Biochar adsorption material as well as preparation method and application thereof

Abstract

The invention discloses a charcoal adsorption material as well as a preparation method and application thereof. The biochar adsorption material comprises sugar biochar and SiO2 or montmorillonite loaded on the surface of the biochar. According to the method, the sugar production wastewater is subjected to biochar synthesis and modification, so that the adsorption capacity on tetracycline is improved.

Description

Technical Field

[0001] The present invention belongs to the field of biomaterials, and in particular relates to a biochar adsorption material and a preparation method and application thereof. Background Art

[0002] Tetracycline (TC) is a widely used antibiotic, and long-term exposure may have adverse effects on human health. Studies have shown that the stable presence of TC in the environment can lead to bacterial imbalances in the natural environment and enhance antibiotic resistance in humans. To address this issue, researchers have developed a variety of methods for removing TC, including biological, chemical, and physicochemical methods. Biochar adsorption, with its simplicity and low cost, is widely used to treat pollutants such as TC in water.

[0003] Sugar industry wastewater is discharged during the sugar production process using beets or sugarcane as raw materials. It primarily comes from the sugar production process and the comprehensive utilization of sugar byproducts. The wastewater has a high sugar content, primarily soluble monosaccharides and disaccharides such as glucose, sucrose, and maltose. COD (chemical oxygen demand) levels can reach as high as 2,000-10,000 mg / L, and BOD (biochemical oxygen demand) levels can range from 1,000-5,000 mg / L. The wastewater also has a dark color, primarily from chute wastewater, sugar refining wastewater, distillation wastewater, and groundwashing water.

[0004] Sugar production wastewater is rich in water-soluble sugars such as sucrose and glucose, and direct discharge of this type of wastewater can have an impact on the ecological environment. Current mainstream treatment methods include activated sludge, flocculation sedimentation, Fenton oxidation, and aerobic biofilm processes. However, these technologies often waste organic resources by emitting CO2 and CH4 gases as end products and incinerating and landfilling sludge. Furthermore, after aerobic and anaerobic treatment of sugar production wastewater, the amount of sludge produced is typically large due to its high organic content and complex composition.

[0005] Conventional disposal methods for sludge generated by the sugar industry include incineration, landfill, and aerobic composting. Incineration utilizes thermal energy to generate electricity, requiring control of dioxin production and emissions. Landfill is simple but requires more land. Aerobic composting, however, is limited in its widespread use due to the high water content of sugar sludge, which is prone to corruption and unstable fermentation. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the present invention synthesizes and modifies biochar from sugar-making wastewater, thereby improving the adsorption capacity for tetracycline.

[0007] According to one aspect of the present invention, a biochar adsorption material is provided, comprising sugar biochar and SiO2 or montmorillonite supported on the surface of the sugar biochar.

[0008] In some embodiments, the sugar biochar includes soluble monosaccharide biochar and / or soluble disaccharide biochar.

[0009] In some embodiments, the sugar biochar includes one or more of sucrose biochar, glucose biochar, fructose biochar, or maltose biochar.

[0010] In some embodiments, the sugar biochar is derived from plant sugar wastewater, preferably sugar wastewater from sugarcane and / or sugar beet.

[0011] In some embodiments, the montmorillonite includes sodium montmorillonite and / or calcium montmorillonite.

[0012] In some embodiments, the biochar adsorption material includes sucrose biochar and SiO2.

[0013] In some embodiments, the XRD pattern of the biochar adsorption material has diffraction peaks at 2θ of 27±1°, 36.8±1°, and 39.27±1°.

[0014] In some embodiments, the Fourier transform infrared spectrum of the biochar adsorption material is at 1020±10, 800±10 and 678±10 cm -1 There is a Si-O stretching vibration peak at .

[0015] In some embodiments, the specific surface area of ​​the biochar adsorption material is 100-300m 2 / g, preferably 150-200m 2 In some embodiments, the specific surface area of ​​the biochar adsorption material is 100m 2 / g, 120m 2 / g, 150m 2 / g, 180m 2 / g, 200m 2 / g, 220m 2 / g, 250m 2 / g, 280m 2 / g、300m 2 / g or any value in between.

[0016] In some embodiments, the pore volume of the biochar adsorption material is 0.1-0.5 cm 3 / g, preferably 0.1-0.3cm 3 / g. In some embodiments, the pore volume of the biochar adsorption material is 0.1cm 3 / g, 0.2cm 3 / g, 0.3cm 3 / g, 0.4cm 3 / g, 0.5cm 3 / g or any value in between.

[0017] In some embodiments, the average pore size of the biochar adsorption material is 2-10 nm, preferably 6-8 nm. In some embodiments, the average pore size of the biochar adsorption material is 2 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 10 nm, or any value therebetween.

[0018] In some embodiments, the raw materials of the biochar adsorption material include SiO2, sucrose and KHCO3.

[0019] In some embodiments, the mass ratio of SiO2 to sucrose in the raw material of the biochar adsorption material is 1:(3-10), preferably 1:(4-6), and more preferably 1:(4.5-5.5). In some embodiments, the mass ratio of SiO2 to sucrose in the raw material of the biochar adsorption material is 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, or any value therebetween.

[0020] In some embodiments, the mass ratio of KHCO3 to sucrose in the raw material of the biochar adsorption material is 1:(3-10), preferably 1:(4-6). In some embodiments, the mass ratio of KHCO3 to sucrose in the raw material of the biochar adsorption material is 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, or any value therebetween.

[0021] In other embodiments, the biochar adsorption material includes glucose biochar and montmorillonite.

[0022] In some embodiments, the XRD pattern of the biochar adsorption material has a diffraction peak at 28.67±1° shifted compared to montmorillonite.

[0023] In some embodiments, the Fourier transform infrared spectrum of the biochar adsorption material is at 2924±10 and 2852±10 cm -1 There are C─H and ─CH2─ stretching vibration peaks.

[0024] In some embodiments, the specific surface area of ​​the biochar adsorption material is 100-200m 2 / g, preferably 120-150m 2 In some embodiments, the specific surface area of ​​the biochar adsorption material is 100m 2 / g, 120m 2 / g, 140m 2 / g, 150m 2 / g, 160m 2 / g, 180m 2 / g, 200m 2 / g or any value in between.

[0025] In some embodiments, the pore volume of the biochar adsorption material is 0.1-0.5 cm 3 / g, preferably 0.15-0.3cm 3 / g. In some embodiments, the pore volume of the biochar adsorption material is 0.1cm 3 / g, 0.15cm 3 / g, 0.2cm 3 / g, 0.25cm 3 / g, 0.3cm 3 / g, 0.4cm 3 / g, 0.5cm 3 / g or any value in between.

[0026] In some embodiments, the average pore size of the biochar adsorption material is 2-10 nm, preferably 5-8 nm. In some embodiments, the average pore size of the biochar adsorption material is 2 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 10 nm, or any value therebetween.

[0027] In some embodiments, the raw materials of the biochar adsorption material include montmorillonite, glucose, and KOH.

[0028] In some embodiments, the mass ratio of montmorillonite to glucose in the raw material of the biochar adsorption material is 1:(0.2-5), preferably 1:(0.5-2), and more preferably 1:(0.8-1.2). In some embodiments, the mass ratio of montmorillonite to glucose in the raw material of the biochar adsorption material is 1:0.2, 1:0.5, 1:0.8, 1:1, 1:1.2, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, or any value therebetween.

[0029] In some embodiments, the mass ratio of KOH to glucose in the raw material of the biochar adsorption material is 1:(3-10), preferably 1:(4-6). In some embodiments, the mass ratio of KOH to glucose in the raw material of the biochar adsorption material is 1:(3-10), preferably 1:(4-6). In some embodiments, the mass ratio of KOH to glucose in the raw material of the biochar adsorption material is 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, or any value therebetween.

[0030] According to another aspect of the present invention, a method for preparing a biochar adsorption material is provided, comprising the following steps:

[0031] S1: hydrothermally reacting a sugar compound with SiO2 or montmorillonite to obtain hydrothermal pre-carbonized carbon;

[0032] S2: activating the hydrothermal pre-carbonized material with potassium salt to obtain the biochar adsorption material.

[0033] In some embodiments, the carbohydrate compound includes soluble monosaccharides and / or soluble disaccharides.

[0034] In some embodiments, the carbohydrate compound includes one or more of sucrose, glucose, fructose, or maltose.

[0035] In some embodiments, the sugar compound is derived from plant sugar wastewater, for example, including but not limited to, sugar wastewater from sugarcane and / or sugar beet.

[0036] In some embodiments, the montmorillonite includes sodium montmorillonite and / or calcium montmorillonite.

[0037] In some embodiments, the potassium salt comprises KHCO3 and / or KOH.

[0038] In some embodiments, the hydrothermal reaction is carried out in plant sugar industry wastewater containing sugar compounds.

[0039] In some embodiments, the COD in the plant sugar industry wastewater is 30,000 to 60,000 mg / L.

[0040] In some embodiments, the preparation method comprises the following steps:

[0041] S1-1: hydrothermally reacting sucrose with SiO2 to obtain hydrothermal pre-carbonized carbon;

[0042] S2-1: activating the hydrothermal pre-carbonized material with KHCO3 to obtain the biochar adsorption material.

[0043] In some embodiments, the mass ratio of SiO2 to sucrose is 1:(3-10), preferably 1:(4-6), and more preferably 1:(4.5-5.5). In some embodiments, the mass ratio of SiO2 to sucrose is 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, or any value therebetween.

[0044] In some embodiments, the hydrothermal reaction temperature is 150-200° C., and the time is 5-20 hours. In some embodiments, the hydrothermal reaction temperature is 150° C., 160° C., 170° C., 180° C., 190° C., 200° C., or any value therebetween. In some embodiments, the hydrothermal reaction time is 5 hours, 8 hours, 10 hours, 12 hours, 15 hours, 18 hours, 20 hours, or any value therebetween.

[0045] In some embodiments, the mass ratio of KHCO3 to sucrose is 1:(3-10), preferably 1:(4-6). In some embodiments, the mass ratio of KHCO3 to sucrose is 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10 or any value therebetween.

[0046] In some embodiments, the activation temperature is 600-800°C and the time is 1-3 hours. In some embodiments, the hydrothermal reaction temperature is 600°C, 650°C, 700°C, 750°C, 800°C, or any value therebetween. In some embodiments, the hydrothermal reaction time is 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, or any value therebetween.

[0047] In some embodiments, the step S2-1 further comprises washing the activated product to neutrality.

[0048] In some embodiments, the preparation method comprises the following steps:

[0049] S1-1: hydrothermally reacting glucose with montmorillonite to obtain hydrothermal pre-carbonized carbon;

[0050] S2-1: activating the hydrothermal pre-carbonized material with KOH to obtain the biochar adsorption material.

[0051] In some embodiments, the mass ratio of montmorillonite to glucose is 1:(0.2-5), preferably 1:(0.5-2), and more preferably 1:(0.8-1.2). In some embodiments, the mass ratio of montmorillonite to glucose is 1:0.2, 1:0.5, 1:0.8, 1:1, 1:1.2, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, or any value therebetween.

[0052] In some embodiments, the hydrothermal reaction temperature is 150-200° C., and the time is 5-20 hours. In some embodiments, the hydrothermal reaction temperature is 150° C., 160° C., 170° C., 180° C., 190° C., 200° C., or any value therebetween. In some embodiments, the hydrothermal reaction time is 5 hours, 8 hours, 10 hours, 12 hours, 15 hours, 18 hours, 20 hours, or any value therebetween.

[0053] In some embodiments, the mass ratio of KOH to glucose is 1:(3-10), preferably 1:(4-6). In some embodiments, the mass ratio of KOH to glucose is 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10 or any value therebetween.

[0054] In some embodiments, the activation temperature is 600-800°C and the time is 1-3 hours. In some embodiments, the hydrothermal reaction temperature is 600°C, 650°C, 700°C, 750°C, 800°C, or any value therebetween. In some embodiments, the hydrothermal reaction time is 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, or any value therebetween.

[0055] In some embodiments, the step S2-2 further comprises washing the activated product to neutrality.

[0056] According to another aspect of the present invention, a method for treating antibiotics is provided, which comprises using the biochar adsorption material of the present invention or the biochar adsorption material obtained by the preparation method of the present invention to perform adsorption treatment on an aqueous solution containing antibiotics.

[0057] In some embodiments, the antibiotic comprises tetracycline.

[0058] In some embodiments, the biochar adsorption material is added in an amount of 30-60 mg / 100 mL, preferably 40-50 mg. In some embodiments, the biochar adsorption material is added in an amount of 30 mg / 100 mL, 35 mg / 100 mL, 40 mg / 100 mL, 45 mg / 100 mL, 50 mg / 100 mL, 55 mg / 100 mL, 60 mg / 100 mL, or any value therebetween.

[0059] In some embodiments, the initial concentration of the antibiotic in the aqueous solution is 1-100 mg / L, preferably 5-50 mg / L. In some embodiments, the initial concentration of the antibiotic in the aqueous solution is 1 mg / L, 2 mg / L, 5 mg / L, 10 mg / L, 20 mg / L, 40 mg / L, 50 mg / L, 60 mg / L, 80 mg / L, 100 mg / L, or any value therebetween.

[0060] In some embodiments, the temperature of the adsorption treatment is 10-80° C., preferably 20-40° C. In some embodiments, the temperature of the adsorption treatment is 10° C., 20° C., 30° C., 40° C., 50° C., 60° C., 70° C., 80° C. or any value therebetween.

[0061] In some embodiments, the pH of the aqueous solution is 2.0-11.0, preferably 5.0-7.0. In some embodiments, the pH of the aqueous solution is 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0 or any value therebetween.

[0062] According to another aspect of the present invention, provided is the use of the biochar adsorption material of the present invention, the biochar adsorption material obtained by the preparation method, or the treatment method in resource utilization of wastewater from plant sugar production industry.

[0063] In some embodiments, the plant sugar industry wastewater includes, but is not limited to, sugar industry wastewater from sugarcane and / or sugar beet.

[0064] The present invention has the following beneficial effects:

[0065] 1. Significant environmental benefits

[0066] Carbon sequestration and emission reduction: Through hydrothermal carbonization, 60% to 70% of the dissolved organic carbon (DOC) in sugar wastewater is converted into stable biochar. Compared with traditional aerobic treatment (CO2 emissions) and anaerobic treatment (CH4 leakage risk), the carbon footprint is reduced by 50% to 70%. For every ton of wastewater treated, about 0.2 to 0.3 tons of CO2 equivalent can be sequestered, which is in line with the carbon neutrality goal.

[0067] Zero sludge generation: Organic matter in wastewater is directly mineralized into biochar, reducing sludge by >95%, avoiding secondary pollution and disposal costs caused by sludge dehydration, incineration or landfill in traditional processes.

[0068] 2. Improved sewage treatment efficiency

[0069] Highly efficient simultaneous removal of pollutants: The mesoporous-microporous hierarchical structure of the biochar adsorption material works synergistically with the oxygen-containing / potassium-containing functional groups (-COOH, KO-Si bonds) on the surface to simultaneously adsorb heavy metals (such as Cr(VI)) and organic pollutants (such as tetracycline), with the effluent COD <100 mg / L (meeting Level A of the "Integrated Sewage Discharge Standard").

[0070] Strong resistance to water quality fluctuations: The ion exchange capacity of montmorillonite can buffer pH fluctuations in wastewater and adsorb inhibitory substances (such as high concentrations of salt and pigments) to ensure process stability.

[0071] 3. Outstanding economic benefits of resource utilization

[0072] High value-added product output: Biochar can be used as an industrial adsorbent, electrode material or soil conditioner.

[0073] Both energy consumption and reagent costs are reduced: the low-temperature hydrothermal process (180°C vs. conventional 250°C) reduces heating energy consumption by 30% to 40%; the low KOH dosage (charcoal:KOH=5:1 vs. conventional 1:2) reduces activator costs by 60% to 80%, and the alkali recovery rate is >85% (K2SiO3 / KAlO2 is recovered through acid washing).

[0074] 4. Process simplification and equipment investment optimization

[0075] Eliminate the biochemical treatment process: no need to build aeration tanks, anaerobic reactors and other facilities.

[0076] 5. Material performance advantages

[0077] High mechanical strength and stability: The interlayer confinement effect of montmorillonite enhances the carbon skeleton structure, with a compressive strength of 25-30 MPa (traditional sugar-based carbon is only 10-15 MPa), and the structural integrity retention rate is >90% after 5 cycles.

[0078] 6. Social benefits

[0079] Promote the circular economy in the sugar industry: transform sugar wastewater from a "treatment burden" into a "resource-based raw material", increase the added value of the industrial chain, and help sugar factories achieve sustainable development.

[0080] Technical universality: It can be expanded to other high-sugar wastewater (such as beverage and fermentation industries) and is suitable for treating organic wastewater with a COD of 5,000 to 50,000 mg / L. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] Figure 1 SEM images of SBC (a) and SiO2@SBC-KHCO3 (b) are shown.

[0082] Figure 2The XRD patterns of SBC, SiO2, and SiO2@SBC-KHCO3 are shown.

[0083] Figure 3 Shows the FTIR spectra of SiO2@SBC-KHCO3 before and after TC adsorption.

[0084] Figure 4 Shown are the nitrogen adsorption / desorption isotherms (a) and pore size distribution curves (b) of SBC and SiO2@SBC-KHCO3.

[0085] Figure 5 The effect of different material ratios of SiO2@SBC-KHCO3 on the adsorption of TC is shown.

[0086] Figure 6 The effect of SiO2@SBC-KHCO3 dosage on TC adsorption is shown.

[0087] Figure 7 The effect of the initial TC concentration on the TC adsorption effect of SiO2@SBC-KHCO3 is shown.

[0088] Figure 8 The effect of reaction temperature on the TC adsorption effect of SiO2@SBC-KHCO3 is shown.

[0089] Figure 9 The effect of initial solution pH on TC adsorption is shown.

[0090] Figure 10 SEM images of GBC (a) and Mt@GBC-KOH (b) are shown.

[0091] Figure 11 The XRD patterns of GBC, Mt, and Mt@GBC-KOH are shown.

[0092] Figure 12 FTIR spectra of GBC and Mt@GBC-KOH are shown.

[0093] Figure 13 Shown are the nitrogen adsorption / desorption isotherms (a) and pore size distribution curves (b) of GBC and Mt@GBC-KOH.

[0094] Figure 14 The effects of different material ratios of Mt@GBC-KOH on the adsorption of TC are shown.

[0095] Figure 15 The effect of Mt@GBC-KOH dosage on TC adsorption is shown.

[0096] Figure 16The effect of the initial TC concentration on the TC adsorption effect of Mt@GBC-KOH is shown.

[0097] Figure 17 The effect of reaction temperature on the adsorption of TC by Mt@GBC-KOH is shown.

[0098] Figure 18 The effect of initial solution pH on the adsorption of TC by Mt@GBC-KOH is shown. DETAILED DESCRIPTION

[0099] Tetracycline (TC), a commonly used broad-spectrum antimicrobial agent, has inhibitory effects against a wide range of bacteria, including Chlamydia, and is widely used in clinical and agricultural settings. Its stable four-membered fused ring and aromatic conjugated structure result in persistent residues in aquatic environments, posing a threat to the environment and human health. Adsorption is a common method for removing TC from water due to its simplicity, high efficiency, and adaptability. The resource utilization of sugar industry wastewater, rich in high-carbon and high-COD substances such as sucrose and glucose, is being explored by preparing hydrothermal biochar adsorbents to treat TC contamination in water. This approach eliminates the need for traditional anaerobic-aerobic wastewater treatment, sequesters carbon and reduces greenhouse gas emissions, significantly reducing sludge disposal pressure and achieving the dual benefits of resource recovery and wastewater treatment. However, biochar's low porosity and limited number of surface functional groups limit its TC adsorption efficiency. To address these challenges, this study synthesized and modified biochar from sugar industry wastewater to enhance its TC adsorption capacity.

[0100] The present invention adopts a two-step method of hydrothermal pre-carbonization and high-temperature chemical activation to prepare two functionalized sugar wastewater biochar composites: potassium bicarbonate-activated silica sucrose biochar (SiO2@SBC-KHCO3) and potassium hydroxide-modified montmorillonite glucose biochar (Mt@GBC-KOH). In one aspect, the present invention uses sucrose and silica (SiO2) for hydrothermal pre-carbonization and high-temperature activation with KHCO3 to prepare SiO2@SBC-KHCO3 composite materials to remove TC from water. On the other hand, the present invention uses glucose to simulate sugar wastewater, and hydrothermally pre-carbonizes Mt@GBC with montmorillonite (Mt), and then activates it at high temperature with KOH to prepare Mt@GBC-KOH composite materials to remove TC from water.

[0101] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and examples. The specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention in any way. In addition, descriptions of known structures and techniques are omitted in the following description to avoid unnecessary confusion about the concepts of the present disclosure. Such structures and techniques are also described in many publications.

[0102] The reagents and / or kits used in the following examples are all commercially available or can be synthesized by known methods.

[0103] 1. Reagents and Materials

[0104] The main reagents and materials used in the following examples are shown in Table 1.

[0105] Table 1

[0106] name Molecular formula level Manufacturer Anhydrous glucose <![CDATA[C6H 12 O6]]> analytically pure Sinopharm Chemical Reagents sucrose <![CDATA[C 12 H 22 O 11 ]]> analytically pure Sinopharm Chemical Reagents Sodium hydroxide NaOH analytically pure McLean Biotechnology hydrochloric acid HCl 36-38％ Cologne Chemicals Montmorillonite <![CDATA[Al2O3·4(SiO2)·H2O]]> analytically pure McLean Biotechnology Silicon dioxide <![CDATA[SiO2]]> analytically pure McLean Biotechnology Tetracycline hydrochloride <![CDATA[C 22 H 25 ClN2O8]]> analytically pure McLean Biotechnology Anhydrous ethanol <![CDATA[C2H6O]]> analytically pure McLean Biotechnology potassium bicarbonate <![CDATA[KHCO3]]> analytically pure McLean Biotechnology potassium hydroxide KOH analytically pure McLean Biotechnology Potassium bromide KBr analytically pure McLean Biotechnology

[0107] 2. Material characterization methods:

[0108] 1) X-ray diffractometer characterization (XRD)

[0109] The prepared adsorbent was analyzed for its crystal structure using a Shimadzu XRD-6000 X-ray diffractometer. XRD operating conditions were: Cu Kα (λ = 0.154 nm) as the radiation source, 40 kV operating voltage, 50 mA operating current, 2° / min speed, and a range of 10°-80°.

[0110] 2) Fourier transform infrared spectroscopy (FI-TR)

[0111] The groups and chemical bonds in the catalyst were analyzed using a Shimadzu Fourier transform infrared spectrometer (IRT racer-100). Potassium bromide (KBr) was used for background treatment of the samples.

[0112] 3) Scanning electron microscopy (SEM) characterization

[0113] The catalyst was analyzed using a Zeiss Sigma 300 scanning electron microscope (Zeiss, Germany) at an accelerating voltage of 20 kV to observe its microscopic morphology.

[0114] 4) Specific surface area test characterization (BET)

[0115] The specific surface area, pore size and pore volume of the samples were studied by nitrogen adsorption / desorption isotherms using a specific surface area and micropore tester (KuBo-X1000) produced by Beijing Biode Company.

[0116] 5) Elemental analysis and ash content

[0117] The carbon (C), hydrogen (H) and nitrogen (N) contents in biochar were determined using the CHN mode of Shimadzu Corporation's organic element analyzer. The ash (Ash) content of biochar can be calculated by the following steps: Weigh 0.5 g of biochar, place it in a constant-weight crucible, place it in a muffle furnace with the mouth open, and burn it at 700°C for 6 hours. After the burning is completed, cool the crucible to about 200°C, take it out, and place it in a desiccator to cool for 30 minutes. Repeat the above burning process until constant weight is reached, and the ash content of the biochar can be calculated. The oxygen (O) element content formula is: O% = 100% - C% - H% - N% - Ash%.

[0118] 2.TC adsorption experiment

[0119] First, use an electronic balance to weigh 1.0000 grams of tetracycline hydrochloride (TC) and transfer it to a beaker. After dissolving, the solution is transferred to a 1L brown volumetric flask and dilute to the mark with deionized water to obtain a TC stock solution with a concentration of 1g / L. Finally, the stock solution is stored in a brown bottle, away from light. Different volumes of liquid are taken out from the stock solution using a pipette to prepare TC solutions with concentrations of 5mg / L, 10mg / L, 20mg / L, 30mg / L, and 50mg / L. A UV-Vis spectrophotometer is used to scan over a wavelength range of 200 to 400nm. The results show that the absorbance reaches a maximum at a wavelength of 357nm. The absorbance at this wavelength is recorded, and a linear fit is performed based on the relationship between absorbance and concentration to draw a standard curve for TC. According to the standard curve, there is a good linear correlation between absorbance and concentration, and the regression equation is: y=0.03293x+0.0051.

[0120] 40 mg of adsorbent (Mt@GBC-KOH, SiO2@SBC-KHCO3) was added to 100 mL of TC (20 mg / L, 30 mg / L) solution and shaken at a constant temperature under the same conditions. 3 mL of the suspension was sampled every 10 minutes. Finally, the suspension was filtered through a 0.22 μm organic filter and spectrally scanned using a TU-1901 spectrophotometer over a wavelength range of 200-400 nm. The highest peak was observed at 357 nm, and the absorbance at this wavelength was recorded. The corresponding removal rate and TC solution concentration were calculated using the standard curve. The TC removal rate (η, %) and adsorption amount were calculated as shown in Formula (2-1) and Formula (2-2):

[0121]

[0122] Where C0 is the concentration of the original TC solution, C t is the concentration of TC solution at time t.

[0123]

[0124] where q e is the equilibrium adsorption capacity of TC, mg / g; C0 is the initial concentration of TC, C e is the equilibrium concentration of TC, mg / g; V is the volume of the solution, mL; m is the amount of adsorbent used, mg.

[0125] Example

[0126] Example 1 Preparation of SiO2@SBC-KHCO3

[0127] Preparation of SiO2@SBC-KHCO3: 5g of sucrose was dissolved in 50mL of H2O and stirred thoroughly to form simulated sugar wastewater. Next, 1g of silica (SiO2) was added and continued to stir and dissolve. The mixture was then transferred to a 75mL polytetrafluoroethylene-lined container, placed in an autoclave, tightened, and placed in an oven. The mixture was heated to 180°C and allowed to react for 8 hours. The autoclave was removed and cooled, and the solution was filtered. After washing twice with ethanol and deionized water, it was dried in a 60°C oven for 12 hours to obtain the product, SiO2@SBC. The SiO2@SBC was mixed with 1g of KHCO3 and thoroughly ground into a fine powder. The powder was placed in a covered crucible and then heated in a muffle furnace at a rate of 15°C / min to 700°C, where it was maintained for calcination for 2 hours. After cooling to room temperature, the calcined product was fully stirred with 1M / L HCl for 2 h, the solution was filtered, rinsed with deionized water until the solution was neutral, and dried to obtain SiO2@SBC-KHCO3.

[0128] Example 2 Characterization of SiO2@SBC-KHCO3

[0129] 1. SEM characterization

[0130] Figure 1 The SEM electron microscope images show the surface morphology of sucrose biochar (SBC) and SiO2@SBC-KHCO3. Figure 1 The SBC in a shows a relatively smooth and regular spherical aggregate. Figure 1 As shown in (b), the SiO2@SBC-KHCO3 core-shell structure has a stronger pore structure. The increased hydroxyl functional groups on the carbonized sucrose surface can make TC more easily adsorbed on the biochar surface, while increasing the number of active sites and expanding the deposition surface area, thereby facilitating the adsorption of TC.

[0131] 2. XRD characterization

[0132] Figure 2The XRD patterns of SBC, SiO2, and SiO2@SBC-KHCO3 are presented. The SBC XRD pattern lacks distinct sharp diffraction peaks, exhibiting only broad, mixed peaks. This is due to the lack of a distinct crystalline structure in the sucrose-derived biochar, resulting in a lack of inorganic crystalline materials that could produce strong diffraction peaks. After silicon modification, SiO2@SBC-KHCO3 exhibits SiO2 crystalline phases at 2θ = 27°, 36.8°, and 39.27°, corresponding to the (100), (012), and (111) planes, respectively (PDF#82–1574), confirming SiO2 attachment to the biochar surface.

[0133] 3. FTIR characterization

[0134] Figure 3 The FTIR spectra of SBC and SiO2@SBC-KHCO3 are shown. SBC has the following wavelengths: 3400 and 1076 cm -1 The characteristic peaks at 3452 cm correspond to the stretching vibrations of OH and CO groups. -1 The bands at 1020, 800 and 678 cm-1 become more intense due to Si-OH vibration. -1 Si-O stretching vibration was observed at , indicating that SiO2 was successfully loaded on the biochar surface.

[0135] 4.BET Analysis

[0136] Adsorption isotherms of SBC and SiO2@SBC-KHCO3 Figure 4 As shown in Figure a, the adsorption amount gradually increases at low relative pressure (P / P0), and rises sharply when approaching the saturation pressure (P / P0≈1.0), which is consistent with the characteristics of the type IV isotherm.

[0137] Pore ​​size distribution of SBC and SiO2@SBC-KHCO3 Figure 4 As shown in b, the pore size of SiO2@SBC-KHCO3 material is mainly distributed in 2-20nm, indicating that the material has a mesoporous structure.

[0138] As shown in Table 2, the specific surface area, pore volume and average pore diameter parameters of SBC and SiO2@SBC-KHCO3 are 22.36 m 2 / g,177.14m 2 / g, and the pore volume is 0.073 cm 3 / g,0.146cm 3 / g, pore diameters of 13.058nm and 7.018nm. Compared with SBC, the BET area of ​​SiO2@SBC-KHCO3 increased by 154.78m2 / g and the pore volume increased by 0.073 cm 3 / g. The increase in specific surface area and pore volume provides more active sites and a larger deposition area for the adsorption of TC pollutants.

[0139] Table 2 Specific surface area, pore volume and average pore diameter of SBC and SiO2@SBC-KHCO3

[0140] sample <![CDATA[Specific surface area (m 2 / g)]]> <![CDATA[Pore volume (cm 3 / g)]]> Pore ​​diameter (nm) SBC 22.36 0.073 13.058 <![CDATA[SiO2@SBC-KHCO3]]> 177.14 0.146 7.018

[0141] Example 3 Effect of SiO2@SBC-KHCO3 on TC Removal

[0142] TC adsorption experiments were carried out on SiO2@SBC-KHCO3.

[0143] 1. Effect of different material ratios on TC adsorption effect

[0144] TC solution was treated with different material ratios of SBC, SiO2, SiO2:SBC=1:1, SiO2:SBC=1:3, SiO2:SBC=1:5 and SiO2:SBC=1:7 (g SiO2 / g sucrose).

[0145] Effects of different ratios of silica and sucrose on adsorption Figure 5 As shown, the TC removal rates of the six materials were 19.9%, 14.7%, 17.49%, 76%, 92.05%, and 71.6%, respectively. The SiO2:SBC = 1:5 ratio achieved the highest removal rate. This is because the unmodified SBC has a low porosity and a small contact area with TC, resulting in low adsorption capacity. The modified material, SiO2@SBC-KHCO3, has a specific surface area eight times that of SBC, meaning that SiO2@SBC-KHCO3 has more sites for TC adsorption. Therefore, in subsequent experiments, the SiO2:SBC = 1:5 ratio was used as the research object and named SiO2@SBC-KHCO3.

[0146] 2. Effect of dosage on TC adsorption effect

[0147] Figure 6The adsorption effect of biochar at different dosages is shown. As the dosage increases from 20 mg to 80 mg, the TC removal efficiency of SiO2@SBC-KHCO3 increases from 57.4% to 100%. This is because the increase in adsorbent dosage provides a higher specific surface area and more adsorption sites. When the dosage is 60 mg, the TC removal efficiency reaches 98%. At a dosage of 40 mg, the removal efficiency is 92%, indicating that TC in the solution can fully contact the adsorption sites on the SiO2@SBC-KHCO3 surface and effectively occupy the active sites. In contrast, even at a removal efficiency of 100%, the adsorption active sites of SiO2@SBC-KHCO3 are not fully occupied, indicating that the adsorbent is not fully utilized, which is not cost-effective from an economic perspective. Therefore, the optimal adsorbent dosage is 40 mg.

[0148] 3. Effect of initial solution concentration on TC adsorption

[0149] The initial concentration of TC solution is an important factor affecting the removal of TC by adsorbent. Figure 7 The effect of different initial concentrations on adsorption performance shows that, since the adsorbent dosage is fixed, the active sites are also determined. For initial TC concentrations of 10 mg / L, 30 mg / L, 50 mg / L, and 70 mg / L, the TC removal rates after 60 minutes were 99.63%, 92%, 80.35%, and 73.7%, respectively. As the initial concentration increases, the TC removal rate gradually decreases. This is because the adsorbent has a limited number of active sites. High TC concentrations result in excess TC not having the opportunity to react with the adsorbent, resulting in a decrease in adsorption efficiency.

[0150] 4. Effect of solution temperature on TC adsorption

[0151] Temperature is one of the key factors affecting adsorption performance because temperature changes the diffusion rate and molecular dynamics of the adsorbate. Figure 8 The effect of different reaction temperatures on adsorption performance shows that at 10°C, 20°C, 25°C, 30°C, and 40°C, the removal rates were 90.16%, 90.67%, 92.5%, 96.28%, and 98.4%, respectively. The SiO2@SBC-KHCO3 adsorption capacity for TC increased with increasing temperature, indicating that the adsorption process is endothermic and that increasing the temperature can enhance the adsorption performance of the adsorbent. The adsorbent also exhibited good adsorption performance at lower and higher temperatures.

[0152] 5. Effect of solution pH on TC adsorption

[0153] During the TC adsorption process, the initial pH value of the solution has an important influence on the chemical form of TC and the charge distribution on the biochar surface.

[0154] Effect of initial pH value on adsorption effect Figure 9 As shown in the figure, the removal rate of SiO2@SBC-KHCO3 is 78.4% at pH 2.0. As the pH increases, the removal rate also increases, reaching a maximum removal rate of 94.8% at pH 6.0. After that, the removal rate begins to decrease with the increase of pH, and the removal rate is 60.1% when the pH reaches 11.0.

[0155] As shown in Examples 1-3, the co-modification of SBC with SiO2 and KHCO3 provides more active sites and a larger deposition area, enhancing its ability to adsorb TC. At a pH of 6.0 and a dosage of 40 mg, the SiO2@SBC-KHCO3 achieved a 94.8% removal rate for 100 mL of a 30 mg / L TC solution.

[0156] Example 4 Preparation of Mt@GBC-KOH

[0157] Preparation of Mt@GBC-KOH: 2.5 g of glucose was dissolved in 50 mL of H₂O and stirred thoroughly to form simulated sugar wastewater. Next, 2.5 g of montmorillonite (Mt) was added and continued to stir and dissolve. The mixture was then transferred to a 75 mL polytetrafluoroethylene-lined container, placed in an autoclave, tightened, and placed in an oven. The mixture was heated to 180°C and reacted for 12 hours. After cooling, the autoclave was removed and the solution was filtered. After washing twice with ethanol and deionized water (1:1), the mixture was dried in a 60°C oven for 12 hours to obtain Mt@GBC. Mt@GBC was mixed with 0.5 g of KOH and ground into a fine powder. The mixture was placed in a covered crucible and heated to 700°C in a muffle furnace at a constant rate of 15°C / min and maintained at this temperature for 2 hours. After cooling to room temperature, the product was washed until neutral and dried at 60°C overnight to obtain Mt@GBC-KOH.

[0158] Example 5 Characterization of Mt@GBC-KOH

[0159] 1. SEM analysis

[0160] Scanning electron microscopy (SEM) is a characterization technique used to observe the surface morphology and microstructure of materials. Figure 10 SEM electron microscope images show the surface morphology of GBC and Mt@GBC-KOH. Figure 10 From a, we can see that glucose biochar is spherical and has a relatively smooth surface. Figure 10As can be seen in b, the surface of Mt@GBC-KOH is relatively rough. The expansibility and confinement effect of montmorillonite promote the formation of mesopores or macropores in the carbon material. After the co-pyrolysis of Mt and glucose, many flaky structures appear on the composite biochar. This is caused by the Mt encapsulating the biochar, indicating that the glucose biochar is successfully loaded with montmorillonite.

[0161] 2.XRD analysis

[0162] Figure 11 The XRD patterns of GBC, Mt and Mt@GBC-KOH are shown. There are no obvious sharp diffraction peaks in the XRD pattern of GBC, only broad miscellaneous peaks. This is because the biochar generated after glucose pyrolysis has no obvious crystal structure and lacks inorganic crystalline substances that can produce strong diffraction peaks. After modification, it was found that the typical diffraction peaks of Mt@GBC-KOH are similar to those of Mt, indicating that the layered structure characteristics of Mt still exist. The diffraction peak intensity of the Mt@GBC-KOH crystal plane is slightly reduced, and at 28.67°, the diffraction angle of the Mt@GBC-KOH crystal plane is offset compared with Mt. The Bragg equation shows that the interlayer spacing of the Mt (001) crystal plane is 1.25nm, and the interlayer spacing of the Mt@GBC-KOH (001) crystal plane is 1.29nm, indicating that the glucose biochar is successfully loaded with montmorillonite, which is consistent with the SEM analysis results.

[0163] 3.FT-IR analysis

[0164] Figure 12 The FTIR spectra of GBC and Mt@GBC-KOH are shown. GBC has the peaks at 3450 and 1046 cm -1 The characteristic peaks at 3450cm -1 The characteristic OH peak at 3425 cm -1 The shift and weakening of the intensity indicate that the number of OH groups is significantly reduced after the modified synthesis; at 1084 cm -1 、912cm -1 and 522cm -1 The characteristic peaks at 2924 and 2852 cm-1 are Si-O stretching vibration peak, Al-O bending vibration peak, and Si-O-Mg stretching vibration absorption peak, all of which are characteristic peaks of Mt. -1 The stretching vibration peaks of C─H and ─CH2─ appeared at , while there are no functional groups such as CH and ─CH2─ in Mt, but there are stretching vibration peaks of C─H and ─CH2─ in GBC. Therefore, the appearance of C─H and ─CH2─ organic functional groups in Mt@GBC-KOH proves that Mt@GBC-KOH has been successfully synthesized.

[0165] 4.BET Analysis

[0166] The adsorption isotherm of Mt@GBC-KOH is shown in Figure 2. Figure 13 As shown in Figure (a), when the relative pressure P / P0 > 0.48, the adsorption isotherm exhibits a clear upward trend. The adsorption-desorption isotherms do not overlap and are accompanied by a hysteresis regression phenomenon, which is a typical H3 type hysteresis regression phenomenon. This feature indicates that Mt@GBC-KOH is not adsorbed at higher relative pressures. According to the traditional classification of Brunauer, Deming, Deming and Teller (BDDT), the adsorption isotherm of GBC in the low relative pressure range is similar to type IV.

[0167] Pore ​​size distribution of Mt@GBC-KOH Figure 13 As shown in b, the pore size is mainly distributed in 2-20 nm, which belongs to a mesoporous structure.

[0168] As shown in Table 3, the specific surface area, pore volume, and pore size parameters of GBC and Mt@GBC-KOH are 18.58 m 2 / g,135.32m 2 / g, and the pore volume is 0.083 cm 3 / g,0.176cm 3 / g, and the average pore diameters are 14.167nm and 5.264nm respectively. Obviously, compared with GBC, the BET area of ​​Mt@GBC-KOH increases by 116.47m 2 / g, the pore volume increased by 0.093 cm 3 / g, and the average pore size decreased by 8.903nm.

[0169] Table 3 Specific surface area, pore volume and average pore diameter of GBC and Mt@GBC-KOH

[0170] sample <![CDATA[Specific surface area (m 2 / g)]]> <![CDATA[Pore volume (cm 3 / g)]]> Pore ​​diameter (nm) GBC 18.58 0.083 14.167 Mt@GBC-KOH 135.32 0.176 5.264

[0171] Example 6 Effect of Mt@GBC-KOH on TC Removal

[0172] 1. Effect of different material ratios on TC adsorption effect

[0173] TC solution was treated with different material ratios of GBC, Mt, Mt:GBC=1:1, Mt:GBC=1:3 and Mt:GBC=3:1 (g Mt / g glucose).

[0174] Effects of different Mt and glucose ratios on adsorption Figure 14As shown, the TC removal rates of the five materials were 44.6%, 36.5%, 92.16%, 81.97%, and 83.1%, respectively. Mt@GBC-KOH (1:1) achieved the highest removal rate. This is because the unmodified GBC has a low porosity and a small contact area with TC, limiting its adsorption capacity. The modified Mt@GBC-KOH has a specific surface area 7.5 times that of GBC, significantly increasing its contact area with TC. The adsorption efficiency decreased when the mass ratio reached 1:3. Therefore, the Mt:GBC (1:1) mixture was selected as the subject of subsequent experiments and designated Mt@GBC-KOH.

[0175] 2. Effect of dosage on TC adsorption effect

[0176] Effects of different Mt@GBC-KOH dosages on adsorption performance Figure 15 As shown, the TC removal rate increases with the Mt@GBC-KOH dosage. After 60 minutes, the removal rates for adsorbent dosages of 10 mg, 20 mg, 40 mg, 60 mg, and 80 mg were 43.11%, 72.04%, 92.16%, 99.6%, and 99.96%, respectively. Increasing the adsorbent dosage increases the number of active sites in Mt@GBC-KOH, leading to improved TC removal. When the concentration of the target pollutant is constant, a smaller dosage can achieve a relatively ideal treatment effect in a shorter period of time. Therefore, considering a comprehensive cost-effectiveness ratio, the optimal adsorbent dosage is 40 mg.

[0177] 3. Effect of initial solution concentration on TC adsorption

[0178] The initial concentration of TC solution is an important factor affecting the removal of TC by adsorbent. Figure 16 The figure shows the effect of different initial TC concentrations on adsorption efficiency. When the initial TC concentrations are 10, 20, 40, 60, and 80 mg / L, the TC removal rates after 60 minutes are 100%, 92.16%, 79.29%, 68%, and 64%, respectively. At an initial concentration of 80 mg / L, 36% of TC remains in the solution after 60 minutes. This is because the adsorbent has a limited number of active sites. When the TC concentration reaches a certain level, the adsorbent's adsorption capacity eventually reaches saturation and remains stable, thus reducing the TC removal rate.

[0179] 4. Effect of solution temperature on TC adsorption

[0180] Temperature is one of the important factors affecting adsorption performance. It not only affects the energy state of the active sites on the adsorbent surface, but also changes the diffusion rate and molecular motion of the adsorbate. Figure 17The TC removal efficiency of Mt@GBC-KOH is affected by reaction temperature. At 10°C, 20°C, 25°C, 30°C, and 40°C, the removal rates were 90.94%, 88.15%, 92.16%, 92.63%, and 89.87%, respectively. Mt@GBC-KOH also exhibited high removal rates at various temperatures, indicating that the adsorption performance of Mt@GBC-KOH is not significantly affected by temperature. Therefore, adsorption can be performed at room temperature.

[0181] 5. Effect of solution pH on TC adsorption

[0182] Effect of initial solution pH on adsorption effect Figure 18 As shown in the figure, in this study, the pH range of 2.0-11.0 was used for testing. At a pH of 3.0, the removal rate was 82%. As the pH increased, the removal rate increased, reaching a maximum of 95% at a pH of 5.0. When the pH reached 11.0, the removal rate decreased to 57.8%.

[0183] As shown in Examples 1-3, the co-modification of GBC with montmorillonite and KOH increases the adsorbent's specific surface area, enriching its pore structure and enhancing its TC removal capacity. At a pH of 5.0 and a dosage of 40 mg, the removal efficiency of Mt@GBC-KOH reached 95% for 100 mL of a 20 mg / L TC solution.

[0184] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. Any technical variations made according to the technical solution of the present invention fall within the protection scope of the present invention.

Claims

1. A biochar adsorption material comprising sugar biochar and SiO2 or montmorillonite supported on the surface of the sugar biochar.

2. The biochar adsorption material according to claim 1, characterized in that The sugar biochar includes soluble monosaccharide biochar and / or soluble disaccharide biochar, preferably includes one or more of sucrose biochar, glucose biochar, fructose biochar or maltose biochar; Preferably, the sugar biochar is derived from plant sugar wastewater, preferably from sugarcane and / or beet sugar wastewater; The montmorillonite includes sodium montmorillonite and / or calcium montmorillonite.

3. The biochar adsorption material according to claim 1 or 2, characterized in that: The biochar adsorption material includes sucrose biochar and SiO2; Preferably, the XRD pattern of the biochar adsorption material has diffraction peaks at 2θ of 27±1°, 36.8±1° and 39.27±1°; Preferably, the Fourier transform infrared spectrum of the biochar adsorption material is at 1020±10, 800±10 and 678±10 cm -1 There is a Si-O stretching vibration peak at Preferably, the specific surface area of ​​the biochar adsorption material is 100-300m 2 / g, preferably 150-200m 2 / g; Preferably, the pore volume of the biochar adsorption material is 0.1-0.5 cm 3 / g, preferably 0.1-0.3cm 3 / g; Preferably, the average pore size of the biochar adsorption material is 2-10 nm, preferably 6-8 nm; Preferably, the raw materials of the biochar adsorption material include SiO2, sucrose and KHCO3; More preferably, in the raw material of the biochar adsorption material, the mass ratio of SiO2 to sucrose is 1:(3-10), preferably 1:(4-6), more preferably 1:(4.5-5.5); More preferably, in the raw material of the biochar adsorption material, the mass ratio of KHCO3 to sucrose is 1:(3-10), preferably 1:(4-6).

4. The biochar adsorption material according to claim 1 or 2, characterized in that: The biochar adsorption material includes glucose biochar and montmorillonite; Preferably, the XRD pattern of the biochar adsorption material has a diffraction peak at 28.67±1° shifted compared to montmorillonite; Preferably, the Fourier transform infrared spectrum of the biochar adsorption material is at 2924±10 and 2852±10 cm -1 There are C─H and ─CH2─ stretching vibration peaks; Preferably, the specific surface area of ​​the biochar adsorption material is 100-200m 2 / g, preferably 120-150m 2 / g; Preferably, the pore volume of the biochar adsorption material is 0.1-0.5 cm 3 / g, preferably 0.15-0.3cm 3 / g; Preferably, the average pore size of the biochar adsorption material is 2-10 nm, preferably 5-8 nm; Preferably, the raw materials of the biochar adsorption material include montmorillonite, glucose and KOH; More preferably, in the raw material of the biochar adsorption material, the mass ratio of montmorillonite to glucose is 1:(0.2-5), preferably 1:(0.5-2), more preferably 1:(0.8-1.2); Preferably, in the raw material of the biochar adsorption material, the mass ratio of KOH to the glucose is 1:(3-10), preferably 1:(4-6).

5. A method for preparing a biochar adsorption material, comprising the following steps: S1: hydrothermally reacting a sugar compound with SiO2 or montmorillonite to obtain hydrothermal pre-carbonized carbon; S2: activating the hydrothermal pre-carbonized material with potassium salt to obtain the biochar adsorption material; Preferably, the carbohydrate compound comprises soluble monosaccharides and / or soluble disaccharides, preferably comprising one or more of sucrose, glucose, fructose or maltose; Preferably, the sugar compound comes from plant sugar wastewater, preferably from sugarcane and / or beet sugar wastewater; Preferably, the montmorillonite comprises sodium montmorillonite and / or calcium montmorillonite; Preferably, the potassium salt comprises KHCO3 and / or KOH; Preferably, the hydrothermal reaction is carried out in plant sugar industry wastewater containing sugar compounds; More preferably, the COD in the plant sugar industry wastewater is 30,000 to 60,000 mg / L.

6. The preparation method according to claim 5, characterized in that The preparation method comprises the following steps: S1-1: hydrothermally reacting sucrose with SiO2 to obtain hydrothermal pre-carbonized carbon; S2-1: activating the hydrothermal pre-carbonized material with KHCO3 to obtain the biochar adsorption material; Preferably, the mass ratio of SiO2 to sucrose is 1:(3-10), preferably 1:(4-6), more preferably 1:(4.5-5.5); Preferably, the temperature of the hydrothermal reaction is 150-200°C and the time is 5-20h; Preferably, the mass ratio of KHCO3 to sucrose is 1:(3-10), preferably 1:(4-6); Preferably, the activation temperature is 600-800°C and the activation time is 1-3h; Preferably, the step S2-1 further comprises washing the activated product to neutrality.

7. The preparation method according to claim 5, characterized in that The preparation method comprises the following steps: S1-1: hydrothermally reacting glucose with montmorillonite to obtain hydrothermal pre-carbonized carbon; S2-1: activating the hydrothermal pre-carbonized material with KOH to obtain the biochar adsorption material; Preferably, the mass ratio of montmorillonite to glucose is 1:(0.2-5), preferably 1:(0.5-2), more preferably 1:(0.8-1.2); Preferably, the temperature of the hydrothermal reaction is 150-200°C and the time is 5-20h; Preferably, the mass ratio of the KOH to the glucose is 1:(3-10), preferably 1:(4-6); Preferably, the activation temperature is 600-800°C and the activation time is 1-3h; Preferably, the step S2-2 further comprises washing the activated product to neutrality.

8. A method for treating antibiotics, comprising adsorbing an aqueous solution containing the antibiotics using the biochar adsorption material according to any one of claims 1 to 4 or the biochar adsorption material obtained by the preparation method according to any one of claims 5 to 7; Preferably, the antibiotic comprises tetracycline.

9. The processing method according to claim 8, characterized in that: In the adsorption treatment, the dosage of the biochar adsorption material is 30-60 mg / 100 mL, preferably 40-50 mg / 100 mL; and / or The initial concentration of the antibiotic in the aqueous solution is 1-100 mg / L, preferably 5-50 mg / L; and / or The temperature of the adsorption treatment is 10-80°C, preferably 20-40°C; and / or The pH of the aqueous solution is 2.0-11.0, preferably 5.0-7.

0.

10. Use of the biochar adsorption material according to any one of claims 1 to 4, the biochar adsorption material obtained by the preparation method according to any one of claims 5 to 7, or the treatment method according to claim 8 or 9 in resource utilization of wastewater from a plant sugar industry; Preferably, the plant sugar industry wastewater comprises sugar industry wastewater from sugar cane and / or sugar beet.

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