastewater, characterized in that, Includes the following steps: S1. Pretreatment: Inorganic flocculants are added to medical wastewater to promote the aggregation and sedimentation of suspended particles and colloids in the medical wastewater; S2. Oxidation treatment: A composite agent is added to the pretreated medical wastewater while a direct current electric field is applied. The composite agent comprises the following components in parts by weight: Potassium persulfate compound salt: 45-55 parts; Aminosulfonic acid: 5-10 parts; Sodium chloride: 1-3 parts; Sodium bromide: 2-4 parts; Surfactant: 10-15 parts; pH buffer: 5-10 parts; Composite corrosion inhibitor: 8-12 parts; Anti-caking agent: 2-4 parts; Anhydrous sodium sulfate: 2-5 parts; After the compound agent dissolves, it generates a strong oxidizing component that mineralizes and decomposes organic matter while killing pathogens. S3. Biochemical treatment: The oxidized medical wastewater is then subjected to biochemical treatment to remove ammonia nitrogen and small molecule organic matter. In step S2, the pretreated medical wastewater is introduced into the adsorption chamber (1). Adsorption particles (2) with surface-loaded nano-adsorption materials are placed in the adsorption chamber (1). The nano-adsorption materials selectively adsorb organic matter in the medical wastewater. Then, the adsorption particles (2) and part of the medical wastewater are introduced into the first oxidation chamber (3). The medical wastewater without adsorption particles (2) is introduced into the second oxidation chamber (4). The amount of medical wastewater introduced into the first oxidation chamber (3) is less than the amount introduced into the second oxidation chamber (4). A composite agent is introduced into the first oxidation chamber (3) while a DC electric field is applied. A composite agent is added to the second oxidation chamber (4), and the amount of composite agent added to the second oxidation chamber (4) is lower than the amount of composite agent added to the first oxidation chamber (3); The medical wastewater treated in the first oxidation chamber (3) and the second oxidation chamber (4) is mixed before proceeding to step S3.

2. The method of claim 1, wherein the method is a synergistic removal of new contaminants and pathogenic microorganisms from medical wastewater. The adsorbent particles (2) are hollow iron oxide particles, and the nano-adsorbent material is one or more of mesoporous silica, graphitic carbon nitride, metal-organic framework materials, covalent organic framework materials, and activated carbon.

3. The medical wastewater treatment method for synergistic removal of new pollutants and pathogenic microorganisms as described in claim 1, characterized in that, The adsorption chamber (1) is provided with a filter layer (5). The diameter of the filter pores of the filter layer (5) is smaller than the particle size of the adsorbed particles (2). A first outlet (6) and a second outlet (7) are respectively provided on both sides of the filter layer (5). The first outlet (6) is connected to the first oxidation chamber (3), and the second outlet (7) is connected to the second oxidation chamber (4).

4. The method of claim 1, wherein the method is a synergistic removal of new contaminants and pathogenic microorganisms from medical wastewater. The outlet of the first oxidation chamber (3) is equipped with an adsorption particle collection mechanism (8), which collects adsorption particles (2) and then puts the adsorption particles (2) back into the adsorption chamber (1).

5. The method of claim 1, wherein the method is a synergistic removal of new contaminants and pathogenic microorganisms from medical wastewater. In the first oxidation chamber (3), the amount of composite agent is 30-50 mg / L and the current density is 5-15 mA / cm²; in the second oxidation chamber (4), the amount of composite agent is 5-10 mg / L.

6. The method of claim 1, wherein the method is a synergistic removal of new contaminants and pathogenic microorganisms from medical wastewater. The preparation method of the compound drug is as follows: Weigh each component according to the weight proportions; Sodium bromide, sodium chloride, surfactant, and anti-caking agent are put into a high-speed mixer. The mechanical force and frictional heat generated by high-speed shearing cause the surfactant and anti-caking agent to extend on the surface of sodium bromide and sodium chloride particles and form a dense physical coating layer, thus obtaining a mixture A with hydrophobic properties. Mixture B is obtained by uniformly mixing potassium persulfate compound salt, aminosulfonic acid, pH buffer, composite corrosion inhibitor and anhydrous sodium sulfate by low-speed stirring. Add mixture A slowly to mixture B and stir slowly until mixture A and mixture B are evenly mixed to obtain a compound agent.

7. The medical wastewater treatment method for synergistic removal of new pollutants and pathogenic microorganisms as described in claim 6, characterized in that, When preparing mixture A, first add sodium bromide, sodium chloride and half of the anti-caking agent to a high-speed mixer and mix for 2-3 minutes at a speed of 800-1000 r / min to allow the anti-caking agent to initially adhere to the particle surface; Add surfactant, increase rotation speed to 1500-1800 r / min, and simultaneously heat material to 50-65℃. Stir for 5-8 minutes, then rapidly cool material to below 35℃. Reduce rotation speed to 300-500 r / min, add remaining anti-caking agent, and stir for 2-3 minutes.

8. The medical wastewater treatment method for synergistic removal of new pollutants and pathogenic microorganisms as described in claim 1, characterized in that, The surfactant is sodium dodecyl sulfonate; the pH buffer is a mixture of citric acid and sodium citrate in a mass ratio of 1:1 to 3:1; the composite corrosion inhibitor is a mixture of sodium silicate, disodium EDTA, sodium gluconate and sodium hexametaphosphate; and the anti-caking agent is a mixture of fumed silica and magnesium chloride.

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