Harmless and recycling treatment method for antibiotic bacterial residues

Abstract

A harmless and recycling treatment method for antibiotic bacterial residues, relating to the technical field of organic solid waste treatment. The treatment method comprises the following treatment steps: performing drying and crushing pretreatment on antibiotic bacterial residues to obtain antibiotic bacterial residue dry base powder; heating the obtained antibiotic bacterial residue dry base powder to 400-800°C and performing constant temperature pyrolysis treatment on same in an inert atmosphere; using a condensing device to collect a volatile substance released during pyrolysis treatment to obtain a condensable bio-oil product, and using a gas bag to collect a non-condensable gas to obtain a pyrolysis gas, a residue substance obtained after the pyrolysis treatment being a biochar product. The problems in the prior art of incomplete degradation of antibiotic bacterial residues, tedious process, high recycling difficulty, waste of resources, etc., in conventional antibiotic bacterial residue treatment are solved; the purpose of making antibiotic bacterial residues harmless is achieved; in addition, nitrogen-containing high-value chemicals in bio-oil are recycled, so that the purpose of recycling the antibiotic bacterial residues is achieved.

Description

A harmless and resourceful treatment method for antibiotic bacterial residue Technical Field

[0001] The present invention belongs to the technical field of organic solid waste treatment, and in particular relates to a method for harmless and resourceful treatment of antibiotic bacterial residues. Background Art

[0002] Antibiotic residue is waste generated during the pharmaceutical industry's antibiotic production process. Its primary components are mycelium, fermentation metabolites, unused culture medium, and small amounts of residual antibiotics. Due to its high moisture content and high organic matter content, antibiotic residue is highly susceptible to spoilage and produces a foul odor. Furthermore, if the residual antibiotics in the residue are not safely disposed of and enter the environment, they can easily induce pathogens to develop drug resistance and resistance genes, rendering the antibiotics ineffective and even leading to the emergence of "superbugs," posing a significant threat to the ecological environment and human health.

[0003] Currently, the main methods for treating antibiotic bacterial residue include incineration, landfill, composting, anaerobic digestion, and other combined technologies. However, these existing technologies all have limitations. Incineration is the most commonly used method by hazardous waste disposal companies and is the most thorough and widely used treatment technology. However, the moisture content of antibiotic bacterial residue is generally over 90%, making direct incineration costly. Furthermore, due to the high nitrogen content in bacterial residue—several to ten times that of coal—direct incineration inevitably produces large amounts of toxic and hazardous substances such as NOx and dioxins, resulting in secondary pollution. As hazardous waste, antibiotic bacterial residue, when delivered to qualified hazardous waste disposal companies, can cost as much as 2,000 to 4,000 yuan per ton, severely hindering the development of pharmaceutical companies. Landfill is only one way to store hazardous waste in the soil. Direct landfilling requires significant space, leachate accumulation, and the potential for secondary soil contamination. Therefore, how to safely and economically treat antibiotic bacterial residue and transform it into products remains a key concern and urgent challenge for pharmaceutical companies.

[0004] Pyrolysis involves heating antibiotic residue at high temperatures in the absence or absence of oxygen to produce biochar, bio-oil, and combustible gases. Antibiotic residue, rich in organic matter such as crude fat, crude protein, and carbohydrates, is an ideal raw material for pyrolysis. Through pyrolysis, the macromolecules in the residue are decomposed into combustible small gases (such as CO, CH, C₂H₁, and H₂) under the action of heat. Furthermore, the high nitrogen content of the residue produces nitrogen-rich, condensable bio-oil during pyrolysis. This high-value byproduct can be recovered through selective separation and enrichment. The bio-oil, pyrolysis gas, and biochar residues collected by condensation are also potentially recyclable resources. Furthermore, high temperatures degrade the structure of any residual antibiotics in the residue, eliminating them. Therefore, pyrolysis treatment of antibiotic residue can both render it harmless and achieve resource recovery and reuse.

[0005] Patent CN108455599A discloses a method for preparing microporous, high-performance activated carbon from dry powder of antibiotic bacterial residue. The dry antibiotic residue undergoes pyrolysis in a nitrogen atmosphere, modification with alkaline solution, vacuum drying, and activation by pyrolysis in a carbon dioxide atmosphere, ultimately yielding microporous activated carbon. While this technology enables the utilization of activated carbon from antibiotic bacterial residue, the steps are complex and the presence of antibiotic residues in the resulting activated carbon is unclear, posing the risk of secondary contamination. Patent CN114212791A discloses a comprehensive disposal method for resource utilization of antibiotic bacterial residue. Specifically, the antibiotic bacterial residue is pyrolyzed in a specific pyrolysis reactor to obtain pyrolysis gas and pyrolysis carbon. The pyrolysis carbon is then mixed with an activator and placed in an activation reactor. The pyrolysis gas is passed into a heat exchange boiler for combustion and heat exchange. The flue gas after heat exchange enters the activation reactor and reacts to finally obtain activated carbon. However, there is also a lack of evaluation of the antibiotic residue in the activated carbon product. At the same time, only the utilization of bacterial residue pyrolysis carbon and pyrolysis gas is considered, and the pyrolysis gas (non-condensed) is directly burned for heat exchange, and the resource utilization value is low.

[0006] Patent CN114276180A discloses a method for producing high-value nitrogen-containing chemicals by co-pyrolysis of forestry waste and antibiotic residue. The method involves grinding and mixing the forestry waste and antibiotic residue in a mass ratio of 1:1 to 10, then co-pyrolyzing the mixture at 450-750°C in an oxygen-free environment to produce high-value nitrogen-containing chemicals, including amides, nitrogen-containing heterocyclic compounds, and nitriles. This invention leverages the advantages of the antibiotic residue's chemical composition to compensate for the low nitrogen content of forestry waste. During biomass pyrolysis, agricultural and forestry waste contains high levels of alkali and alkaline earth metals, such as K and Ca, which significantly alter the distribution of pyrolysis products. By co-pyrolyzing the forestry waste and antibiotic residue, the synergistic effect of the two can not only increase the yield of high-value nitrogen-containing chemicals, but also achieve the harmless disposal and resource utilization of the hazardous antibiotic residue, as well as the resource utilization of agricultural and forestry waste. Although this patent can achieve high-value utilization of fungus residue, it also lacks the evaluation of the residual antibiotics in the residual carbon of the fungus residue after pyrolysis, which poses a risk of secondary contamination of antibiotics. It also does not fully utilize the components of the fungus residue and lacks the utilization of pyrolysis gas (non-condensable).

[0007] Summary of the Invention

[0008] In view of the shortcomings and deficiencies of the above-mentioned prior art, the primary purpose of the present invention is to provide a method for harmless and resource-based treatment of antibiotic bacterial residues. The method of the present invention can fully utilize the components of antibiotic bacterial residues. The volatile substances produced by pyrolysis are collected by a condensing device to obtain bio-oil, and the recyclable components of the nitrogen-rich bio-oil are recycled. The non-condensable gas is collected as pyrolysis gas, which can also be used for energy utilization; the residual material after pyrolysis treatment is a biochar product, which can be used to prepare activated carbon or applied to contaminated soil for soil remediation.

[0009] The purpose of the present invention is achieved through the following technical solutions:

[0010] A method for harmless and resourceful treatment of antibiotic bacterial residues, comprising the following steps:

[0011] (1) Pretreatment: Drying and crushing the antibiotic residue to obtain dry powder of the antibiotic residue;

[0012] (2) Pyrolysis reaction: heating the dry powder of antibiotic residue obtained in step (1) to a temperature of 400 to 800° C. and performing constant temperature pyrolysis treatment under an inert atmosphere;

[0013] (3) Product collection: The volatile substances released by the pyrolysis treatment in step (2) are collected by a condensing device to obtain a condensable bio-oil product; the non-condensable gas is collected by an air bag to obtain pyrolysis gas; the residual substance after the pyrolysis treatment is the biochar product.

[0014] Furthermore, the antibiotic bacterial residue in step (1) is the vancomycin bacterial residue after dehydration and drying, and its moisture content is 50% to 80%.

[0015] Further preferably, the vancomycin content in the antibiotic bacterial residue dry powder is 50 to 300 mg / kg.

[0016] Furthermore, the drying and crushing pretreatment in step (1) refers to preheating and drying at 60-105° C. for 12-48 hours, and then crushing through a 60-100 mesh sieve.

[0017] Furthermore, the heating rate in step (2) is 5 to 20° C. / min.

[0018] Furthermore, the inert atmosphere in step (2) is N or CO2 atmosphere.

[0019] Furthermore, the time of the constant temperature pyrolysis treatment in step (2) is 20 to 120 minutes.

[0020] Further preferably, the temperature of the constant temperature pyrolysis treatment in step (2) is 600° C. and the time is 30 minutes.

[0021] Furthermore, in step (3), the bio-oil yield is 15% to 30%, the biochar yield is 30% to 50%, and the main components of the obtained pyrolysis gas include at least one of CO2, CH4, CO, and H2.

[0022] Furthermore, the bio-oil product in step (3) is further utilized as a nitrogen-containing chemical upstream crude product; the biochar product is further used to prepare activated carbon or applied to contaminated soil for soil remediation treatment.

[0023] The principle of the present invention is:

[0024] The present invention utilizes high temperature conditions to destroy the antibiotic structure in antibiotic residues, efficiently degrades residual antibiotics, and achieves the purpose of harmless residues; at the same time, high temperature conditions can also promote the decomposition of macromolecular organic matter in the residues into volatile organic matter in the gas phase, recover nitrogen-rich bio-oil through condensation, collect pyrolysis gas in air bags, and obtain residual biochar, thereby realizing the utilization of all components of the antibiotic residues.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The method of the present invention solves the problems of incomplete degradation of antibiotic residues, complicated process, high difficulty in resource utilization and waste of resources in the conventional treatment of antibiotic residues, thereby achieving the purpose of harmless antibiotic residues and resource utilization of all components.

[0027] (2) The nitrogen-rich bio-oil obtained by the method of the present invention can be further used for purification and separation to prepare high-value nitrogen-containing chemical products; the obtained pyrolysis gas can be reused as an energy gas raw material; the obtained biochar can be further used to prepare activated carbon or applied to contaminated soil for soil remediation treatment, with a high degree of resource utilization and great application prospects. DETAILED DESCRIPTION

[0028] FIG1 is a process flow chart of the method for harmless treatment and resource utilization of antibiotic bacterial residues in Example 1 of the present invention.

[0029]

[0030] The present invention will be further described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto.

[0031] Example 1

[0032] The present embodiment provides a method for harmless and resourceful treatment of dehydrated and dried antibiotic residues, the process flow diagram of which is shown in FIG1 , and includes the following steps:

[0033] (1) The dehydrated vancomycin residue cake was placed in a forced air drying oven at 80-85°C for 48 hours. The dried vancomycin residue was crushed, ground, and passed through a 100-mesh sieve to obtain a residue powder. The moisture content of the dehydrated vancomycin residue to be treated was 77.3%, and the moisture content of the dried residue powder was 8.7%. The vancomycin residual concentration in the residue powder was 147.8 mg / kg.

[0034] (2) 15 g of fungus residue powder was placed in a tubular furnace pyrolysis reactor, with N2 as the carrier gas at a gas flow rate of

[0035] 250mL / min, and then heated to 600℃ at a rate of 10℃ / min, and maintained for 30min.

[0036] (3) Pyrolysis oil was collected through a condenser with a yield of 23.3%. The relative contents of various nitrogen-containing chemicals in the pyrolysis products were analyzed by gas chromatography-mass spectrometry, and the relative content of nitrogen-containing compounds in the pyrolysis products was calculated to be 59.4%, of which the relative content of indolizine was 11.4%, the relative content of oleamide was 6.4%, the phase content of 5H-1-4-indolizine was 0.0%, and the relative content of 2-acetyl-1-methylpyrrole was 3.19%. Pyrolysis gas was collected through an air bag with a yield of 41.1%, and the main components were CO (23.4%), CH (9.9%), and CO (2.4%). The biochar yield was 35.6%, and no vancomycin was detected in the biochar, indicating that the treatment method of this embodiment has achieved complete degradation of antibiotics.

[0037] Example 2

[0038] The present embodiment provides a method for harmless and resource-recycling treatment of dehydrated and dried antibiotic residue, comprising the following steps:

[0039] (1) The dehydrated vancomycin residue was placed in a forced air drying oven at 80-85°C for 48 hours. The dried vancomycin residue was crushed, ground, and passed through a 100-mesh sieve to obtain a residue powder. The moisture content of the dehydrated vancomycin residue to be treated was 77.3%, the moisture content of the dried residue powder was 8.7%, and the vancomycin residual concentration in the residue powder was 147.8 mg / kg.

[0040] (2) 15 g of fungus residue powder was placed in a tubular furnace pyrolysis reactor, with N2 as the carrier gas at a gas flow rate of

[0041] 250mL / min, and then increase the temperature to 700℃ at a heating rate of 10℃ / min, and maintain it for 30min.

[0042] (3) Pyrolysis oil was collected through a condenser with a yield of 24.3%. The relative contents of various nitrogen-containing chemicals in the pyrolysis products were analyzed by gas chromatography-mass spectrometry, and the relative content of nitrogen-containing compounds in the pyrolysis products was calculated to be 55.2%, of which the relative content of indolizine was 11.5%, the relative content of oleamide was 10.1%, the phase content of 5H-1-4-indolizine was 0.0%, and the relative content of 2-acetyl-1-methylpyrrole was 3.1%. Pyrolysis gas was collected through an air bag with a yield of 41.6%, the main components of which were CO (22.9%), CH4 (9.6%), and CO (2.7%). The biochar yield was 34.1%. No vancomycin was detected in the biochar, indicating that the treatment method of this embodiment has achieved complete degradation of antibiotics.

[0043] Example 3

[0044] The present embodiment provides a method for harmless and resource-recycling treatment of dehydrated and dried antibiotic residue, comprising the following steps:

[0045] (1) The dehydrated vancomycin residue was placed in a forced air drying oven at 80-85°C for 48 hours. The dried vancomycin residue was crushed, ground, and passed through a 100-mesh sieve to obtain a residue powder. The moisture content of the dehydrated vancomycin residue to be treated was 77.3%, the moisture content of the dried residue powder was 8.7%, and the vancomycin residual concentration in the residue powder was 147.8 mg / kg.

[0046] (2) 15 g of fungus residue powder was placed in a tubular furnace pyrolysis reactor, with N2 as the carrier gas at a gas flow rate of

[0047] 250mL / min, and then increase the temperature to 800℃ at a heating rate of 10℃ / min, and maintain it for 30min.

[0048] (3) Pyrolysis oil was collected through a condenser with a yield of 20.5%. The relative contents of various nitrogen-containing chemicals in the pyrolysis products were analyzed by gas chromatography-mass spectrometry, and the relative content of nitrogen-containing compounds in the pyrolysis products was calculated to be 51.4%, of which the relative content of indolizine was 0.0%, the relative content of oleamide was 4.6%, the phase content of 5H-1-4-indolizine was 9.9%, and the relative content of 2-acetyl-1-methylpyrrole was 4.2%. Pyrolysis gas was collected through an air bag with a yield of 46.3%, the main components of which were CO2 (22.5%), CH4 (10.1%), and CO (2.8%). The biochar yield was 33.2%, and no vancomycin was detected in the biochar, indicating that the treatment method of this embodiment has achieved complete degradation of antibiotics.

[0049] Example 4

[0050] The present embodiment provides a method for harmless and resource-recycling treatment of dehydrated and dried antibiotic residue, comprising the following steps:

[0051] (1) The dehydrated vancomycin residue was placed in a forced air drying oven at 80-85°C for 48 hours. The dried vancomycin residue was crushed, ground, and passed through a 100-mesh sieve to obtain a residue powder. The moisture content of the dehydrated vancomycin residue to be treated was 77.3%, the moisture content of the dried residue powder was 8.7%, and the vancomycin residual concentration in the residue powder was 147.8 mg / kg.

[0052] (2) 15 g of fungus residue powder was placed in a tubular furnace pyrolysis reactor, CO2 was used as the carrier gas, the gas flow rate was 250 mL / min, the temperature was raised to 600 °C at a rate of 10 °C / min, and maintained for 30 min.

[0053] (3) Pyrolysis oil was collected through a condenser with a yield of 22.0%. The relative contents of various nitrogen-containing chemicals in the pyrolysis products were analyzed by gas chromatography-mass spectrometry, and the relative content of nitrogen-containing compounds in the pyrolysis products was calculated to be 50.7%, of which the relative content of indolizine was 0.0%, the relative content of oleamide was 0.0%, the phase content of 5H-1-4-indolizine was 8.4%, and the relative content of 2-acetyl-1-methylpyrrole was 5.5%. Pyrolysis gas was collected through an air bag with a yield of 42.7%. After excluding the influence of CO2 carrier gas, its main components were CH4 (11.4%) and CO (2.3%). The biochar yield was 35.3%. No vancomycin was detected in the biochar, indicating that the treatment method of this embodiment has achieved complete degradation of antibiotics.

[0054] Example 5

[0055] The present embodiment provides a method for harmless and resource-recycling treatment of dehydrated and dried antibiotic residue, comprising the following steps:

[0056] (1) The dehydrated vancomycin residue was placed in a forced air drying oven at 80-85°C for 48 hours. The dried vancomycin residue was crushed, ground, and passed through a 100-mesh sieve to obtain a residue powder. The moisture content of the dehydrated vancomycin residue to be treated was 77.3%, the moisture content of the dried residue powder was 8.7%, and the vancomycin residual concentration in the residue powder was 147.8 mg / kg.

[0057] (2) 15 g of fungus residue powder was placed in a tubular furnace pyrolysis reactor, CO was used as the carrier gas, the gas flow rate was 250 mL / min, the temperature was raised to 700 °C at a rate of 10 °C / min, and maintained for 30 min.

[0058] (3) Pyrolysis oil was collected through a condenser with a yield of 22.8%. The relative contents of various nitrogen-containing chemicals in the pyrolysis products were analyzed by gas chromatography-mass spectrometry, and the relative content of nitrogen-containing compounds in the pyrolysis products was calculated to be 50.8%, of which the relative content of indolizine was 0.0%, the relative content of oleamide was 0.0%, the phase content of 5H-1-4-indolizine was 7.9%, and the relative content of 2-acetyl-1-methylpyrrole was 5.9%. Pyrolysis gas was collected through an air bag with a yield of 43.5%. After excluding the influence of CO2 carrier gas, the main components were CH4 (11.3%) and CO (3.2%). The biochar yield was 33.7%. No vancomycin was detected in the biochar, indicating that the treatment method of this embodiment has achieved complete degradation of antibiotics.

[0059] Example 6

[0060] The present embodiment provides a method for harmless and resource-recycling treatment of dehydrated and dried antibiotic residue, comprising the following steps:

[0061] (1) The dehydrated vancomycin residue was placed in a forced air drying oven at 80-85°C for 48 hours. The dried vancomycin residue was crushed, ground, and passed through a 100-mesh sieve to obtain a residue powder. The moisture content of the dehydrated vancomycin residue to be treated was 77.3%, the moisture content of the dried residue powder was 8.7%, and the vancomycin residual concentration in the residue powder was 147.8 mg / kg.

[0062] (2) 15 g of fungus residue powder was placed in a tubular furnace pyrolysis reactor, CO was used as the carrier gas, the gas flow rate was 250 mL / min, the temperature was raised to 800 °C at a rate of 10 °C / min, and maintained for 30 min.

[0063] (3) Pyrolysis oil was collected through a condenser with a yield of 22.4%. The relative contents of various nitrogen-containing chemicals in the pyrolysis products were analyzed by gas chromatography-mass spectrometry, and the relative content of nitrogen-containing compounds in the pyrolysis products was calculated to be 48.0%, of which the relative content of indolizine was 0.0%, the relative content of oleamide was 0.0%, the phase content of 5H-1-4-indolizine was 8.8%, and the relative content of 2-acetyl-1-methylpyrrole was 5.5%. Pyrolysis gas was collected through an air bag with a yield of 46.6%. After excluding the influence of CO and carrier gas, the main components were CH4 (10.7%) and CO (5.9%). The biochar yield was 31.0%. No vancomycin was detected in the biochar, indicating that the treatment method of this embodiment has achieved complete degradation of antibiotics.

[0064] The above embodiments are preferred implementations of the present invention, but the implementations of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A method for harmless and resourceful treatment of antibiotic bacterial residues, characterized in that: The processing steps include: (1) Pretreatment: Pretreatment of the antibiotic residue by drying and crushing to obtain a dry powder of the antibiotic residue; (2) pyrolysis reaction: heating the dry powder of antibiotic residue obtained in step (1) to 400-800° C. and subjecting it to constant temperature pyrolysis treatment under an inert atmosphere; (3) Product collection: The volatile substances released by the pyrolysis treatment in step (2) are collected by a condensing device to obtain a condensable bio-oil product; the non-condensable gas is collected by an air bag to obtain pyrolysis gas; the residual substance after the pyrolysis treatment is the biochar product.

2. The method for harmless and resourceful treatment of antibiotic bacterial residues according to claim 1, characterized in that: The antibiotic bacterial residue in step (1) is the vancomycin bacterial residue after dehydration and drying, and its moisture content is 50% to 80%.

3. The method for harmless and resourceful treatment of antibiotic bacterial residues according to claim 2, characterized in that: The vancomycin content in the antibiotic bacterial residue dry powder is 50-300 mg / kg.

4. The method for harmless and resourceful treatment of antibiotic bacterial residues according to claim 1, characterized in that: The drying and crushing pretreatment in step (1) refers to preheating and drying at 60-105°C for 12-48 hours, and then crushing through a 60-100 mesh sieve.

5. The method for harmless and resourceful treatment of antibiotic bacterial residues according to claim 1, characterized in that: The heating rate in step (2) is 5 to 20°C / min.

6. The method for harmless and resourceful treatment of antibiotic bacterial residues according to claim 1, characterized in that: The inert atmosphere in step (2) is N2 or CO2 atmosphere.

7. The method for harmless and resourceful treatment of antibiotic bacterial residues according to claim 1, characterized in that: The time of the constant temperature pyrolysis treatment in step (2) is 20 to 120 minutes.

8. The method for harmless and resourceful treatment of antibiotic bacterial residues according to claim 7, characterized in that: The temperature of the constant temperature pyrolysis treatment in step (2) is 600°C and the time is 30 minutes.

9. The method for harmless and resourceful treatment of antibiotic bacterial residues according to claim 1, characterized in that: The bio-oil yield in step (3) is 15% to 30%, the bio-char yield is 30% to 50%, and the main components of the obtained pyrolysis gas include at least one of CO2, CH, CO, and H2.

10. The method for harmless and resourceful treatment of antibiotic bacterial residues according to claim 1, characterized in that The bio-oil product is further utilized as a nitrogen-containing chemical upstream crude product; the biochar product is further used to prepare activated carbon or applied to contaminated soil for soil remediation treatment.

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