Biological recycling and harmless treatment method and device for cefradine waste medicine

Abstract

The invention discloses a biological recycling and harmless treatment method and a biological recycling and harmless treatment device for cefradine waste medicines. The method comprises the following steps: dissolving a cefradine waste medicine in a sodium hydroxide solution, and carrying out heating treatment to obtain medicine residues; the medicine residues are subjected to long-period anaerobic digestion treatment, methane is generated, and anaerobic digestion liquid is obtained; the anaerobic digestion liquid is used as an external carbon source to be supplemented into municipal sewage with a low carbon nitrogen ratio, and sequencing batch activated sludge treatment is carried out. According to the method for treating the cefradine waste medicine, medicine residues with low biotoxicity can be obtained, available resources which are originally difficult to utilize are secondarily utilized through long-period anaerobic digestion treatment, the green approach and diversity of the technology for treating the waste medicine are expanded, and the method is suitable for industrial production. The anaerobic digestion liquid with high carbon, low nitrogen and low harmful components is supplemented into the sequencing batch activated sludge treatment process for municipal sewage with low carbon-nitrogen ratio, so that the denitrification efficiency of the sewage is greatly improved, and a new thought for coupling the drug hazardous waste with the municipal sewage is provided.

Description

Technical Field

[0001] The invention belongs to the technical field of environmental science and hazardous waste treatment, and specifically relates to a method and device for bioresource and harmless treatment of discarded cephradine drugs. Background Art

[0002] According to the provisions of my country's "National List of Hazardous Wastes" (2021 edition), waste drugs and medicines of hazardous waste category HW03 are invalid, deteriorated, unqualified, obsolete, and counterfeit chemical drugs and biological products generated during sales and use (excluding vitamins and mineral drugs listed in the "National Essential Medicines List", water, electrolyte and acid-base balance regulating drugs), as well as toxic traditional Chinese medicines listed in the "Regulations on the Management of Toxic Drugs for Medical Use". Abandoned cefradine drugs belong to this category of substances and need to be legally transported to relevant institutions with hazardous waste treatment and disposal for treatment and disposal. Generally speaking, the methods for treating and disposing of hazardous wastes include high-temperature incineration, resource recovery, solidification stabilization, and safe landfill. For discarded drugs, traditional treatment methods such as high-temperature incineration and safe landfill are mostly adopted, but there are few reports on the attempt of low-temperature pyrolysis pretreatment methods, and the parameters of the pretreatment are not clear.

[0003] According to the results of life cycle assessment, about 5% of discarded antibiotics are generated during the entire process of cephalosporin antibiotic production, sales, use and scrapping. Since there are a large number of excipients in actual cephalosporin drugs, such as starch, cellulose or sugar, accounting for more than 90% of the mass. Therefore, it is very green and feasible to use biotreatment technology to recycle and detoxify these easily bioavailable excipients. However, the active ingredient (cephalosporin) in the drug has a relatively strong biological toxicity. Therefore, it is crucial to study efficient and economical pretreatment methods to degrade the active ingredients in actual drugs.

[0004] Cefradine has the property of acid resistance and its chemical formula is C 16 H 19 N3O4S, chemical name is (6R,7R)-7-[(R)-2-amino-2-(1,4-cyclohexadien-1-yl)acetylamino]-3-methyl-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid. The pure substance is white powder with a slight odor. In synthetic drugs, it is doped with other sugars to give a light orange color. It is slightly soluble in water, soluble in acid / alkaline solutions, easily hydrolyzed in aqueous solutions, and almost insoluble in ethanol or ether.

[0005] Currently, there is no full-process biological treatment method for discarded antibiotics. Summary of the invention

[0006] In view of the shortcomings of the prior art, the object of the present invention is to provide a method and device for bioresource and harmless treatment of waste cephradine drugs.

[0007] The technical solution adopted by the present invention is as follows:

[0008] The present invention provides a method for bioresource and harmless treatment of waste cephradine drugs, comprising the following steps:

[0009] (1) dissolving the discarded cephradine drug in a sodium hydroxide solution, and heating the solution (low-temperature pyrolysis pretreatment) to obtain a drug residue (low biotoxicity and easy biodegradation);

[0010] (2) subjecting the drug residue of step (1) to long-term anaerobic digestion to produce methane and obtain anaerobic digestion liquid (high in carbon, low in nitrogen, and low in toxicity);

[0011] (3) The anaerobic digestion liquid obtained in step (2) is added as an external carbon source to municipal sewage with a low carbon-nitrogen ratio to perform sequencing batch activated sludge treatment.

[0012] The low-temperature pyrolysis pretreatment of step (1) is to add alkali liquor and medicine into the reactor, and heat the solution in a timed manner. The preparation method of the alkali liquor and the medicine solution is as follows: 120g NaOH is dissolved in 5L water to obtain 0.6mol / L alkali liquor, 15kg of cephradine waste drug particles are weighed and dissolved in the aforementioned alkali liquor, and a uniform clear orange viscous liquid is obtained after sufficient stirring, which is a 3kg / L cephradine solution. The heat treatment is sealed in a low-temperature reactor at 95°C and heated for 40min. The timing starts when the ambient temperature of the reactor cavity reaches 95°C, and the material is fed. After the 40min timing ends, the material is discharged from the discharge port and cooled and mixed with the matrix in the matrix mixing tank.

[0013] Preferably, in step (1), the concentration of the sodium hydroxide solution is 0.6 mol / L;

[0014] Preferably, in step (1), the mass volume ratio of the waste cefradine drug and the sodium hydroxide solution is 15kg:5L.

[0015] Preferably, in step (1), the heating treatment temperature is 95° C. and the time is 40 min.

[0016] Preferably, in step (1), the components of the discarded cephradine drug are: 5 wt % of cephradine active ingredient, 93 wt % of sucrose, and 2 wt % of other components.

[0017] The long-term anaerobic digestion treatment process of step (2) is a fully enclosed reactor, with a 35°C constant temperature water bath installed outside, a motor set on the top, a stirring rod installed, and the prepared anaerobic sludge nutrient salt solution mixed with drug residues is added to the anaerobic digestion system, and stirred regularly. The gas collection bag and the feed port are connected at the top, and the pH of the digestate is monitored every day and adjusted to 6.5-7.5 with sodium bicarbonate. The feeding and discharging cycles are set to collect the gas and anaerobic digestate generated in the reactor.

[0018] Preferably, in step (2), the temperature of the long-term anaerobic digestion treatment is 35° C. and the pH is 6.5 to 7.5. The pH is adjusted by adding sodium bicarbonate.

[0019] Preferably, in step (2), the dosage of the drug residue is 2.5 g / L / d.

[0020] Preferably, in step (2), biochar material is also added to the long-term anaerobic digestion treatment, and the addition amount is 10 g / L.

[0021] Preferably, in step (2), the long-term anaerobic digestion treatment is carried out in an anaerobic fermentation tank or an anaerobic tank. The long-term anaerobic digestion treatment converts a large amount of sugars in the pharmaceutical excipients into methane and VFA.

[0022] Preferably, in step (2), the COD of the anaerobic digestion liquid is ~4000 mg / L.

[0023] The sequencing batch activated sludge treatment process of step (3) is to set a sequencing batch activated sludge reactor (SBR), add stirring, the aeration volume of the bottom aeration plate is 0.7-1.5L / min, the HRT is 12h, the volume exchange rate is 50%, the time ratio of the anoxic cycle to the aerobic cycle is 8:3, and the static sedimentation time is not less than 15 minutes. Stirring is performed during the anoxic cycle, and water is regularly inlet (after the municipal sewage is mixed with the digestate in the digestate dilution mixing tank) and outlet.

[0024] Preferably, in step (3), the carbon-nitrogen ratio of the mixed solution after the anaerobic digestion liquid is supplemented with municipal sewage with a low carbon-nitrogen ratio is 4 to 6:1.

[0025] Preferably, in step (3), the aeration rate of the sequencing batch activated sludge treatment is 0.7-1.5 L / min, the HRT is 12 h, the volume exchange rate is 50%, the time ratio of the anoxic period to the aerobic period is 8:3, the static sedimentation time is not less than 15 minutes, stirring is performed during the anoxic period, and water is regularly introduced and discharged.

[0026] Preferably, in step (3), the carbon-nitrogen ratio of the low carbon-nitrogen ratio municipal sewage is <4.0.

[0027] The present invention provides a bioresource and harmless treatment device for waste cephradine medicine, comprising a heating reactor, an anaerobic reactor and a sequencing batch activated sludge reactor;

[0028] The heating reactor is provided with an electric stirrer, a feed inlet and a discharge outlet;

[0029] The anaerobic reactor is provided with an electric stirrer, a gas collecting port, a feed port, a discharge port and a feeding port;

[0030] The sequencing batch activated sludge reactor is provided with an electric stirrer, a feed inlet, a discharge outlet and an aeration hole;

[0031] A substrate mixing pool is arranged between the heating reaction kettle and the anaerobic reactor, and the substrate mixing pool is connected with the discharge port of the heating reaction kettle and the feed port of the anaerobic reactor; the substrate mixing pool is also provided with a liquid adding port;

[0032] A digestate dilution mixing tank is arranged between the anaerobic reactor and the sequencing batch activated sludge reactor, and the digestate dilution mixing tank is connected with the discharge port of the anaerobic reactor and the feed port of the sequencing batch activated sludge reactor; the digestate dilution mixing tank is also provided with a water inlet.

[0033] The electric stirrer of the heating reactor enables the liquid medicine to be evenly stirred during heating; the heating reactor can control temperature and timing.

[0034] The feed port of the heating reactor is used to feed the waste cefradine medicine and the sodium hydroxide solution.

[0035] The discharge from the heating reactor enters the substrate mixing tank, is mixed with the anaerobic sludge nutrient solution in a certain proportion, and then enters the anaerobic reactor.

[0036] The anaerobic reactor is sealed, and a water seal is set at the connection between the motor and the stirring rod to ensure that the internal and external air are isolated.

[0037] The gas collecting port of the anaerobic reactor is connected to a gas collecting bag or a gas collecting device to collect the gas produced by the anaerobic reactor.

[0038] The feeding port of the anaerobic reactor is used to feed sodium bicarbonate and biochar materials.

[0039] The anaerobic reactor discharge enters the digestate dilution mixing tank, and is mixed with municipal sewage with a low carbon-nitrogen ratio in a certain proportion before entering the sequencing batch activated sludge reactor. The treatment process ensures that the COD in the sequencing batch activated sludge treatment process meets the denitrification requirements.

[0040] The effluent and influent between the anaerobic reactor and the sequencing batch activated sludge reactor, as well as the matrix mixing tank and the digestate dilution mixing tank are all transported by peristaltic pumps.

[0041] The invention dissolves unqualified and expired waste cefradine drugs in an alkaline solution, heats the solution (95°C) to generate waste drug residues without obvious biological toxicity, recovers methane from sucrose in the residues by anaerobic digestion technology, and then uses the anaerobic fermentation liquid as an external carbon source for biological treatment of low-carbon-nitrogen ratio municipal sewage, thereby enhancing the denitrification effect of the sewage and achieving the harmlessness of the waste cefradine drugs, thereby forming a treatment process that is harmless to the ecological environment.

[0042] The invention provides a safe, efficient, energy-saving and low-toxic forced degradation method for waste cefradine drug particles, and discharges the generated residue into an anaerobic digestion system, so that organic matter in the pretreated residue is recycled to produce methane, and auxiliary agents such as sucrose are recycled.

[0043] The process involved in the present invention focuses on the removal, biochemical treatment, resource utilization and harmlessness of waste cefradine drugs from beginning to end, and proposes a green and safe biological treatment and resource utilization method that can replace traditional treatment methods for waste drugs. The harmlessness of waste drugs is verified and realized based on the actual operation of the process.

[0044] Anaerobic sludge can withstand a high organic load. In the anaerobic reactor involved in the present invention, the anaerobic sludge degrades auxiliary components such as sucrose and amino acids in the pretreatment residue through four stages of hydrolysis, acidification, acetic acidification, and methanation to produce resource gas whose main component is methane. The biological toxicity of the product pretreated by low-temperature pyrolysis is very small, and the inhibitory effect on anaerobic sludge is very low. In theory, it is possible to efficiently convert sugars into methane and short-chain volatile fatty acids (VFA). The methane produced can be recycled and used as a combustible gas. The large amount of VFA present in the digestate can be used as a carbon source to supplement the municipal sewage treatment system to enhance the denitrification effect of municipal sewage. The gas produced by anaerobic digestion contains most (>60%) methane and a small amount of carbon dioxide and other gases (volatile acids, H2). After alkali absorption, the obtained gas is almost methane. At the same time, most of the existing research focuses on the pretreatment of antibiotic fermentation residues or the treatment of antibiotic-containing wastewater, with less attention paid to discarded drugs. In addition, most of the research remains at the pretreatment stage, and there is no detailed report on the specific parameters and processes for subsequent biological treatment resource utilization and harmlessness.

[0045] The efficiency of the entire anaerobic digestion process is affected by the efficiency of electron transfer of microorganisms, so the electron transfer effect can be enhanced by adding conductive materials to the system. The biochar added in the third stage of the anaerobic digestion reactor involved in the present invention can well promote the metabolic activity of anaerobic microorganisms and the methane production efficiency of the system. Its mechanism is divided into two types: the physicochemical properties of biochar (such as surface functional groups and surface structures) increase the conductivity of the system, thereby promoting the anaerobic digestion reaction; the pores on the surface of biochar can attach more electroactive microorganisms, and such microorganisms can enhance complex metabolic regulation (such as secretion and electron transfer and enzymes that utilize nutrient sources) to achieve more flexible electron transfer with substances in the system, thereby enhancing the production of methane.

[0046] In existing research, there are cases of using fermentation broth of complex organic matter as a carbon source to supplement the denitrification system to enhance the denitrification efficiency. Most reports focus on kitchen waste fermentation broth, agricultural waste fermentation broth, aquaculture and livestock waste fermentation broth, etc. These fermentation broths themselves have extremely high VFA and are very suitable as carbon sources for denitrifying bacteria. However, there are almost no cases that focus on the feasibility of anaerobic digestion broth of antibiotic waste drugs as a carbon source. Considering the possible risks, there are the following points: Even after pretreatment, antibiotic drugs cannot completely eliminate the original substances. Using such substances as a long-term carbon source will cause antibiotic pollution to municipal sewage treatment systems and natural water bodies. At the same time, resistance genes will be generated in the sludge system, and the resistance genes will cause a wider range of impacts as they spread in the water body. In the present invention, the active ingredients of the drugs and the harmful degradation products in the entire process flow are monitored, and the propagation path of the resistance genes is tracked.

[0047] Compared with other similar technologies and inventions, the process involved in the present invention has the following innovative features:

[0048] 1. CN103820315A proposes a combined treatment process of ultrasound + hot alkali + two-stage pretreatment + anaerobic digestion to treat cephalosporin residues, and proposes a perfect antibiotic waste residue treatment process, but the invention is aimed at production waste residues, the carbon source is seriously lacking, the ammonia nitrogen and protein content are very high, and before entering the anaerobic digestion, cow dung acidification liquid must be added for water quality adjustment, and the excessive ammonia nitrogen is not suitable for adding to the municipal sewage treatment system for subsequent treatment. For the pyrolysis of the cephradine waste drug particles proposed by the present invention, since the waste is a finished drug product, a waste material generated by a non-production process, the carbon source is sufficient, and the ammonia nitrogen content is low, only low-temperature pyrolysis pretreatment is required to achieve a toxic substance degradation rate of more than 97%, and the upper limit of methane production of sludge can also be increased in anaerobic fermentation, increasing the recovery rate.

[0049] 2. CN103146761A discloses a method for thermal decomposition and anaerobic digestion of cephalosporin residues, the specific steps of which are: ① putting cephalosporin production residues, water, and sodium hydroxide into a reactor in a weight ratio of 200:800:4, then decomposing at 40-55°C for 3.0-5.5h, then standing at 35-40°C for 10-14h, and then performing solid-liquid separation; ② putting 50-80% anaerobic sludge by volume into an anaerobic fermentation tank, adding 2-6% of a sediment sludge mixture, and intermittently digesting and feeding under stirring and 50-60°C, and no further treatment is performed on subsequent ecological safety and harmlessness issues.

[0050] In view of this, the innovations made by the present invention are:

[0051] ① The present invention can reduce the amount of alkali used. The drug-alkali ratio disclosed in CN103146761A is 50:1, while the drug-alkali ratio of the present invention is 125:1, which greatly reduces the amount of sodium hydroxide used;

[0052] ② When 1% volume ratio of anaerobic sludge is added, the methane production rate can reach 70%. When 7% volume ratio of sludge is added, the maximum methane production rate can reach 85-88%. According to the volume ratio of the reactor, 108-124% of the reactor volume of methane can be produced every 24 hours, which is much higher than the current methane production from production residues (2%-6% every 24 hours).

[0053] ③After heat-alkali pretreatment, cool at room temperature for 15-20 minutes before putting into the anaerobic reactor;

[0054] ④ The digestate produced after anaerobic digestion is put into the municipal sewage treatment system as a carbon source, so that it can be utilized and rendered harmless at the same time.

[0055] 3. Currently, there is no invention for the whole process biological treatment of waste antibiotics. The present invention has high innovation in three processes:

[0056] ① According to the previous article, the "heat-alkaline" pretreatment optimizes both the parameters and the treatment effect, and pretreats a completely new form of waste;

[0057] ② The anaerobic digestion stage not only efficiently converts a large amount of organic matter in harmful drugs into resource gas (methane) and volatile fatty acids (VFA), but also can further effectively reduce the drug content;

[0058] ③ In the aerobic stage, according to the actual situation, the digestate is added as a carbon source to the municipal sewage treatment system to enhance the denitrification efficiency and meet the standards, while eliminating the ecological impact of the drug. Overall, the entire process has achieved a good closed loop, and the entire process focuses on the actual cefradine waste drugs. Through continuous processes, it realizes resource utilization and harmlessness, and realizes the original intention of green, low consumption, high recovery, and harmlessness, making up for the current technical gap in the coupling treatment of waste drugs and biological processes, and provides a reference for other similar waste biological treatments.

[0059] 4. The inventions disclosed in the above two patents are all concerned with what conditions and processes can better recycle the organic matter in the cephalosporin residues, and do not target the harmlessness of harmful components. The discarded drug particles mentioned in the present invention and the cephalosporin residues mentioned in the above two patents are wastes produced by different processes, and existing research and inventions have not recycled discarded drugs. The low-temperature thermal decomposition coupled biological process proposed in the present invention can realize the resource utilization and harmlessness of hazardous waste, providing a new way for the green treatment of hazardous pharmaceutical waste.

[0060] Compared with the prior art, the present invention has the following beneficial effects:

[0061] The method of the present invention can treat waste cefradine drugs to obtain drug residues with low biological toxicity, and can secondary utilize the originally difficult-to-utilize available resources through anaerobic digestion treatment, thereby expanding the green approach and diversity of waste drug treatment processes.

[0062] The present invention adds high-carbon, low-nitrogen, and low-harmful component anaerobic fermentation liquid into the low-carbon-nitrogen ratio municipal sewage sequencing batch activated sludge treatment process, thereby greatly improving the denitrification efficiency of the sewage. At the same time, it achieves the two requirements of no risk of resistance gene transmission and meeting the municipal sewage treatment plant emission standards, providing a new idea for coupling pharmaceutical hazardous waste with municipal sewage treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 It is a process flow chart of the present invention.

[0064] Figure 2 This is the structural formula of cefuroxime.

[0065] Figure 3 This is a gas production chart for the stable operation 80 days before the start-up of the long-cycle anaerobic digestion treatment process in Example 2 (from the acclimatization stage to the high-load intensification stage).

[0066] Figure 4 This is a graph showing changes in total nitrogen concentration in the effluent from each reactor one week after the sequencing batch activated sludge treatment process of Example 3 was started.

[0067] Figure 5This is the composition and toxicity analysis of the degradation products of the discarded cefradine drug in Example 4. DETAILED DESCRIPTION

[0068] In order to make the implementation means, feasibility and objectives of the technical solution of the present invention easy to understand and comprehend, the following is an explanation in combination with different embodiments. It should be noted that based on the embodiments of the present invention, all other implementation methods obtained by ordinary persons in the art without making creative work are within the scope of protection of the present invention.

[0069] The process flow chart of the present invention is as follows Figure 1 , including low-temperature pyrolysis pretreatment, long-cycle anaerobic digestion treatment and sequencing batch activated sludge treatment.

[0070] Example 1

[0071] Low-temperature pyrolysis pretreatment of waste cephradine drugs:

[0072] The drug used in this embodiment comes from the cephradine waste drug particles produced by a pharmaceutical factory in Guangzhou. The cephradine waste drug particles mainly have powder and strip particles. After testing, the two forms of particles have the same content of active ingredients. The cephradine waste drug particles contain 5wt% of cephradine active ingredients, 93wt% of sucrose, and 2wt% of other ingredients. The chemical formula of cephradine is C 16 H 19 N3O4S, its molecular structure is as follows Figure 2 shown.

[0073] 15 kg of cefradine waste drug particles were added to a 6L constant temperature and normal pressure reactor, and 5L of 0.6 mol / L sodium hydroxide solution was added. After sufficient stirring, a uniform clear orange viscous liquid was obtained. The constant temperature heating temperature of the reactor was set to 95°C. When the set temperature was reached, the drug solution was heated. After heating for 40 minutes, it was quickly cooled. The residue (viscous liquid) was detected to obtain a CRD degradation rate of more than 97.3%.

[0074] Example 2

[0075] Long-term anaerobic digestion treatment of waste cephradine after low-temperature pyrolysis pretreatment:

[0076] Two CSTR reactors are now set up to compare whether pretreatment of drugs will affect anaerobic digestion and methanogenesis. Its effective volume is 1L, the inner diameter is 9cm, and it is equipped with a 1cm wide insulation layer. 35℃ water is continuously introduced for insulation, and anaerobic sludge is added at an amount of 4-5gTS / L. The anaerobic sludge nutrient solution (0.5g / L KCl, 0.1g / L CaCl2, 0.1g / L MgCl2·6H2O, 0.2g / L KH2PO4, 0.2g / L K2HPO4, 0.05mg / L ZnCl2, 0.05mg / L NiCl2·6H2O, 2mg / L FeCl2·4H2O, 0.03mg / L CuCl2·2H2O, 0.5mg / LMnCl2·4H2O, 1mg / LC 10 H 14 N2Na2O8·2H2O, 0.2mg / L CoCl2·6H2O) as the matrix, one of which was added with the pretreated drug residue (A1) of Example 1, and the other was added with an equal amount of the original drug (A2) without pretreatment, and stirred at a speed of 150-200r / min (stirring for 5 minutes every 144 minutes).

[0077] Three stages are set up: 1. Acclimation stage (low load stage). At the initial start-up of the reactor, a buffer acclimation period needs to be reserved. Sucrose is used as the carbon source, and the nutrient solution is replaced every 2 days (prepared according to COD = ~2000 mg / L). It can be stable in the first 7 days or so. Then feed with 1.25g / L / d of drugs (COD = ~2000mg / L), replace the digestion solution every 2 days, and add alkaline buffer substances at 0.5g / L sodium bicarbonate every day to maintain the system pH between 6.8 and 7.2 to ensure the activity of methanogens, and run for 30 to 40 days. 2. High load stage. In the second stage, the pollutant load is increased, and 2.5g / L / d of drugs (COD = ~4000mg / L) are fed, the digestion solution is replaced every 2 days, and 1.5g / L sodium bicarbonate is added every day to maintain the pH between 6.5 and 7.2. 3. High load strengthening stage. At the beginning of the third stage, 10 g / L of biochar material was added to the reactor, and the other parameters remained unchanged (the same as the second stage). Stable operation was maintained, gas was measured every day, samples were taken when the digestate was replaced, and the composition, pH and gas production of the digestate were measured.

[0078] During the acclimation stage, the methane production of A1 was basically stable at 388.47±14.35mL / d, reaching 88% of the theoretical output value, while the methane production efficiency of A2 dropped significantly to only 271.81±70.32mL / d. In the high-load stage, the drug load was increased to twice the original, and the methane production of A1 dropped to 566.76±53.49mL / d, which dropped to 64.77% of the theoretical value. The performance of A2 was completely destroyed, dropping to 142.35±50.74mL / d, indicating that the drug had an impact on the system under high load. In the high-load intensification stage, the methane production rate of A1 increased to 80.67%, and the output was 705.83±38.91mL / d, while A2 could not recover (methane production 181.37±31.02mL / d), proving that under the action of biochar, the system can be maintained stable. The gas production data of the whole process are shown in the figure. Figure 3 Therefore, this pretreatment method is feasible and can ensure the feasibility and stability of long-term addition of drugs to the anaerobic system.

[0079] Example 3

[0080] Sequencing batch activated sludge treatment of long-cycle anaerobic digestion liquid:

[0081] Three SBR reactors are now set up, and the water quality parameters of each SBR reactor are different to illustrate the enhanced effect of denitrification after the digestate is added to the sewage. The three reactors are set up as follows: one of them adds the third stage drug anaerobic digestate of Example 2 as the only external carbon source (B1), one of them adds the standard carbon source sodium acetate as the only external carbon source (B2), and the other does not add any carbon source, so that the original carbon source in the system is not enough to support denitrification (B3). The experimental water and sludge were taken from a municipal sewage treatment plant in Guangzhou, and the ratio of chemical oxygen demand (COD) to ammonia nitrogen was 2.4 to 3.2.

[0082] The reactor is set up as follows: set up a SBR reactor with a volume of 1.5L, an actual volume of 1L, an inner diameter of 10cm, add stirring, set a suitable cycle and aeration amount, stir in the anoxic cycle, fill according to 7-8gTS / L activated sludge, the SBR cycle is 5 minutes of water inflow, 240 minutes of anoxic stirring, 90 minutes of aeration, 20 minutes of static sedimentation, 5 minutes of water outflow, stir at a speed of 60r / min in the anoxic cycle, the aeration flow rate is 1L / min, the HRT is 12 hours, the volume exchange rate is 50%, and 500mL of water is inflow and outflow each time. Each time water is inflowed, the anaerobic digestion liquid produced in Example 2 is diluted and mixed with municipal sewage so that the ratio of COD to ammonia nitrogen in the mixed water is between 4 and 6, and its denitrification effect is enhanced. Water samples are taken out every 1 day for detection.

[0083] Ensure that the final COD of B1 and B2 reactors remain consistent, and all other parameters of the three reactors remain consistent.

[0084] Among them, the COD concentration of the municipal sewage used was 60 - 80 mg / L, and the total nitrogen concentration was 25 - 30 mg / L. The contained COD was relatively low. In groups B1 and B2, the COD was supplemented to 150 - 200 mg / L using digestion fluid and sodium acetate respectively, and then it was run for 40 - 50 days. After 7 days of adaptation and acclimation in the initial stage, starting from the 8th day, the denitrification efficiency of B1 and B2 gradually increased. Compared with the total nitrogen in the effluent of B3 (20 - 25 mg / L), the total nitrogen in B1 and B2 (10 - 12 mg / L and 9 - 11 mg / L respectively) was better removed, as shown in Figure 4 . It has reached the first-class A standard in the "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants" (GB18918 - 2002), and the digestion fluid will not affect the total nitrogen in the influent of the reactor.

[0085] Example 4

[0086] (1) Determine the intermediate products generated during the degradation of cefradine in Example 1. Dilute the degraded residue by 500 times, and after passing through a 0.45 μm aqueous polyethersulfone filter membrane, concentrate it using solid-phase extraction technology (SPE). The concentrated solution obtained is detected using high-resolution ultra-high performance liquid chromatography-quadrupole-time-of-flight mass spectrometry (UPLC-QTOF-MS) to analyze the specific degradation products, and apply ECOSAR software to evaluate the biotoxicity of these 17 products. As Figure 5 shown, it can be seen that most of the degradation intermediate products are harmless.

[0087] Note: According to the EU standard (Annex VI of Directive 67 / 548 / EEC), acute toxicity is divided into four levels: harmless (LC 50 / EC 50 > 100 mg / L), harmful (10 mg / L < LC 50 / EC 50 < 100 mg / L), toxic (1 mg / L < LC 50 / EC 50 < 10 mg / L) and highly toxic (LC 50 / EC 50 < 1 mg / L). According to the Hazard Assessment Standard for New Chemical Substances in China (HJ / T154 - 2004), chronic toxicity includes four levels: non-toxic (ChV > 10 mg / L), harmful (1 mg / L < ChV < 10 mg / L), toxic (0.1 mg / L < ChV < 1 mg / L) and highly toxic (ChV < 0.1 mg / L). The risk level shown in this table is the risk level index obtained by comprehensively evaluating the two toxicities.

[0088] (2) Cefuroxime can be quantitatively detected by high performance liquid chromatography (HPLC). Ultra high performance liquid chromatography (Ultimate 3000, Thermo Fisher Scientific, USA) was used for detection. The chromatographic column was C18, the mobile phase was 0.1% formic acid water-acetonitrile (v:v=70:30), the column box temperature was 35°C, the flow rate was 0.3 mL / min, the detection wavelength was 288 nm, and the detection time was 10 min.

[0089] The drug degradation residue obtained in Example 1, the third stage digestion liquid of Example 2, and the aerobic effluent of SBR (B1) of Example 3 were taken for SPE and detection, and the residual concentration of CRD in the effluent of each process section was obtained as shown in Table 1. In the anaerobic digestion liquid, after metabolism and adsorption by microorganisms, the abundance of CRD was 0.94‰ of the original drug (after pretreatment). Under the further dilution effect of aerobic influent, the concentration of CRD further decreased. In the aerobic effluent, the abundance of CRD was also reduced to 2.47‰ in the digestion liquid.

[0090] Risk assessment: Based on the impact of the concentration of environmental samples on ecological risks in the EMEA introduction, the risk quotient calculation method (Hazard Quotient, HQ) is used to assess the risk level. The calculation method is as follows:

[0091]

[0092]

[0093] in:

[0094] AF=1000,

[0095] MEC - calculated by measuring the environmental concentration (μg / L),

[0096] PNEC – predicted no effect concentration (μg / L),

[0097] L(EC) 50 - Using L(EC) obtained from the ECOSAR program (version 2.0) 50 parameters (fish, Daphnia and green algae).

[0098] Many scholars often divide HQ into three levels when evaluating the ecological risk assessment of antibiotics. When HQ is greater than 1, it means there is a high risk; when HQ is greater than 0.1 and less than 1, there is a medium risk; when HQ is greater than 0.01 and less than 0.1, there is a low risk. It can be seen that the HQ value of anaerobic digestion liquid is less than 0.1, which means that the substance is harmless to the environment and can be put into municipal sewage treatment plants. In aerobic effluent, the HQ value is less than 0.001, which is basically harmless to the environment.

[0099] Table 1 CRD concentration and risk quotient (HQ) of effluent (discharge) in each process stage

[0100]

[0101] Example 5

[0102] Assessing whether an environmental sample has long-term ecological impacts also requires evaluating the spread of resistance genes.

[0103] The third stage digestion liquid of Example 2, the effluent of SBR (B1) of Example 3, and the effluent of SBR (B3) without drug addition were filtered with a 0.22 μm aqueous mixed cellulose filter membrane, and the sediment on the filter membrane was collected, and the DNA of microorganisms in the sediment was extracted for metagenomic sequencing. A total of 103 families and 871 genera of cephalosporin resistance genes including cephradine were detected, and the abundance of each resistance gene in the effluent of SBR (B1) was greatly reduced compared with the digestion liquid, and the removal rate reached 99.5% to 100%. When the effluent from the drug-doped SBR (B1) was compared with the effluent from the digestate SBR (B3) without drug addition, the abundance of resistance genes was basically similar. For example, 147 resistance gene genera, such as CTX-M-3, DHA-1, ADC-227, GOB-7, TEM-216, and TEM-145, and 76 resistance gene families, such as PDC beta-lactamase, ADC beta-lactamases, and DHA beta-lactamase, which were detected in large quantities in the digestate, could not be detected in the effluent from SBR (B1), indicating that there was no risk of resistance gene transmission in the effluent from the entire process.

[0104] The residue products and resistance gene tests of Example 4 and Example 5 show that the waste cefradine drugs treated by the method can be rendered harmless.

[0105] The above contents are further feasibility descriptions of the present invention in combination with the embodiments, and the specific implementation of the present invention cannot be considered to be limited to these embodiments. For technicians in the field to which the invention belongs, they can make several simple deductions and substitutions without departing from the core idea of ​​the present invention, which are all considered to fall within the protection scope of the present invention.

Claims

1. A method for bioresource and harmless treatment of waste cephradine drugs, characterized in that: The following steps are involved: (1) dissolving the discarded cephradine drug in a sodium hydroxide solution and heating the solution to obtain a drug residue; (2) subjecting the drug residue of step (1) to long-term anaerobic digestion to produce methane and obtain anaerobic digestion liquid; (3) The anaerobic digestion liquid obtained in step (2) is added as an external carbon source to municipal sewage with a low carbon-nitrogen ratio to perform sequencing batch activated sludge treatment.

2. The method for bioresource recovery and harmless treatment of waste cephradine according to claim 1, characterized in that: In step (1), the concentration of the sodium hydroxide solution is 0.6 mol / L; In step (1), the mass volume ratio of the waste cefradine drug and the sodium hydroxide solution is 15kg:5L.

3. The method for bioresource recovery and harmless treatment of waste cephradine according to claim 1, characterized in that: In step (1), the heating temperature is 95° C. and the heating time is 40 min.

4. The method for bioresource recovery and harmless treatment of waste cephradine according to claim 1, characterized in that: In step (1), the components of the discarded cephradine drug are: 5wt% of cephradine active ingredient, 93wt% of sucrose, and 2wt% of other components.

5. The method for bioresource recovery and harmless treatment of waste cephradine according to claim 1, characterized in that: In step (2), the temperature of the long-term anaerobic digestion treatment is 35° C. and the pH is 6.5 to 7.

5.

6. The method for bioresource recovery and harmless treatment of waste cephradine according to claim 1, characterized in that: In step (2), the dosage of the drug residue is 2.5 g / L / d.

7. The method for bioresource recovery and harmless treatment of waste cephradine according to claim 1, characterized in that: In step (2), biochar material is also added to the long-term anaerobic digestion treatment, and the addition amount is 10g / L.

8. The method for bioresource recovery and harmless treatment of waste cephradine according to claim 1, characterized in that: In step (3), the carbon-nitrogen ratio of the mixed solution after the anaerobic digestion liquid is supplemented with municipal sewage with a low carbon-nitrogen ratio is 4 to 6:

1.

9. The method for bioresource recovery and harmless treatment of waste cephradine according to claim 1, characterized in that: In step (3), the aeration rate of the sequencing batch activated sludge treatment is 0.7-1.5 L / min, the HRT is 12 h, the volume exchange rate is 50%, the time ratio of the anoxic period to the aerobic period is 8:3, the static sedimentation time is not less than 15 minutes, stirring is performed during the anoxic period, and water is regularly introduced and discharged.

10. A bioresource and harmless treatment device for waste cephradine drugs, characterized in that: It includes a heating reactor, an anaerobic reactor and a sequencing batch activated sludge reactor; The heating reactor is provided with an electric stirrer, a feed inlet and a discharge outlet; The anaerobic reactor is provided with an electric stirrer, a gas collecting port, a feed port, a discharge port and a feeding port; The sequencing batch activated sludge reactor is provided with an electric stirrer, a feed inlet, a discharge outlet and an aeration hole; A substrate mixing pool is arranged between the heating reaction kettle and the anaerobic reactor, and the substrate mixing pool is connected with the discharge port of the heating reaction kettle and the feed port of the anaerobic reactor; the substrate mixing pool is also provided with a liquid adding port; A digestate dilution mixing tank is arranged between the anaerobic reactor and the sequencing batch activated sludge reactor, and the digestate dilution mixing tank is connected with the discharge port of the anaerobic reactor and the feed port of the sequencing batch activated sludge reactor; the digestate dilution mixing tank is also provided with a water inlet.

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