Disinfection method for synchronously removing antibiotics, drug-resistant bacteria and resistance genes in water and reducing disinfection byproducts

Abstract

The invention discloses a disinfection method for synchronously removing antibiotics, drug-resistant bacteria and resistance genes in water and reducing disinfection byproducts, and belongs to the technical field of sewage treatment. The disinfection method comprises the following steps: adding sodium hypochlorite into to-be-disinfected water to ensure that the concentration of available chlorine in the to-be-disinfected water is 2-15mg / L; further introducing DO through aeration and carrying out VUV disinfection so as to synchronously remove antibiotics, drug-resistant bacteria and resistance genes in the water to be disinfected and reduce disinfection by-products. The aeration coupling VUV / NaClO technology is used for advanced treatment of the reclaimed water, microorganisms can be efficiently inactivated and prevented from reviving, ARGs are effectively removed, horizontal gene transfer is controlled, meanwhile, residual antibiotics are degraded, bacterial drug resistance spreading is thoroughly blocked, and the water quality safety of the reclaimed water can be effectively guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment, and in particular relates to a disinfection method for simultaneously removing antibiotics, drug-resistant bacteria and resistance genes in water and reducing disinfection by-products. Background Art

[0002] Driven by climate change, population growth and economic development, global water demand and sewage generation are increasing year by year. Freshwater shortage, water pollution and water environment ecological damage are major challenges facing sustainable development; municipal sewage generation is large, water volume and water quality are relatively stable, and treatment and reuse after meeting standards is an important way to solve the current water crisis. At present, as an important supplement to conventional water resources, unconventional water sources such as recycled water have played the role of "second water source" in some water-scarce cities. Improving sewage treatment efficiency and accelerating the development and utilization of recycled water play an important role in alleviating the contradiction between water supply and demand.

[0003] Compared with conventional water resources such as surface water and groundwater, sewage has complex water quality and contains high concentrations of pathogenic microorganisms and chemical pollutants. The extensive use and abuse of antibiotics has led to widespread antibiotic residues in sewage, and a large number of antimicrobial-resistant bacteria (ARBs) and resistance genes (ARGs) have been produced. Improper treatment will cause serious health and ecological risks. Therefore, ensuring the safety of recycled water quality is an important prerequisite for promoting the resource utilization of sewage. In water treatment, disinfection plays an important role in inactivating pathogens and preventing the spread of diseases, and is the last barrier to ensure the safety of recycled water.

[0004] The most commonly used recycled water disinfection technologies include chlorine disinfection and ultraviolet (UV) disinfection, both of which have defects to varying degrees:

[0005] (1) Chlorine disinfection has low cost and simple process, and residual chlorine can maintain continuous disinfection ability. However, chlorine disinfection will produce a large number of disinfection by-products (DBPs) with "tri-toxic" toxicity, and will induce the formation of chlorine-resistant bacteria, such as Pseudomonas, Coleus and Acinetobacter. In addition, a large number of studies have shown that under the commonly used chlorine doses in water disinfection processes, chlorine disinfection not only cannot effectively destroy ARGs, but also promotes the release of intracellular ARGs to the extracellular space, increases the frequency of horizontal transfer of ARGs, and increases the risk of bacterial resistance.

[0006] (2) UV disinfection equipment is simple and does not require the addition of chemicals. It can directly destroy the DNA of bacteria and has the potential to remove ARGs in water bodies. However, UV disinfection does not have the ability to continuously disinfect, and some bacteria are not completely killed after UV disinfection. They enter a viable but non-culturable state (VBNC) and can be revived when external conditions are suitable, which still poses serious health risks.

[0007] (3) Chlorine disinfection and ultraviolet disinfection, two conventional water disinfection processes, have poor removal effects on antibiotics. Although they can kill ARBs, the resulting cell fragments still contain intact DNA fragments. These DNA fragments can spread resistance to downstream bacterial populations through natural transformation or conjugation and transduction. At the same time, residual antibiotics can also induce the production of new resistant bacteria. Wastewater treatment plants have become reservoirs of ARBs and ARGs.

[0008] (4) UV / NaClO combined disinfection process, through UV excitation of low-dose NaClO to produce a large number of active oxidizing substances such as chlorine free radicals (Cl·) and hydroxyl free radicals (·OH), can significantly improve the bacterial inactivation rate, inhibit bacterial resurrection, enhance the degradation of pollutants such as antibiotics, greatly reduce the amount of chemical agents used, make up for the shortcomings of a single disinfection process, and has been widely used in drinking water, wastewater and recycled water treatment. However, the chlorine free radicals (Cl·) produced in the UV / NaClO system will react with organic matter, resulting in an increase in the production of DBPs. Among them, the more toxic nitrogen-containing DBPs, such as halogenated acetonitriles, increase more significantly, resulting in a greatly increased disinfection risk. In addition, many studies have shown that the removal effect of the UV / NaClO system on ARGs is unstable. Summary of the invention

[0009] In order to overcome the defects of the prior art in water disinfection, the present invention provides a disinfection method for simultaneously removing antibiotics, drug-resistant bacteria and resistance genes in water and reducing disinfection by-products.

[0010] To achieve the above object, the present invention provides the following technical solutions:

[0011] One of the technical solutions of the present invention is to provide a disinfection method for simultaneously removing antibiotics, drug-resistant bacteria and resistance genes in water and reducing disinfection by-products, comprising the following steps:

[0012] Sodium hypochlorite is added to the water to be disinfected to ensure that the concentration of effective chlorine in the water to be disinfected is 2-15 mg / L; dissolved oxygen (DO) is further introduced through aeration and vacuum ultraviolet light (VUV) disinfection is performed to simultaneously remove antibiotics, drug-resistant bacteria and resistance genes in the water to be disinfected and reduce disinfection by-products.

[0013] The present invention utilizes DO provided by aeration to strengthen VUV's catalytic reaction of low-concentration free chlorine in water, greatly increasing the production of oxidative active substances such as O3, hydroxyl radicals and active chlorine radicals, and can significantly improve the oxidation capacity of the system, strengthen the degradation of antibiotics and other difficult-to-degrade organic matter, increase the degree of structural damage to bacteria and other microorganisms and resistance genes, block bacterial resurrection and DNA repair function, efficiently remove antibiotics, ARBs, ARGs, control horizontal gene transfer, and completely block the spread of antibiotic resistance in water.

[0014] The present invention controls the concentration of effective chlorine to 2-15 mg / L, which can ensure the disinfection effect and avoid the pollution of the environment by excessive chlorine.

[0015] The VUV (10-195nm) in the present invention has a higher energy density than the traditional UV (254nm). The active chlorine species produced by VUV exciting NaClO are mainly chlorine oxygen radicals (ClO·) rather than Cl·. Unlike the substitution reaction of Cl·, ClO· mainly reacts with organic matter through electron transfer, thereby effectively avoiding the generation of halogenated disinfection byproducts DBPs. Therefore, replacing traditional UV with VUV and constructing a VUV / NaClO advanced oxidation system for reclaimed water disinfection can effectively control the risk of DBPs.

[0016] Preferably, the aeration rate of the aeration is 0.3-1 mL / min.

[0017] Preferably, the VUV irradiation dose is 300-1000 mJ / cm 2 .

[0018] Preferably, the aeration is achieved through a microporous aeration membrane with a diameter of 0.1 to 5 μm.

[0019] More preferably, the microporous aeration membrane is made of ceramic.

[0020] Traditional organic micro-nano aeration membranes are easily corroded and damaged by chlorine, oxidative free radicals, etc., and have a short service life. The ceramic membrane of the present invention has the advantages of small bubbles, large number, large effective area, high oxygen dissolution efficiency, etc., and has the unique advantages of being resistant to fouling and clogging, easy to clean, acid and alkali resistant, resistant to oxidation, resistant to high temperature, strong, not easy to damage, and long service life. The micro-nano aeration process based on the aeration membrane of the present invention can increase the level of dissolved oxygen in water with lower energy consumption.

[0021] Preferably, the chemical oxygen demand (COD) and ammonia nitrogen of the water to be disinfected are tested before adding sodium hypochlorite. When COD≤50mg / L and ammonia nitrogen≤8mg / L in the water to be disinfected, the amount of chlorine added is 5-15mg / L; when 50<COD≤60mg / L and 5<ammonia nitrogen≤15mg / L in the water to be disinfected, the amount of chlorine added is 8-20mg / L.

[0022] The present invention establishes a prediction model for the removal effect of antibiotics, bacteria and drug-resistant genes through a back propagation neural network (BPNN), and constructs a chlorine dosage control model based on BPNN model machine learning. The model determination coefficient is 0.9531, and the chlorine dosage is calculated in Cl2.

[0023] The second technical solution of the present invention is to provide an application of the above-mentioned disinfection method for simultaneously removing antibiotics, drug-resistant bacteria and resistance genes in water and reducing disinfection by-products in sewage treatment.

[0024] The beneficial technical effects of the present invention are as follows:

[0025] The disinfection method provided by the present invention for simultaneously removing antibiotics, drug-resistant bacteria and resistance genes in water and reducing disinfection by-products couples free chlorine with vacuum ultraviolet irradiation and aeration technology, and realizes the coupling effect of hydroxyl radicals, active chlorine radicals and ultraviolet photon radiation by regulating the free chlorine and VUV irradiation in appropriate proportions and doses and by means of the DO synergistic catalysis and hydraulic regulation of micro-nano aeration, thereby efficiently realizing the disinfection and sterilization of recycled water and the removal of refractory organic matter.

[0026] The disinfection method provided by the present invention can effectively inactivate UV-resistant cells (such as spores), chlorine-resistant bacteria and viruses, and can destroy pathogenic microorganisms more thoroughly, and can effectively prevent bacterial resurrection; in addition, the concentration and oxidation capacity of highly active oxidizing substances produced by VUV activation are much higher than those of UV activation products, and can effectively degrade highly toxic, difficult to degrade, and large-molecule organic matter in water, converting them into small-molecule organic matter, and even completely mineralizing them into carbon dioxide, thereby achieving efficient removal of pollutants.

[0027] The present invention uses aeration-coupled VUV / NaClO technology for deep treatment of reclaimed water, which can efficiently inactivate microorganisms and prevent their revival, effectively remove ARGs, control horizontal gene transfer, and degrade residual antibiotics, completely blocking the spread of bacterial resistance, and can effectively ensure the safety of reclaimed water quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a flow chart of the ceramic membrane micro-nano aeration coupled VUV / NaClO reclaimed water disinfection method in Example 1.

[0029] Figure 2 and Figure 3 This is a schematic diagram of the water purification and disinfection reactor in Example 1.

[0030] Figure 4 It is a three-dimensional schematic diagram of the deflector 10.

[0031] Figure 5 It is the bacteria removal rate of the scheme of Example 1 and Comparative Examples 1-4.

[0032] Figure 6 It is the antibiotic degradation rate of the solutions of Example 1 and Comparative Examples 1 to 4.

[0033] Figure 7 It is the sul1 gene removal rate of the solutions of Example 1 and Comparative Examples 1 to 4.

[0034] Figure 2 and Figure 3 In the figure, 1-upper plate, 2-quartz tube, 3-vacuum ultraviolet lamp, 4-support rod, 5-exhaust pipe, 6-blower, 7-aeration plate, 8-lower plate, 9-reactor shell, 10-flow guide, 11-liquid surface, (1-1)-air inlet, (4-1)-air outlet, (8-1)-opening, (9-1)-water outlet, (10-1)-water inlet. DETAILED DESCRIPTION

[0035] Now, various exemplary embodiments of the present invention are described in detail, and this detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present invention. It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention.

[0036] In addition, for the numerical range in the present invention, it is understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0037] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the invention pertains. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention.

[0038] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0039] In the water quality automatic detection unit of the embodiment of the present invention and the comparative example, the COD value is monitored by a commercially available COD online automatic monitoring instrument. A certain amount of potassium dichromate is added to the water sample. In a strong acid medium, silver sulfate is used as a catalyst. After high-temperature digestion, potassium dichromate is converted into hexavalent chromium (Cr 6+ ) is reduced to produce trivalent chromium (Cr 3+ ), COD concentration in water samples and hexavalent chromium (Cr 6 + ) reduction, trivalent chromium (Cr 3+) increases in proportion, and its absorbance is detected by the corresponding light source and then converted into the COD value of the water sample through software; the ammonia nitrogen value can be monitored by a conventional commercially available ammonia nitrogen online monitor. After the water sample and the masking agent are mixed, the ammonia nitrogen in the form of free ammonia or ammonium ions reacts with salicylate and hypochlorite ions in an alkaline environment and in the presence of a sensitizer to form a blue complex. The analyzer detects the photometric change of this color and converts it into an ammonia nitrogen value; the turbidity is measured using an online turbidity detector, which reflects the turbidity of water quality by measuring the degree of scattering of light by suspended particles in water, and the degree of scattering is proportional to the turbidity; the chromaticity is monitored using an online chromaticity monitor.

[0040] Example 1

[0041] Ceramic membrane micro-nano aeration coupled VUV / NaClO reclaimed water disinfection method:

[0042] 1) The recycled water first enters the water quality automatic detection unit. The online automatic monitoring platform measures COD, ammonia nitrogen, turbidity and color indexes of 45.12 mg / L, 4.95 mg / L, 7.10 NTU and 25.03 respectively. The detection data is transmitted to the control center in real time to provide data support for subsequent treatment steps. This recycled water is taken from the effluent of the sewage plant before disinfection. The plate count shows that the culturable bacteria are 4.33×10 4 CFU / mL, sulfonamide resistance gene sul1 was 1.09×10 9 copies / mL, and the total concentration of sulfonamide antibiotics with the highest detection rate was 0.34μg / L.

[0043] 2) Based on the data provided by the water quality detection unit, the control center calculated that the required free chlorine dosage is 7.50 mg / L, and sent a signal to start the metering pump, quickly and fully mixing sodium hypochlorite with recycled water through pipeline mixing. The free chlorine control system detected that the effective chlorine concentration was 4.22 mg / L, and the intelligent analysis and control center confirmed that the effective chlorine concentration was within the range of 2 to 15 mg / L. By accurately controlling the dosage of chlorine, the treatment effect is guaranteed and the pollution of the environment by excessive chlorine is avoided.

[0044] 3) The chlorinated regenerated water enters the ceramic membrane aeration + VUV irradiation unit. The average pore size of the ceramic membrane is 1μm. The unit receives the control signal from the intelligent analysis and control center, starts aeration and VUV irradiation, and adjusts the aeration volume to 0.5mL / min and the vacuum ultraviolet irradiation dose to 600mJ / cm according to the signal. 2 (Radiation intensity 10mW / cm 2, hydraulic retention time 60s). By increasing the dissolved oxygen content of the water body through a specific aeration volume, VUV catalysis of free chlorine is strengthened to produce highly active oxidative free radicals, effectively kill microorganisms in the water, degrade resistance genes, remove residual antibiotics, block the spread of bacterial resistance, and improve the quality of effluent.

[0045] 4) The reclaimed water after disinfection treatment enters the post-water quality detection unit to detect conventional water quality indicators. The COD, ammonia nitrogen, turbidity and color indicators are 27.5mg / L, 0.30mg / L, 6.57NTU, and 9.50 respectively. Water samples are further taken to detect the content of bacteria, ARGs and antibiotics. Bacteria and antibiotics are not detected, and the removal rate of bacteria and antibiotics reaches 100%. The log removal of sul1 gene reaches 4.01-log, that is, the removal rate of sul1 gene is 99.99%. The effluent is reused.

[0046] The flowchart of the ceramic membrane micro-nano aeration coupled VUV / NaClO reclaimed water disinfection method according to Example 1 of the present invention is shown in Figure 1 .

[0047] The schematic diagram of the water purification and disinfection reactor used in Example 1 is shown in Figure 2 and Figure 3 .

[0048] Figure 2 and Figure 3 In the figure, 1-upper plate, 2-quartz tube, 3-vacuum ultraviolet lamp, 4-support rod, 5-exhaust pipe, 6-blower, 7-aeration plate, 8-lower plate, 9-reactor shell, 10-flow guide, 11-liquid surface, (1-1)-air inlet, (4-1)-air outlet, (8-1)-opening, (9-1)-water outlet, (10-1)-water inlet.

[0049] The deflector 10 is a hollow tank structure, and its three-dimensional schematic diagram is shown in FIG. Figure 4 shown.

[0050] The water disinfection and purification reactor is composed of an upper plate, a quartz tube, a vacuum ultraviolet lamp, a support rod, an exhaust pipe, a blower, a ceramic membrane aerator, a lower plate, a reactor shell and a flow guide. The flow guide is sealed with the side wall of the reactor body; the support rod is fixed between the upper plate and the lower plate, the air outlet of the support rod is connected to the blower, and the air outlet of the blower is connected to the ceramic membrane aerator; the vacuum ultraviolet lamp is fixed inside the quartz tube; the ceramic membrane aerator is arranged below the lower plate. The flow guide is used to guide the direction of water flow, ensure that the water is evenly distributed inside the reactor, and improve the treatment effect; the support rod is used to fix ultraviolet lamps, filtration systems and other components to ensure their stability and safety during operation. In order to ensure the quality of the effluent, the reactor is also equipped with a control system for monitoring and controlling the operating parameters of the reactor, such as water inlet flow, disinfection time, aeration volume, etc.

[0051] In the water disinfection and purification reactor, the ceramic membrane micro-nano aeration introduced at the bottom of the VUV irradiation area can promote the formation of micro-environment turbulence in the regenerated water in the disinfection reaction system, which can effectively overcome the problems of short ultraviolet penetration distance and low transmittance in the regenerated water, and ensure that the pollutants can fully contact the VUV light and oxidative active substances, so as to be efficiently removed. The water disinfection and purification reactor efficiently creates appropriate hydraulic conditions, fully kills ARGs and avoids the waste of ultraviolet supply. On the one hand, the bacterial cell structure is directly destroyed by micro-nano bubbles. More importantly, the micro-bubbles provided by microporous aeration create hydraulic conditions of micro-environment turbulence, so that free chlorine, oxygen and vacuum ultraviolet react to produce highly oxidatively active OH, ClO and O3, which not only improves the disinfection effect, but also forms advanced oxidation to remove organic pollutants. At the same time, it ensures that the water is evenly irradiated with ultraviolet doses when flowing in the vertical direction, greatly improving the utilization rate of ultraviolet irradiation, avoiding the waste of ultraviolet supply, and thus saving energy input. The disinfection process implemented by the water disinfection and purification reactor is stable and energy-saving.

[0052] Comparative Example 1

[0053] Take the effluent from the sewage treatment plant before disinfection as in the example, and treat it as follows:

[0054] 1) The recycled water first enters the water quality automatic detection unit. The online automatic monitoring platform measures COD, ammonia nitrogen, turbidity and color indexes of 45.65 mg / L, 5.23 mg / L, 7.15 NTU and 25.06 respectively. The culturable bacteria measured by plate counting are 4.33×10 4 CFU / mL, sulfonamide resistance gene sul1 was 1.09×10 9 copies / mL, and the total concentration of sulfonamide antibiotics with the highest detection rate was 0.34μg / L. After the data is detected, it is transmitted to the intelligent analysis and control center in real time.

[0055] 2) Based on the detected water quality parameters, the control center sends a signal to the free chlorine dosing unit, and adds 7.50 mg / L sodium hypochlorite to the reaction system through the metering pump and pipeline mixing system, so that the sodium hypochlorite and the recycled water are fully mixed and the chlorination reaction occurs fully.

[0056] 3) The free chlorine monitoring unit detects that the effective chlorine concentration after mixing is 4.18 mg / L, and transmits the chlorine concentration signal to the control center in real time to ensure that the effective chlorine concentration is within the range of 2 to 15 mg / L.

[0057] 4) After chlorine disinfection, the reclaimed water enters the post-water quality detection unit, and water samples are taken to detect the content of bacteria, ARGs and antibiotics. The bacteria are removed by 2.01-log, that is, the bacteria removal rate is 99.02%; the sul1 gene is removed by 0.15-log, that is, the sul1 gene removal rate is 29.21%, and the antibiotic degradation rate is 51.5%. The effluent is reused.

[0058] Comparative Example 2

[0059] Similarly, the effluent from the sewage treatment plant before disinfection in the same embodiment is treated as follows:

[0060] 1) The recycled water first enters the water quality automatic detection unit. The online automatic monitoring platform measures COD, ammonia nitrogen, turbidity and color indexes of 46.32 mg / L, 5.51 mg / L, 7.22 NTU and 25.12 respectively. The culturable bacteria measured by plate counting are 4.33×10 4 CFU / mL, sulfonamide resistance gene sul1 was 1.09×10 9 The total concentration of sulfonamide antibiotics with the highest detection rate was 0.34μg / L. The detected data was fed back to the intelligent analysis and control center in real time through sensors.

[0061] 2) UV irradiation. The control center monitors the data, analyzes it and sends a control signal to the UV irradiation unit. The UV irradiation amount is 600mJ / cm 2 (Radiation intensity 10mW / cm 2 , hydraulic retention time 60s). Ultraviolet rays can destroy the DNA or RNA structure of pathogenic microorganisms, making them lose their reproductive ability, thus achieving the purpose of disinfection.

[0062] 3) After UV disinfection, the reclaimed water enters the post-water quality detection unit to detect the content of bacteria, ARGs and antibiotics, and the bacteria removal is 2.54-log, that is, the bacteria removal rate is 99.71%, the sul1 gene log removal is 0.57-log, that is, the sul1 gene removal rate is 73.08%, and the antibiotic degradation rate is 20.3%. The effluent is reused.

[0063] Comparative Example 3

[0064] Similarly, the effluent from the sewage treatment plant before disinfection in the same embodiment is treated as follows:

[0065] 1) The recycled water first enters the water quality automatic detection unit. The online automatic monitoring platform measures COD, ammonia nitrogen, turbidity and color indexes of 45.33 mg / L, 5.12 mg / L, 7.25 NTU and 24.36 respectively. The culturable bacteria measured by plate counting are 4.33×10 4 CFU / mL, sulfonamide resistance gene sul1 was 1.09×109 The total concentration of sulfonamide antibiotics with the highest detection rate was 0.34μg / L. The detected data was fed back to the intelligent analysis and control center in real time through sensors.

[0066] 2) The control center sends a quantitative dosing signal to the free chlorine dosing unit, and 7.5 mg / L of sodium hypochlorite is added to the sewage through a metering pump, and mixed through pipes to allow the recycled water to fully contact and react with sodium hypochlorite, killing most pathogenic microorganisms in the water. The free chlorine monitoring unit monitors the effective chlorine concentration in real time. The effective chlorine concentration after mixing is 4.13 mg / L ， And feed back to the control center to ensure that the effective chlorine concentration is within the range of 2 to 15 mg / L.

[0067] 3) The sewage that has been disinfected with chlorine and has qualified effective chlorine content enters the UV irradiation unit, receives the control signal from the control center, and starts ultraviolet radiation. The ultraviolet radiation amount is 600mJ / cm 2 (Radiation intensity 10mW / cm 2 , hydraulic retention time 60s) to further inactivate residual pathogenic microorganisms.

[0068] 4) The reclaimed water after UV / NaClO combined disinfection treatment enters the post-water quality detection unit to detect the content of bacteria, ARGs and antibiotics. No bacteria were detected, and the sul1 gene log removal was 1.53-log, that is, the sul1 gene removal rate was 97.05%, and the antibiotic degradation rate was 72.5%. The effluent was reused.

[0069] Comparative Example 4

[0070] Similarly, the effluent from the sewage treatment plant before disinfection in Example 1 was treated as follows:

[0071] 1) The recycled water first enters the water quality automatic detection unit. The online automatic monitoring platform measures COD, ammonia nitrogen, turbidity and color indexes of 44.69 mg / L, 5.78 mg / L, 7.02 NTU and 24.56 respectively. The culturable bacteria measured by plate counting are 4.33×10 4 CFU / mL, sulfonamide resistance gene sul1 was 1.09×10 9 The total concentration of sulfonamide antibiotics with the highest detection rate was 0.34μg / L. The detected data was fed back to the intelligent analysis and control center in real time through sensors.

[0072] 2) The control center sends a quantitative dosing signal to the free chlorine dosing unit, and 7.5 mg / L sodium hypochlorite is added to the sewage through a metering pump, and mixed through pipes to allow the recycled water to fully contact and react with sodium hypochlorite, killing most pathogenic microorganisms in the water. The free chlorine monitoring unit monitors the effective chlorine concentration in real time. After mixing, the effective chlorine concentration is 4.25 mg / L ， And feed back to the control center to ensure that the effective chlorine concentration is within the range of 2 to 15 mg / L.

[0073] 3) The sewage that has been disinfected with chlorine and has qualified effective chlorine content enters the VUV irradiation unit, receives the control signal from the control center, starts ultraviolet radiation, and the vacuum ultraviolet irradiation amount is 600mJ / cm 2 (Radiation intensity 10mW / cm 2 , hydraulic retention time 60s) to further inactivate residual pathogenic microorganisms.

[0074] 4) The reclaimed water after VUV / NaClO combined disinfection treatment enters the post-water quality detection unit to detect the content of bacteria, ARGs and antibiotics. No bacteria were detected, and the sul1 gene log removal was 1.98-log, that is, the sul1 gene removal rate was 98.95%, and the antibiotic degradation rate was 85.4%. The effluent was reused.

[0075] Comparative Examples 1 to 4 use the same reactor as Example 1, the difference being the switches of some units, wherein the ultraviolet lamp used in Comparative Example 3 is a UV254 lamp.

[0076] Figure 5 It is the bacteria removal rate of the scheme of Example 1 and Comparative Examples 1-4.

[0077] Figure 6 It is the antibiotic degradation rate of the solutions of Example 1 and Comparative Examples 1 to 4.

[0078] Figure 7 It is the sul1 gene removal rate of the solutions of Example 1 and Comparative Examples 1 to 4.

[0079] Figure 5 to Figure 7 In the figure, abscissas A to E represent the results of Example 1 and Comparative Examples 1 to 4, respectively.

[0080] By comparison Figure 5 to Figure 7 It can be found that Example 1 can significantly improve the removal rate of sul1 gene and antibiotics and completely inactivate bacteria, and the effect is significantly better than the other four comparative examples.

[0081] Compared with chlorine disinfection alone (Comparative Example 1), UV disinfection alone (Comparative Example 2) improved the bacterial removal rate and sul1 gene removal rate, but the antibiotic degradation rate was not as good as chlorine disinfection alone.

[0082] Compared with chlorine disinfection alone and UV disinfection alone (Comparative Examples 1 and 2), the combined UV / chlorine disinfection (Comparative Example 3) can greatly improve the quality of discharged wastewater, and the bacteria removal rate, antibiotic degradation rate, and sul1 gene removal rate are all improved.

[0083] The shorter the wavelength of the ultraviolet lamp, the better the disinfection effect. According to the comparison of the treatment conditions of VUV / NaClO disinfection (Comparative Example 4) and UV / NaClO disinfection (Comparative Example 3), VUV / NaClO can not only completely inactivate bacteria, but also improve the antibiotic degradation rate and sul1 gene removal rate.

[0084] During treatment, increasing aeration (Example 1) can also optimize the disinfection effect. Compared with Example 4, Example 1 adds ceramic membrane micro-nano aeration, which significantly improves the degradation rate of antibiotics in the effluent and further ensures the water quality safety of the reclaimed water.

[0085] In summary, the coupling scheme of ceramic membrane micro-nano aeration technology and VUV / NaClO advanced oxidation process provided by the present invention can effectively remove antibiotic-resistant pollutants in reclaimed water, break through the limitations of existing technologies, significantly improve the disinfection and sterilization efficiency, and at the same time reduce the biological toxicity of water bodies and reduce ecological safety risks, thereby more comprehensively ensuring the safety and reliability of water quality.

[0086] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A disinfection method for simultaneously removing antibiotics, drug-resistant bacteria and resistance genes in water and reducing disinfection by-products, characterized in that: The following steps are involved: Sodium hypochlorite is added to the water to be disinfected to ensure that the concentration of effective chlorine in the water to be disinfected is 2-15 mg / L; DO is further introduced through aeration and VUV disinfection is performed to simultaneously remove antibiotics, drug-resistant bacteria and resistance genes in the water to be disinfected and reduce disinfection by-products.

2. The disinfection method for simultaneously removing antibiotics, drug-resistant bacteria and resistance genes in water and reducing disinfection by-products according to claim 1, characterized in that: The aeration rate of the aeration is 0.3-1 mL / min.

3. The disinfection method for simultaneously removing antibiotics, drug-resistant bacteria and resistance genes in water and reducing disinfection by-products according to claim 1, characterized in that: The VUV irradiation dose is 300-1000 mJ / cm 2 .

4. The disinfection method for simultaneously removing antibiotics, drug-resistant bacteria and resistance genes in water and reducing disinfection by-products according to claim 1, characterized in that: The aeration is achieved through a microporous aeration membrane with a diameter of 0.1 to 5 μm.

5. The disinfection method for simultaneously removing antibiotics, drug-resistant bacteria and resistance genes in water and reducing disinfection by-products according to claim 4, characterized in that: The material of the microporous aeration membrane is ceramic.

6. The disinfection method for simultaneously removing antibiotics, drug-resistant bacteria and resistance genes in water and reducing disinfection by-products according to claim 1, characterized in that: Before adding sodium hypochlorite, test the COD and ammonia nitrogen of the water to be disinfected. When the COD of the water to be disinfected is ≤50mg / L and the ammonia nitrogen is ≤8mg / L, the chlorine dosage is 5-15mg / L; when 50<COD≤60mg / L and 5<ammonia nitrogen≤15mg / L, the chlorine dosage is 8-20mg / L.

7. Use of the disinfection method for simultaneously removing antibiotics, drug-resistant bacteria and resistance genes in water and reducing disinfection by-products as described in any one of claims 1 to 6 in sewage treatment.

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