Treatment method of sewage containing fentanyl drugs

Abstract

The invention relates to the technical field of advanced oxidation and sewage treatment, in particular to a treatment method of sewage containing fentanyl drugs. The treatment method comprises the following steps: pretreating sewage containing fentanyl drugs, and then adjusting the pH value to be acidic, so as to obtain acidified sewage; nanoscale zero-valent iron (Fe < 0 >) and a hydrogen peroxide solution are added into the acidified sewage to react at room temperature, and degradation of the fentanyl drugs in the sewage containing the fentanyl drugs is achieved. The method disclosed by the invention has the following advantages: 1, efficient removal: the removal rate of fentanyl within 60 minutes reaches 99%; 2, the method is environment-friendly: Fe0 and H2O2 are adopted, the reaction byproduct is nontoxic ferric oxide, and the risk of secondary pollution is avoided; and 3, the method has strong adaptability, is suitable for different pH values (2-4) and sewage scales, has low cost and is easy for industrial application. 4, products are clear, 11 TPs are systematically identified for the first time, and degradation paths (such as hydroxyl substitution and piperidine ring breakage) are clarified;

Description

Technical Field

[0001] The present invention relates to the fields of advanced oxidation technology and sewage treatment technology, and in particular to a method for treating sewage containing fentanyl drugs. Background Art

[0002] Fentanyls are widely used in the medical field due to their highly effective analgesic effects, but their extremely high lipid solubility (log P = 4.05) and bioaccumulation have led to an increasingly serious problem of persistent pollution in the environment. Studies have shown that the residual concentration of fentanyls in sewage treatment plant effluent is 100% detected, ranging from 0 to 87 ng / L (Gushgar et al., Water Research, 2019, 161:171-180). However, conventional sewage treatment methods, including MBR, ultraviolet light, and chlorine treatment, only remove fentanyl and its common metabolite, norfentanyl, by 1.59% (Simpson et al., Chemosphere, 2024, 364:143-307). Furthermore, in traditional chlorination disinfection processes (such as hypochlorite oxidation), fentanyl's benzene ring and piperidine groups are easily attacked by active chlorine, resulting in substitution reactions and the formation of more toxic fentanyl derivatives, such as β-hydroxyfentanyl and methoxyfentanyl. The acute toxicity of β-hydroxyfentanyl and methoxyfentanyl to zebrafish embryos (LC50 = 1.55 mg / L) is significantly higher than that of the parent compound (LC50 = 5.2 mg / L) (data from the U.S. Environmental Protection Agency (EPA) model ECOSAR.V.2.2), and they can accumulate through the food chain and threaten human health.

[0003] At present, wastewater treatment technologies for fentanyl mainly rely on traditional chemical oxidation methods such as hypochlorite oxidation and peracetic acid treatment. However, these methods have significant limitations: (1) Byproduct toxicity risk: the oxidation process is prone to generate intermediate products (TPs) with the structural characteristics of the parent fentanyl, especially the chlorinated derivatives produced by the chlorination process, which may be more toxic than the original compound; (2) Incomplete degradation: Traditional processes (peracetic acid, hypochlorite and liquid chlorine) are not capable of identifying and removing TPs, resulting in the risk of secondary pollution. The residual hydroxylated or methoxylated intermediates (such as β-hydroxyfentanyl, methoxyfentanyl, etc.) still have strong ecotoxicity (LC50~=1.2~3.73mg / L, data from the U.S. Environmental Protection Agency (EPA) model ECOSAR.V.2.2); (3) Lack of ecotoxicity assessment: Existing studies mostly focus on the removal rate of the parent compound, and there is a serious lack of degradation pathways and ecotoxicity assessment of wastewater, resulting in the hidden danger of "incomplete degradation and unelimination of risks" in wastewater treatment processes.

[0004] In recent years, based on zero-valent iron (Fe0 )'s advanced oxidation technology (Fe 0 Due to its high reducing activity and low cost, zero-valent iron (ZVI) has been used to degrade antibiotics such as sulfamethoxazole (Shanableh et al., Sci. Total Environ, 2021, 761: 143-307) and pesticides such as atrazine (Shen et al., J. Hazard. Mater, 2018, 357: 408-414). However, the application of zero-valent iron systems in the field of opioid treatment still faces the following technical bottlenecks: (1) Active passivation problem: The surface of zero-valent iron is easily passivated to form an oxide layer, resulting in a reduction in active sites and a significant decrease in degradation efficiency with reaction time; (2) Unclear degradation pathway: The types of TPs produced during the degradation process are complex, especially the formation of highly toxic chlorinated products in traditional chlorination processes must be avoided. However, existing technologies lack systematic identification of their structure, toxicity and degradation pathways, making it impossible to evaluate the environmental safety of the technology; (3) Lack of product identification: Traditional analytical methods (such as LC-MS / MS targeted detection) are limited by the coverage of the database, making it difficult to achieve non-targeted screening of unknown TPs, which restricts the in-depth analysis of the degradation mechanism.

[0005] In response to the above problems, there is an urgent need to develop a fentanyl wastewater treatment technology that is efficient, environmentally friendly, and has product traceability capabilities. Summary of the Invention

[0006] Based on the above content, the present invention provides a method for treating wastewater containing fentanyl drugs.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] One of the technical solutions of the present invention is a method for treating fentanyl-containing wastewater, comprising the following steps:

[0009] Pre-treating the fentanyl-containing wastewater and adjusting the pH to acidic to obtain acidified wastewater;

[0010] Nano-zero-valent iron and hydrogen peroxide solution are added to the acidified sewage to react at room temperature, thereby achieving degradation of fentanyl drugs in the fentanyl-containing sewage.

[0011] The second technical solution of the present invention is a comprehensive evaluation method for degradation products of fentanyl drugs in sewage, comprising the following steps:

[0012] The wastewater was treated using the above-mentioned treatment method, wherein nano-zero-valent iron and hydrogen peroxide solution were added to the acidified wastewater and reacted at room temperature. Samples were taken through a 0.22 μm filter membrane at 0, 10, 30, and 60 minutes of the reaction. The degradation products in the resulting filtrate were analyzed non-targeted using ultra-high pressure liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS). Compound Discoverer 3.1 software was then used for non-targeted screening, matching against a fentanyl compound database, and inferring the product structure based on fragment ion characteristics.

[0013] The present invention discloses the following technical effects:

[0014] The method of the present invention has the following advantages: 1. High efficiency removal: the removal rate of fentanyl reaches 99% within 60 minutes, avoiding the problems of residual benzene derivatives in traditional methods. 2. Environmentally friendly: Fe 0 The reaction product is non-toxic iron oxide, eliminating the risk of secondary pollution. 3. Strong adaptability: Suitable for different pH values (2-4) and wastewater scales, low cost, and easy industrial application. 4. Clear product identification: For the first time, 11 TPs were systematically identified, and their degradation pathways (such as hydroxyl substitution and piperidine ring cleavage) were elucidated.

[0015] The present invention innovatively integrates zero-valent iron Fenton (Fe 0 The research team used a novel chlorinated organic amine (Citric Acid / H2O2) oxidation system and ultra-high pressure liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) non-targeted analysis technology to not only achieve the efficient removal of fentanyl (removal rate >99% within 60 minutes), avoiding the formation of highly toxic chlorinated products in the chlorination process, but also systematically identified the structures and evolutionary pathways of 11 new degradation products for the first time, providing a scientific basis and technical guarantee for the safe management of fentanyl-contaminated water bodies. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 a) Performance effect diagram of fentanyl degradation by zero-valent iron-based Fenton system under different degradation systems and different materials; b) Performance effect diagram of fentanyl degradation by zero-valent iron-based Fenton system under different pH conditions; c) Reaction rate constant of fentanyl degradation by zero-valent iron-based Fenton system under different degradation systems and different materials; d) Reaction rate constant of fentanyl degradation by zero-valent iron-based Fenton system under different pH conditions.

[0018] Figure 2 a) The effect diagram of fentanyl degradation by zero-valent iron-based Fenton system under different free radical quenching conditions; b) The reaction rate constant of fentanyl degradation by zero-valent iron-based Fenton system under different free radical quenching conditions.

[0019] Figure 3 a) and c) Fe 0 / Scanning electron microscope (SEM) images before H2O2 degradation; b), d) Fe 0 / Scanning electron microscope (SEM) images after H2O2 degradation; e), f), h), i)Fe 0 / Transmission electron microscopy (TEM) images before and after H2O2 degradation; g), j) Fe 0 Scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-Mapping) image.

[0020] Figure 4 X-ray photoelectron spectroscopy (XPS) spectra of a) Fe 2p and c) O 1s energy regions; b) Fe 0 Full spectrum XPS spectra before and after / H2O2 reaction; d) Electron paramagnetic resonance (ESR) spectrum of hydroxyl radical (·OH) using DMPO as a spin trapping agent.

[0021] Figure 5 Fe 0 Mechanism diagram of fentanyl (FTN) degradation by H2O2 / H2O2 system.

[0022] Figure 6 Shown are the MS / MS spectra and structural formulas of 11 TPs (P1-P11) and FTN.

[0023] Figure 7 EIC mass spectra of 11 TPs and FTN.

[0024] Figure 8 Quantitative change analysis of TP in the degradation process in the two systems; among them, a) is the quantitative change trend of TP in the pure water system, b) is the quantitative change trend of TP in the trichloroisocyanuric acid system, c) and d) are the change trends of the data of the two systems after data enhancement by linear interpolation.

[0025] Figure 9 For different concentrations of PO4 3- a),a1),b),b1)Cl - 、c),c1)CO3 2- 、d),d1)SO4 2- ,e),e1)C2O4 2-、f),f1)NO3 - Performance diagram and reaction rate constant of fentanyl degradation by Fenton system in the presence of zero-valent iron. DETAILED DESCRIPTION

[0026] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0027] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value within any stated value or stated range, and each smaller range between any other stated value or intermediate value within the stated range, is also encompassed within the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0028] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0029] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be exemplary only.

[0030] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0031] Unless otherwise specified, the "%" in the present invention refers to mass percentage.

[0032] A first aspect of the present invention provides a method for treating fentanyl-containing wastewater, comprising the following steps:

[0033] Pre-treating the fentanyl-containing wastewater and adjusting the pH to acidic to obtain acidified wastewater;

[0034] Nano-zero-valent iron and hydrogen peroxide solution are added to the acidified sewage to react at room temperature, thereby achieving degradation of fentanyl drugs in the fentanyl-containing sewage.

[0035] The purpose of pretreatment is to remove large particles and suspended solids in wastewater containing fentanyl drugs to ensure the high efficiency of subsequent reactions.

[0036] In a preferred embodiment of the present invention, the pretreatment method is precipitation or filtration; the filtration is specifically filtering through filter paper with a pore size of 0.45 μm;

[0037] The pH is adjusted to be acidic by adding sulfuric acid or sodium hydroxide solution to adjust the pH to 2-4.

[0038] The purpose of adjusting the pH to acidic is to optimize the Fenton reaction conditions.

[0039] In a preferred embodiment of the present invention, the mass volume ratio of the nano-zero-valent iron to the fentanyl-containing wastewater is (0.05-0.2) g:1 L; the volume ratio of the hydrogen peroxide solution to the fentanyl-containing wastewater is (1.0-10.0):1000;

[0040] The mass concentration of the hydrogen peroxide solution is 30%.

[0041] In a preferred embodiment of the present invention, the mass volume ratio of the nano zero-valent iron and the hydrogen peroxide solution is 0.05 g:1 mL.

[0042] In a preferred embodiment of the present invention, the reaction is carried out under stirring at a speed of 500 rpm; and the reaction time is 10-60 minutes.

[0043] The treatment method of the present invention utilizes Fe 0 The hydroxyl radicals (·OH) generated by the / H2O2 system can effectively degrade fentanyl and its structural analogs, achieving complete removal.

[0044] A second aspect of the present invention provides a method for comprehensively evaluating degradation products of fentanyl-based drugs in sewage, comprising the following steps:

[0045] The wastewater was treated using the above-mentioned treatment method, wherein nano-zero-valent iron and hydrogen peroxide solution were added to the acidified wastewater and reacted at room temperature. Samples were taken through a 0.22 μm filter membrane at 0, 10, 30, and 60 minutes of the reaction, and the degradation products in the resulting filtrate were analyzed non-targeted using ultra-high pressure liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS). Compound Discoverer 3.1 software was then used for non-targeted screening, matching against a fentanyl compound database, and inferring the product structure based on fragment ion characteristics.

[0046] In a preferred embodiment of the present invention, the chromatographic conditions are set as follows:

[0047] Hypersil TM BDS C18 chromatographic column (150 mm × 2.1 mm, 1.9 μm); column temperature 40°C; flow rate 0.3 mL / min; mobile phase: phase A is 0.1% formic acid in water, phase B is acetonitrile; gradient elution: 5% phase B from 0 to 5 min, linearly increasing to 95% phase B from 5 to 15 min, and maintained for 5 min.

[0048] In a preferred embodiment of the present invention, the mass spectrometry conditions are set as follows: Orbitrap Exploris TM 480 mass spectrometer, positive / negative ion mode combined with HCD fragmentation, collecting full scan and target ion secondary mass spectrometry data Full MS / dd-MS 2 ;

[0049] By comparing the mass spectrometry data of blank samples and treated samples at m / z 50-500, new chromatographic peaks were screened out: signal-to-noise ratio > 3, intensity > 10 5 , sample / blank peak area ratio>10, and combined with the fentanyl compound library established by Compound Discover software, degradation products including hydroxylation, methoxylation and cleavage products were identified based on characteristic fragment ions and retention time matching.

[0050] The present invention uses non-targeted analysis based on HPLC-HRMS to analyze the solution before and after zero-valent iron Fenton degradation. The acquired data files include ESI-positive [M+H] + and ESI-negative [MH] -The newly formed products were identified by comparing the pure water fentanyl solution sample with the control sample of fentanyl solution prepared from simulated disinfection wastewater, as well as the pollutant sample data after zero-valent iron Fenton treatment. Special attention was paid to those chromatographic peaks that appeared only in the treated samples and were not detected in the control group. In order to confirm that these peaks represent newly generated compounds, the present invention set a threshold: then implemented a workflow that integrates suspected target and non-target screening. In order to minimize background interference, the raw data were preliminarily filtered using the following criteria: (1) signal-to-noise ratio (S / N)>3, (2) intensity>10 5 , (3) the ratio of sample intensity to program blank is >10. Then, the pure water system and simulated disinfection wastewater system were screened. The newly generated compounds were compared with the 236 fentanyl compound library established in the CompoundDiscover software. Based on the similarity of the parent and metabolite structures and the common characteristic fragments, the parent secondary characteristic fragment ions were imported into the CompoundDiscoverer software for characteristic fragment search to determine the structure of the unknown TP. Through this method, the unknown compound (TP) produced by the degradation of fentanyl by the zero-valent iron Fenton system can be accurately identified.

[0051] The mass spectrometric data (m / z 50-500) of a pure water fentanyl solution sample were compared with a control sample of a fentanyl solution prepared from simulated disinfectant wastewater, as well as a sample degraded by zero-valent iron Fenton reaction. Unknown peaks were screened using high-performance liquid chromatography-mass spectrometry in positive electrospray ionization mode.

[0052] Linear interpolation is a method of estimating between known data points, based on the assumption that the data varies linearly between adjacent points. Given two known data points (x0, y0) and (x1, y1). For any x∈[x 0， x1], the y value of the interpolation point can be calculated using the linear interpolation formula:

[0053]

[0054] By linear interpolation, the time series data of the amount of degradation substances changing with time (per minute) were constructed. However, since the data obtained by linear interpolation may be relatively rough, a smoothing method was further used to optimize the time series data. Specifically, a smoothing method based on the moving average was used to calculate the average of each data point S. i Calculate the mean of p (Smoothing value) points before and after it to reduce data noise and make the time series trend more stable. The smoothing calculation formula is as follows:

[0055]

[0056] Where si represents the smoothed data, p represents the smoothing window size, and si+j represents the unsmoothed data at the i+jth moment.

[0057] This method achieves complete fentanyl removal through a zero-valent iron Fenton system, avoiding the residual benzene derivatives and other issues associated with traditional methods. It also employs dynamic monitoring using a zero-valent iron Fenton system combined with UHPLC-HRMS non-targeted analysis to systematically identify 11 TPs (P1-P11) produced during the degradation process, including hydroxylation, methoxylation, and cleavage products. The Chinese names, structural formulas, and molecular formulas of P1-P11 are as follows:

[0058] P1

[0059] Chinese name: Methoxyfentanyl

[0060] Structural formula: The oxygen atom of the amide group (-CON-) in the fentanyl molecule is replaced by a methoxy group (-OCH3).

[0061]

[0062] Molecular formula: C 22 H 28 N2O2

[0063] P2-P4

[0064] Chinese name: Hydroxyfentanyl (isomer)

[0065] Structural formula: Hydroxyl groups (-OH) are introduced at different positions of the benzene ring or piperidine ring in the fentanyl molecule.

[0066] P2: Benzene ring ortho-hydroxyl substitution P3: Benzene ring para-hydroxyl substitution P4: β-hydroxy substituted on the piperidine ring (β-hydroxyfentanyl) Molecular formula: Molecular formula: C 22 H 28 N2O2

[0067] P5-P6

[0068] Chinese name: Dihydroxyfentanyl (isomer)

[0069] Structural formula: A hydroxyl group (-OH) is introduced into two different positions in the fentanyl molecule (such as the benzene ring and the piperidine ring).

[0070]

[0071] Molecular formula: C 22 H 28 N2O3

[0072] P7

[0073] Chinese name: Demethylfentanyl (Norfentanyl, Norfentanyl)

[0074] Structural formula: The methyl group (-CH3) on the piperidine ring in the fentanyl molecule is removed.

[0075]

[0076] Molecular formula: C 14 H 20 N2OP8

[0077] Chinese name: Hydroxydesmethylfentanyl

[0078] Structural formula: A hydroxyl group (-OH) is introduced into the piperidine ring of demethylfentanyl (P7).

[0079]

[0080] Molecular formula: C 14 H 20 N2O2

[0081] P9

[0082] Chinese name: 4-[phenyl(propionyl)amino]piperidine-1-carboxylic acid ethyl ester.

[0083] Structural formula: The 1-position of the piperidine ring is a carboxylic acid ethyl ester group, and the 4-position is a phenylpropionamide group.

[0084]

[0085] Molecular formula: C 17 H 24 N2O3

[0086] P10

[0087] Chinese name: 2-[Ethyl(butyl)amino]-1-phenylethanol Structural formula: A benzene ring is connected to an ethanol group (-CH2CH2OH), and the amino group is substituted with ethyl and butyl groups.

[0088]

[0089] Molecular formula: C 14 H 23 NOP11

[0090] Chinese name: N-ethyl-N-(4-hydroxyphenyl)acetamide Structural formula: The nitrogen atom of the acetamide group (-CONH-) connects the ethyl group and the 4-hydroxyphenyl group.

[0091]

[0092] Molecular formula: C 11 H 15 NO2

[0093] The present invention provides a method for treating wastewater containing fentanyl-like drugs, while also identifying intermediate transformation products to assess whether fentanyl can be completely degraded. The present invention utilizes a dynamic monitoring technology called "zero-valent iron Fenton system + UHPLC-HRMS non-targeted analysis" to identify 11 new transformation products (TPs) using ultra-high pressure liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) non-targeted analysis, thereby determining their removal mechanisms and degradation pathways. The method achieved a 99% removal rate for fentanyl-like drugs within 60 minutes. The present invention is highly efficient, environmentally friendly, and scientifically sound, providing a solution for the management of fentanyl-contaminated water bodies.

[0094] Unless otherwise specified, the technical solutions described in the present invention are all conventional solutions in the field, and the reagents or raw materials used, unless otherwise specified, are purchased from commercial channels or have been disclosed.

[0095] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0096] Example 1

[0097] 1. Experimental Materials and Equipment

[0098] 1.1 Reagents:

[0099] Fentanyl standard (purity ≥98%, Sigma-Aldrich); nano zero-valent iron (Fe 0 , purity ≥99%, particle size 50-100 nm, Aladdin); 30% hydrogen peroxide solution (H2O2, Sinopharm Group); sulfuric acid (H2SO4, analytical grade), sodium hydroxide (NaOH, analytical grade); ultrapure water (resistivity ≥18.2 MΩ·cm, prepared by Milli-Q system).

[0100] 1.2 Instruments:

[0101] pH meter (Mettler Toledo FE28); magnetic stirrer (IKARCT Basic); ultra-high pressure liquid chromatography-high resolution mass spectrometry system (UHPLC-HRMS, Thermo Scientific Vanquish Flex UHPLC+OrbitrapExploris 480); scanning electron microscope (SEM, Hitachi SU8010); X-ray photoelectron spectrometer (XPS, ThermoScientific K-Alpha).

[0102] 2. Experimental Procedure

[0103] (1) Sewage pretreatment: 1 L of fentanyl solution (with an effective chlorine concentration of 10 mg / L and an initial fentanyl concentration of 1 mg / L) prepared from simulated disinfection wastewater was taken and filtered through filter paper (pore size 0.45 μm) to remove suspended matter and large particle impurities to obtain pretreated sewage.

[0104] (2) Acidification and pH adjustment: Add 0.1M H2SO4 solution to the pretreated sewage to adjust the pH to 3.0±0.1, and continue stirring for 5 minutes to make the solution uniform.

[0105] (3) Fenton oxidation reaction: 0.05 g of nano-zero-valent iron (Fe) was added to 1 L of acidified wastewater. 0 ) and 1mL30% H2O2 solution, the addition ratio is Fe 0 :H2O2=0.05g:1mL.

[0106] The reaction was stirred at 500 rpm at room temperature (25±1°C), and samples were taken at 0, 10, 30, and 60 minutes of the reaction. After sampling, a quencher was added to terminate the reaction immediately, and the mixture was filtered through a 0.22 μm filter membrane.

[0107] (4) Analysis of degradation products

[0108] UHPLC conditions:

[0109] Chromatographic column: Hypersil BDS C18 (150 mm × 2.1 mm, 1.9 μm);

[0110] Mobile phase: phase A (0.1% formic acid in water), phase B (acetonitrile);

[0111] Gradient elution: 5% B in 0-5 min, linearly increasing to 95% B in 5-15 min, and maintaining for 5 min;

[0112] Flow rate: 0.3 mL / min; column temperature: 40°C.

[0113] HRMS conditions:

[0114] Ion source: electrospray ionization (ESI), positive ion mode;

[0115] Scan range: m / z 50-1000;

[0116] Resolution: 120,000 (Full MS), 30,000 (MS / MS);

[0117] Fragmentation mode: HCD (high energy collision induced dissociation), energy 30 eV.

[0118] Data analysis: CompoundDiscoverer 3.1 software was used for non-targeted screening, matching the fentanyl compound database (containing 236 structures), and the product structure was inferred based on the fragment ion characteristics.

[0119] 3. Experimental Results

[0120] (1) Fentanyl degradation efficiency

[0121] Removal rate: fentanyl removal rate reached 99.2% within 60 minutes ( Figure 1 As shown in a), in the figure, ZVI (98%) + 0.0025g means that the reaction conditions are to add 98% pure Fe to 1L of acidified sewage. 0 , the dosage is 0.0025g, ZVI (98%) + 0.01g means the reaction conditions are to add 98% pure Fe to 1L of acidified sewage 0 , the dosage is 0.01g, ZVI (99%) + 0.0025g means the reaction conditions are to add 99% pure Fe to 1L of acidified sewage 0 , the dosage is 0.0025g, ZVI (99%) + 0.01g means the reaction conditions are to add 99% pure Fe to 1L of acidified wastewater 0 , the dosage is 0.01g, ZVI / H2O2 means the reaction conditions are to add 0.0025g of 99% pure Fe into 1L of acidified wastewater 0 and 50 μL of 30% H2O2. H2O2 means that the reaction conditions are to add only 50 μL of 30% H2O2 to 1L of acidified wastewater. ZVI means that the reaction conditions are to add only 0.0025 g of 99% pure Fe 0 ;

[0122] Removal efficiency: The total organic carbon (TOC) removal efficiency was 98.7%, indicating that fentanyl was almost completely converted into CO2 and H2O.

[0123] (2) Identification of degradation products

[0124] Through non-targeted HRMS analysis, a total of 11 new transformation products (TPs) were identified, including hydroxylation (P1-P6), methoxylation (P7-P8) and fragmentation products (P9-P11). The specific characteristics are as follows:

[0125] P1~P4:m / z 353.22247(C 22 H 28 N2O2), a hydroxyl-substituted fentanyl isomer ( Figure 6 );

[0126] P7: m / z 234.10760 (C 14 H 20 N2O), corresponding to norfentanil ( Figure 6 );

[0127] P10: m / z 222.18526 (C 14 H 23 NO), which is the piperidine ring cleavage product (Table 1).

[0128] Table 1

[0129]

[0130] As shown in Table 1, in order to further clarify the structures of the 11 unknown TPs detected, the present invention used CompoundDiscover software for analysis. Based on the molecular formula calculation, the retention time tolerance parameter was 0.1 min, and the m / z tolerance parameter was 0.015 Da. The ratio of the sample peak area to the reference peak area (t0) must be greater than 10 times to be considered as a fentanyl TP. Table 1 includes all possible candidate m / z. Among them, P1-P8 are TPs produced by degradation in a fentanyl pollutant solution system prepared with ultrapure water. P9 is a newly discovered product in a simulated disinfection system, and P10 and P11 are cleavage products of the degradation product that is further degraded in a zero-valent iron system. Therefore, the interpretation of the precursor molecular structure is mainly based on fragmentation by secondary mass spectrometry.

[0131] The results of non-targeted mass spectrometry analysis are as follows Figure 6 、 Figure 7 As shown in the figure, the fragmentation pattern of fentanyl was analyzed using MASS Frontier to provide a basis for structural identification. FTN showed [M+H] at m / z 337.22740. + ions, generating a phenethyl characteristic fragment of m / z 105.06982 and a phenethylpiperidin characteristic fragment of m / z 188.14334, representing the protonated phenethyl ion [C8H9] + and phenethylpiperidinium ion [C 13 H 18 N] + .

[0132] P1-P4 are isomers with an m / z of 353.22247. The MS / MS spectrum of P1 shows the same characteristic fragments as the parent FTN. Therefore, its fragmentation pattern is confirmed to produce two characteristic fragments at m / z 105.06982 and m / z 188.14334. Therefore, the oxygen substitution in P1 is confirmed to be at the amide group. Structural comparison indicates that P1 is methoxyfentanyl. For P2-P4, retention time matching and comparison of MS and MS / MS spectra with FTN reveal that m / z 121.06475 and m / z 204.13823, two characteristic fragments corresponding to fentanyl fragmentation, each have an additional oxygen, consistent with hydroxyl substitution. Therefore, the characteristic fragments containing m / z 121.06475 and m / z 204.13823 are confirmed to be hydroxyfentanyl with different hydroxyl substitution positions. Among them, m / z 121.06475 corresponds to the characteristic fragment of a benzyl group replaced by a hydroxyl group, and m / z 204.13823 corresponds to the characteristic fragment of a phenyl ring replaced by a hydroxyl group on phenethylpiperidine. Similarly, P5 and P6 contain two characteristic fragments, m / z 121.06475 and m / z 204.13823, but combined with the m / z values of the parent ions, it can be inferred that P5 and P6 are dihydroxyfentanyl structures with different hydroxyl substitution positions.

[0133] Both P7 and P8 exhibited a characteristic fragment ion at m / z 84.08057, consistent with a piperidine ring, indicating that both compounds contain a piperidine ring structure. Furthermore, considering the mass-to-charge ratio of the parent ion, the mass spectral data for P7 matched that of norfentanil, confirming that P7 was norfentanil. The parent ion of P8, on the other hand, exhibited an additional oxygen compared to P7. The highly similar mass spectral patterns of P7 and P8 in their mass spectra suggest that they share similar molecular structures. Based on this observation, it can be inferred that P8 is likely a hydroxylated derivative of P7, namely, hydroxynorfentanil.

[0134] P9 was found in a simulated disinfection system and was distinguished from the TP in the pure water system. From the mass spectrometry data, the characteristic fragments of the piperidine ring at m / z 84.08084 and the characteristic fragment of ethyl piperidine carboxylate at m / z 156.10190 were detected in P9. Therefore, the structure of P9 can be inferred to be 4-[phenyl(propionyl)amino]piperidine-1-carboxylic acid ethyl ester.

[0135] P10 and P11 are likely further fragmentation products in the zero-valent iron system. Characteristic fragment analysis revealed that the MS / MS spectra of P10, corresponding to m / z 177.12738, are 2-[ethyl(methyl)amino]-1-phenylethanol. The structure of P10 can be inferred through comparison of these characteristic fragments.

[0136] P11 is a further degradation product. Characteristic fragment ion analysis revealed m / z 107.04916 and m / z 135.04402 for P11, representing the protonated hydroxyphenyl ion and hydroxyphenylamide ion, respectively. Therefore, the structure of P11 was inferred to be N-ethyl-N-(4-hydroxyphenyl)acetamide.

[0137] At the same time, according to the monitoring results of the above degradation products at different times in high-resolution mass spectrometry, such as Figure 8 As shown in (a) and (b), the above unknown TPs all followed a logical increase-decrease pattern over time, increasing sharply in the first 5-10 min and then decreasing sharply. This behavior can be attributed to the fact that they are all degradation products of fentanyl. At the same time, the zero-valent iron system successfully degraded fentanyl and its by-products, avoiding the residue of highly toxic derivatives.

[0138] In order to further quantify the stability of the substance during degradation, the present invention introduces the half-life 4 The half-life indicator is used to describe the time required for a substance to decrease from its peak value to half. Based on the half-life analysis, significant differences in the degradation rates of different substances were observed. Figure 8 As shown in Figure c), the degradation rates of P8 and P2 are slower than those of P11 and P7, with half-lives of 15 minutes and 12 minutes, respectively. The degradation rate of the latter is about half of that of the former. Figure 8 Middle (d) shows that P4 has the highest degradation difficulty, and the time required for degradation is more than three times that of P10, with a half-life of 31 minutes.

[0139] Example 2

[0140] Comparison between different degradation systems

[0141] Three different systems were tested (Fe 0 、H2O2、Fe 0 / H2O2), and compared the use of Fe 0 (ZVI), H2O2, Fe 0 The degradation performance of fentanyl under different system methods such as / H2O2 system treatment (i.e., based on the experimental steps 2., only 0.0025g of nano zero-valent iron (Fe 0 ) and 50 μL 30% H2O2 solution were replaced by adding only 0.0025Fe 0 , only 50 μL of 30% H2O2 solution was added, and 0.0025 g of nano zero-valent iron (Fe 0) and 50μL 30% H2O2, with the other steps and parameters remaining unchanged). The results showed that the removal rates of fentanyl within 60 minutes were 11.40%, 6.20% and 94.65%, respectively. Fentanyl had a higher removal rate in the zero-valent iron Fenton system within 60 minutes, such as Figure 1 As shown in a). Figure 1 In c), we can see that Fe 0 The degradation rate constant of fentanyl in the / H2O2 system can reach 0.1192min -1 .

[0142] Effect of different pH

[0143] The effects of different pH values (pH = 1, 3, 5, 7, 9) on degradation were tested (i.e., based on the experimental steps in 2, only the pH values were adjusted to 1, 5, 7, and 9, and the other steps and parameters remained unchanged). The test results at different pH values are shown in the figure below. Figure 1 When the solution pH is 3, the degradation performance of fentanyl reaches the best. When the pH increases, the degradation performance decreases. When the pH is 9, only 70% of the degradation effect remains. This is because at pH 3, the divalent iron species mainly exists in the form of free Fe 2+ exists in the form of hydroxyl radicals The best conditions. Hydroxyl radicals are the key active species used to degrade organic matter in Fenton-like reactions. When the pH is too high, the trivalent iron species in the solution begin to form a large amount of iron sludge precipitation, resulting in a sharp drop in reaction activity. When the pH is <3, which is too low, hydrogen peroxide (H2O2) is easily protonated to form H3O2 + This form of hydrogen peroxide cannot be catalyzed by iron species to produce hydroxyl radicals (·OH), which seriously affects the oxidative degradation of organic matter. Figure 1 As can be seen in (d), when pH is 3, the degradation rate constant of fentanyl can reach 0.14577 min -1 .

[0144] Reaction mechanism verification

[0145] Free radical contribution analysis: through quenching experiment ( Figure 2 In the figure, L-Histidine represents L-histidine, BQ represents benzoquinone, TBA represents tert-butyl alcohol, MeOH represents methanol, and AgNO3 represents silver nitrate). Figure 2 b) It was confirmed that hydroxyl radical (·OH) was the main active substance in degradation (contribution rate > 90%);

[0146] Fe 0 Surface characterization: SEM shows Fe 0 A porous oxide layer is formed on the surface ( Figure 3In a)-b), c)-d), XPS confirmed that Fe 0 Oxidized to Fe 2+ / Fe 3+ ( Figure 4 a)-c)), promoting the continuous generation of ·OH.

[0147] Figure 2 Through free radical quenching experiments, it was shown that Fe 0 The role of reactive oxygen species (ROS) in the degradation of fentanyl by Fenton-like degradation. By introducing different free radical quenchers, the free radical species involved in the degradation reaction were identified, including hydroxyl radicals (·OH), singlet oxygen ( 1 O2), superoxide radicals (O2 ·- ). The experimental results show that when benzoquinone is added, there is almost no effect on the degradation of fentanyl, indicating that superoxide radicals do not play a role in the degradation system. After the introduction of L-histidine, the degradation rate decreases, but it is still completely degraded in the end, which shows that the effect of singlet oxygen on the degradation system is low. When tert-butyl alcohol (TBA) and methanol are further added as quenchers of hydroxyl radicals, the degradation rate is significantly reduced, confirming the important role of hydroxyl radicals in fentanyl degradation. At the same time, ESR tests were performed using DMPO as a spin trap ( Figure 4 In d), it can be observed that Fe 0 A clear 1:2:2:1 peak DMPO-·OH signal was detected in the / H2O2 system, and the signal intensity gradually increased with the extension of the reaction time, indicating that ·OH was continuously generated. Combined with the results of the free radical quenching experiment, it can be shown that ·OH is Fe 0 The main active species that plays a degradation role in the / H2O2 system.

[0148] Fe 0 The influence of purity

[0149] The commercially available Fe 0 Perform performance comparison tests, such as Figure 1 As shown in a), high-purity Fe 0 The degradation effect is better than that of low-purity zero-valent iron, 99% Fe 0 It can be degraded, and when the dosage is increased, the degradation effect is improved. 0 Shows higher efficiency in degrading organic pollutants, high-purity Fe 0 It has more active sites, thus providing more reduction reaction opportunities. 0 There are certain impurities in the material, which may affect the electron transfer rate. 0An oxide layer is more likely to form on the surface, which hinders its contact with pollutants and reduces the effective reduction reaction.

[0150] according to Figure 3 Scanning electron microscopy results of a)-b), c)-d), Fe 0 Fe before and after H2O2 treatment 0 The surface is relatively smooth, and the Fe 0 After H2O2 treatment, Fe 0 The surface is corroded to form a rough deposit layer and a large number of pore structures. 0 Oxidation and deposition occur simultaneously on the surface. The reason for this phenomenon may be that Fe 0 An iron oxide layer is formed on the surface. Figure 3 As shown in the EDS images of (i) and (j), Fe 0 The distribution of oxygen atoms on the surface increases significantly. These results show that the oxidation layer on the Fe0 surface increases significantly before and after the reaction. Figure 3 The results of HRTEM (high resolution transmission electron microscopy) in f), g), h), and i) show that Fe 0 The particles aggregate into clusters, and the surface is surrounded by a pre-existing iron oxide film, corresponding to the (111) plane of Fe2O3 with a lattice spacing of 0.30nm. 0 The size of the aggregated particles is significantly reduced. Combined with the previous SEM results, Fe 0 The surface becomes rougher, which may be due to the formation of Fe oxide / hydroxide layer on the surface. This can be confirmed by the two different planes of Fe3O4 and FeOOH corresponding to the (220) and (110) planes of 0.28nm and 0.33nm respectively. 0 Molar ratio test with H2O2.

[0151] Different molar ratios of Fe 0 The mechanism of the effect of / H2O2 on the generation of hydroxyl radicals (·OH) is demonstrated by free radical capture experiments (such as ESR) to show that the ·OH yield is highest at a specific ratio (1g:1mL). 0 Surface elements were further analyzed, such as Figure 4 As shown in a) and c), the peak positions of Fe 2p and O1s can be observed. 3 / 2 The binding energies of Fe2p of Fe(Ⅲ) and Fe(II) are 711.5eV, 709.8eV and 706.7eV respectively. 1 / 2 The peaks are located at 725.1eV and 723.4eV. Fe 2p 3 / 2There is an accompanying satellite peak at 718.2 eV. In addition, the Fe 2p 1 / 2 The satellite peak of the Fe 0 In comparison, the intensity of the Fe(0) peak decreased, the proportion of Fe(II) decreased from 28.1% to 21.6%, and the proportion of Fe(III) increased from 23.4% to 26.1%, which indicates that Fe(0) was gradually oxidized to Fe(II) and Fe(III) during the reaction. 0 After the / H2O2 reaction, the ratio of Fe(0) to Fe(II) increased again, which is consistent with the results of high-resolution transmission electron microscopy (HRTEM).

[0152] In order to further prove the existence of ROS in the zero-valent iron Fenton system, DMPO was used as a spin trap to perform ESR tests, such as Figure 4 As shown in (d), it can be observed that Fe 0 A clear 1:2:2:1 peak DMPO-·OH signal was detected in the / H2O2 system, and the signal intensity gradually increased with the extension of the reaction time, indicating that ·OH was continuously generated. Combined with the results of the free radical quenching experiment, it can be shown that ·OH is Fe 0 The main ROS in the / H2O2 system.

[0153] Interference test of different ions

[0154] In the complex matrix of water, PO4 3- 、Cl - 、CO3 2- 、SO4 2- 、C2O4 2- 、NO3 - The coexistence of anions and organic pollutants may affect the degradation efficiency of zero-valent iron Fenton system in two ways: (1) competing with the target compound for OH radicals; (2) occupying the active sites on the catalyst surface. Figure 9 As shown in Figure 2), the inhibitory effects of different anions on fentanyl (FTN) degradation showed significant differences: C2O4 2- Basically no effect, while PO4 3- 、Cl - 、SO4 2- and NO3 - The degradation efficiency of FTN decreased to 70%, 85%, 80% and 82% (1 mM concentration), respectively, of which PO4 3- The inhibitory effect was the most prominent.

[0155] PO4 3-The significant inhibitory effect of PO4 can be attributed to its unique mechanism of action: on the one hand, the hydrolysis of the anion will cause the pH value of the system to increase, affecting the Fenton reaction process; on the other hand, PO4 3- It forms an inner sphere complex with the catalyst surface through strong affinity, directly blocking the exposure of the active site. It is worth noting that even under the high salt concentration of 20mM, the system still maintains 50% (PO4 3- )、60%(Cl - / SO4 2- ) and 65% (NO3 - )'s FTN degradation efficiency, and this salt-resistance property shows the application potential of zero-valent iron Fenton-like systems in the remediation of complex water bodies.

[0156] Example 3

[0157] Traditional hypochlorite oxidation method (Xu Lin. Research on degradation methods of fentanyl compounds [D]. Beijing University of Chemical Technology, 2015): The removal rate of fentanyl is 85% in 60 minutes, and chlorofentanyl (m / z 371.18321, LD 50 30% reduction);

[0158] The method of the present invention: no chlorinated products are detected, and the toxicity of TPs is significantly reduced.

[0159] Example 4

[0160] The degradation of pharmaceutical wastewater (fentanyl concentration: 0.8 mg / L, COD value: 23.5 mg / L) was verified using the method described in "2. Experimental Procedure" of the present invention (i.e., the only difference from "2. Experimental Procedure" was that the simulated fentanyl-containing wastewater was replaced with pharmaceutical wastewater). The results showed a fentanyl removal rate of >99% within 60 minutes, with the types of TPs consistent with the simulation experiment. Furthermore, the potassium permanganate index of the wastewater treated with the present invention was reduced from 23.5 mg / L before degradation to 1.52 mg / L, demonstrating significant removal of both fentanyl and organic matter.

[0161] Example 5

[0162] The degradation of pharmaceutical factory wastewater (fentanyl concentration: 0.2 mg / L; COD value: 16.3 mg / L) was verified using the method described in "2. Experimental Procedure" of the present invention (i.e., the only difference from "2. Experimental Procedure" was that the simulated fentanyl-containing wastewater was replaced with pharmaceutical factory wastewater). The results showed that the fentanyl removal rate was >99.2% in 60 minutes, and the COD value was reduced from 16.3 mg / L before degradation to 1.22 mg / L, demonstrating significant removal of both fentanyl and organic matter.

[0163] Example 6

[0164] The degradation of hospital wastewater (fentanyl concentration: 0.5 mg / L; COD value: 16.3 mg / L) was verified using the method described in "2. Experimental Procedure" of the present invention (i.e., the only difference from "2. Experimental Procedure" was that the simulated fentanyl-containing wastewater was replaced with hospital wastewater). The results demonstrated a fentanyl removal rate of >99.4% within 60 minutes, and the COD value decreased from 16.3 mg / L before degradation to 0.26 mg / L, demonstrating significant removal of both fentanyl and organic matter.

[0165] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for treating fentanyl-containing wastewater, characterized in that: The following steps are involved: Pre-treating the fentanyl-containing wastewater and adjusting the pH to acidic to obtain acidified wastewater; Nano-zero-valent iron and hydrogen peroxide solution are added to the acidified sewage to react at room temperature, thereby achieving degradation of fentanyl drugs in the fentanyl-containing sewage.

2. The method for treating fentanyl-containing wastewater according to claim 1, wherein: The pretreatment method is precipitation or filtration; the filtration is specifically filtering through filter paper with a pore size of 0.45 μm; The pH is adjusted to be acidic by adding sulfuric acid or sodium hydroxide solution to adjust the pH to 2-4.

3. The method for treating fentanyl-containing wastewater according to claim 1, wherein: The mass volume ratio of the nano-zero-valent iron to the fentanyl-containing wastewater is (0.03-0.2) g:1 L; the volume ratio of the hydrogen peroxide solution to the fentanyl-containing wastewater is (0.5-10.0):1000; The mass concentration of the hydrogen peroxide solution is 30%.

4. The method for treating fentanyl-containing wastewater according to claim 1, wherein: The mass-to-volume ratio of the nano-zero-valent iron and the hydrogen peroxide solution is 0.05 g:1 mL.

5. The method for treating fentanyl-containing wastewater according to claim 1, wherein: The reaction is carried out under stirring conditions at a stirring speed of 500 rpm; the reaction time is 10-60 minutes.

6. A comprehensive evaluation method for degradation products of fentanyl drugs in sewage, characterized in that: The following steps are involved: The sewage is treated using the treatment method according to any one of claims 1 to 5, wherein, during the process of adding nano-zero-valent iron and hydrogen peroxide solution to the acidified sewage and reacting at room temperature, samples are respectively taken through a 0.22 μm filter membrane at 0, 10, 30, and 60 minutes of the reaction, and the degradation products in the obtained filtrate are subjected to non-targeted analysis using ultra-high pressure liquid chromatography-high-resolution mass spectrometry. Subsequently, non-targeted screening is performed using Compound Discoverer 3.1 software, matching with a fentanyl compound database, and inferring the product structure based on fragment ion characteristics.

7. The comprehensive evaluation method for degradation products of fentanyl drugs in sewage according to claim 6, characterized in that: The chromatographic conditions were set as follows: Hypersil TM BDS C18 chromatographic column (150 mm × 2.1 mm, 1.9 μm); column temperature 40°C; flow rate 0.3 mL / min; mobile phase: phase A is 0.1% formic acid in water, phase B is acetonitrile; gradient elution: 5% phase B from 0 to 5 min, linearly increasing to 95% phase B from 5 to 15 min, and maintained for 5 min.

8. The comprehensive evaluation method for degradation products of fentanyl drugs in sewage according to claim 6, characterized in that: Mass spectrometry conditions were set as follows: Orbitrap Exploris TM 480 mass spectrometer, positive / negative ion mode combined with HCD fragmentation, collecting full scan and target ion secondary mass spectrometry data Full MS / dd-MS 2 ; By comparing the mass spectrometry data of blank samples and treated samples at m / z 50-500, new chromatographic peaks were screened out: signal-to-noise ratio > 3, intensity > 10 5 , sample / blank peak area ratio>10, and combined with the fentanyl compound library established by Compound Discover software, degradation products including hydroxylation, methoxylation and cleavage products were identified based on characteristic fragment ions and retention time matching.

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