A method for alleviating the inhibitory effect of fluoroquinolone antibiotics on anaerobic digestion

Abstract

The present application provides a method for alleviating the inhibitory effect of fluoroquinolone antibiotics on anaerobic digestion, which belongs to the technical field of sewage treatment. The method comprises: adding uncompounded biochar to a system to be treated for anaerobic digestion of fluoroquinolone antibiotic sewage using an activated sludge method. By adding uncompounded biochar, the method can effectively alleviate the inhibitory effect of antibiotics on anaerobic digestion, effectively increase the methane production and the removal rate of antibiotics, and has low reagent cost, equipment and operation requirements.

Description

Technical Field

[0001] The present application relates to the technical field of sewage treatment, and in particular to a method for alleviating the inhibitory effect of fluoroquinolone antibiotics on anaerobic digestion. Background Art

[0002] Antibiotics have long been widely used to treat bacterial diseases in humans and animals because they can inhibit or kill bacteria. However, organisms can only absorb and metabolize small amounts of antibiotics, and most of the ingested antibiotics enter the aquatic environment through urine or feces. Currently, antibiotic concentrations ranging from ng / L to mg / L have been detected in municipal, hospital, livestock, and pharmaceutical wastewaters. In December 2022, the Ministry of Ecology and Environment issued the "List of New Pollutants to be Controlled (2023 Edition)", which included antibiotics and strictly controlled and governed antibiotics. Among them, fluoroquinolones have a broad antibacterial spectrum and strong antibacterial activity and are widely used; especially ciprofloxacin, as a third-generation fluoroquinolone, has been detected in some pharmaceutical wastewaters at concentrations significantly higher than many other antibiotics, about 0.8mg / L to 19.6mg / L.

[0003] At present, the treatment of fluoroquinolone antibiotics such as ciprofloxacin in wastewater mainly includes adsorption, advanced oxidation and biological methods. Among them, the adsorption method uses porous materials as adsorbents to achieve wastewater treatment by adsorbing antibiotics through porous materials; however, during the adsorption process, the adsorbent is easily saturated, and the adsorbent will not only adsorb antibiotics, but also adsorb other substances in the wastewater, so a large amount of adsorbent is required. At the same time, the regeneration of the adsorbent is also a problem that limits its application. Advanced oxidation methods mainly include Fenton method and modified Fenton method, activated persulfate, photoelectrocatalysis, etc., with high reagent, energy consumption and equipment costs, and will cause subsequent pollution problems. The biological method treats pollutants through anaerobic digestion. Anaerobic digestion is a sustainable development technology for sewage treatment. It has the advantages of low sludge production, low energy consumption and high biogas production, and occupies an important position in sewage treatment plants.

[0004] However, various studies have shown that fluoroquinolone antibiotics in wastewater can destroy the stability of the anaerobic system, affect methane production and carbon source recovery, and seriously restrict the pollution reduction and carbon reduction of anaerobic digestion. Summary of the invention

[0005] The applicant's research found that the reason why fluoroquinolone antibiotics in wastewater can destroy the stability of the anaerobic system and affect methane production and carbon source recovery is that fluoroquinolone antibiotics, as an antibiotic, themselves have antibacterial effects, which can damage the functional microorganisms in the anaerobic digestion system and affect their normal growth and metabolic activities, thereby causing acid accumulation and inhibition, low methane yield and production in the anaerobic system, thereby seriously restricting the pollution reduction and carbon reduction of anaerobic digestion.

[0006] In some technical solutions, the inhibitory effect of antibiotics on anaerobic digestion is effectively improved by adding nano-iron-carbon composite materials to antibiotic wastewater. However, this method usually requires the use of liquid phase reduction to reduce iron salts to generate nano-zero-valent iron, and requires the use of highly corrosive and explosive reducing agent sodium borohydride, and an oxygen-free environment must be maintained during the preparation process.

[0007] Moreover, the applicant has found that in the technical solution of adding nano iron-carbon composite materials, if the dosage is excessive, the introduced nanoparticles will cause additional redox stress on the microorganisms, which will limit the methane production and the upper limit of the antibiotic removal rate.

[0008] The promoting effect of conductive materials in anaerobic digestion under general conditions is widely recognized. However, it is also generally believed that antibiotic contaminants will cause stress to them. Therefore, it has not been clear whether they can effectively alleviate the inhibitory effect of antibiotics on anaerobic digestion under antibiotic stress environment.

[0009] The applicant has found through further research that the addition of uncompounded biochar alone to a treatment system for anaerobic digestion of fluoroquinolone antibiotic wastewater using the activated sludge method can effectively alleviate the inhibitory effect of antibiotics on anaerobic digestion, effectively increase the anaerobic digestion rate, and effectively increase methane production and antibiotic removal rate.

[0010] Based on the above research findings, the purpose of this application is to provide a method for alleviating the inhibitory effect of fluoroquinolone antibiotics on anaerobic digestion, which can effectively alleviate the inhibitory effect of antibiotics on anaerobic digestion, effectively increase methane production and antibiotic removal rate, and has low drug cost, equipment and operation requirements.

[0011] The embodiment of the present application is implemented as follows:

[0012] The embodiment of the present application provides a method for alleviating the inhibitory effect of fluoroquinolone antibiotics on anaerobic digestion, comprising: adding uncompounded biochar to a system to be treated for anaerobic digestion of fluoroquinolone antibiotic wastewater using an activated sludge process.

[0013] The method for alleviating the inhibitory effect of fluoroquinolone antibiotics on anaerobic digestion provided in the embodiment of the present application, by adding uncompounded biochar to the system to be treated, has at least the following beneficial effects:

[0014] 1. Biochar can effectively alleviate the inhibitory effect of antibiotics on anaerobic digestion, and can effectively increase methane production and antibiotic removal rate.

[0015] 2. The biological method of anaerobic digestion can not only effectively remove antibiotics, but also produce and recycle a large amount of methane gas compared with the adsorption method and advanced oxidation method. It has the dual advantages of pollutant removal and biogas recovery. It does not require wastewater pretreatment, is simple to operate, resistant to toxicity, occupies a small area, and is economical and efficient.

[0016] 3. Directly using uncompounded biochar, compared with nano iron-carbon composite materials, on the one hand, the material does not require pretreatment, the cost of adding chemicals is low, the equipment and operation requirements are low, it is economical and efficient, and is conducive to practical engineering applications; on the other hand, its improvement effect is not affected by the omission of nano zero-valent iron, but because it avoids the higher active oxygen pressure in the microorganisms, it is conducive to further improving the methane production and antibiotic removal rate.

[0017] In some embodiments, in the fluoroquinolone antibiotic wastewater, the fluoroquinolone antibiotics include at least one of ciprofloxacin, norfloxacin, levofloxacin, ofloxacin, moxifloxacin and lomefloxacin.

[0018] In some embodiments, before anaerobic digestion, the concentration of fluoroquinolone antibiotics in the fluoroquinolone antibiotic wastewater is ND-19.6 mg / L.

[0019] In some embodiments, before anaerobic digestion, the concentration of fluoroquinolone antibiotics in the fluoroquinolone antibiotic wastewater is 9 mg / L to 11 mg / L.

[0020] In some embodiments, the added weight of biochar is X1, and the volume of fluoroquinolone antibiotic wastewater is X2, wherein 5g / L≤X1 / X2≤20g / L.

[0021] In some embodiments, 5 g / L ≤ X1 / X2 ≤ 10 g / L.

[0022] In some embodiments, 10 g / L ≤ X1 / X2 ≤ 20 g / L.

[0023] In some embodiments, the uncomplexed biochar includes corn stover biochar.

[0024] In some embodiments, the volume of fluoroquinolone antibiotic wastewater is X2, the volume of activated sludge added to the system to be treated is X3, and 2≤X2 / X3≤4.

[0025] In some embodiments, at least one of the following conditions (a1) and (a2) is met; (a1) the pH value of the fluoroquinolone antibiotic wastewater and / or the activated sludge in the system to be treated is 6.4-7.8; (a2) after adding uncompounded biochar, the system to be treated is anaerobically digested at a temperature of 36°C to 38°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 A bar chart showing the cumulative methane production of some embodiments and comparative examples;

[0028] Figure 2 The figures are histograms of volatile acid contents of some embodiments and comparative examples at different time periods during the experiment;

[0029] Figure 3 Statistical diagrams of the distribution of ciprofloxacin after experiments in some embodiments and comparative examples;

[0030] Figure 4 The figures are bar charts showing the production of active oxygen in different time periods during the experiment of some embodiments and comparative examples;

[0031] Figure 5 Column statistical graphs of lactate dehydrogenase production at different time periods during the experiment of some embodiments and comparative examples;

[0032] Figure 6 The bar graphs of the superoxide dismutase production at different time periods during the experiment of some embodiments and comparative examples are shown. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0034] It should be noted that “and / or” in this application, such as “Feature 1 and / or Feature 2”, refers to the three situations of “Feature 1” alone, “Feature 2” alone, or “Feature 1” plus “Feature 2”.

[0035] In addition, in the description of the present application, unless otherwise specified, the meaning of "multiple" in "one or more" refers to two or more; the range of "value a ~ value b" includes the two end values ​​"a" and "b", and the "unit" in "value a ~ value b + unit of measurement" represents the "unit of measurement" of both "value a" and "value b".

[0036] The technical solutions of the embodiments of the present application are exemplarily described below.

[0037] The embodiment of the present application provides a method for alleviating the inhibitory effect of fluoroquinolone antibiotics on anaerobic digestion, comprising: adding uncompounded biochar to a system to be treated for anaerobic digestion of fluoroquinolone antibiotic wastewater using an activated sludge process.

[0038] In the embodiments of the present application, uncompounded biochar refers to biochar obtained directly by pyrolysis without further compounding with other functional materials; wherein other functional materials refer to materials that promote the removal of antibiotics, such as photoelectrocatalysts, functional nanomaterials, etc.

[0039] The method for alleviating the inhibitory effect of fluoroquinolone antibiotics on anaerobic digestion provided in the embodiment of the present application, adding uncompounded biochar to the system to be treated, has the following working mechanism:

[0040] 1. The rich porous structure of biochar can provide a habitat for microorganisms, enriching and protecting them by colonizing them on biochar; that is, biochar can reduce the reactive oxygen pressure produced by fluoroquinolone antibiotics such as ciprofloxacin when microorganisms are exposed to it, thereby avoiding severe oxidative stress reactions in cells and affecting their normal metabolism.

[0041] 2. Biochar is a carbon-fixing organic material containing a variety of functional groups. Its rich functional groups (such as phenolic -OH, -C=O and π-groups) have a charge and discharge function similar to a capacitor, which can store and provide electrons and serve as a bridge for electron transfer between electricity-producing bacteria and electricity-receiving archaea. Among them, the π-π group, as a medium, can maintain H + The electron transfer rate.

[0042] 3. Biochar is a carbon-fixing organic material containing a variety of functional groups. Its rich oxygen-containing groups (such as -COOH, -OH, -C=O and -COC) can effectively balance the pH value in the environment and avoid acid accumulation that affects the activity of methanogens (archaea).

[0043] 4. Biochar can adsorb fluoroquinolone antibiotics such as ciprofloxacin during anaerobic digestion, promoting the degradation and transformation of antibiotics.

[0044] 5. Biochar not only enriched electroactive microorganisms involved in direct interspecies electron transfer (DIET), but also promoted the growth of functional organisms related to methanogenesis and degradation of fluoroquinolone antibiotics such as ciprofloxacin.

[0045] The method for alleviating the inhibitory effect of fluoroquinolone antibiotics on anaerobic digestion provided in the embodiment of the present application, by adding uncompounded biochar to the system to be treated, has at least the following beneficial effects:

[0046] 1. Based on the above working mechanism, it can be seen that this method can effectively alleviate the inhibitory effect of antibiotics on anaerobic digestion through biochar, and can effectively increase methane production and antibiotic removal rate.

[0047] 2. The biological method of anaerobic digestion can not only effectively remove antibiotics, but also produce and recycle a large amount of methane gas compared with the adsorption method and advanced oxidation method. It has the dual advantages of pollutant removal and biogas recovery. It does not require wastewater pretreatment, is simple to operate, resistant to toxicity, occupies a small area, and is economical and efficient.

[0048] 3. Directly using uncompounded biochar, compared with nano iron-carbon composite materials, on the one hand, the material does not require pretreatment, the cost of adding chemicals is low, the equipment and operation requirements are low, it is economical and efficient, and is conducive to practical engineering applications; on the other hand, its improvement effect is not affected by the omission of nano zero-valent iron, but because it avoids the higher active oxygen pressure in the microorganisms, it is conducive to further improving the methane production and antibiotic removal rate.

[0049] Specific experiments show that when nano-iron-carbon composite materials are used, the introduction of nanoparticles in the anaerobic system causes additional redox pressure on microorganisms, and the maximum cumulative methane production and the maximum ciprofloxacin removal rate are 143 mL / gCOD and 87%, respectively; while in the present application, due to the use of uncompounded biochar, no additional redox pressure is caused to microorganisms. Under equivalent conditions, the maximum cumulative methane production can reach more than 300 mL / gCOD, and the antibiotic removal rate can reach up to about 99%.

[0050] It should be noted that, in the embodiments of the present application, except for cases where special instructions are given, the types of fluoroquinolone antibiotics are not limited, and their sources include, for example but not limited to, fruit trees, straw, tea leaves, etc.

[0051] In some embodiments, the uncomplexed biochar includes corn stover biochar.

[0052] In the above technical scheme, the source of biochar is straw. On the one hand, the annual output of crop straw in my country is about 700 million tons, among which corn straw ranks first among all kinds of crop straw in the country (accounting for more than 30%), and the output of corn straw is large; compared with other biological materials such as waste tea leaves, corn straw has a higher cellulose content, and the hydrolysis and acidification time is long during the composting process, the digestion efficiency is low, and it is difficult to handle. Therefore, the need for corn straw to be recycled is more urgent. On the other hand, corn straw biochar has the advantages of abundant resources, low cost, environmental friendliness, and waste resource utilization.

[0053] It should be noted that the method provided in the embodiments of the present application can be applied to the wastewater treatment of common fluoroquinolone antibiotics. Therefore, in the embodiments of the present application, except for special instructions, the types of fluoroquinolone antibiotics are not limited.

[0054] In some embodiments, in the fluoroquinolone antibiotic wastewater, the fluoroquinolone antibiotics include at least one of ciprofloxacin, norfloxacin, levofloxacin, ofloxacin, moxifloxacin and lomefloxacin.

[0055] As an example, in fluoroquinolone antibiotic wastewater, the fluoroquinolone antibiotic is ciprofloxacin.

[0056] It should be noted that the method provided in the embodiments of the present application can play a better role in wastewater with a high concentration of fluoroquinolone antibiotics, and therefore can be better applied to pharmaceutical wastewater with a high concentration of antibiotics.

[0057] As an example, fluoroquinolone antibiotic wastewater is pharmaceutical wastewater containing fluoroquinolone antibiotics, such as pharmaceutical wastewater containing ciprofloxacin.

[0058] In some embodiments, before anaerobic digestion, the concentration of fluoroquinolone antibiotics in the fluoroquinolone antibiotic wastewater is ND-19.6 mg / L.

[0059] Among them, ND stands for not detected.

[0060] Optionally, the fluoroquinolone antibiotic is ciprofloxacin; before anaerobic digestion, the concentration of ciprofloxacin in the fluoroquinolone antibiotic wastewater is 0.8 mg / L to 19.6 mg / L.

[0061] As an example, in fluoroquinolone antibiotic wastewater, the concentration of fluoroquinolone antibiotics is, for example but not limited to, any one of 0.8 mg / L, 1 mg / L, 2 mg / L, 3 mg / L, 4 mg / L, 5 mg / L, 6 mg / L, 7 mg / L, 8 mg / L, 9 g / L, 10 mg / L, 11 mg / L, 12 mg / L, 13 mg / L, 14 mg / L, 15 mg / L, 16 mg / L, 17 mg / L, 18 mg / L, 19 mg / L and 19.6 mg / L, or a range between any two of them.

[0062] In the above technical solution, the concentration of fluoroquinolone antibiotics is relatively high and corresponds to the concentration of fluoroquinolone antibiotics in common pharmaceutical wastewater.

[0063] Optionally, before anaerobic digestion, the concentration of fluoroquinolone antibiotics in the fluoroquinolone antibiotic wastewater is 9 mg / L to 11 mg / L.

[0064] In some embodiments, the added weight of biochar is X1, and the volume of fluoroquinolone antibiotic wastewater is X2, wherein 5g / L≤X1 / X2≤20g / L.

[0065] As an example, the value of X1 / X2 may be, but is not limited to, any one of 5g / L, 6g / L, 7g / L, 8g / L, 9g / L, 10g / L, 11g / L, 12g / L, 13g / L, 14g / L, 15g / L, 16g / L, 17g / L, 18g / L, 19g / L and 20g / L, or a range between any two of them.

[0066] In the above technical solution, the biochar has a suitable addition amount, which can effectively alleviate the inhibitory effect of antibiotics on anaerobic digestion and effectively increase the methane production and the removal rate of antibiotics. For example, when it is applied to the treatment of pharmaceutical wastewater with a high concentration of fluoroquinolone antibiotics, it can also achieve good results.

[0067] Optional, 5g / L≤X1 / X2≤10g / L.

[0068] In this technical solution, the methane production and antibiotic removal rate can reach higher standards. At the same time, compared with 10g / L≤X1 / X2≤20g / L, the amount of biochar added can be reduced.

[0069] Optional, 10g / L≤X1 / X2≤20g / L.

[0070] In this technical solution, the methane production can reach a higher standard. At the same time, compared with 5g / L≤X1 / X2≤10g / L, it is also beneficial to further improve the removal rate of antibiotics.

[0071] In some embodiments, the volume of fluoroquinolone antibiotic wastewater is X2, the volume of activated sludge added to the system to be treated is X3, and 2≤X2 / X3≤4.

[0072] As an example, the value of X2 / X3 is, for example but not limited to, any one of 2, 2.5, 3, 3.5 and 4, or a range of values ​​between any two of them.

[0073] In the above technical solution, the fluoroquinolone antibiotic wastewater and activated sludge have an appropriate dosage ratio, which is conducive to more thorough anaerobic digestion.

[0074] In some embodiments, after adding the uncomplexed biochar, at least one of the following conditions (a1) and (a2) is satisfied.

[0075] (a1) The pH value of the fluoroquinolone antibiotic wastewater and / or the activated sludge in the system to be treated is 6.4-7.8; as an example, the pH value is, for example but not limited to, any one of 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7 and 7.8, or a range between any two of them.

[0076] In the above technical solution, the pH value is adjusted to a suitable range of 6.4 to 7.8, corresponding to the pH value of pharmaceutical wastewater; moreover, it is beneficial to the growth of methanogens, thereby facilitating the increase of methane production.

[0077] (a2) After adding the uncompounded biochar, the system to be treated is subjected to anaerobically digestion at a temperature of 36°C to 38°C; as an example, the temperature condition is, but not limited to, any one of 36°C, 36.5°C, 37°C, 37.5°C and 38°C, or a range between any two of them.

[0078] In the above technical solution, carrying out anaerobic digestion at a suitable temperature is conducive to more thorough anaerobic digestion.

[0079] The features and performance of the present application are further described in detail below in conjunction with the embodiments.

[0080] 1. Preparation of experimental materials

[0081] Obtaining anaerobic sludge: The anaerobic sludge was domesticated in the laboratory for one year, with a pH value of 7.0-7.3, a total sludge solids (TS) of 24.49±0.20, and a volatile matter content (VS) of 18.64±0.30 g / L.

[0082] Biochar pretreatment: Commercial corn straw biochar was purchased (purchased from Henan Li Ze Environmental Protection Technology Co., Ltd., the biochar was prepared from corn straw at a high temperature of 500°C to 600°C). The biochar was washed repeatedly in deionized water for 3 times, dried in an oven at 60°C, and ground through a 100-mesh sieve after cooling for later use.

[0083] Preparation of ciprofloxacin wastewater: in ciprofloxacin wastewater, COD10000mg / L, COD:N:P200:5:1, glucose concentration is 9.3720g / L, ammonium chloride concentration is 0.9553g / L, potassium dihydrogen phosphate concentration is 0.2193g / L, ciprofloxacin concentration is 10mg / L; use 1mol / L hydrochloric acid to adjust the pH value to 7.0.

[0084] Preparation of wastewater without ciprofloxacin: In the wastewater without ciprofloxacin, COD10000mg / L, COD:N:P200:5:1, glucose concentration is 9.3720g / L, ammonium chloride concentration is 0.9553g / L, potassium dihydrogen phosphate concentration is 0.2193g / L; use 1mol / L hydrochloric acid to adjust the pH to 7.0.

[0085] 2. Conduct anaerobic digestion experiments

[0086] Under a nitrogen atmosphere, 600 mL of wastewater, 200 mL of anaerobic sludge, and a certain amount of biochar were added to a 1000 mL serum bottle and placed in a constant temperature shaker at 37 °C and incubated at 150 rpm.

[0087] The gas produced by anaerobic digestion is collected from the upper end of the bottle.

[0088] In Example 1, wastewater containing ciprofloxacin was used, and the amount of biochar used (ie, X1 / X2) was 5 g / L.

[0089] In Example 2, wastewater containing ciprofloxacin was used, and the amount of biochar used was 10 g / L.

[0090] In Example 3, wastewater containing ciprofloxacin was used, and the amount of biochar used was 20 g / L.

[0091] In Comparative Example 1, wastewater containing ciprofloxacin was used, and the amount of biochar used was 0 g / L.

[0092] In Comparative Example 2, wastewater without ciprofloxacin was used, and the amount of biochar used was 0 g / L.

[0093] 3. Experimental Results

[0094] Detection method:

[0095] 1. Check the composition and content of the gas every day; regularly measure the COD and ciprofloxacin concentration in the system.

[0096] 2. Gas composition and content were detected by gas chromatography equipped with a thermal conductivity detector; COD concentration was determined by rapid digestion spectrophotometry; ciprofloxacin concentration was determined by high performance liquid chromatography; microbial composition was based on Illumina MiSeq high-throughput sequencing technology.

[0097] Test results:

[0098] 1. Below Figure 1 to Figure 6 The pollutants and products in the wastewater treatment process are shown in some distribution conditions and yields. Among them, BC5 is Example 1, BC20 is Example 3, Control is Comparative Example 1, and Blank is Comparative Example 2.

[0099] Figure 1The figure is a bar chart showing the cumulative methane production of some embodiments and comparative examples.

[0100] according to Figure 1 It can be seen that the example with added biochar has a higher methane production.

[0101] Figure 2 The following are bar charts showing the volatile acid contents of some embodiments and comparative examples at different time periods during the experiment.

[0102] according to Figure 2 It can be seen that as the experimental time increases, in the wastewater treatment system containing antibiotics, the conversion of volatile acids in Comparative Example 1 without the addition of biochar is slow, and acid accumulation and acid inhibition occur; while in the example with the addition of biochar, the conversion of volatile acids is accelerated, and the volatile acid content gradually decreases.

[0103] Figure 3 The figure is a statistical diagram of the distribution of ciprofloxacin after the experiments in some embodiments and comparative examples.

[0104] Among them, from bottom to top in the bar graph are ciprofloxacin remaining in the liquid, adsorbed on the solid phase and degraded part.

[0105] according to Figure 3 It can be seen that compared with the control example without adding biochar, the example with added biochar has a higher antibiotic removal rate; moreover, the amount of biomass added in Example 3 is higher, and the corresponding antibiotic removal rate is also higher.

[0106] Figure 4 The following are bar charts showing the production of active oxygen in different time periods during the experiment of some embodiments and comparative examples.

[0107] according to Figure 4 It can be seen that the embodiment with the addition of biochar has a lower active oxygen production, which is beneficial to reducing the active oxygen pressure.

[0108] Figure 5 The bar graphs of the lactate dehydrogenase production in different time periods during the experiment of some embodiments and comparative examples are shown.

[0109] according to Figure 5 It can be seen that the embodiment with the addition of biochar has a lower lactate dehydrogenase production, which is beneficial to reducing the secretion of lactate dehydrogenase and reducing the degree of damage to the microbial cell membrane structure.

[0110] Figure 6 The bar graphs of the superoxide dismutase production at different time periods during the experiment of some embodiments and comparative examples are shown.

[0111] according to Figure 6It can be seen that the embodiment with the addition of biochar has a lower superoxide dismutase production, which is beneficial to reduce the secretion of superoxide dismutase and avoid the intense oxidative stress reaction in the microorganism.

[0112] 2. The detection results of methanogens in the embodiments and comparative examples are as follows.

[0113] In the microbial composition of Example 1, compared with Comparative Example 1, the functional bacteria norank_f__norank_o__SBR1031, Clostridium_sensu_stricto_5, norank_f__Bacteroidetes_vadinHA17, and JGI-0000079-D21 related to CIP degradation increased; the electroactive bacteria norank_f__Bacteroidetes_vadinHA17, JGI-0000079-D21 and Syntrophomonas involved in DIET can all be enriched by the conductive material biochar and their abundance increased; the abundance of the dominant methanogenic archaea Methanosaeta can not only avoid the phenomenon of acid accumulation in the anaerobic system caused by CIP, but also participate in DIET to promote the anaerobic methanogenesis process.

[0114] In the microbial composition of Example 2, compared with Comparative Example 1, the functional bacteria norank_f__norank_o__SBR1031, Clostridium_sensu_stricto_5, norank_f__Bacteroidetes_vadinHA17, and JGI-0000079-D21 related to CIP degradation increased; among them, the electroactive bacteria norank_f__Bacteroidetes_vadinHA17 and JGI-0000079-D21 involved in DIET could be enriched by conductive material biochar and their abundance increased; the dominant methanogenic archaea Methanosaeta increased in abundance.

[0115] In the microbial composition of Example 3, compared with Comparative Example 1, the functional bacteria norank_f__norank_o__SBR1031, Clostridium_sensu_stricto_5, norank_f__Bacteroidetes_vadinHA17, Longilinea, norank_f__JG30-KF-CM45, and JGI-0000079-D21 related to CIP degradation increased; the electroactive bacteria norank_f__Bacteroidetes_vadinHA17, JGI-0000079-D21 and Syntrophomonas involved in DIET could all be enriched by the conductive material biochar and their abundance increased; the dominant methanogenic archaea Methanosaeta increased in abundance.

[0116] 3. The main conditions, methane production data, and ciprofloxacin removal rate data of the embodiments and comparative examples are shown in Table 1 below.

[0117] Table 1. Main experimental conditions, methane production data, ciprofloxacin removal rate data

[0118]

[0119] Each experiment was conducted in three parallel groups, the methane production was the range covered by the three groups of experimental results, and the ciprofloxacin removal rate was the average value of the three groups of experimental results.

[0120] According to Table 1, we can see that:

[0121] In Examples 1 to 3, uncompounded biochar was added. Compared with Comparative Example 1 in which no biochar was added, the methane production and the removal rate of ciprofloxacin were significantly improved.

[0122] In Examples 1 to 3, the amount of biochar used was between 5 g / L and 20 g / L, and both the methane production and the ciprofloxacin removal rate reached a relatively high level; moreover, within this range, as the amount of biochar used gradually increased, the ciprofloxacin removal rate also gradually increased.

[0123] The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

Claims

1. A method for alleviating the inhibitory effect of fluoroquinolone antibiotics on anaerobic digestion, characterized in that: include: Uncompounded biochar was added to a treatment system for anaerobic digestion of fluoroquinolone antibiotic wastewater using an activated sludge process; The uncompounded biochar is corn straw biochar; The pH value of the fluoroquinolone antibiotic wastewater is 6.4-7.

8.

2. The method for alleviating the inhibitory effect of fluoroquinolone antibiotics on anaerobic digestion according to claim 1, characterized in that: In the fluoroquinolone antibiotic wastewater, the fluoroquinolone antibiotics include at least one of ciprofloxacin, norfloxacin, levofloxacin, ofloxacin, moxifloxacin and lomefloxacin.

3. The method for alleviating the inhibitory effect of fluoroquinolone antibiotics on anaerobic digestion according to claim 2, characterized in that: Before the anaerobic digestion is performed, the concentration of the fluoroquinolone antibiotics in the fluoroquinolone antibiotic wastewater is ND~19.6 mg / L.

4. The method for alleviating the inhibitory effect of fluoroquinolone antibiotics on anaerobic digestion according to claim 3, characterized in that: Before the anaerobic digestion is performed, the concentration of the fluoroquinolone antibiotics in the fluoroquinolone antibiotic wastewater is 9 mg / L to 11 mg / L.

5. The method for alleviating the inhibitory effect of fluoroquinolone antibiotics on anaerobic digestion according to claim 1, characterized in that: The added weight of the biochar is X1, and the volume of the fluoroquinolone antibiotic wastewater is X2, wherein 5g / L≤X1 / X2≤20g / L.

6. The method for alleviating the inhibitory effect of fluoroquinolone antibiotics on anaerobic digestion according to claim 5, characterized in that: 5g / L≤X1 / X2≤10g / L.

7. The method for alleviating the inhibitory effect of fluoroquinolone antibiotics on anaerobic digestion according to claim 5, characterized in that: 10g / L≤X1 / X2≤20g / L.

8. The method for alleviating the inhibitory effect of fluoroquinolone antibiotics on anaerobic digestion according to any one of claims 1 to 7, characterized in that: The volume of the fluoroquinolone antibiotic wastewater is X2, the added volume of the activated sludge in the system to be treated is X3, and 2≤X2 / X3≤4.

9. The method for alleviating the inhibitory effect of fluoroquinolone antibiotics on anaerobic digestion according to any one of claims 1 to 7, characterized in that: Satisfy at least one of the following conditions (a1) and (a2); (a1) The pH value of the activated sludge in the system to be treated is 6.4-7.8; (a2) After adding the uncompounded biochar, the system to be treated is subjected to anaerobic digestion at a temperature of 36° C. to 38° C.

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