Co-loaded peanut shell biochar / peroxyacetic acid water treatment synergistic system and application thereof

Abstract

This application discloses a cobalt-supported peanut shell biochar / peracetic acid synergistic system for water treatment and its application. The synergistic system includes cobalt-supported peanut shell biochar, peracetic acid, and water. The cobalt-supported peanut shell biochar comprises a peanut shell biochar matrix and cobalt-containing substances supported on the matrix. The cobalt-containing substances include metallic cobalt and / or cobalt oxides. The mass ratio of cobalt-supported peanut shell biochar to peracetic acid is (2-132):1. The atomic ratio of cobalt to carbon in the matrix is ​​(0.2-0.3):1. The cobalt-supported peanut shell biochar has a mesoporous structure with a total pore volume of not less than 0.07 cm³ / g and a specific surface area of ​​not less than 100 m². 2 / g. When this synergistic system is used to treat water containing organic pollutants, especially sulfamethoxazole, it can achieve a removal rate of over 90% within 3-5 minutes. The system maintains high activity and good stability over a wide pH range and in the presence of common anions, exhibiting excellent continuous operation performance. The degradation pathway of this synergistic system is environmentally friendly and can effectively reduce the toxicity of the products.

Description

Technical Field

[0001] This application relates to the field of advanced oxidation technology in water treatment, specifically to a cobalt-supported peanut shell biochar / peracetic acid water treatment synergistic system and its application. Background Technology

[0002] Sulfamethoxazole (SMX), a widely used prescription antibiotic for treating infections in humans and animals, is increasingly becoming a novel environmental pollutant. Residual sulfamethoxazole can enter aquatic systems through multiple pathways, posing ecotoxicological risks to aquatic organisms and exhibiting significant bioaccumulation potential. Advanced oxidation processes have shown remarkable potential for eliminating sulfamethoxazole, effectively degrading it into less toxic byproducts by generating highly reactive substances (such as hydroxyl radicals, sulfate-containing radicals, and organic radicals), and even completely mineralizing it into H₂O and CO₂.

[0003] Peracetic acid (PAA), as an environmentally friendly oxidant, has attracted much attention in the field of water treatment in recent years. This is due to its advantages such as high redox potential, strong antibacterial activity, and low production of toxic byproducts. The lower O2O bond energy in the peracetic acid molecule is significantly lower than that of hydrogen peroxide and persulfate, which is conducive to its activation to generate highly reactive substances, such as hydroxyl radicals (•OH), organic free radicals (R–O•, e.g., CH3C(O)OO•, CH3C(O)O•), and singlet oxygen (•OH). 1 O2), etc. It is worth noting that transition metal-mediated peracetic acid activation, especially through cobalt with multivalent redox cycles, has shown significant effectiveness in peracetic acid activation. Existing technology Wang Z, Wang J, Xiong B, et al. Application of cobalt / peracetic acid to degrade sulfamethoxazole at neutral condition: efficiency and mechanisms [J]. Environmental science technology, 2019, 54(1): 464-475 reported that under neutral conditions, homogeneous Co 2+ The / PAA system can achieve over 90% degradation of sulfamethoxazole within 15 minutes, mainly through Co... 2+ / Co 3+ The catalytic activation of peracetic acid generates acetoxy radicals. However, homogeneous cobalt systems face challenges such as metal leaching and secondary contamination risks, thus necessitating the development of supported cobalt catalytic systems.

[0004] Biochar is renowned for its abundant surface functional groups (CO and C=O), economic efficiency, and environmental sustainability, providing an ideal catalyst support for catalytic applications. Existing technology, such as Dong J, Xu W, Liu S, et al. Lignin-derived biochar to support CoFe2O4: effective activation of peracetic acid for sulfamethoxazole degradation [J]. Chemical Engineering Journal, 2022, 430: 132868, developed magnetic biochar (CoFe2O4@BC) using lignin to activate peracetic acid, achieving 95.8% degradation of sulfamethoxazole (10 mg / L) within 60 minutes, while simultaneously improving catalyst stability and recyclability. However, it still faces challenges such as complex preparation processes, limited catalytic rates, unclear applicability in complex aquatic bodies and continuous flow systems, unclear structure-activity relationship between cobalt-supported configuration and peracetic acid activation mechanism, need for further catalytic activity improvement, and insufficient systematic assessment of the degradation pathways and product toxicity of target pollutants. Summary of the Invention

[0005] To address the aforementioned technical issues, this application provides a cobalt-loaded peanut shell biochar / peracetic acid water treatment synergistic system and its application.

[0006] In a first aspect, this application provides a cobalt-loaded peanut shell biochar / peracetic acid water treatment synergistic system, comprising cobalt-loaded peanut shell biochar, peracetic acid, and water;

[0007] The cobalt-loaded peanut shell biochar includes a peanut shell biochar matrix and cobalt-containing substances loaded on the peanut shell biochar; the cobalt-containing substances include metallic cobalt and / or cobalt oxides.

[0008] The water body in question contains organic pollutants.

[0009] Furthermore, the mass ratio of cobalt-loaded peanut shell biochar to peracetic acid is (2-132):1; preferably, the mass ratio of cobalt-loaded peanut shell biochar to peracetic acid is (3-53):1; more preferably, the mass ratio of cobalt-loaded peanut shell biochar to peracetic acid is (13-14):1.

[0010] Furthermore, the atomic ratio of cobalt to C in the cobalt-supported peanut shell biochar is (0.2-0.3):1.

[0011] Furthermore, the cobalt-loaded peanut shell biochar has a mesoporous structure.

[0012] Furthermore, the total pore volume of the cobalt-supported peanut shell biochar is not less than 0.07 cm³ / g; preferably, the total pore volume of the cobalt-supported peanut shell biochar is 0.07-0.08 cm³ / g.

[0013] Furthermore, the specific surface area of ​​the cobalt-supported peanut shell biochar is not less than 100 m². 2 / g; preferably, the specific surface area of ​​the cobalt-supported peanut shell biochar is 110-120m². 2 / g.

[0014] Furthermore, the concentration of cobalt-supported peanut shell biochar was 50 mg / L-500 mg / L; the concentration of peracetic acid was 0.05 mM-0.25 mM.

[0015] Furthermore, the cobalt oxide includes Co. 2+ oxides, Co 3+ Oxides.

[0016] Furthermore, the pH value suitable for the water treatment synergistic system is 5-9.

[0017] Furthermore, the water treatment synergistic system achieves a removal rate of over 90% for organic pollutants in water within 3-5 minutes.

[0018] Furthermore, when the water treatment synergistic system is running under continuous operating conditions, it maintains a removal rate of over 90% for organic pollutants in the water body for 100 hours.

[0019] Furthermore, the organic pollutant is sulfamethoxazole.

[0020] Furthermore, the water in the water treatment synergistic system contains humic acid at a concentration not exceeding 10 mg / L;

[0021] And / or, the water body contains Cl at a concentration of not less than 3 mM. - ;

[0022] And / or, the water body contains NO3. - and / or SO4 2- .

[0023] Furthermore, the cobalt-loaded peanut shell biomaterial is prepared by the following method:

[0024] Peanut shell biochar was dispersed in a cobalt salt aqueous solution and subjected to a hydrothermal reaction. After the reaction was completed, the product was dried to obtain a solid product. The solid product was then pyrolyzed in an inert atmosphere to obtain the cobalt-supported peanut shell biochar.

[0025] Furthermore, the mass ratio of the peanut shell biochar to cobalt salt is 1:(4-5).

[0026] Furthermore, the concentration of the cobalt salt aqueous solution is 0.09M.

[0027] Furthermore, the cobalt salt is CoCl2·6H2O.

[0028] Furthermore, the hydrothermal reaction conditions include a reaction temperature of 65℃-75℃ and a reaction time of 3-5h; preferably, the hydrothermal reaction conditions are a reaction temperature of 70℃ and a reaction time of 4h.

[0029] Furthermore, the drying conditions include a drying temperature of 75℃-85℃ and a drying time of 10-14h; preferably, the drying conditions are a drying temperature of 80℃ and a drying time of 12h.

[0030] Furthermore, the conditions for heating and pyrolysis include heating to 750-850°C at a heating rate of 4-6°C / min and holding at that temperature for 2-4 hours; preferably, the conditions for heating and pyrolysis are heating to 800°C at a heating rate of 5°C / min and holding at that temperature for 3 hours.

[0031] Furthermore, the product after pyrolysis is washed repeatedly with ethanol and ultrapure water until the washing liquid is neutral, and then dried to obtain the cobalt-supported peanut shell biochar.

[0032] Furthermore, the preparation method of the peanut shell biochar includes: placing peanut shell powder in an inert atmosphere and heating it to pyrolyze to obtain peanut shell biochar powder; repeatedly washing the obtained peanut shell biochar powder with ultrapure water until neutral, and drying it to obtain the peanut shell biochar.

[0033] Furthermore, the peanut shell powder has a particle size of 180-220 mesh.

[0034] Furthermore, the pyrolysis conditions in the preparation method of peanut shell biochar include heating to 650-750℃ at a heating rate of 4-6℃ / min and pyrolysis for 1.5-3 hours.

[0035] Furthermore, the drying conditions in the preparation method of peanut shell biochar include a drying temperature of 75-85℃ and a drying time of 2-4h.

[0036] Secondly, this application provides a method for degrading organic pollutants based on a cobalt-supported peanut shell biochar / peracetic acid water treatment synergistic system, using the cobalt-supported peanut shell biochar / peracetic acid water treatment synergistic system described in the first aspect, comprising the following steps:

[0037] Cobalt-loaded peanut shell biochar and peracetic acid were added to water containing organic pollutants to prepare a synergistic water treatment system for cobalt-loaded peanut shell biochar / peracetic acid, which was then subjected to catalytic oxidation reaction.

[0038] Furthermore, the organic pollutant is sulfamethoxazole.

[0039] Furthermore, in the catalytic oxidation reaction, the initial concentration of organic pollutants is 1-10 mg / L.

[0040] Furthermore, the initial mass ratio of the cobalt-loaded peanut shell biochar to the organic pollutant is (5-500):1; preferably, the initial mass ratio of the cobalt-loaded peanut shell biochar to the organic pollutant is (10-200):1; more preferably, the initial mass ratio of the cobalt-loaded peanut shell biochar to the organic pollutant is 40:1.

[0041] Further, the initial mass ratio of peracetic acid to the organic pollutant is (0.3-20):1; preferably, the initial mass ratio of peracetic acid to the organic pollutant is (0.7-16):1; more preferably, the initial mass ratio of peracetic acid to the organic pollutant is 3:1.

[0042] Furthermore, the pH value of the catalytic oxidation reaction is 5-9.

[0043] Furthermore, the temperature of the catalytic oxidation reaction is 20-30℃.

[0044] Furthermore, in the catalytic oxidation reaction, cobalt-supported peanut shell biochar activates peracetic acid to generate CH3C(O)O• free radicals, •OH free radicals, CH3C(O)OO• free radicals, and O2. •- free radicals and 1 O2 is a non-free radical.

[0045] Furthermore, the catalytic oxidation reaction achieves a removal rate of over 90% for sulfamethoxazole within 3-5 minutes.

[0046] Furthermore, when the catalytic oxidation reaction is operated continuously, the removal rate of sulfamethoxazole remains above 90% for 100 hours.

[0047] Furthermore, sulfamethoxazole produces degradation products with the following structures:

[0048] , , , , , , , , , , .

[0049] Thirdly, this application provides the application of the first aspect of the cobalt-supported peanut shell biochar / peracetic acid water treatment synergistic system or the second aspect of the method for degrading organic pollutants based on the cobalt-supported peanut shell biochar / peracetic acid water treatment synergistic system in water treatment.

[0050] Compared with the prior art, this application includes the following beneficial technical effects:

[0051] The cobalt-loaded peanut shell biochar / peracetic acid water treatment synergistic system provided in this application can achieve a degradation and removal rate of over 90% for 5 mg / L sulfamethoxazole in just 3-5 minutes under near-neutral conditions, demonstrating excellent reaction rate.

[0052] Co in this application cobalt-loaded peanut shell biochar 0 Co 2+ Co 3+ Multiple valence states coexist, exhibiting strong interactions with the conjugated π system and surface oxygen-containing functional groups (C=O, CO) of peanut shell biochar. This structure not only promotes the co-oxidation of Co... 2+ / Co 3+ The efficient redox cycle of peanut shell biochar effectively activates peracetic acid to generate free radicals such as CH3C(O)OO•; simultaneously, the surface functional groups and mesoporous structure of peanut shell biochar can also directly activate peracetic acid to generate ¹O2 and O2. •- These reactive species form free radicals (•OH, CH3C(O)OO•, CH3C(O)O•, O2). •- The synergistic degradation mechanism of cobalt-loaded peanut shell biochar / peracetic acid water treatment system is the key reason for its high efficiency.

[0053] The cobalt-supported peanut shell biochar / peracetic acid water treatment synergistic system provided in this application maintains high degradation activity over a wide pH range (5-9), and is effective against common Cl- in water. - NO3 - SO4 2- The catalyst exhibits good tolerance to anions. Its activity decreases only slightly after multiple cycles, and it maintains high efficiency and stability in continuous flow dynamics experiments over a long period, demonstrating good potential for practical applications.

[0054] The cobalt-loaded peanut shell biochar / peracetic acid water treatment synergistic system provided in this application degrades sulfamethoxazole, and most of the intermediate products are less toxic than the parent compound. ECOSAR model predictions indicate a reduction in overall environmental risk. This provides a promising technical solution for the safe and efficient treatment of antibiotic-contaminated water.

[0055] The cobalt-loaded peanut shell biochar / peracetic acid water treatment synergistic system provided in this application shows excellent removal effects on a variety of recalcitrant organic pollutants and has wide applicability.

[0056] This application successfully prepared cobalt-loaded peanut shell biochar using agricultural waste peanut shells as raw material via a hydrothermal combined with high-temperature heat treatment method, realizing the resource utilization of waste. The process is simple and low-cost. The cobalt-loaded peanut shell biochar has a high cobalt loading, and the cobalt species exhibits extremely high dispersibility, providing highly active sites for activating oxidants. Strong chemical bonds such as Co-C, Co-OC, or Co-O-Si are formed between the cobalt species and the carbon support, firmly binding the high cobalt content to the carbon framework. The peanut shell biochar also has high lignin and silicon content, and abundant mesopores, which strongly adsorb Co during the hydrothermal reaction. 2+ This improves the loading capacity, significantly inhibits the leaching of active cobalt species, exhibits high stability, avoids secondary pollution, and demonstrates good environmental compatibility and practical application potential. Biochar, as a carrier, provides high specific surface area and conductivity, promotes electron transfer, and can adsorb and enrich pollutants, thereby increasing the local reaction concentration. Cobalt-loaded peanut shell biochar has a stable structure, enhancing its catalytic efficiency for peracetic acid.

[0057] In summary, this application provides a cobalt-loaded peanut shell biochar / peracetic acid water treatment synergistic system. When this synergistic system is used to activate peracetic acid to degrade sulfamethoxazole, the reaction is rapid under near-neutral conditions, with a removal rate exceeding 90% within 3-5 minutes. Mechanistic studies show that this synergistic system utilizes Co... 2+ / Co 3+ The redox cycle and the synergistic activation of the peanut shell biochar surface generated free radicals (•OH, CH3C(O)OO•, CH3C(O)O•, O2). •- This study describes a highly efficient degradation pathway that utilizes the synergistic effect of sulfamethoxazole and non-radical (¹O2). The synergistic system exhibits good stability, a wide pH range adaptability, and strong anti-interference capabilities. It demonstrates excellent performance in continuous flow experiments and effectively reduces the environmental toxicity of sulfamethoxazole degradation products. This provides an efficient, economical, and green solution for antibiotic wastewater treatment and shows excellent removal effects on various recalcitrant organic pollutants, making it widely applicable. Attached Figure Description

[0058] The present application will be described in further detail below with reference to the accompanying drawings and preferred embodiments. However, those skilled in the art will understand that these drawings are drawn only for the purpose of explaining the preferred embodiments and therefore should not be construed as limiting the scope of this disclosure. Furthermore, unless specifically indicated, the drawings are only schematic representations of the composition or structure of the described objects and may contain exaggerated depictions, and the drawings are not necessarily drawn to scale.

[0059] Figure 1 The effects of different reaction conditions on the degradation of sulfamethoxazole are shown in the following figures: (a) shows the effect of the amount of cobalt-supported peanut shell biochar on the degradation of sulfamethoxazole; (b) shows the effect of the initial concentration of sulfamethoxazole on the degradation of sulfamethoxazole; (c) shows the effect of the initial concentration of peracetic acid on the degradation of sulfamethoxazole; (d) shows the effect of pH on the degradation of sulfamethoxazole; (e) shows the effect of humic acid concentration on the degradation of sulfamethoxazole; and (f) shows the effect of different inorganic anions on the degradation of sulfamethoxazole.

[0060] Figure 2 The graph shows the effect of different concentrations of inorganic anions on the degradation of sulfamethoxazole.

[0061] Figure 3 This is a schematic diagram of a continuous flow experimental setup for a small column.

[0062] Figure 4 Figure 1 shows the results of a continuous flow experiment on a cobalt-loaded peanut shell biochar / peracetic acid synergistic water treatment system.

[0063] Figure 5 The diagram shows the effect of the cobalt-loaded peanut shell biochar / peracetic acid water treatment synergistic system under different water quality substrates.

[0064] Figure 6 Figure 1 shows the results of a free radical quenching experiment used to detect active species; where (a) the free radical quencher is methanol; (b) the free radical quencher is tert-butanol; (c) the free radical quencher is 2,4-hexadiene; (d) the free radical quencher is L-histidine; (e) the free radical quencher is furfuryl alcohol; and (f) the free radical quencher is p-benzoquinone; the reaction conditions were: initial cobalt-loaded peanut shell biochar concentration 200 mg / L, initial peracetic acid concentration 0.2 mM, initial sulfamethoxazole concentration 5 mg / L, initial pH 6.8, and temperature 25℃.

[0065] Figure 7 The graph shows the concentration changes of methyl phenyl sulfoxide and its oxidation product PMSO2 in the cobalt-supported peanut shell biochar / peracetic acid water treatment synergistic system.

[0066] Figure 8 A diagram showing the degradation pathway of sulfamethoxazole in a cobalt-supported peanut shell biochar / peracetic acid water treatment synergistic system; where (a) represents the electrostatic potential distribution; (b) represents the highest occupied molecular orbital and the lowest unoccupied molecular orbital; and (c) represents the degradation pathway of sulfamethoxazole in the cobalt-supported peanut shell biochar / peracetic acid water treatment synergistic system.

[0067] Figure 9The median lethal concentrations (LD50) for the cobalt-loaded peanut shell biochar / peracetic acid water treatment synergistic system are shown in the diagrams. (a) represents the acute toxicity to fish; (b) represents the 48-hour median lethal concentration for Daphnia davidii, representing the acute toxicity to Daphnia davidii; (c) represents the 48-hour median lethal concentration for Chlorella spp., representing the acute toxicity to Chlorella spp.; (d) represents the chronic toxicity to fish; (e) represents the chronic toxicity to Daphnia davidii; and (f) represents the chronic toxicity to Chlorella spp. Detailed Implementation

[0068] The following is in conjunction with the appendix Figures 1 to 9 This application will be described in detail.

[0069] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0070] Chemicals and reagents

[0071] The peanut shells were purchased from Taobao.

[0072] Cobalt chloride hexahydrate, sodium hydroxide (NaOH), sodium thiosulfate pentahydrate (Na2S2O3·5H2O), hydrochloric acid (HCl), sodium sulfate (Na2SO4), sodium nitrate (NaNO3), sodium chloride (NaCl), sodium phosphate (Na3PO4), and sodium bicarbonate (NaHCO3) were purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China).

[0073] Humic acid (HA), 2,4-hexadiene (2,4-HD) and dimethyl sulfoxide (DMSO) were supplied by Maclean Biochemical Co., Ltd. (Shanghai, China).

[0074] tert-butanol (TBA), p-benzoquinone (C6H4O2, p-BQ), peracetic acid compound disinfectant (CH3COOOH, PAA), histidine (L-HD), and formic acid (≥98%, HCOOH) were purchased from Aladdin Biochemical Technology Co., Ltd. (Shanghai, China).

[0075] Methanol (CH3OH, MeOH) and acetonitrile (ACN) were purchased from Fisher Scientific (USA).

[0076] Wahaha purified water is purchased from Yichang Wahaha Qili Food Co., Ltd. (Yichang, China).

[0077] Ultrapure water was prepared using the Milli-Q IQ 7000 system.

[0078] Except for peracetic acid disinfectant, all chemicals used in the experiment were of analytical grade and could be used directly without purification. Excess catalase was used to quench H2O2 in the peracetic acid disinfectant, and the concentration of the peracetic acid solution was determined according to the national standard method (GB / T19104–2021).

[0079] Unless otherwise specified, all other reagents used in the embodiments of this application are from conventional commercially available products.

[0080] Detection methods

[0081] Sulfamethoxazole concentration determination

[0082] The concentration of sulfamethoxazole was determined using a Shimadzu ultra-high performance liquid chromatography-triple quadrupole mass spectrometry (LC-MS / MS, model LC20AD, 8045, Shimadzu Corporation, Japan). LC conditions: Separation was performed using a C18 column (3 μm, 2.1 × 100 mm) with isocratic elution (mobile phase A (water containing 0.1% formic acid) 70%, mobile phase B (acetonitrile) 30%), flow rate 0.3 mL / min, column temperature 35 °C.

[0083] Mass spectrometry conditions: ESI ion source, positive ion mode; parent ion m / z 254.1, daughter ions m / z 92 (collision energy -28V) and m / z 156 (collision energy -16V). Injection volume 2 μL, retention time 4 min.

[0084] Screening and identification of sulfamethoxazole conversion products

[0085] The transformation products of sulfamethoxazole were screened and identified using ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS, model 1290UPLC, 6545B Q-TOF MS, Agilent Technologies, USA). An Acquity BEH C18 column (2.1 mm × 100 mm, 1.7 μm) was used. HPLC conditions: mobile phase A was acetonitrile, and mobile phase B was 0.1% formic acid aqueous solution; column temperature 30℃; flow rate 0.4 mL / min; injection volume 10 µL. Elution program: 0–2.0 min, 3% A; 2.0–14.0 min, 3%–100% A; 14.0–15.0 min, 100% A; 15.0–15.5 min, 100%–3% A; 15.5–18.0 min, 3% A. Mass spectrometry conditions: Ion source was electrospray ionization (ESI+); monitoring mode was MSE mode; mass scan range m / z 50–500; capillary voltage 3.0 kV; cone voltage 30 V; ion source temperature 120 °C; desolvation gas temperature 450 °C; cone gas flow rate 10 L / h; desolvation gas flow rate 800 L / h. Mass Hunter workstation software (Agilent) was used for instrument control and data acquisition / analysis.

[0086] Characterization methods

[0087] The material morphology was analyzed using a field emission scanning electron microscope (SEM, model SU8230, Hitachi Regulus, Japan).

[0088] Specific surface area and pore size distribution were determined by nitrogen physical adsorption (BET, model ASAP 2460, McMurray, USA).

[0089] Phase structure data were acquired using an X-ray diffractometer (XRD, model X'Pert Pro MPD, SmartLab, Japan).

[0090] The structural defects and stability of the material were analyzed using a high-resolution Raman spectrometer (Raman, model LabRAM HR evolution, Horiba, France).

[0091] Density functional theory calculations

[0092] All density functional theory-based calculations were performed using the Gaussian 09W software package. The molecular structure of sulfamethoxazole was constructed using GaussView 5.0. The geometric structure, frequency analysis, and energy calculation of sulfamethoxazole were performed using B3LYP functionals combined with the 6-31+G(d) basis set and with the introduction of Grimme empirical dispersion correction. All calculations used an integral equation form polarized continuum model (IEF-PCM) with water as the solvent to account for solvation effects. The optimized molecular structure was analyzed using the Multiwfn program. The electrostatic potential distribution and isosurface plots of the highest occupied molecular orbitals and the lowest unoccupied molecular orbitals were obtained using Visual Molecular Dynamics (VMD) software. In addition, the Fukui function was calculated using the Multiwfn program to predict the active sites of the molecule that are susceptible to electrophilic, nucleophilic, and free radical attacks. The expression of the Fukui function is shown in Eqs.(1), and its condensed form can be calculated using Eqs.(2)-(4). In the condensed Fukui function, the atomic population is used to characterize the distribution of electron density around an atom.

[0093]

[0094] in, ρ (r) represents the electron density at point r in space, N is the total number of electrons in the current system, and ν is the external potential. A ƒ represents the atomic charge of atom A in the corresponding state. A The Fukui function value representing atom A.

[0095] The specific implementation method of this application is as follows. Example 1

[0096] This embodiment provides a method for preparing cobalt-supported peanut shell biochar, as detailed below:

[0097] Peanut shell powder of 200 mesh was placed in a nitrogen atmosphere and heated to 700°C at a heating rate of 5°C / min for 2 hours. The resulting biochar powder was repeatedly washed with ultrapure water until neutral and then dried at 80°C for 3 hours to obtain peanut shell biochar.

[0098] 0.5 g of peanut shell biochar was uniformly dispersed in 100 mL of 0.09 M CoCl2·6H2O solution at a mass ratio of 1:4.28 to cobalt salt. The reaction was carried out under continuous magnetic stirring (70 °C, 4 h). Subsequently, the product was dried at 80 °C for 12 h to obtain a solid product, which was then pyrolyzed at 800 °C for 3 h under a nitrogen atmosphere at a heating rate of 5 °C / min. The product was then washed sequentially with ethanol and ultrapure water (3 times each) until the washings were neutral. Finally, it was vacuum dried at 80 °C for 8 h to obtain cobalt-supported peanut shell biochar. Example 2

[0099] This embodiment provides a method for degrading organic pollutants based on a cobalt-loaded peanut shell biochar / peracetic acid water treatment synergistic system.

[0100] A 5 mg / L sulfamethoxazole solution was placed in a 250 mL glass reactor. 200 mg / L of cobalt-supported peanut shell biochar prepared in Example 1 was added as a catalyst, bringing the total concentration in the reactor to 200 mg / L. The reactor was magnetically stirred at a constant speed of 500 rpm at 25 °C, and the pH was adjusted to 6.8. 0.2 mM peracetic acid solution was added to initiate the reaction. The total volume of the reaction system was 200 mL. Samples were taken periodically using a precision pipette, 1 mL each time. Immediately after sampling, the reaction was quenched with 50 μL of 0.1 M Na₂S₂O₃ solution, and the sample was filtered through a 0.22 μm needle filter before analysis. Used cobalt-supported peanut shell biochar was collected by centrifugation, thoroughly rinsed with ultrapure water, and dried in a vacuum oven at 60 °C for subsequent reuse. In Example 2, the mass ratio of cobalt-loaded peanut shell biochar to peracetic acid was 13.1:1, the mass ratio of cobalt-loaded peanut shell biochar to sulfamethoxazole was 40:1, and the mass ratio of peracetic acid to sulfamethoxazole was 3.0:1.

[0101] XPS analysis was performed on the peanut shell biochar prepared in Example 1, the cobalt-loaded peanut shell biochar prepared in Example 1, and the used cobalt-loaded peanut shell biochar collected in Example 2. The results are shown in Table 1.

[0102] Table 1. Elemental composition based on XPS analysis (atomic percentage, %)

[0103]

[0104] Table 1 shows that the Co atomic percentage in the cobalt-supported peanut shell biochar composite is as high as 12.75%, and the atomic ratio of cobalt to C is 0.258:1, which directly confirms the successful loading of a high cobalt content. Simultaneously, the C content decreases to 49.39%, and the O content increases to 30.99%, indicating that cobalt mainly exists in the form of oxides / hydroxides, and additional oxygen is introduced. In the used cobalt-supported peanut shell biochar composite, the Co content decreases from 12.75% to 6.80%, which is not a simple leaching process. The C content rebounds to 60.36%, and the O content decreases to 26.05%. This is attributed to the consumption or transformation of unstable, high-valence cobalt species on the surface during the reaction, while exposing more carbon substrate, and changes in the oxygen-containing functional groups on the carbon substrate surface. It is also noteworthy that approximately 53% of Co is retained (6.80 / 12.75), indicating that the material has good structural stability and that the active components are not easily completely lost.

[0105] The specific surface area and pore volume of the peanut shell biochar prepared in Example 1 and the cobalt-supported peanut shell biochar were tested in this application, and the results are shown in Table 2.

[0106] Table 2. Specific surface area and pore volume characterization results of cobalt-supported peanut shell biochar

[0107]

[0108] This embodiment, based on Example 2, investigated the effect of cobalt-supported peanut shell biochar dosage on the degradation of sulfamethoxazole in the cobalt-supported peanut shell biochar / peracetic acid synergistic system. Except for the dosage of cobalt-supported peanut shell biochar, all other parameters were the same as in Example 2. The dosages of cobalt-supported peanut shell biochar were 50 mg / L, 100 mg / L, 200 mg / L, 350 mg / L, and 500 mg / L. The results of Example 3 are as follows: Figure 1 As shown in (a).

[0109] The mass ratios of cobalt-loaded peanut shell biochar, peracetic acid, and sulfamethoxazole in Example 3 are shown in Table 3.

[0110] Table 3

[0111]

[0112] Example 4

[0113] This example, based on Example 2, investigated the effect of the initial concentration of sulfamethoxazole on the degradation of sulfamethoxazole in a cobalt-supported peanut shell biochar / peracetic acid synergistic system. Except for the initial concentration of sulfamethoxazole, all other parameters were the same as in Example 2. The initial concentrations of sulfamethoxazole were 1 mg / L, 3 mg / L, 5 mg / L, 8 mg / L, and 10 mg / L. The results of Example 4 are as follows: Figure 1 As shown in (b).

[0114] Example 4: The mass ratios of peanut shell biochar supported on sulfamethoxazole, peracetic acid, and cobalt are shown in Table 4.

[0115] Table 4

[0116]

[0117] Example 5

[0118] This example, based on Example 2, investigated the effect of the initial concentration of peracetic acid on the degradation of sulfamethoxazole by the cobalt-supported peanut shell biochar / peracetic acid synergistic system. Except for the initial concentration of peracetic acid, all other parameters were the same as in Example 2. The initial peracetic acid concentrations were 0.05 mM, 0.10 mM, 0.15 mM, 0.20 mM, and 0.25 mM, respectively. The results of Example 5 are as follows: Figure 1 As shown in (c).

[0119] Example 5: The mass ratios of peanut shell biochar supported on peracetic acid, sulfamethoxazole, and cobalt are shown in Table 5.

[0120] Table 5

[0121]

[0122] Example 6

[0123] This example, based on Example 2, investigated the effect of the initial pH value of the reaction system on the degradation of sulfamethoxazole by the cobalt-supported peanut shell biochar / peracetic acid synergistic system. Except for the initial pH value, all other parameters were the same as in Example 2, with initial pH values ​​of 3, 5, 7, 9, and 11. The results of Example 7 are as follows. Figure 1 As shown in (d).

[0124] Example 7

[0125] This example, based on Example 2, uses humic acid as a model substance to evaluate the effect of naturally occurring organic matter commonly found in actual water bodies on the degradation of sulfamethoxazole by a cobalt-loaded peanut shell biochar / peracetic acid synergistic system. All other parameters are the same as in Example 2, with humic acid concentrations of 0, 1, 3, 5, and 10 mg / L. The results of Example 7 are as follows: Figure 1 As shown in (e).

[0126] Example 8

[0127] This example, based on Example 2, evaluates the effects of common inorganic anions on the degradation of sulfamethoxazole in a cobalt-supported peanut shell biochar / peracetic acid synergistic system. All other parameters are the same as in Example 2, except that the inorganic anion is PO42-.- NO3 - SO4 2- CO3 2- HCO3 - Cl - The concentrations of the added inorganic anions were 0 mM, 0.5 mM, 1 mM, 3 mM, and 5 mM. The results of Example 8 are as follows: Figure 1 (f) and Figure 2 As shown.

[0128] like Figure 1 As shown in Figure (a), within 3 minutes, as the dosage of cobalt-supported peanut shell biochar increased from 50 mg / L to 350 mg / L, the degradation efficiency of sulfamethoxazole in the cobalt-supported peanut shell biochar / peracetic acid synergistic system significantly increased from 33.5% to 91.2%. When the dosage of cobalt-supported peanut shell biochar was further increased to 500 mg / L, the degradation rate of sulfamethoxazole did not change significantly. This may be because more catalyst provides more active sites to promote peracetic acid activation, while excessive cobalt-supported peanut shell biochar leads to catalyst aggregation, making the promoting effect less significant. Figure 1 Figure (b) illustrates the effect of sulfamethoxazole concentration on the cobalt-supported peanut shell biochar / peracetic acid synergistic system. As the sulfamethoxazole concentration increased from 1 mg / L to 10 mg / L, the degradation efficiency of the system significantly decreased from 99.7% to 50.2% within 4 minutes. Sulfamethoxazole and its intermediates may adsorb onto the surface of the cobalt-supported peanut shell biochar catalyst, occupying limited active sites and thus hindering peracetic acid activation. Furthermore, under constant peracetic acid and cobalt-supported peanut shell biochar catalyst dosages, the number of active species generated in the system is limited. Therefore, increasing the sulfamethoxazole concentration may lead to significant competition for these limited active species. Meanwhile, as... Figure 1 (c) illustrates the effect of peracetic acid concentration on the degradation of sulfamethoxazole. When the peracetic acid concentration increased from 0.05 mM to 0.25 mM, the degradation rate of sulfamethoxazole in the system increased from 49.9% to 96.6% within 4 minutes. The increase in peracetic acid concentration can promote the generation of highly reactive free radicals such as •OH, CH3C(O)OO• and CH3C(O)O• in the cobalt-supported peanut shell biochar / peracetic acid system, thereby accelerating the efficient degradation of sulfamethoxazole (Eqs.(5)–(7)). Based on the above results and practical economic considerations, the experimental conditions of 200 mg / L cobalt-supported peanut shell biochar, 0.20 mM peracetic acid, and 5 mg / L sulfamethoxazole were selected as the experimental conditions for the study.

[0129]

[0130] In a cobalt-loaded peanut shell biochar / peracetic acid system, at initial pH values ​​of 3, 5, 7, 9, and 11, the degradation efficiencies of sulfamethoxazole within 4 minutes were 25.3%, 89.8%, 90.1%, 63.8%, and 10.8%, respectively (e.g., ...). Figure 1 (d) . Under the condition of an initial pH of 3, excess H+ + It can form hydrogen bonds with the O–O groups of peracetic acid, enhancing intermolecular forces and stabilizing the peracetic acid structure, thereby inhibiting the activation of peracetic acid. When pH=5, Co... 2+ It can be converted to CoOH + This activates peracetic acid to generate free radicals, thus promoting the reaction (Eqs. (8)–(9)). Therefore, the degradation efficiency of sulfamethoxazole is optimal before 3 minutes. Under pH=7 conditions, the degradation efficiency decreases, at which point intermolecular interactions dominate the degradation pathway. In an alkaline environment, both peracetic acid and sulfamethoxazole exist in anionic form, and electrostatic repulsion inhibits the direct oxidation of sulfamethoxazole. At the same time, OH... - It will inhibit the generation of free radicals, further reducing the degradation efficiency of sulfamethoxazole.

[0131]

[0132] As the concentration of humic acid (based on total organic carbon) increased from 0 mg / L to 10 mg / L, the degradation efficiency of sulfamethoxazole decreased from 90.1% to 69.8% (e.g., Figure 1 (e)). This inhibitory effect stems from a dual mechanism: (1) humic acid consumes CH3C(O)OO• free radicals; (2) it competes with peracetic acid for catalyst active sites, thereby inhibiting peracetic acid activation. The effects of common inorganic anions on the degradation of sulfamethoxazole in the cobalt-supported peanut shell biochar / peracetic acid system were further investigated. Figure 1 (f) and Figure 2 Cl - (0.5–1 mM, Figure 2 (f) exhibits an inhibitory effect due to the scavenging of free radicals (CH3C(O)OO• + Cl) - → Cl•), while at higher concentrations (3 and 5 mM), a stable sulfamethoxazole removal rate (approximately 79.5%) can still be maintained by generating active chlorine species (Eqs. (10)–(12)). HCO3 - The presence of [a specific substance] significantly inhibited the degradation of sulfamethoxazole, with its removal rate decreasing from 90.9% in the control group to 60% (5 mM). Notably, the system formed CO3 within 50 seconds. •- (HCO3 - → CO3 •- →CH3C(O)OO -A brief acceleration occurs due to the free radical's oxidation potential being higher than that of •OH. The subsequent equilibrium state arises from free radical quenching (Eqs. (13)–(14)). Furthermore, CO32-... 2- By removing •OH (CO3) 2- + •OH → CO3 •- +OH - The degradation of sulfamethoxazole was inhibited in a concentration-dependent manner (Eqs. (15)–(16)), and the inhibition was further aggravated by an increase in pH. NO3... - and SO4 2- The impact is negligible (sulfamethoxazole removal rate remains above 85%), PO4 3- It significantly inhibits the degradation of sulfamethoxazole, possibly because it interferes with the degradation of Co. 2+ / Co 3+ Caused by redox cycle.

[0133]

[0134] Example 9

[0135] This embodiment conducts a continuous flow experiment on the degradation of organic pollutants based on a cobalt-supported peanut shell biochar / peracetic acid water treatment synergistic system to investigate the long-term potential stability of the cobalt-supported peanut shell biochar / peracetic acid water treatment synergistic system under dynamic conditions.

[0136] Continuous column experiments were conducted using a miniature packed column (1.0 cm inner diameter × 30 cm height). A schematic diagram of the apparatus is shown below. Figure 3 The bottom of the column was first filled with silica sand as a support layer, followed by the loading of 1 g of cobalt-supported peanut shell biochar catalyst, which was then compacted with silica sand. Cotton layers were placed at the top and bottom of the packing to prevent particle leakage during operation. A mixture of peracetic acid and sulfamethoxazole was pumped into the column in a continuous upflow mode, flowing through the cobalt-supported peanut shell biochar catalyst. The column flow rate was controlled at 1.0 mL / min by adjusting a peristaltic pump.

[0137] The results of the continuous flow experiment in Example 9 of this application are as follows: Figure 4 As shown, under the conditions of a flow rate of 1 mL / min, a catalyst dosage of 1 g cobalt-supported peanut shell biochar, and a sulfamethoxazole concentration of 5 mg / L, the cobalt-supported peanut shell biochar / peracetic acid water treatment synergistic system maintained a sulfamethoxazole removal efficiency of over 90% for 100 hours, highlighting the long-term potential stability of the cobalt-supported peanut shell biochar / peracetic acid system under dynamic conditions.

[0138] Example 10

[0139] This embodiment, based on Embodiment 2, uses water samples from actual local water sources for experiments. These actual water sources include lake water, river water, secondary sedimentation tank water, tap water, and purified water. The results of the experiments using actual local water source samples in Embodiment 10 of this application are as follows: Figure 5 As shown, by Figure 5 It can be seen that although the efficiency is somewhat reduced due to the free radical quenching effect mediated by natural organic matter, the cobalt-supported peanut shell biochar / peracetic acid synergistic system for water treatment can still maintain a sulfamethoxazole removal efficiency of over 80%. This competitive performance in complex matrices demonstrates the practical application potential of the cobalt-supported peanut shell biochar / peracetic acid synergistic system in the remediation of antibiotic wastewater.

[0140] Example 11

[0141] To clarify the role of active species in the cobalt-supported peanut shell biochar / peracetic acid synergistic system, a free radical quenching experiment was conducted. A 5 mg / L sulfamethoxazole solution was placed in a 250 mL glass reactor, and a 0-10 mM free radical quencher was added. Cobalt-supported peanut shell biochar prepared in Example 1 was then added as a catalyst, bringing the total concentration in the reactor to 200 mg / L. The reactor was magnetically stirred at a constant speed of 500 rpm at 25 °C, and the pH was adjusted to 6.8. 0.2 mM peracetic acid solution was added to initiate the reaction. The total volume of the reaction system was 200 mL. Samples were taken periodically using a precision pipette, 1 mL each time. Immediately after sampling, the reaction was quenched with 50 μL of 0.1 M Na₂S₂O₃ solution, and the samples were filtered through a 0.22 μm needle filter before analysis. The concentrations of the free radical quenchers were 0 mM, 1 mM, 3 mM, 5 mM, and 10 mM, and the free radical quenchers were methanol, tert-butanol, 2,4-hexadiene, L-histidine, furfuryl alcohol, and p-benzoquinone, respectively.

[0142] The results of the free radical quenching experiment are as follows Figure 6 As shown, by Figure 6 tert-butanol is a quencher of •OH (k [•OH] =6×10 8 M -1 s -1 Methanol can quench both •OH and RO• free radicals. Meanwhile, 2,4-hexadiene is the main quencher of RO•. Figure 6 As shown in (a), when 10 mM methanol was added to the cobalt-supported peanut shell biochar / peracetic acid synergistic system, the degradation efficiency of sulfamethoxazole decreased from 90.1% to 60.1% within 4 minutes, demonstrating that the free radicals •OH, CH3C(O)OO•, and CH3C(O)O• may have participated in the reaction. After adding 10 mM tert-butanol (… Figure 6In (b), the degradation efficiency of sulfamethoxazole was slightly inhibited (from 90.1% to 81.9%), indicating that the •OH radical plays a minor role in the cobalt-supported peanut shell biochar / peracetic acid synergistic system. Meanwhile, 10 mM 2,4-hexadiene significantly inhibited the degradation efficiency of sulfamethoxazole (from 90.1% to 72.4%). Figure 6 (c) indicates the presence of CH3C(O)OO• and CH3C(O)O• free radicals in the system. Furthermore, CH3C(O)O• can further react with peracetic acid to generate CH3C(O)OO• (Eqs. (7)), confirming that CH3C(O)OO• and •OH jointly drive the degradation of sulfamethoxazole.

[0143] To further clarify 1 O2 and O2 •- The role of cobalt-loaded peanut shell biochar / peracetic acid system was investigated using specific quenching agents: L-histidine and furfuryl alcohol. 1 O2, p-benzoquinone is used to quench O2. •- After adding 10 mM L-histidine and furfuryl alcohol ( Figure 6 In (d) and (e) of the study, the degradation efficiency of sulfamethoxazole decreased sharply from 90.1% to 10.9% and 13.2%, respectively, confirming that... 1 The crucial role of O2 in the cobalt-supported peanut shell biochar / peracetic acid synergistic system. Furthermore, the addition of 10 mM p-benzoquinone significantly inhibited the degradation of sulfamethoxazole to 15.6% (from 90.1%). Figure 6 (f) proves O2 •- It plays an important role in the cobalt-supported peanut shell biochar / peracetic acid synergistic system.

[0144] Example 12

[0145] This embodiment, based on Example 2, further uses methyl phenyl sulfoxide (PMSO) as a probe to verify Co. 4+ Potential role of cobalt-supported peanut shell biochar / peracetic acid synergistic system, reaction conditions: cobalt-supported peanut shell biochar 200 mg / L, peracetic acid 0.2 mM, PMSO 5 mg / L, pH 6.8, temperature 25℃, results as follows. Figure 7 As shown, no PMSO2 was detected after adding PMSO, indicating that Co was not present. 4+ The remaining conditions are the same as in Example 2.

[0146] In summary, the quenching experiments in Examples 11 and 12 jointly demonstrate the presence of [a specific substance] in the cobalt-supported peanut shell biochar / peracetic acid synergistic system. 1 O2, O2 •-The synergistic effect of CH3C(O)OO• and •OH.

[0147] Degradation pathway and toxicity assessment

[0148] Density functional theory calculations were used to determine the active sites of sulfamethoxazole molecules to further deduce its possible degradation pathway in a cobalt-supported peanut shell biochar / peracetic acid synergistic system. The electrostatic potential distribution of sulfamethoxazole (e.g., Figure 8 As shown in (a), the negatively charged region is mainly concentrated around N11, S14, and O15 and O16 centered on S14. In the sulfamethoxazole molecule, the lowest unoccupied molecular orbitals mainly cover the cationic sulfur center (S14) and the electronegative N11 atom region, while the highest occupied molecular orbitals span the aniline ring system and SN bonds, exhibiting high electron density at the nucleophilic sites N11, N17, and ortho / meta carbon atoms (C1, C3, C5). Figure 8 (as shown in (b)).

[0149] Since the frontier molecular orbitals and electrostatic potential distributions have limited accuracy in identifying atomic site sensitivity, this study further used the Fukui function to evaluate the regioselectivity of sulfamethoxazole (as shown in Table 6).

[0150] Table 6. Fukui function index of sulfamethoxazole

[0151]

[0152] The calculated Fukui index ( f + , f - , f 0 The values ​​() respectively map the sites on the molecule that are susceptible to nucleophilic, electrophilic, and free radical attacks; higher values ​​indicate stronger reactivity. As shown in Table 6, the high values ​​at C1-C6 and N11 sites... f - and f 0 The values ​​indicate that the aniline group is more susceptible to attack than heterocyclic substituents. Notably, the N11 site exhibits the highest [value / value]. f - and f 0 The values ​​were identified as the main targets for electrophilic and free radical attacks. Therefore, DFT calculations identified C1, C3, C5, and N11 as the most electrophilic / free radical-vulnerable atomic sites in the sulfamethoxazole molecule, while the SN bond showed high susceptibility to breakage in subsequent degradation steps.

[0153] The results of DFT calculations are combined with the UPLC-TOF-MS analysis data, which are shown in Table 7.

[0154] Table 7. Sulfamethoxazole degradation intermediates identified by UPLC-TOF MS

[0155]

[0156] Based on DFT calculations and UPLC-TOF-MS analysis data, the degradation pathway of sulfamethoxazole was proposed, such as... Figure 8 As shown in (C), the -NH2 group first undergoes addition with the CH3C(O)OO• radical to form nitro-sulfamethoxazole (P1). Driven by the instability of the SN bond, P1 is further oxidized to P2-P4. Simultaneously, the CS bond breaks to generate P5, which is further oxidized to P2-P4. In addition, the hydroxylation of the -NH2 group on the sulfamethoxazole benzene ring produces P6, which is subsequently oxidized to P7 containing a nitroso group. The free radical-mediated hydrogen abstraction reaction of the aniline ring leads to the formation of the hydroxylated product P8, which is further oxidized to P9. Direct oxidation of the -NH2 group produces P10, while the instability of the SN bond in P11 makes it susceptible to free radical attack.

[0157] Furthermore, based on the quantitative structure-activity relationship (QSAR) principle, the ecostructure-activity relationship (ECOSAR v2.0 USA) software was used to predict the acute (LC50) effects of sulfamethoxazole and its transformation products on fish, daphnia, and green algae in a cobalt-supported peanut shell biochar / peracetic acid system. 50 Acute and chronic (ChV) toxicity. The Ecostructure-Activity Relationship (ECOSAR) model is an expert system based on the quantitative structure-activity relationship (QSAR) principle. Its core logic is that there is a quantifiable mathematical relationship between the molecular structure of a compound (including functional groups, molecular weight, hydrophobicity, etc.) and its ecotoxicity. Inputting the SMILES code, CAS number, or chemical formula of the compound to be evaluated, the model automatically predicts the acute and chronic toxicity values ​​of the compound to various aquatic organisms (such as fish, water fleas, and green algae) based on its extensive internal classification rules and calculation formulas derived from experimental data. Results are as follows: Figure 9As shown, the acute toxicity (96-hr LC50, 48-hr LC50, and 48-hr EC50) and chronic toxicity (ChV) of fish, water fleas, and green algae were evaluated. The results showed that the toxicity of most intermediates was reduced, demonstrating the system's effectiveness in mitigating environmental risks. However, the nitro derivative P1 exhibited increased chronic toxicity in fish, which may be attributed to the electron-withdrawing effect and bioaccumulation potential of the nitro group. Similarly, the azo coupling product P10 showed higher toxicity due to its high molecular weight intermediate characteristics and bioaccumulation tendency. Overall, the cobalt-supported peanut shell biochar / peracetic acid system not only effectively degrades sulfamethoxazole but also reduces the environmental hazards associated with its conversion products, highlighting its potential as a safe and sustainable advanced oxidation process in water treatment.

[0158] In summary, this application prepared a cobalt-supported peanut shell biochar composite material using a hydrothermal method for activating peracetic acid to degrade sulfamethoxazole. Through a series of structural and performance optimizations, the cobalt-supported peanut shell biochar achieved a 90.1% sulfamethoxazole removal rate within 4 minutes under conditions of 200 mg / L catalyst and 0.2 mM peracetic acid. This system exhibited stable degradation efficiency within a pH range of 5-9 and maintained high activity in the presence of common inorganic anions. Quenching experiments showed that the cobalt-supported peanut shell biochar / peracetic acid system contains both free radicals (•OH and CH3C(O)OO•) and non-free radicals (•OH and CH3C(O)OO•). 1 The synergistic degradation effect of the O2 pathway was investigated. Based on density functional theory (DFT) calculations, vulnerable sites (C1, C3, C5, and N11) in the sulfamethoxazole molecule were identified. The transformation products and possible degradation pathways of sulfamethoxazole were resolved by ultra-high performance liquid chromatography-time-of-flight mass spectrometry (UPLC-TOF MS), and most intermediate products exhibited low toxicity. In both cyclic and continuous flow column experiments, the cobalt-supported peanut shell biochar composite material demonstrated a sustained and efficient degradation rate and good stability. This application provides a sustainable and efficient solution for the application of the biochar-peracetic acid advanced oxidation system in water treatment.

[0159] The present application has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present application. The descriptions of the embodiments above are only for the purpose of helping to understand the present disclosure and its core ideas. It should be noted that those skilled in the art can make several improvements and modifications to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A cobalt-supported peanut shell biochar / peracetic acid water treatment synergistic system, characterized in that, Including cobalt-loaded peanut shell biochar, peracetic acid, and water; The cobalt-loaded peanut shell biochar comprises a peanut shell biochar matrix and a cobalt-containing compound supported on the matrix; the cobalt-containing compound comprises metallic cobalt and cobalt oxides. The mass ratio of the cobalt-supported peanut shell biochar to the peracetic acid is (2-132):1; Based on XPS analysis, the atomic ratio of cobalt to carbon in the cobalt-supported peanut shell biochar is (0.2-0.3):

1. The cobalt-supported peanut shell biochar has a mesoporous structure; the total pore volume of the cobalt-supported peanut shell biochar is not less than 0.07 cm³ / g; The specific surface area of the cobalt-loaded peanut shell biochar is not less than 100 m 2 / g. The water body contains organic pollutants; the organic pollutant is sulfamethoxazole. The water body contains humic acid at a concentration not exceeding 10 mg / L; and / or the water body contains Cl⁻ at a concentration not less than 3 mM; and / or the water body contains NO⁻ and / or SO₄²⁻; The water treatment synergistic system is suitable for a pH of 5-9; the concentration of peracetic acid is 0.05mM-0.25mM; and the removal rate of sulfamethoxazole in water reaches over 90% within 3-5 minutes. The cobalt-loaded peanut shell biochar was prepared by the following method: Peanut shell biochar was dispersed in a cobalt salt aqueous solution and subjected to a hydrothermal reaction. After the reaction was completed, the product was dried to obtain a solid product. The solid product was then pyrolyzed in an inert atmosphere to obtain the cobalt-supported peanut shell biochar. The cobalt salt is CoCl2·6H2O; The conditions for the hydrothermal reaction include a reaction temperature of 65℃-75℃ and a reaction time of 3-5 hours. The conditions for pyrolysis include heating to 750-850℃ at a heating rate of 4-6℃ / min and holding at that temperature for 2-4 hours. The cobalt-loaded peanut shell biochar / peracetic acid water treatment synergistic system does not contain Co. 4+ .

2. The cobalt-supported peanut shell biochar / peracetic acid water treatment synergistic system as described in claim 1, characterized in that, The concentration of cobalt-loaded peanut shell biochar in the water treatment synergistic system is 50 mg / L-500 mg / L.

3. The cobalt-supported peanut shell biochar / peracetic acid water treatment synergistic system as described in claim 1, characterized in that, When the water treatment synergistic system is running continuously, it can maintain a removal rate of sulfamethoxazole in the water body of more than 90% for 100 hours.

4. A method for degrading sulfamethoxazole based on a cobalt-supported peanut shell biochar / peracetic acid water treatment synergistic system, using the cobalt-supported peanut shell biochar / peracetic acid water treatment synergistic system according to any one of claims 1-3, characterized in that, Includes the following steps: Cobalt-supported peanut shell biochar and peracetic acid were added to water containing sulfamethoxazole to prepare a synergistic water treatment system for cobalt-supported peanut shell biochar / peracetic acid, and a catalytic oxidation reaction was carried out.

5. The method for degrading sulfamethoxazole based on the cobalt-supported peanut shell biochar / peracetic acid water treatment synergistic system as described in claim 4, characterized in that, The initial mass ratio of the cobalt-loaded peanut shell biochar to the sulfamethoxazole is (5-500):1; The initial mass ratio of the peracetic acid to the sulfamethoxazole is (0.3-20):

1.

6. The method for degrading sulfamethoxazole based on the cobalt-supported peanut shell biochar / peracetic acid water treatment synergistic system as described in claim 5, characterized in that, The initial concentration of the sulfamethoxazole is 1-10 mg / L.

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