A method for electron beam irradiation of solid waste

Abstract

The present application provides a method for treating solid waste by electron beam irradiation, and in particular, provides a method for treating steroid hormone bacterial residue, which comprises the following steps: 1) mixing methanol with the steroid hormone bacterial residue to be treated to obtain a first mixed solution; 2) adding calcium chloride into the first mixed solution to obtain a second mixed solution; and 3) performing ionizing radiation treatment on the second mixed solution to remove steroid hormone substances in the steroid hormone bacterial residue. The method can efficiently remove steroid androgen pollutants in the bacterial residue.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid waste treatment, and particularly relates to a method for treating solid waste by electron beam irradiation. Background Art

[0002] Steroid hormones refer to hormone drugs containing a steroid structure in the molecule. Their basic structure contains a cyclopentane polyhydrophenanthrene nucleus and three side chains. The nucleus is like the Chinese character "田" (field), and the three side chains are like the Chinese character "巛". Therefore, the character "甾" is used to vividly represent this type of compound. Steroid hormones mainly include sex hormones (estrogen and androgen), adrenocortical hormones, and anabolic hormones. They are the second largest class of drugs after antibiotics and are widely used in the medical field. Among them, androgens represented by androstenedione, 9α-hydroxyandrostenedione, etc. are key intermediates for synthesizing various steroid hormone drugs, and the market scale is huge. It is expected that the global market scale of androstenedione will reach 210 million US dollars by 2025.

[0003] The production methods of steroid androgens mainly include chemical synthesis and microbial fermentation. The chemical synthesis process is complex, with high raw material costs, low yields, and serious environmental pollution, and has gradually been phased out. At present, the microbial fermentation method has become the mainstream technology for producing steroid hormone drugs. After fermentation is completed and steroid hormone drugs are extracted, a large amount of bacterial residue waste remains. The safe disposal and effective utilization of steroid hormone pharmaceutical waste have become one of the important factors restricting the profit growth and production capacity expansion of enterprises.

[0004] Steroid hormones are a class of important endocrine disrupting chemicals (EDCs). Even at extremely low concentrations, they can cause hermaphroditism and reproductive system disorders in aquatic organisms, causing significant harm to the ecological environment and human health. Together with persistent organic pollutants, antibiotics, and microplastics, EDCs are currently "new pollutants" that have attracted extensive international attention.

[0005] The main components of steroid hormone bacterial residues are mycelia, culture media, and residual steroid hormones. The pollution source comes from the residual steroid hormones. If they can be removed from the bacterial residues, the harmless bacterial residues can be made into fertilizers for resource reuse, thereby solving the problems of treatment and disposal of steroid hormone bacterial residues. Steroid androgens have good thermal stability. Even under high-temperature conditions of 165 °C, the structures of androgens including androstenedione, 9α-hydroxyandrostenedione, and testosterone basically remain unchanged. Therefore, the pyrolysis process commonly used by pharmaceutical factories for treating antibiotic bacterial residues is not applicable to the treatment of steroid hormone bacterial residues.

[0006] The advanced oxidation technologies represented by ultraviolet light catalysis and Fenton oxidation have good degradation and removal effects on steroid hormones in wastewater, but have poor removal effects on steroid hormones in bacterial sludge. The bacterial sludge is a viscous solid-liquid mixture, and these conventional methods are difficult to penetrate into the interior of the bacterial sludge for reaction. Moreover, steroid hormones are strong hydrophobic compounds with high octanol-water partition coefficients (K ow ). Under the combined action of hydrophobic partitioning and electrostatic interaction, steroid hormones are firmly adsorbed and bound in the bacterial sludge cell solids, and it is difficult for them to react with active particles such as hydroxyl radicals in water.

[0007] Therefore, there is an urgent need for an effective method for treating steroid hormone bacterial sludge. SUMMARY

[0008] The present application aims to at least partially solve one of the problems in the related art. To this end, one object of the present application is to provide a steroid hormone bacterial sludge treatment method for efficiently removing steroid androgen pollutants in bacterial sludge.

[0009] In one aspect of the present application, a steroid hormone bacterial sludge treatment method is provided. According to an embodiment of the present application, the method includes:

[0010] 1) performing first mixing treatment of methanol with the steroid hormone bacterial sludge to be treated to obtain a first mixed solution;

[0011] 2) adding calcium chloride to the first mixed solution to obtain a second mixed solution;

[0012] 3) performing ionizing radiation treatment on the second mixed solution to remove steroid hormone substances in the steroid hormone bacterial sludge. This method can efficiently remove steroid androgen pollutants in bacterial sludge.

[0013] According to an embodiment of the present application, the above method can further include at least one of the following additional technical features:

[0014] According to an embodiment of the present application, the methanol solution is added in an amount of 2% to 4% (methanol concentration / residual steroid hormone concentration).

[0015] According to an embodiment of the present application, the calcium chloride is added in an amount of 10% to 20% (calcium chloride concentration / residual steroid hormone concentration).

[0016] According to an embodiment of the present application, the ionizing radiation treatment is performed by electron beam ionizing radiation treatment on the second mixed solution.

[0017] According to an embodiment of the present application, the absorbed dose of the electron beam irradiation is 25kGy-50kGy.

[0018] According to an embodiment of the present application, the steroid hormone residue-containing residue is a residue generated in the process of producing steroid hormones.

[0019] According to an embodiment of the present application, the steroid hormone is androstenedione or 9α-hydroxyandrostenedione.

[0020] According to an embodiment of the present application, the concentration of androstenedione residue in the steroid hormone residue is 200mg / kg.

[0021] According to an embodiment of the present application, the concentration of 9α-hydroxyandrostenedione residue in the steroid hormone residue is 500mg / kg.

[0022] According to an embodiment of the present application, the first mixing treatment is performed by vortex oscillation.

[0023] According to an embodiment of the present application, the second mixing treatment is performed by vortex oscillation.

[0024] In another aspect of the present application, the present application further provides a method for treating steroid hormone residue. According to an embodiment of the present application, the method is as follows:

[0025] 1) adding a certain concentration of methanol into the steroid hormone residue, vortex oscillating and mixing uniformly;

[0026] 2) adding a certain concentration of calcium chloride into the mixture, vortex oscillating and mixing uniformly;

[0027] 3) sending the mixture to the irradiation chamber of an electron accelerator, and using electron beam to perform ionizing irradiation on the mixture, so as to degrade and remove the steroid hormone substance in the residue. This method can efficiently remove the steroid androgen pollutants in the residue.

[0028] According to an embodiment of the present application, the above method can further include at least one of the following additional technical features:

[0029] According to the embodiment of the present application, the electron beam is a dense high-speed electron stream with extremely high energy density, and can react deeply into the inside of the fungus residue. Methanol can be combined with the steroid hormone molecules adsorbed on the fungus cell by hydrophobic interaction, and remove the steroid hormone molecules from the fungus residue solid to release into the solution. Calcium ions can replace the steroid hormone molecules adsorbed on the fungus residue solid by ion exchange. Under the above synergistic effect, the steroid hormone is removed from the fungus residue solid and released into the solution. Under the combined action of the direct radiation of the high-energy electron beam, the active particles such as hydroxyl radicals generated by the electron-excited water molecules, and the chlorine radicals generated by the irradiation-excited chlorine ions, the steroid hormone pollutants in the fungus residue are efficiently degraded and removed.

[0030] According to the embodiment of the present application, the steroid hormone fungus residue is the fungus residue containing residual steroid hormones generated in the steroid hormone production process, and the steroid hormone is androstenedione (AD) or 9α-hydroxyandrostenedione (OHAD).

[0031] According to the embodiment of the present application, the dosage of the methanol solution is 2% to 4% (methanol concentration / residual steroid hormone concentration).

[0032] According to the embodiment of the present application, the dosage of the calcium chloride is 10% to 20% (calcium chloride concentration / residual steroid hormone concentration).

[0033] According to the embodiment of the present application, the irradiation absorbed dose of the electron beam is 25 kGy to 50 kGy.

[0034] According to the embodiment of the present application, methanol and calcium chloride cooperate to remove the steroid hormone molecules from the fungus residue solid cell by hydrophobic interaction and cation exchange. The acid environment (pH=4.7-5.7) of the steroid hormone fungus residue helps the generation of chlorine radicals during irradiation, and strengthens the removal of the steroid hormone in the fungus residue. The removal rate of the steroid hormone can be more than 99%. In the method provided by the embodiment of the present application, the electron beam irradiation is carried out at room temperature, which is easy to realize large-scale engineering application. It can be seen that the method provided by the embodiment of the present application is efficient and widely applicable, and can be applied to the treatment of steroid hormone fungus residue, and has a wide application prospect in the field of harmful solid waste treatment.

[0035] According to the embodiment of the present application, the electron beam is generated by an electron accelerator, and is a dense high-speed electron stream with extremely high energy. Electron beam irradiation is an ionizing irradiation technology. After water molecules are excited by high-energy electron beam irradiation, active particles such as hydroxyl radicals (·OH) with strong oxidizing property, hydrated electrons (e aq - ) with strong reducing property, and hydrogen radicals (·H) are generated (as shown in formula 1, the values in the brackets are the radiation chemical yield G value of each active particle). The steroid hormone molecules can be oxidized and reduced by these active particles to be degraded.

[0036]

[0037] According to the embodiment of the present application, the electron beam irradiation has a higher degradation rate for the steroid hormones in aqueous solution, such as AD, OHAD, but the degradation rate is significantly reduced for the steroid hormones in the solid waste of the fungus residue. The adsorption of the steroid hormones by the cell of the fungus significantly affects the irradiation degradation efficiency. The steroid hormones are strong hydrophobic compounds, and have a high octanol-water partition coefficient (for example, the logK ow of AD is 2.75, and the logK ow of OHAD is 3.98). Under the combined action of the hydrophobic partition, electrostatic interaction and other mechanisms, the steroid hormones are firmly adsorbed and bound in the solid of the fungus residue, and it is difficult to react with the active particles such as hydroxyl radicals in water. If the steroid hormone molecules can be removed from the fungus residue solid, and the concentration of the steroid hormone in the supernatant is increased, the irradiation degradation efficiency of the steroid hormone in the fungus residue can be improved.

[0038] According to the embodiment of the present application, methanol is an organic compound that is completely miscible with water, and is commonly used as a solubilizer for organic compounds. The methanol can be combined with the steroid hormone molecules adsorbed on the cell of the fungus through hydrophobic interaction, and the steroid hormone molecules are removed from the fungus residue solid and released into the supernatant. In addition, under the acidic environment of the fungus residue, most of the steroid hormone molecules exist in the form of positive ions, and the metal cation Ca 2+ can be replaced from the steroid hormone molecules adsorbed on the fungus residue solid through ion exchange, and the concentration of the steroid hormone in the supernatant is further increased, and the collision and reaction with the active particles such as hydroxyl radicals in the solution are strengthened. Further, the chloride ion can generate chlorine radicals under the acidic condition of the fungus residue through the following reaction, and the chlorine radicals have a high reaction rate constant (the order of magnitude is 10 10 L / mol s) with the steroid hormone molecules. The steroid hormone molecules are efficiently degraded under the combined action of the active particles such as hydroxyl radicals, chlorine radicals, and hydrated electrons.

[0039] Cl - +·OH→ClOH ·- k=4.3×10 9 L / mols (2)

[0040] ClOH ·- +H + →Cl·+H2O k=2.1×10 9 L / mols (3) DETAILED DESCRIPTION

[0041] The embodiments described below are exemplary and are intended to serve for explanation of the present application, and cannot be understood as a limitation of the present application.

[0042] Moreover, the terms "first", "second", etc. are used herein for descriptive purposes only and should not be construed as indicating or implying relative importance or an ordered sequence. Thus, features referring to "first", "second" etc. can include, explicitly or implicitly, at least one of these features. In the description of the application, the meaning of "a plurality" is at least two, such as two, three or the like, unless explicitly specified otherwise.

[0043] The application will be described with respect to the following specific examples, which are merely illustrative, and are not to be construed as limiting the application in any way.

[0044] Example 1

[0045] AD fermentation residue was obtained from a pharmaceutical enterprise in Hebei Province, China, with a moisture content of 79%, a pH value of 5.6, a total solid (TS) content of 212 g / kg, a volatile solid (VS) / TS ratio of 85%, and a residual AD concentration of about 200 mg / kg. Methanol was commercially available and of analytical purity. Calcium chloride was commercially available and of analytical purity.

[0046] About 10 g of AD fermentation residue was weighed and mixed uniformly with 4 mg / L (2%), 8 mg / L (4%), or 12 mg / L (6%) of methanol by vortex shaking. About 10 g of AD fermentation residue was weighed, mixed with 4 mg / L of methanol, and then mixed with 10 mg / L (5%), 20 mg / L (10%), or 40 mg / L (20%) of calcium chloride by vortex shaking. The uniformly mixed residue samples were placed in sample bags and sent to the irradiation chamber of an electron accelerator for irradiation. Pure residue samples without methanol and calcium chloride and residue samples with only calcium chloride were irradiated at the same time for comparison.

[0047] Different absorbed doses of 10 kGy, 25 kGy, and 50 kGy were obtained by controlling the beam intensity of the electron beam and the transmission speed of the sample. The detection index was the concentration of the steroid hormone AD in the residue before and after electron beam irradiation.

[0048] The residual AD in the residue was first extracted with acetonitrile and then detected by liquid chromatography.

[0049] The AD extraction method in the residue was as follows: about 0.2 g of residue was placed in a 15 mL polypropylene centrifuge tube, 5 mL of acetonitrile was added, vortexed for 3 min, and ultrasonic-assisted extraction was performed for 20 min. Centrifugation was performed at 10000 rpm for 10 min, the supernatant was filtered with a 0.22 μm filter membrane, and the filtered solution was diluted to an appropriate multiple for high performance liquid chromatography detection.

[0050] The high performance liquid chromatograph used is an Agilent 1200 from Agilent Technologies, the column is an XDB-C18 reversed-phase column, the column temperature is 30°C, the mobile phase is 0.1% formic acid aqueous solution and acetonitrile (mixed at a ratio of 30:70), and the detector is an ultraviolet detector with an AD detection wavelength of 245 nm.

[0051] The AD removal rates in the fermentation residue under different absorbed doses, methanol and calcium chloride dosages are shown in Table 1. It can be seen that when the absorbed dose is 10 kGy, the AD removal rate can reach 79%, but as the absorbed dose further increases, the improvement of the AD removal rate is small. When the absorbed dose is 50 kGy, the AD removal rate is 90%, and a high concentration of AD (about 20 mg / L) remains in the fermentation residue.

[0052] When the methanol dosage is 2% and 4%, the AD removal efficiency can be significantly improved. When the absorbed dose is 50 kGy, the AD removal rate can reach 93% to 96%. However, if the methanol dosage is too high (6%), the AD removal rate decreases. Methanol can react with the hydroxyl radicals generated by irradiation of water molecules, and if the concentration is too high, the quenching effect of hydroxyl radicals is greater than the promotion effect of AD desorption and dissolution, which will reduce the AD removal efficiency.

[0053] When the methanol dosage is 2% to 4%, and calcium chloride is further added, the AD removal efficiency is further improved. When the methanol dosage is 2% to 4%, the calcium chloride dosage is 20%, and the absorbed dose is 25 to 50 kGy, the AD removal rate can reach more than 99%. The addition of calcium chloride alone also has a certain promoting effect on AD degradation. When the calcium chloride dosage is 20% and the absorbed dose is 50 kGy, the AD removal rate is 92%.

[0054] Table 1 AD removal rates (%) in fermentation residue under different experimental conditions

[0055]

[0056] Example 2

[0057] The OHAD fermentation residue is taken from a pharmaceutical enterprise in Hubei Province, China, and has a water content of 37%, a pH value of 4.6, a total solid (TS) content of 332 g / kg, a volatile solid (VS) / TS ratio of 99%, and a residual OHAD concentration of about 500 mg / kg. The methanol is commercially available analytical pure. The calcium chloride is commercially available analytical pure.

[0058] Take 10g or so OHAD fermentation residue, respectively, add methanol 10mg / L (2%), 20mg / L (4%), 30mg / L (6%), vortex shock mixed uniformly. Take 10g or so OHAD fermentation residue, first add methanol 10mg / L, then add calcium chloride 25mg / L (5%), 50mg / L (10%), 100mg / L (20%) respectively, vortex shock mixed uniformly. The mixed uniform residue sample is put into a sample bag, and sent to the irradiation room of the electron accelerator for irradiation. The pure residue sample without methanol and calcium chloride and the residue sample with calcium chloride alone are irradiated at the same time for comparison.

[0059] Different irradiation absorbed doses 10kGy, 25kGy, 50kGy are obtained by controlling the beam intensity of the electron beam and the transmission speed of the sample. The detection index is the concentration of steroid hormone OHAD in the residue before and after electron beam irradiation.

[0060] The residual OHAD in the residue is first extracted with acetonitrile, and then detected by liquid chromatography.

[0061] Among them, the extraction method of OHAD in the residue is: take 0.2g or so residue and put it in a 15mL polypropylene centrifuge tube, add 5mL acetonitrile, vortex for 3min, and ultrasonic assisted extraction for 20min. Centrifuge at 10000rpm for 10min, take the supernatant and filter with a 0.22μm filter membrane, dilute the filtered solution to an appropriate multiple for high performance liquid chromatography detection.

[0062] Among them, the high performance liquid chromatograph used is Agilent 1200 of Agilent Company, USA, the chromatographic column is XDB-C18 reversed phase column, the column temperature is 30℃. The mobile phase is 0.1% formic acid aqueous solution and acetonitrile (mixed ratio 30:70). The detector is ultraviolet detector, and the OHAD detection wavelength is 254nm.

[0063] Under the conditions of different absorbed doses, methanol and calcium chloride dosages, the removal rate of OHAD in the residue is shown in Table 2. It can be seen that when the irradiation absorbed dose is 10kGy, the removal rate of OHAD can reach 74%, but with the further increase of the absorbed dose, the improvement of the removal rate of OHAD is small. When the absorbed dose is 50kGy, the removal rate of OHAD is 88%, and there is still a high concentration of OHAD (about 60mg / L) in the residue.

[0064] The removal efficiency of OHAD can be significantly improved when the amount of methanol added is 2% to 4%. When the absorbed dose is 50 kGy, the removal rate of OHAD can reach 90% to 95%. However, if the amount of methanol is too high (6%), the removal rate of OHAD will decrease. Methanol can react with hydroxyl radicals generated by irradiation of water molecules. If the concentration is too high, the quenching effect of hydroxyl radicals is greater than the promotion effect of hydroxyl radicals generated by the dissolution of OHAD, which reduces the removal efficiency of OHAD.

[0065] When the amount of methanol added is 2% to 4%, and calcium chloride is further added, the removal rate of OHAD is further improved. When the amount of methanol added is 4%, the amount of calcium chloride added is 20%, and the absorbed dose is 25 to 50 kGy, the removal rate of OHAD can reach more than 99%. The addition of calcium chloride alone can promote the degradation of OHAD. When the amount of calcium chloride added is 20% and the absorbed dose is 50 kGy, the removal rate of OHAD is 91%.

[0066] Table 2 Removal rate of OHAD in the mushroom residue under different experimental conditions (%)

[0067]

[0068] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in the present specification and the features of the different embodiments or examples can be combined and combined by those skilled in the art without contradiction.

Claims

1. A method for treating a steroid hormone-containing bacterial residue, characterized by, The method comprises the following steps: 1) mixing methanol with the steroid hormone-containing residue to obtain a first mixture, wherein the amount of methanol is 2% to 4%; 2) adding calcium chloride to the first mixture to obtain a second mixture, wherein the amount of calcium chloride is 10% to 20%; 3) performing ionizing radiation treatment on the second mixture to remove steroid hormone substances in the steroid hormone-containing residue, wherein the ionizing radiation treatment is performed by electron beam ionizing radiation treatment, and the absorbed dose of the electron beam is 25 kGy to 50 kGy.

2. The treatment method according to claim 1, characterized in that, The steroid hormone-containing residue is a residue containing residual steroid hormones generated in the production process of steroid hormones.

3. The treatment method of claim 1, wherein, The steroid hormone is androstenedione or 9α-hydroxyandrostenedione.

4. The treatment method according to claim 1, characterized in that, The concentration of residual androstenedione in the steroid hormone-containing residue is 200 mg / kg.

5. The treatment method according to claim 1, characterized in that, The concentration of residual 9α-hydroxyandrostenedione in the steroid hormone-containing residue is 500 mg / kg.

6. The treatment method of claim 1, wherein The first mixing treatment is performed by vortex oscillation.

7. The treatment method according to claim 6, characterized in that, The addition of calcium chloride to the first mixture is performed by vortex oscillation.

Images