An improved zero-discharge method and system for medical wastewater treatment

Abstract

The present invention relates to the technical field of medical wastewater treatment, and more specifically to an improved zero-discharge method and system for medical wastewater treatment. Medical wastewater is pretreated in advance so that it can be fed into an activated sludge tank for sludge treatment. After treatment in the activated sludge tank, medical clean water and sludge are obtained. The medical clean water is fed into a disinfection tank, and the disinfectant content is determined by combining the flow rate of the clean water, the type and quantity of pathogens, the organic matter and ammonia nitrogen concentration in the wastewater with temperature and light. The dosage of the disinfectant is then determined, thereby achieving precise disinfection of the medical clean water and improving the adaptability of the disinfection. Furthermore, after disinfection, random inspections are performed to determine whether the zero-discharge standard has been met, thereby improving the current purification and disinfection efficiency of medical wastewater. The disinfected discharge water can be used as hospital toilet flushing water. Flushing with the disinfectant can remove toilet odors, further reducing fecal water pollution and treatment costs, and reducing toilet scaling.

Description

Technical Field

[0001] The present invention relates to the technical field of medical wastewater treatment, and in particular to an improved zero-discharge method and system for medical wastewater treatment. Background Art

[0002] With the acceleration of industrialization and urbanization, water shortages and pollution are becoming increasingly severe. Wastewater discharge poses a particularly significant threat to the environment, particularly in highly polluting industries like healthcare and chemicals. To address this challenge, achieving "zero wastewater discharge" has become a key environmental goal. Zero wastewater discharge systems not only help reduce pollution but also, by recycling water resources, alleviate water pressure on businesses and society, promoting sustainable development.

[0003] Zero-discharge wastewater treatment means that after a series of treatment processes, wastewater is not directly discharged into the environment. Instead, it is completely purified and reused, ultimately achieving the goal of "zero liquid discharge." This process requires not only the effective treatment of pollutants in the wastewater, but also the recycling and reuse of the treated water and the safe disposal or resource utilization of solid waste.

[0004] However, at present, when treating medical wastewater, there is no precise control of the treatment steps, such as the adaptive setting of the disinfectant dosage and the effective disinfection process of the disinfection tank after the disinfectant is added. Therefore, in order to achieve more refined zero discharge of medical wastewater, the present invention proposes an improved medical wastewater treatment zero discharge method and system. Summary of the Invention

[0005] In response to the above-mentioned shortcomings of the existing technology, the present invention provides an improved zero-discharge method and system for medical wastewater treatment, which can effectively solve the problems in the existing technology involving precise control of treatment steps, affecting the accuracy and efficiency of zero-discharge medical wastewater treatment.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0007] The present invention provides an improved zero-discharge method and system for medical wastewater treatment, comprising the following steps:

[0008] Step 1: Pre-treat medical wastewater to remove particulate pollutants and suspended solids;

[0009] Step 2: The treated medical wastewater is fed into a regulating tank to balance the pH value and organic matter concentration of the water quality of the medical wastewater;

[0010] Step 3: The medical wastewater is fed into an activated sludge tank to continuously aerate the medical wastewater to maintain oxygen supply, allowing pollutants in the medical wastewater to come into close contact with microorganisms for degradation. Furthermore, the treated medical wastewater is fed into a sedimentation tank to separate the sludge from the medical wastewater. Treated medical water is obtained by separating the wastewater from the clean water.

[0011] Step 4: Disinfect the treated medical water, wherein the disinfection method and steps are as follows:

[0012] Medical clean water is input into the disinfection pool;

[0013] Determine the disinfectant content; specifically, combine the flow rate of medical water, the type and number of pathogens, organic matter and ammonia nitrogen concentration in the wastewater with temperature and light to determine the disinfectant content and determine the disinfectant dosage;

[0014] Disinfectant is evenly distributed;

[0015] Sampling and testing of disinfectant concentration;

[0016] Step 5: After the medical clean water is disinfected, the medical clean water is collected and judged to determine whether the disinfection is completed and the discharge index is met. If the disinfection is completed and the discharge index is met, a discharge signal is generated, otherwise no signal is generated.

[0017] Furthermore, the removal of particulate pollutants and suspended matter is specifically performed through a grid or a screen.

[0018] Furthermore, after the medical sewage is input into the activated sludge tank, the amount of aged sludge to be discharged is determined, and the calculation formula for the amount of aged sludge discharged is as follows:

[0019] Calculate the total amount of sludge in the activated sludge tank

[0020] X=V×MLSS

[0021] Where: X is the total amount of sludge, V is the volume of the aeration tank, and MLSS is the sludge concentration in the aeration tank;

[0022] Determine the amount of sludge to be discharged daily:

[0023]

[0024] Where Q p The sludge volume is the amount of aged sludge that needs to be discharged daily, and SRT is the sludge age.

[0025] Furthermore, the method for determining the disinfectant content is:

[0026] Determine the state influence coefficient ChlZ A :

[0027]

[0028] Where Qm is the flow rate of medical clean water, C patfebs is the concentration of pathogens in medical water, Bj ods is the biochemical oxygen demand in medical water, N mg is the ammonia nitrogen concentration in medical water, CQB is the number of calculation items, β1, β2, β3 and β4 are the corresponding weight coefficients, and Cβx is the constant correction coefficient, where;

[0029] Determine the environmental impact coefficient Chod B :

[0030]

[0031] Where: T pcs is the ambient temperature, Lj ux is the light intensity, and is the weight coefficient, is the constant correction coefficient, TLC is the number of calculation items;

[0032] Determine the actual impact coefficient of Chlorids:

[0033]

[0034] Where: ω1 and ω2 are the corresponding weight coefficients, CCH is the number of calculation items, is the constant correction coefficient;

[0035] Based on the actual influence coefficient Chlorids, the corresponding disinfectant content matching interval is obtained to obtain the disinfectant content, that is, the chlorine dosage.

[0036] When performing uniform distribution of disinfectant, chlorine is placed in the chlorine disinfection tank and mixed by a hydraulic mixer to calculate the mixing time. The total time is calculated according to the following relationship:

[0037]

[0038] Where: t mix is the mixing time, V is the effective volume of the chlorine disinfection tank, μ is the mixing efficiency coefficient, and μ takes a value of 1.2 to 2, which is used to adjust the actual mixing effect.

[0039] Furthermore, the disinfectant concentration sampling test determines the uniform distribution of chlorine in the chlorine disinfection tank, and the specific steps are as follows:

[0040] N medical water samples were drawn from different locations in the chlorine disinfection pool, and the chlorine concentration value (in mg / L) of each medical water sample was obtained. These concentration values were recorded as C1, C2, C3, ... C n ;

[0041] By calculating the average value of chlorine concentration The standard deviation σ of the chlorine concentration values can be used to determine whether the chlorine concentration distribution is uniform.

[0042] Furthermore, the average value of the chlorine concentration value is The calculation formula is:

[0043]

[0044] Where: n is the total number of sampling points, C i is the chlorine concentration value of the i-th sampling point;

[0045] Furthermore, the calculation formula for the standard deviation σ of the chlorine concentration value is:

[0046]

[0047] Furthermore, the determination of whether the chlorine concentration distribution is uniform is specifically as follows:

[0048] Calculate the coefficient of variation CV:

[0049]

[0050] Based on this judgment, if the coefficient of variation CV is smaller, the chlorine concentration distribution is more uniform, otherwise it is uneven.

[0051] Furthermore, the present invention provides a medical wastewater treatment zero-discharge system, which is implemented according to the improved medical wastewater treatment zero-discharge method.

[0052] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0053] By pre-treating medical sewage in advance so that it can be input into the activated sludge tank for sludge treatment, and after treatment in the activated sludge tank, medical clean water and sludge are obtained, and the medical clean water is input into the disinfection tank, the flow rate of medical clean water, the type and amount of pathogens, the organic matter and ammonia nitrogen concentration in the sewage are combined with the temperature and light to determine the disinfectant content, and the dosage of the disinfectant is clarified, so as to achieve accurate disinfection of medical clean water and improve the adaptability of disinfection. Furthermore, after disinfection, random inspections are conducted to determine whether the zero emission standard is met, so as to improve the current purification and disinfection efficiency of medical sewage and achieve zero emission. The discharge water after disinfection is piped to various toilets in the hospital and used as flushing water. Flushing with disinfectant can remove toilet odor, further reduce the pollution and treatment cost of fecal water, reduce cleaning workload, and reduce toilet scaling. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0055] Figure 1 Schematic diagram of the overall method of the present invention. DETAILED DESCRIPTION

[0056] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0057] The present invention will be further described below with reference to the embodiments.

[0058] Example 1 (see Figure 1 ): An improved zero-discharge method for treating medical wastewater, comprising the following steps:

[0059] Step 1: Pre-treat the medical wastewater by removing particulate pollutants and suspended solids in the medical wastewater through a grid or screen in the flow pipe of the medical wastewater, thereby facilitating the subsequent purification steps of the medical wastewater.

[0060] In the above, it should be noted that when removing particulate pollutants and suspended matter in medical wastewater by means of a grid or screen, for coarse grids: medical wastewater may contain larger particles of waste, such as gauze, cotton balls, syringe casings, etc., the aperture of the coarse grid is generally 10-20mm, which is used to intercept these larger debris and prevent them from entering subsequent treatment equipment; for fine grids or screens: for small particles of waste and suspended matter, such as fibers, paper scraps, etc., the aperture of the fine grid is generally 1-5mm, which can intercept relatively small particles and reduce the burden of subsequent treatment steps.

[0061] Step 2: The treated medical wastewater is fed into a regulating tank to equalize the water quality and volume. The regulating tank can balance the pH value and organic matter concentration of the medical wastewater to ensure the stable operation of the subsequent treatment system.

[0062] Step 3: The medical wastewater is fed into the activated sludge tank to continuously aerate the medical wastewater to maintain oxygen supply. Aeration allows the medical wastewater and activated sludge to be fully mixed, ensuring close contact between pollutants in the wastewater and microorganisms, thereby improving degradation efficiency.

[0063] It should be noted that common organic pollutants in medical wastewater include patient body fluids, drug residues, disinfectants, etc. These organic substances are decomposed through the metabolism of microorganisms, gradually reducing the chemical oxygen demand (COD) and biological oxygen demand (BOD) in the water, that is, the pollution load in medical wastewater is significantly reduced. Nutrient removal: In addition to organic matter, nutrients such as nitrogen and phosphorus in wastewater are also taken up by microorganisms and used as elements required for their growth;

[0064] Furthermore, in the activated sludge tank, microorganisms reproduce by utilizing organic matter in the medical wastewater to form new activated sludge.

[0065] In the above, in the process of treating medical wastewater through the activated sludge tank, as the activated sludge continues to proliferate, part of the activated sludge will gradually lose its activity and be recorded as aged sludge. This aged sludge needs to be discharged from the system regularly and then treated. Therefore, the amount of aged sludge that needs to be discharged is determined to facilitate the normal treatment of medical wastewater in the activated sludge tank. The calculation formula for the amount of aged sludge discharged is as follows:

[0066] Calculate the total amount of sludge in the aeration tank (activated sludge tank)

[0067] X=V×MLSS

[0068] Where: X is the total amount of sludge, V is the volume of the aeration tank, and MLSS is the sludge concentration in the aeration tank;

[0069] Determine the amount of sludge to be discharged daily:

[0070]

[0071] Where Q p is the amount of aged sludge that needs to be discharged daily, and SRT is the sludge age;

[0072] Therefore, based on the above, the sludge volume of the aged sludge is discharged regularly, and the return sludge is returned to the aeration tank to maintain a stable microbial concentration in the system.

[0073] Furthermore, the treated medical wastewater is input into a sedimentation tank to separate sludge and clean water from the medical wastewater. By separating the wastewater and clean water, a treated supernatant, i.e., medical clean water, is obtained. At this time, a large amount of suspended matter in the medical wastewater is removed.

[0074] Step 4: Disinfect the treated medical water using chlorine. After disinfection, the pathogen content in the medical water is significantly reduced, ensuring that the water quality meets national emission standards and can be safely discharged or reused.

[0075] In the above scheme, the method steps of disinfection by chlorine are:

[0076] S100, inputting the medical clean water into the disinfection tank: inputting the treated medical clean water into the chlorine disinfection tank, and setting the chlorine disinfection time T, so that the clean water is disinfected in the chlorine disinfection tank;

[0077] S200. Determine the disinfectant content: During the chlorine disinfection process of medical water, the chlorine dosage needs to take into account multiple factors, including: the flow rate of medical water, the type and number of pathogens, organic matter (BOD) in the wastewater, and ammonia nitrogen concentration. Environmental and weather conditions such as temperature and light will also have a certain impact on the disinfection efficiency of chlorine. Therefore, this department combines the flow rate of medical wastewater, the type and number of pathogens, organic matter (BOD) in the wastewater, and ammonia nitrogen concentration factors, and introduces environmental and weather conditions to comprehensively calculate the disinfectant, that is, the chlorine dosage. The specific determination steps are as follows:

[0078] Determine the state influence coefficient ChlZ A :

[0079]

[0080] Where Qm is the flow rate of medical clean water (m 3 / h), C patfebs is the concentration of pathogens in medical water (individuals / L), Bj ods is the biochemical oxygen demand in medical water (mg / L), N mgis the ammonia nitrogen concentration in medical water (mg / L), CQB is the number of calculation items, which is preset to 4, β1, β2, β3, and β4 are the corresponding weight coefficients, and Cβx is the constant correction coefficient. The weight coefficients can be determined by the least squares method, which is not described here.

[0081] Determine the environmental impact coefficient Chod B :

[0082]

[0083] Where: T pcs is the ambient temperature (℃, it should be noted that the lower the temperature, the greater the demand for chlorine), Lj ux is the light intensity (Lux, the stronger the light, the faster the hypochlorous acid decomposes due to ultraviolet rays, that is, the greater the demand for chlorine), and is the weight coefficient, is the constant correction coefficient, TLC is the number of calculation items, and the default value is 2;

[0084] Determine the actual impact coefficient of Chlorids:

[0085]

[0086] Where: ω1 and ω2 are the corresponding weight coefficients, CCH is the number of calculation items, which is preset to 2. is the constant correction coefficient;

[0087] In this way, the corresponding disinfectant content matching interval is obtained based on the actual influence coefficient Chlorids, so as to obtain the chlorine dosage, so as to obtain a more accurate chlorine dosage, so that chlorine can be accurately added to the chlorine disinfection pool, ensuring the accuracy and efficiency of medical water disinfection without causing excessive waste of disinfectants.

[0088] S300, uniform distribution of disinfectant: The determined dosage of chlorine is placed in the chlorine disinfection tank and mixed. A hydraulic mixer can be used to allow the chlorine to fully contact with the medical water in the chlorine disinfection tank to achieve uniform mixing. The mixing time of the hydraulic mixer is calculated according to the following relationship:

[0089]

[0090] Where: t mix is the mixing time (min, usually the greater the flow rate of medical sewage, the faster the medical sewage passes through the chlorine disinfection tank. When the flow rate is large, stronger stirring or higher mixing efficiency is required to ensure sufficient contact between chlorine and medical sewage), V is the effective volume of the chlorine disinfection tank (m 3Volume is the basis for ensuring that there is sufficient contact space between sewage and chlorinating agent. Generally, the larger the pool volume, the longer the mixing time may be required). μ is the mixing efficiency coefficient. According to the type, layout and stirring intensity of the hydraulic mixer, μ usually takes a value of 1.2 to 2, which is used to adjust the actual situation of the mixing effect.

[0091] S400, sampling test of disinfectant concentration: Based on the uniform distribution of disinfectant, sampling points are set up at multiple locations in the chlorine disinfection tank. Usually, different depths and horizontal positions are selected at the bottom, middle and surface of the tank. This can reflect the chlorine distribution in different areas of the mixing tank. Typical sampling points can be arranged at the entrance, middle and exit of the chlorine disinfection tank to ensure that clear water samples from different flow paths are tested. It should be noted that when sampling clear water samples from different flow paths, sampling needs to be carried out after chlorine has been added to the chlorine disinfection tank for a certain period of time to ensure that there is sufficient contact time for the chlorine to fully diffuse and react.

[0092] Specifically, the chlorine concentration at each sampling point can be detected by a residual chlorine detector or chemical reagents. The residual chlorine concentration is usually measured using a colorimetric method or an electrochemical method to ensure accuracy. The test results should show that the chlorine concentrations at different locations are basically consistent, and the difference should not exceed the set threshold (such as within 10%). If the difference is too large, it indicates that the mixing effect is poor and the hydraulic mixer needs to be adjusted.

[0093] It is worth noting that this embodiment provides a method for determining the uniform distribution of chlorine in a mixing tank (chlorine disinfection tank), and the specific steps are as follows:

[0094] N medical water samples were drawn from different locations in the chlorine disinfection pool, and the chlorine concentration value (in mg / L) of each medical water sample was obtained. These concentration values were recorded as C1, C2, C3, ... C n ;

[0095] Calculate the average chlorine concentration value

[0096]

[0097] Where: n is the total number of sampling points, C i is the chlorine concentration value of the i-th sampling point;

[0098] Calculate the standard deviation σ of the chlorine concentration values:

[0099]

[0100] Calculate the coefficient of variation CV:

[0101]

[0102] Based on this judgment, the smaller the coefficient of variation CV, the more uniform the chlorine concentration distribution. Usually, when the coefficient of variation CV is lower than 10%, the chlorine distribution is considered to be relatively uniform, otherwise it is uneven. If it is uneven, it is necessary to adjust the hydraulic mixer, increase the chlorine addition point or adjust the water flow path.

[0103] Step 5: After chlorine disinfection, collect medical water and make the following judgments:

[0104] SA, pathogen removal

[0105] Ensure that the number of pathogens reaches the national limit after disinfection. Common disinfection indicators include fecal coliform concentration, total coliform count and virus removal rate to ensure that medical water meets the standards;

[0106] Residual concentrations of SB, organic matter, and ammonia nitrogen

[0107] Although chlorine disinfection mainly acts on pathogens, the reaction of chlorine with organic matter or ammonia nitrogen will reduce the disinfection effect. Therefore, the concentration of organic matter and ammonia nitrogen needs to be checked after disinfection to ensure that they meet the discharge standards.

[0108] SC, residual chlorine control

[0109] Although residual chlorine has a continuous bactericidal effect, excessive residual chlorine will have a negative impact on the ecosystem. The purpose of setting the residual chlorine index is to avoid further pollution of the water body while ensuring the disinfection effect;

[0110] Therefore, the above-mentioned pathogen removal, residual concentration of organic matter and ammonia nitrogen, and residual chlorine control are used to determine whether the medical clean water meets the discharge standards. If it meets the standards, the treatment is completed and a discharge signal is generated. Otherwise, no discharge signal is generated.

[0111] Finally, the present invention also provides a zero-discharge system for medical wastewater treatment, which is implemented according to the improved zero-discharge method for medical wastewater treatment. Please refer to the above-mentioned machine and will not be described in detail here.

[0112] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the various embodiments of the present invention.

Claims

1. An improved zero-discharge method for medical wastewater treatment, characterized in that: The steps include: Step 1: Pre-treat medical wastewater to remove particulate pollutants and suspended solids; Step 2: The treated medical wastewater is fed into a regulating tank to balance the pH value and organic matter concentration of the water quality of the medical wastewater; Step 3: The medical wastewater is fed into an activated sludge tank to continuously aerate the medical wastewater to maintain oxygen supply, allowing pollutants in the medical wastewater to come into close contact with microorganisms for degradation. Furthermore, the treated medical wastewater is fed into a sedimentation tank to separate the sludge from the medical wastewater. Treated medical water is obtained by separating the wastewater from the clean water. Step 4: Disinfect the treated medical water, wherein the disinfection method and steps are as follows: Medical clean water is input into the disinfection pool; Determine the disinfectant content; specifically, combine the flow rate of medical water, the type and number of pathogens, organic matter and ammonia nitrogen concentration in the wastewater with temperature and light to determine the disinfectant content and determine the disinfectant dosage; Disinfectant is evenly distributed; Sampling and testing of disinfectant concentration; Step 5: After the medical water is disinfected, the medical water is collected and judged to determine whether the disinfection is complete and meets the discharge index. If the disinfection is complete and the discharge index is met, a discharge signal is generated, otherwise no signal is generated; The method for determining the disinfectant content is: Determine the state influence coefficient ChlZ A : Where Qm is the flow rate of medical clean water, C patfebs is the concentration of pathogens in medical water, Bj ods is the biochemical oxygen demand in medical water, N mg is the ammonia nitrogen concentration in medical water, CQB is the number of calculation items, β1, β2, β3 and β4 are the corresponding weight coefficients, and Cβx is the constant correction coefficient, where; Determine the environmental impact coefficient Chod B : Where: T pcs is the ambient temperature, Lj ux is the light intensity, and is the weight coefficient, is the constant correction coefficient, TLC is the number of calculation items; Determine the actual impact coefficient of Chlorids: Where: ω1 and ω2 are the corresponding weight coefficients, CCH is the number of calculation items, is the constant correction coefficient; Based on the actual influence coefficient Chlorids, the corresponding disinfectant content matching interval is obtained to obtain the disinfectant content, that is, the chlorine dosage.

2. The improved zero-discharge method for medical wastewater treatment according to claim 1, characterized in that: The removal of particulate pollutants and suspended solids is specifically performed through a grid or a screen.

3. The improved zero-discharge method for medical wastewater treatment according to claim 1, characterized in that: After the medical sewage is input into the activated sludge tank, the amount of aged sludge to be discharged is determined. The calculation formula for the amount of aged sludge discharged is as follows: Calculate the total amount of sludge in the activated sludge tank X=V×MLSS Where: X is the total amount of sludge, V is the volume of the aeration tank, and MLSS is the sludge concentration in the aeration tank; Determine the amount of sludge to be discharged daily: Where Q p The sludge volume is the amount of aged sludge that needs to be discharged daily, and SRT is the sludge age.

4. The improved zero-discharge method for medical wastewater treatment according to claim 1, characterized in that: When performing uniform distribution of disinfectant, chlorine is placed in the chlorine disinfection tank and mixed by a hydraulic mixer to calculate the mixing time. The total time is calculated according to the following relationship: Where: t mix is the mixing time, V is the effective volume of the chlorine disinfection tank, μ is the mixing efficiency coefficient, and μ takes a value of 1.2 to 2, which is used to adjust the actual mixing effect.

5. The improved zero-discharge method for medical wastewater treatment according to claim 1, characterized in that: The uniform distribution of chlorine in the chlorine disinfection tank is determined by sampling and testing the disinfectant concentration. The specific steps are as follows: N medical water samples were extracted from different locations of the chlorine disinfection pool, and the chlorine concentration value of each medical water sample was obtained. These concentration values were recorded as C1, C2, C3, ... C n ; By calculating the average value of chlorine concentration The standard deviation σ of the chlorine concentration values can be used to determine whether the chlorine concentration distribution is uniform.

6. The improved zero-discharge method for medical wastewater treatment according to claim 5, characterized in that: The average value of the chlorine concentration values The calculation formula is: Where: n is the total number of sampling points, C i is the chlorine concentration value of the i-th sampling point.

7. An improved zero-discharge method for medical wastewater treatment according to claim 6, characterized in that: The calculation formula for the standard deviation σ of the chlorine concentration value is: 。 8. An improved zero-discharge method for medical wastewater treatment according to claim 7, characterized in that: The determination of whether the chlorine concentration distribution is uniform is specifically as follows: Calculate the coefficient of variation CV: Based on this judgment, if the coefficient of variation CV is smaller, the chlorine concentration distribution is more uniform, otherwise it is uneven.

9. A zero-discharge system for medical wastewater treatment, characterized in that: The system is implemented according to the improved zero-discharge method for medical wastewater treatment described in claim 1.

Images