Method for removing nitrate and degrading antibiotics through sulfur autotrophy-heterotrophy synergy

Abstract

The invention discloses a method for synergistically removing nitrate and degrading antibiotics through sulfur autotrophy-heterotrophy, which comprises the following steps: (1) taking an SBR (sequencing batch reactor), inoculating anoxic sludge of a sewage treatment plant, adding CH3NaS, Na2S2O3 and NaHCO3 into influent water containing nitrate, and domesticating the sludge; and (2) after domestication in the step (1) is completed, carrying out anoxic stirring, introducing nitrate-containing wastewater, adding a solution containing CH3NaS and antibiotics into the reactor, carrying out a stirring reaction, determining a first-order derivative of ORP, when the first-order derivative dORP / dt is less than or equal to r, repeating the steps of adding the solution containing CH3NaS and antibiotics, carrying out a stirring reaction, and determining the first-order derivative of ORP for many times, and when the last first-order derivative dORP / dt is less than or equal to r, stopping adding the solution containing CH3NaS and antibiotics. Carrying out anaerobic stirring, precipitating, draining and stopping to complete domestication of the sludge; and (3) introducing wastewater to be treated to remove nitrate and antibiotics. The method provided by the invention can realize sulfur autotrophy-heterotrophy synergistic efficient removal of nitrate and tolerate beta-lactam antibiotic stress.

Description

Technical Field

[0001] The invention relates to the technical field of sewage treatment, and in particular to a method for sulfur autotrophic-heterotrophic synergistic removal of nitrate and degradation of antibiotics. Background Art

[0002] Antibiotics are widely used in the fields of medicine, animal husbandry, aquaculture, etc., but most of the underutilized antibiotic residues are discharged into the water environment in their original form. The continuous accumulation of these pollutants will threaten environmental safety and human health. β-lactam antibiotics are widely used due to their high efficiency, universality, and low toxicity. They account for more than 65% of the global antibiotic market and are potential pollutants in wastewater treatment. They have been detected in sewage plant effluent, aquaculture wastewater, medical wastewater, rainwater and other water bodies. In addition to antibiotics, these wastewaters usually contain: COD, NH4 + -N, TP and other pollutants, after the front-end aerobic treatment, further carbon sources need to be added to remove TN, TP and other pollutants. In addition, antibiotic pollutants have poor biodegradability and are difficult to completely degrade during the back-end treatment process. They often remain in the remaining sludge and effluent, further causing environmental pollution.

[0003] In addition, the traditional nitrification and denitrification process also faces problems such as high drug consumption, large amount of residual sludge discharge, long process and high labor cost. The research on related autotrophic denitrification has become one of the hot spots. Sulfur autotrophic denitrification is a promising back-end deep denitrification process with the advantages of high efficiency, no need for carbon source, low sludge production, and resistance to shock loads. Traditional sulfur autotrophic denitrification usually uses granular solid fillers such as sulfur, calcium sulfide, and pyrite as carriers to build filter bed reactors. Although it has the advantage of high efficiency, it still has problems such as filter bed clogging, high backwashing energy consumption, excessive sulfate ions in the effluent, and the need for continuous alkalinity supplementation.

[0004] In summary, the invention of a back-end treatment method that can efficiently and stably denitrify and remove β-lactam antibiotics at the same time has practical significance for ensuring the safety and sustainable development of the water environment. Summary of the invention

[0005] In view of the problem that the existing treatment process cannot effectively treat nitrate and β-lactam antibiotics at the same time, the present invention provides a method for sulfur autotrophic-heterotrophic synergistic removal of nitrate and degradation of antibiotics, which can achieve sulfur autotrophic-heterotrophic synergistic efficient removal of nitrate and tolerance to β-lactam antibiotic stress, and has a certain degradation effect on β-lactam antibiotics such as amoxicillin, procaine and ceftriaxone, and can be applicable to the treatment of a variety of antibiotic-containing wastewaters.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] The present invention provides a method for sulfur autotrophic-heterotrophic synergistic removal of nitrate and degradation of antibiotics, comprising the following steps:

[0008] (1) Sulfur autotrophic-heterotrophic synergistic nitrate removal acclimation: Take the SBR reactor, inoculate the anoxic sludge from the sewage treatment plant, add CH3NaS, Na2S2O3, and NaHCO3 to the nitrate-containing influent water to perform sludge acclimation;

[0009] (2) Domestication under antibiotic stress: After the domestication in step (1) is completed, anoxic stirring is performed, and then nitrate-containing wastewater is introduced. A solution containing CH3NaS and antibiotics is added to the reactor, stirred for reaction, and the first-order derivative of ORP is measured. When the first-order derivative |dORP / dt|≤r, the steps of adding the solution containing CH3NaS and antibiotics, stirring for reaction, and measuring the first-order derivative of ORP are repeated multiple times. When the first-order derivative |dORP / dt|≤r for the last time, anaerobic stirring is performed, and then sedimentation, drainage, and stopping are performed to complete the domestication of the sludge;

[0010] (3) After the sludge is domesticated, the wastewater to be treated is introduced to remove nitrates and antibiotics.

[0011] Preferably, in step (1), during the acclimation phase, the SBR adopts an operation mode of water intake, anoxic stirring, standing, and drainage, and the inlet and outlet NO X Concentration, wait for NO3 - The acclimatization stage is completed when the -N removal rate is stabilized at above 95%.

[0012] Preferably, in step (1), the influent NO3 - -N, CH3NaS, Na2S2O3 mass concentration ratio is 1:0.8~2.5:0.5~1; the NO3 - -N concentration is 80-120 mg / L; the NaHCO3 concentration is 200-240 mg / L.

[0013] Preferably, in step (1), 1.5-2.5 g / L KH2PO4, 0.4-0.6 g / LMgSO4·7H2O, and 0.008-0.012 g / L FeSO4·7H2O are added to the reactor during the acclimation stage.

[0014] Preferably, in step (1), after inoculation with anoxic sludge from a sewage treatment plant, the suspended solids concentration of the sludge mixed liquor is 5000 to 6000 mg / L.

[0015] Preferably, in step (1), the HRT of the SBR reactor is 20 to 28 hours; further preferably, the HRT of the SBR reactor is 22 to 24 hours. In some specific embodiments of the present invention, the HRT of the SBR reactor is 24 hours, and the water exchange ratio is set to 0.5.

[0016] Preferably, in step (1), the pH of the influent is adjusted using an acid solution, and the pH value is 7.5 to 8.2.

[0017] Using Na2S2O3 as one of the electron donors in the acclimatization of sulfur autotrophic-heterotrophic synergistic nitrate removal can preferentially promote the sulfur autotrophic denitrification process and prevent excessive proliferation of heterotrophic bacteria. CH3NaS as an electron donor can not only promote the sulfur autotrophic-heterotrophic synergistic effect, but also the sulfur group formed after hydrolysis can promote the transfer of substances inside and outside the cell membrane, accelerate the metabolic process of pollutants, and speed up the startup process.

[0018] After the sulfur autotrophic-heterotrophic synergistic nitrate removal acclimatization stage is completed, multiple antibiotic stress acclimatizations are carried out in a single cycle. In this stage, the influent NO3 is gradually increased. - -N concentration, and logical parameters are used to control the reaction time and dosing. The basic principle of this stage is: multiple antibiotic stresses in a single cycle help microorganisms maintain a continuous response to antibiotic stress. The first-order derivative of ORP in the reaction process is used as a control parameter for the reaction process, and electron donors and antibiotics are added multiple times. Traditional single addition of high-concentration antibiotics often produces a large amount of sludge adsorption and may cause toxicity to microorganisms.

[0019] In addition, in the influent NO3 - After the -N concentration gradually increases, splitting a single cycle into multiple small cycles helps maintain the enzyme activity of microorganisms. According to the enzymatic reaction kinetics, as the substrate concentration decreases, the enzymatic reaction rate gradually decreases. After splitting into small cycles, multiple additions of electron donors help degrade high-concentration pollutants. At the same time, higher enzyme activity helps microorganisms degrade antibiotics.

[0020] Preferably, in step (2), the total amount of CH3NaS added multiple times is equal to the amount of NO3 in the influent. - -N mass ratio is 1.3-3.5:1; the total dosage of the antibiotics and NO3 in the influent - -N mass ratio is 1:18~22.

[0021] Preferably, in step (2), the steps of adding a solution containing CH3NaS and antibiotics, stirring the reaction, and determining the first-order derivative of ORP are performed 6 to 7 times in total.

[0022] Preferably, in step (2), the r value ranges from 0 to 0.1.

[0023] Preferably, in step (2), the antibiotic is a β-lactam antibiotic.

[0024] Preferably, in step (2), the time of pre-anoxic stirring is 25 to 35 minutes; and the time of anaerobic stirring is 20 to 30 minutes.

[0025] Preferably, in step (2), multiple antibiotic stress acclimation cycles can be performed, and the NO3 in the influent can be gradually increased in different cycles. - -N concentration.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) It can achieve sulfur autotrophic-heterotrophic synergistic and efficient removal of nitrate and β-lactam antibiotics. It can be applied to the back-end treatment of various antibiotic-containing wastewaters.

[0028] (2) Using CH3NaS as a liquid sulfur source and carbon source can promote heterotrophic denitrification and sulfur autotrophic denitrification at the same time. In addition, the sulfur group has nucleophilicity, metal chelation, redox properties, etc., which can react with the disulfide bonds in the cell membrane to mediate the transfer of substances and accelerate the reaction rate.

[0029] (3) The method of multiple antibiotic stress acclimation in a single cycle helps microorganisms maintain a continuous response to antibiotic stress, avoiding the sludge adsorption and toxic effects caused by a single addition of high-concentration antibiotics.

[0030] (4) Using the first-order derivative of ORP |dORP / dt| as the control parameter and controlling the addition of electron donors to divide a single cycle into multiple small cycles helps maintain the enzyme activity of the microorganisms and accelerate the reaction process.

[0031] (5) Pre-anaerobic stirring and dosing to extend stirring were adopted to reduce the impact of abnormal peaks on the program progress. In addition, two judgment cycles were combined to improve the accuracy of controlling the end of the reaction.

[0032] (6) Gradually increasing the influent nitrate concentration and the added antibiotic concentration during the antibiotic stress tolerance acclimatization stage helps to simultaneously increase the reactor denitrification load and the removal effect of β-lactam antibiotics.

[0033] (7) The heterotrophic-autotrophic combined treatment method is adopted to combine heterotrophic denitrification and sulfur autotrophic denitrification in one unit to achieve alkalinity complementarity, reduce the amount of alkalinity added, and save drug consumption. At the same time, it helps to remove nitrogen efficiently, reduce the production of sulfate ions, and avoid secondary pollution of sulfur autotrophic denitrification.

[0034] (8) Although CH3NaS can effectively promote the sulfur autotrophic-heterotrophic denitrification process, its aqueous solution is strongly alkaline after dissolving in water. When the load is increased, if a large amount of CH3NaS is added at one time, it will cause microbial intolerance and death. Traditional batch addition requires multiple sample tests, which is too cumbersome. The use of a logic control system can achieve uniform batch addition and reduce labor costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is the NO3 in reactor A - -N removal effect;

[0036] Figure 2 NO3 in reactor B - -N removal effect;

[0037] Figure 3 is the SO4 of reactor A and B 2- Yield map;

[0038] Figure 4 The control logic diagram for multiple antibiotic stress acclimation operations in a single cycle;

[0039] Figure 5 Different influent NO3 for reactor A - -N and denitrification effect under antibiotic stress;

[0040] Figure 6 Different influent NO3 for reactor B - -N and denitrification effect under antibiotic stress;

[0041] Figure 7 Comparison of community richness between the experimental group and the control group. DETAILED DESCRIPTION

[0042] The specific embodiments of the present invention are further described below. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0043] The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental materials used in the following examples are commercially available unless otherwise specified.

[0044] Example 1

[0045] Start-up denitrification effect of mixed autotrophic-heterotrophic synergistic denitrification reactor and traditional reactor.

[0046] The SBR reactor A with an effective volume of 10L was used as the experimental group, and the anoxic sludge of the biochemical system in the municipal sewage treatment plant was inoculated for acclimatization. The suspended solids concentration of the sludge mixed liquor after inoculation was about 5000-6000mg / L. The HRT was set to 24h, and the water exchange ratio was set to 0.5. The SBR adopted the operation mode of water inlet (10min), anoxic stirring (11h), static (40min), and drainage (10min).

[0047] The influent is synthetic wastewater, and NO3 is provided by NaNO3 - -N: about 100mg / L. Sodium methyl mercaptan (CH3NaS): 150mg / L, sodium thiosulfate (Na2S2O3): 80mg / L and sodium bicarbonate (NaHCO3): 220mg / L were added to the influent. In addition, 2g / L KH2PO4, 0.5g / L MgSO4·7H2O, 0.01g / L FeSO4·7H2O were added to promote cell growth and reproduction, and 1mol / L hydrochloric acid was used to adjust the influent pH to 7.5-8.2.

[0048] An upflow fixed bed reactor B with an effective volume of 10L was used as the control group, and traditional sulfur granules were used as the fixed bed filler. The inoculated sludge was consistent with that of the experimental group. The sludge and sulfur granules were mixed evenly and then inoculated into the reactor. The fixed bed is divided into four layers, connected by permeable baffles and flanges. A three-phase separator and a reflux pipe are provided at the top of the fixed bed to reflux to the water inlet at the bottom of the reactor. The fixed bed adopts an operating mode of water inlet, reflux, standing, and drainage, and the reaction cycle is the same as that of the experimental group. No additional electron donor CH3NaS is added to the influent, and the other components are consistent with the experimental group.

[0049] like Figure 1 As shown, after 20 days of operation of reactor A in the experimental group, NO3 - -N removal rate (RE.NO3 - -N) was maintained at around 99%, while the control group's NO3 - -N removal rate is only about 70% ( Figure 2 ). The use of sodium methyl mercaptan (CH3NaS) and sodium thiosulfate (Na2S2O3) can quickly start sulfur autotrophic-heterotrophic synergistic denitrification, which has a higher denitrification efficiency than the traditional sulfur autotrophic filter bed.

[0050] NO2 in the effluent of reactor A in the experimental group - -N was almost completely degraded after 10 days, while NO2 appeared in the effluent of the control reactor B. - -N accumulation phenomenon (average outlet NO2 - -N>10mg / L), long-term NO2 - -N accumulation may be toxic to microorganisms.

[0051] In addition, if Figure 3 Compared with the control group B, the SO4 2- The yield is lower, which may be due to heterotrophic denitrification. In addition, the organic electron donor may be used for the reduction of sulfate, allowing it to further participate in the sulfur cycle and synergistically remove nitrogen.

[0052] Example 2

[0053] Acclimation to multiple antibiotic stresses within a single cycle.

[0054] After the 20th day, the reactor entered the antibiotic stress acclimatization stage. In this stage, four influent NO3 - -N concentration: 100, 200, 300, 400 mg / L. The corresponding antibiotic stress concentration was set to: 5, 10, 15, 20 mg / L. Experimental group A used an automatic control system to control the operation of the reactor according to the logic parameter control method. The total CH3NaS dosage: NO3 - -N mass ratio was 2.5. Further, antibiotics were also added in an evenly divided manner according to the total dosage, with one cycle per day.

[0055] Details are as attached Figure 4As shown, 1) the function of the start-up unit is to start the control program. 2) The function of the pre-anaerobic stirring unit is to perform pre-anoxic stirring for 30 minutes to remove the residual NOx from the previous cycle. 3) The function of the water inlet unit is to feed nitrate synthetic wastewater into the reactor. 4) The function of the dosing unit is to add medicine to the reactor for the first time after the water is introduced. 5) The function of the first anoxic stirring unit is to fully stir for sulfur autotrophic-heterotrophic denitrification. Further, in this stage, the ORP value in the reactor is tested by a sensor and input, and then the computer calculates and outputs |dORP / dt|. 6) The function of the judgment unit is to judge whether the |dORP / dt| value is ≤ the set value r. If the judgment result is "no", it returns to the first anoxic stirring calculation unit to continue running. If the judgment result is "yes", it enters the dosing unit again. 7) The re-dosing unit includes: stirring after dosing and extending stirring for 15 minutes. Its function is to continue stirring for 15 minutes after the dosing is completed and then enter the stirring calculation unit. Further, it can make the reagents fully mixed while avoiding the ORP peak generated during the dosing process affecting the calculation and judgment results. 8) The function of the anoxic stirring unit is to continue anoxic stirring for biochemical reaction and calculate |dORP / dt|. The calculation method is consistent with step 5). 9) The judgment method of the secondary judgment unit is consistent with 6). Further, if the output result of the secondary judgment unit is "no", it returns to the first anoxic stirring unit and calculates |dORP / dt|. Further, if the output result of the secondary judgment unit is "yes", it enters the anaerobic stirring unit. 10) The function of the anaerobic stirring unit is to end the reaction by anaerobic stirring for 10 to 20 minutes. 11) The function of the sedimentation unit is to let the sedimentation stand to separate the mud and water. 12) The function of the drainage unit is to discharge the supernatant after the reaction from the reactor. 13) The function of the stop unit is to stop the logic control program.

[0056] Among them, the setting value r in 6) is in the range of 0 to 0.1.

[0057] The operating conditions of reactor A are shown in Table 1.

[0058] At the end of each acclimation stage, the reactor was evaluated for antibiotic removal. After being washed with clean water to remove the background value, it was operated according to the working conditions of that stage, and the concentration of antibiotics in the effluent was measured to evaluate the pollutant removal effect of the reactor. The average value was obtained by three measurements in each stage. Antibiotics were determined by solid phase extraction-high performance liquid chromatography. The water sample was filtered with a 0.22μm filter membrane and extracted through an activated HLB column, and then the column was eluted with methanol. The extract and eluent were blown dry with nitrogen to 1mL and stored in a brown sample bottle, and determined by high performance liquid chromatography.

[0059] Table 1

[0060]

[0061] The control group reactor B uses continuous flow in and out water, and the hydraulic retention time is controlled to 24h by adjusting the flow rate of the water inlet pump. The operating conditions of the reactor are shown in Table 2.

[0062] Table 2

[0063]

[0064] Different influent NO3 - -N and antibiotic stress denitrification effect:

[0065] like Figure 5 The overall denitrification effect of experimental group A remained stable, and the denitrification rate gradually increased with the increase of influent nitrogen load. During this period, the antibiotic stress level also increased synchronously. In stage IV, the antibiotic level increased to 20 mg / L, resulting in NO in the reactor effluent. X However, after 35 days of acclimatization, the denitrification efficiency of reactor A recovered to 90% at the end of stage IV.

[0066] The denitrification effect of the traditional sulfur autotrophic filter bed in the control group is as follows Figure 6 As shown in the figure, with the increase of antibiotic stress level, its denitrification performance was seriously damaged. In stage IV, the denitrification efficiency was only about 50%.

[0067] In summary, the heterotrophic-autotrophic denitrification experimental group has better denitrification performance and shock load resistance. Especially when facing β-lactam antibiotics stress, the experimental group showed better denitrification efficiency and higher nitrogen removal rate.

[0068] Effect of removing antibiotics:

[0069] The experimental group was much better than the control group B in removing antibiotics. This was due to the use of a logic-controlled dosing method, which added antibiotics in small amounts over multiple times, giving the microorganisms more time to adapt during the reaction cycle. In addition, the experimental group used activated sludge, which allowed the microorganisms to contact the antibiotics more evenly, preventing the bactericidal effect caused by excessive local concentrations. In addition, the experimental group used a combination of heterotrophic and autotrophic denitrification, and the mixed colonies formed had a stronger tolerance to antibiotics.

[0070] Alpha diversity comparison of microbial communities:

[0071] The inoculated sludge, the 130th day sludge sample of the experimental group A, and the 130th day sludge sample of the control group B were selected for high-throughput sequencing to analyze the microbial diversity information. The mixed solution of the inoculated sludge and the sludge samples of the experimental group A was directly extracted from the reactor, centrifuged and washed, and then stored at -20°C. The sulfide particles in the column of the control group B were extracted by ultrasonication, centrifuged, washed, and stored.

[0072] As shown in Table 3, the coverage index in the sludge samples was higher than 0.99. Compared with the inoculated sludge, the diversity index of the experimental group A increased significantly, indicating an increase in the richness of the microbial community, while the population richness of the control group B declined significantly. This shows that compared with the traditional sulfur autotrophic denitrification, the heterotrophic-autotrophic synergistic denitrification established a richer microbial community, which can effectively resist the stress of antibiotics.

[0073] Table 3

[0074] Sample_Estimators ace Chao coverage shannon sobs Inoculation sludge 567.182 574.067 0.999 5.011 670 Experimental Group A 696.004 714.132 0.999 5.845 813 Control group B 412.031 403.426 0.999 3.897 516

[0075] Comparison of community richness at the genus level:

[0076] The community richness at the genus level was compared to further analyze the community evolution and dominant bacterial species in the experimental and control groups. Figure 7 As shown in the figure: Compared with the inoculated sludge, both the experimental group and the control group underwent significant community evolution. In the experimental group, Sulfurimonas, Acinetobacter, and Sphingobium were the top three dominant genera in abundance. Sulfurimonas is a typical sulfur autotrophic bacterium, which was significantly enriched in the experimental group with a relative abundance of 40.76%. In addition, Acinetobacter is related to heterotrophic denitrification, while Sphingobium is related to the degradation of β-lactam antibiotics. The effective enrichment of these genera indicates the effective synergy of the autotrophic-heterotrophic combined denitrification bacteria in the experimental group. In addition, effective genera were also enriched in the community under the stress of β-lactam antibiotics.

[0077] Example 3

[0078] Long-term stable operation experiment

[0079] Reactor A in the experimental group was adjusted to the stage III operating conditions, maintaining the influent NO3--N: 300 mg / L, the daily antibiotic stress level of 15 mg / L, and operating stably for 50 days. The influent and effluent nitrogen were measured every day, and the antibiotic removal effect was measured every 10 days. The experimental results are shown in Table 4: During the 50-day long-term operation, the reactor showed stable denitrification performance and antibiotic removal effect, indicating that the use of autotrophic-heterotrophic combined denitrification method can effectively achieve the removal of pollutants and has the potential for practical application in the back-end treatment of wastewater containing β-lactam antibiotics. Table 4

[0080]

[0081] The embodiments of the present invention are described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the protection scope of the present invention.

Claims

1. A method for sulfur autotrophic-heterotrophic synergistic removal of nitrate and degradation of antibiotics, characterized in that: The following steps are involved: (1) Sulfur autotrophic-heterotrophic synergistic nitrate removal acclimation: Take the SBR reactor, inoculate the anoxic sludge from the sewage treatment plant, add CH3NaS, Na2S2O3, and NaHCO3 to the nitrate-containing influent water to perform sludge acclimation; (2) Domestication under antibiotic stress: After the domestication in step (1) is completed, anoxic stirring is performed, and then nitrate-containing wastewater is introduced. A solution containing CH3NaS and antibiotics is added to the reactor, stirred for reaction, and the first-order derivative of ORP is measured. When the first-order derivative |dORP / dt|≤r, the steps of adding the solution containing CH3NaS and antibiotics, stirring for reaction, and measuring the first-order derivative of ORP are repeated multiple times. When the first-order derivative |dORP / dt|≤r for the last time, anaerobic stirring is performed, and then sedimentation, drainage, and stopping are performed to complete the domestication of the sludge; (3) After the sludge is domesticated, the wastewater to be treated is introduced to remove nitrates and antibiotics.

2. The method for sulfur autotrophic-heterotrophic synergistic nitrate removal and antibiotic degradation according to claim 1, characterized in that: In step (1), during the acclimation phase, the SBR adopts the operation mode of water intake, anoxic stirring, standing, and drainage, and the inlet and outlet NO X Concentration, wait for NO3 - The acclimatization stage is completed when the -N removal rate is stabilized at above 95%.

3. The method for sulfur autotrophic-heterotrophic synergistic removal of nitrate and degradation of antibiotics according to claim 1, characterized in that: In step (1), the influent NO3 - -N, CH3NaS, Na2S2O3 mass concentration ratio is 1:0.8~2.5:0.5~1; the NO3 - -N concentration is 80-120 mg / L; the NaHCO3 concentration is 200-240 mg / L.

4. The method for sulfur autotrophic-heterotrophic synergistic removal of nitrate and degradation of antibiotics according to claim 1, characterized in that: In step (1), during the acclimation stage, 1.5-2.5 g / L KH2PO4, 0.4-0.6 g / LMgSO4·7H2O, and 0.008-0.012 g / LFeSO4·7H2O are added to the reactor.

5. The method for sulfur autotrophic-heterotrophic synergistic nitrate removal and antibiotic degradation according to claim 1, characterized in that: In step (1), after inoculating the anoxic sludge from the sewage treatment plant, the suspended solid concentration of the sludge mixed liquor is 5000-6000 mg / L.

6. The method for sulfur autotrophic-heterotrophic synergistic nitrate removal and antibiotic degradation according to claim 1, characterized in that: In step (1), the HRT of the SBR reactor is 20 to 28 hours.

7. The method for sulfur autotrophic-heterotrophic synergistic nitrate removal and antibiotic degradation according to claim 1, characterized in that: In step (2), the total amount of CH3NaS added multiple times is equal to the amount of NO3 in the influent. - -N mass ratio is 1.3-3.5:1; the total dosage of the antibiotics and NO3 in the influent - -N mass ratio is 1:18~22.

8. The method for sulfur autotrophic-heterotrophic synergistic nitrate removal and antibiotic degradation according to claim 1, characterized in that: In step (2), the steps of adding the solution containing CH3NaS and antibiotics, stirring the reaction, and measuring the first-order derivative of ORP are performed 6 to 7 times in total.

9. The method for sulfur autotrophic-heterotrophic synergistic nitrate removal and antibiotic degradation according to claim 1, characterized in that: In step (2), the r value ranges from 0 to 0.

1.

10. The method for sulfur autotrophic-heterotrophic synergistic nitrate removal and antibiotic degradation according to claim 1, characterized in that: In step (2), the antibiotic is a β-lactam antibiotic.

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