Preparation method and application of charcoal-based sponge material
By preparing biochar-based sponge materials, the problems of easy loss of biochar powder and high iron loading were solved, achieving efficient degradation of organic pollutants in water, adapting to complex water quality, reducing costs and making it easy to recycle, and suitable for practical engineering applications.
Patent Information
- Application Number
- CN202511049943.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-29
- Publication Date
- 2025-11-07
AI Technical Summary
Existing biochar powder materials are prone to loss, clogging, and difficult to recycle in water treatment. Furthermore, their high iron loading leads to increased costs and makes it difficult to efficiently degrade organic pollutants in complex water conditions.
Biochar-based sponge material was prepared using sugarcane bagasse and Fenton sludge. A three-dimensional porous structure was formed through hydrothermal treatment and pyrolysis. Biochar was then fixed using sodium alginate crosslinking technology to form a stable core-shell structure, which was then loaded onto polyurethane sponge. Organic pollutants were degraded by persulfate catalysis.
This study achieves efficient degradation of pollutants using biochar materials, facilitates easy recycling, adapts to complex water qualities, reduces preparation costs, and improves catalytic activity and stability, making it suitable for large-scale practical applications.
Smart Images
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Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of new materials for treating pollutants, and particularly relates to a preparation method of a biochar-based sponge material and application thereof. BACKGROUND
[0002] With the rapid development of industry, a large amount of organic pollutants are generated, and the discharge of organic pollutants into water bodies has caused great threat to ecological environment systems and human life safety. At present, the treatment of organic pollutants in water mainly includes adsorption, biodegradation and chemical oxidation. The adsorption method uses materials such as activated carbon to enrich pollutants, the biodegradation method decomposes organic matter through microorganisms, and the chemical oxidation method efficiently removes refractory organic matter through the generation of oxidizing species. Among them, the advanced oxidation method is the most commonly used chemical method for removing organic pollutants in water. However, the traditional treatment methods have the following defects: the adsorption method only transfers organic matter and cannot truly remove it; the microbial method is greatly affected by the environment; and the chemical oxidation method relies on high-priced reagents or high-energy-consumption equipment.
[0003] Biochar has the advantages of large specific surface area, developed pore structure, stable structure, low cost, low toxicity and renewability, is a widely sourced and environmentally friendly material, has good effect in environmental pollution control, and can be compounded with other elements (N / Fe / Cu) to improve its performance. At present, the biochar modified by iron retains the original adsorption performance of biochar, and significantly improves the catalytic activity through the introduction of iron species, especially the activation ability of persulfate, which can efficiently degrade refractory organic pollutants. However, the additional addition of iron source increases the cost of preparation, and too high iron loading easily blocks the pore structure of the carbon material.
[0004] In addition, in order to fully realize the thermal conversion of biomass raw materials, the existing biochar materials are generally pyrolyzed in powder state. Although the powder biochar shows excellent catalytic activity, it still faces problems such as easy loss, frequent blockage and difficult recovery in actual water treatment engineering applications, which restricts its large-scale practical application.
[0005] Therefore, it is urgent to develop a biochar formed material which can efficiently degrade pollutants, is easy to recover and is suitable for complex water quality to meet the actual engineering application requirements. SUMMARY
[0006] The technical problem to be solved by the present application is to provide a preparation method of a biochar-based sponge material and application thereof. The biochar-based sponge material obtained by the method can efficiently degrade pollutants, is easy to recover and can adapt to complex water quality, solves the problems of poor dispersibility, high iron leaching rate and low mass transfer efficiency of traditional powder biochar, and has good effect in removing organic pollutants 2,4-dichlorophenol in water by using the biochar-based sponge material to activate the oxidant persulfate.
[0007] The present application solves the above technical problems by the following technical scheme:
[0008] The present application discloses a preparation method of a biochar-based sponge material, comprising the following operation steps:
[0009] (1) Dry and grind bagasse and Fenton sludge, mix them according to a mass ratio of 1:2, add chelating agent polyethylene glycol, the amount of polyethylene glycol added is 20% of the total amount of the mixture of bagasse and Fenton sludge, then put them into a hydrochloric acid solution with a pH value of 2, fully mix and stir for 12 hours, the solid-liquid ratio in the mixing system is 1:10 (g / mL), then transfer the mixed solution to an autoclave, react at 190℃ for 12 hours, filter and dry to obtain a hydrothermal biochar precursor in powder form;
[0010] (2) Put the hydrothermal biochar precursor obtained in step (1) into a tube furnace, pyrolyze it under a nitrogen atmosphere, the heating rate during pyrolysis is 5℃ / min, keep the temperature at 900℃ for 2 hours after reaching 900℃, then naturally cool to room temperature, put it into a hydrochloric acid solution with a pH value of 4, the solid-liquid ratio in this process is 1:200 (g / mL), after acid washing, obtain a co-pyrolysis biochar;
[0011] (3) Add the co-pyrolysis biochar in step (2) into a sodium alginate aqueous solution with a mass concentration of 2%, the solid-liquid ratio in the mixing system is 1:100 (g / mL), fully stir to form a uniformly dispersed suspension solution, then add several pieces of polyurethane sponge, fully stir to make the suspension completely loaded on the pores of the sponge, then take out the polyurethane sponge and transfer it to a calcium chloride solution with a concentration of 50g / L for cross-linking and solidification, after solidification, freeze-dry to obtain a biochar-based sponge material.
[0012] In step (1) of the present application, the bagasse and Fenton sludge are ground through a 100-mesh sieve.
[0013] In step (1) of the present application, after filtration, dry at room temperature or 60℃ for 12 hours.
[0014] In step (2) of the present application, the acid washing time is 60 minutes.
[0015] In step (3) of the present application, after adding the sodium alginate aqueous solution, stir for 12 hours; each piece of polyurethane sponge has a size of 1cm×1cm×1cm, after adding the polyurethane sponge, stir for 30 minutes; 50ml of calcium chloride solution is needed for each piece of polyurethane sponge; the cross-linking and solidification time is 12 hours.
[0016] In step (3) of the present application, the freeze-drying refers to freezing at-50℃ for 24 hours to shape.
[0017] The application of the biochar-based sponge material: the biochar-based sponge material is used for removing organic pollutants 2,4-dichlorophenol in water by catalytic oxidant persulfate.
[0018] The persulfate is peroxodisulfate (PDS).
[0019] The application has the following beneficial effects:
[0020] (1) In the preparation of the biochar-based sponge, the polyurethane sponge is taken out and put into a calcium chloride solution for solidification, and the biochar-based sponge material is prepared after freeze-drying. The solidification process is derived from the ionic crosslinking between sodium alginate and calcium ions. The calcium ions in the solution are coordinated with the carboxylate ions on the molecular chain of sodium alginate to form a stable "egg-box" structure gel network. This network effectively coats and fixes the biochar particles loaded in the pores of the polyurethane sponge, and finally obtains a biochar-based sponge material with a three-dimensional porous structure.
[0021] (2) The bagasse used in the application can provide a rich pore structure carbon skeleton, and the Fenton sludge can provide an iron source, thereby constructing an active center.
[0022] (3) In the hydrothermal treatment, the iron species can promote the hydrolysis and self-assembly of biomass components lignin and cellulose, which is conducive to the reconstruction of carbon configuration and the distribution of iron components, forming a precursor with an iron core as the center and carbon components coated outside. Then, through the action of pyrolysis, the core-shell precursor is further carbonized to strengthen the iron-carbon interface bonding, and finally the modified biochar is obtained.
[0023] (4) The polyurethane sponge carrier used in the application can provide three-dimensional through pores with a pore size of 50-1000 μm, which is beneficial to the loading of biochar. Sodium alginate forms a gel network coating biochar through Ca 2+ crosslinking, realizing the fixation of biochar.
[0024] (5) The biomass raw material used in the application is waste, which can significantly reduce the cost of raw materials. The biochar-based sponge material prepared has no obvious difference in pollutant removal performance compared with traditional powder materials, has a good prospect in modular preparation, and has a simple preparation process, strong operability, easy recovery, is suitable for large-scale production and practical application, and the reagents used are all environmentally friendly reagents, non-toxic and harmless. BRIEF DESCRIPTION OF DRAWINGS
[0025] Figure 1 SEM images of co-pyrolysis biochar before and after acid washing in Example 1 of the application, wherein a is the biochar before acid washing, and b is the co-pyrolysis biochar after acid washing.
[0026] Figure 2SEM image of the biochar-based sponge material prepared for Example 1 of the present application.
[0027] Figure 3 Figure for the effect of different biochar on the removal of 2,4-dichlorophenol by catalyzing peroxymonosulfate.
[0028] Figure 4 Figure for the removal efficiency of pollutants by the co-pyrolysis biochar in Example 1 and the biochar-based sponge material of the present application in different water matrices.
[0029] Figure 5 Figure for the removal efficiency of pollutants by the biochar-based sponge material of the present application in the recycling experiment. DETAILED DESCRIPTION
[0030] The technical solutions of the present application will be described in detail below in conjunction with specific embodiments. The following examples will help those skilled in the art to further understand the present application, but do not limit the present application in any form. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made. These all belong to the protection scope of the present application.
[0031] Example 1
[0032] The preparation method of the biochar-based sponge material of the present application is as follows:
[0033] 1. After the bagasse and Fenton sludge are completely dried, they are ground through a 100-mesh sieve, mixed in a mass ratio of 1:2, 20% of polyethylene glycol is added as a chelating agent, and a pH = 2 hydrochloric acid solution is added and stirred for 12 h to make them fully mixed. The solid-liquid ratio in the mixed system is 1:10 (g / ml), and then the mixed solution is transferred to an autoclave, reacted at 190℃ for 12 h, filtered, and dried at room temperature for 12 h to obtain a powder-shaped hydrothermal biochar precursor;
[0034] 2. The hydrothermal biochar precursor of step 1 is placed in a tube furnace and pyrolyzed under a nitrogen atmosphere. The heating rate during pyrolysis is 5℃ / min, the temperature is kept at 900℃ for 2 h, and then naturally cooled to room temperature to obtain a biochar material, which is named S12F@BC. The S12F@BC is added to a pH = 4 hydrochloric acid solution for acid washing for 60 min, and the solid-liquid ratio in the acid washing mixed solution is 1:200 (g / ml). After acid washing, a co-pyrolysis biochar is obtained, which is named S12F@HBC.
[0035] 3. The co-pyrolysis biochar S12F@HBC of step 2 is added into a 2% sodium alginate aqueous solution, and the dosage ratio of S12F@HBC to the sodium alginate aqueous solution is 1:100 (g / ml). After being stirred for 12 hours, a uniformly dispersed suspension mixture is formed. Then, a number of polyurethane sponges with a size of 1cm*1cm*1cm are added and stirred for 30 minutes, so that the suspension is completely loaded on the pores of the polyurethane sponges. After the polyurethane sponges are taken out, they are transferred into a calcium chloride solution with a concentration of 50g / L, and 50ml of the calcium chloride solution is needed for each polyurethane sponge. Cross-linking and solidification are performed, and after being solidified for 12 hours, the polyurethane sponges are frozen and dried at-50℃ for 24 hours, so that the biochar-based sponge material of the application is obtained, which is named as S12F@HBC·SS.
[0036] The sodium alginate used in the embodiment is food grade, and the polyurethane sponge is ordinary type.
[0037] In the embodiment, the SEM images of the co-pyrolysis biochar before and after acid washing are shown in Figure 1 The a in the figure is the co-pyrolysis biochar S12F@BC, and the b in the figure is the co-pyrolysis biochar S12F@HBC after acid washing. Figure 1 It can be seen that the iron species attached to the surface of the co-pyrolysis biochar is selectively removed after the acid washing step, which reduces the leaching amount of Fe in the reaction process, so that the Fe content in the solution after the reaction is as low as the surface water environmental quality standard (GB 3838-2002). The SEM images of the biochar-based sponge material S12F@HBC·SS in the embodiment are shown in Figure 2 The a in the figure is the biochar-based sponge material under 100μm, and the b in the figure is the biochar-based sponge material under 500nm. Figure 2 It can be seen that the biochar is loaded in the three-dimensional structure of the polyurethane sponge.
[0038] Comparative Example 1
[0039] The raw bagasse is naturally air-dried and ground through a 100-mesh sieve to obtain bagasse powder. Then, the bagasse powder is added into a hydrochloric acid solution with pH=2 at a solid-liquid ratio (w / v) of 1:10 (g / mL), stirred for 12 hours, and then put into an autoclave for hydrothermal treatment at 190℃ for 12 hours. Subsequently, the product is filtered and dried, and then put into a tube furnace for pyrolysis under a nitrogen atmosphere. The heating rate during pyrolysis is 5℃ / min, and after the temperature reaches 900℃, the product is kept at this temperature for 2 hours, and then naturally cooled to room temperature to obtain raw bagasse biochar. After acid washing to remove impurities, the bagasse biochar is obtained, which is named as SHBC.
[0040] Comparative Example 2
[0041] The original Fenton sludge was naturally air-dried and ground through a 100-mesh screen to obtain Fenton sludge powder. The Fenton sludge powder was added to a hydrochloric acid solution with a solid-liquid ratio (w / v) of 1:10 (g / mL) at pH 2, stirred for 12 h, and then placed in a hydrothermal kettle. The product was heated at 190°C for 12 h, then filtered and dried, and then placed in a tube furnace for pyrolysis under a nitrogen atmosphere. The heating rate during pyrolysis was 5°C / min, and the temperature was maintained at 900°C for 2 h before being naturally cooled to room temperature to obtain the original Fenton sludge biochar. Impurities were removed by acid washing to obtain the Fenton sludge biochar, designated as FHBC.
[0042] Comparative Example 3
[0043] The bagasse and Fenton sludge were dried and ground through a 100-mesh screen, mixed in a mass ratio of 1:2, and then 20% of the total mass of the mixture was added as a chelating agent. The mixture was then added to a hydrochloric acid solution with a solid-liquid ratio of 1:10 (g / mL) at pH 2, mixed thoroughly, stirred for 12 h, filtered and dried, and then placed in a tube furnace for pyrolysis under a nitrogen atmosphere. The heating rate during pyrolysis was 5°C / min, and the temperature was maintained at 900°C for 2 h before being naturally cooled to room temperature to obtain the co-pyrolysis biochar. Impurities were removed by acid washing to obtain the bagasse / Fenton sludge co-pyrolysis biochar, designated as SFHBC.
[0044] Performance Test
[0045] Experiment 1
[0046] The products of Example 1 and Comparative Examples 1-3 were applied in the degradation of organic pollutants in water bodies by activated persulfate, specifically for treating 2,4-dichlorophenol wastewater. The operation method included the following steps:
[0047] (1) 10 mg of co-pyrolysis biochar S12F@HBC (A) after acid washing in Example 1, 10 mg of bagasse biochar SHBC (B) after acid washing in Comparative Example 1, 10 mg of Fenton sludge biochar FHBC (C) after acid washing in Comparative Example 2, and 10 mg of bagasse / Fenton sludge co-pyrolysis biochar SFHBC (D) after acid washing in Comparative Example 3 were placed in a conical flask (250 mL) containing a 50 mL solution of 2,4-dichlorophenol with a pollutant concentration of 50 mg / L.
[0048] (2) 23.8 mg of peroxydisulfate (PDS) was added to the conical flask in step (1), i.e. the concentration of peroxydisulfate in the solution was 2 mM, to trigger the oxidative degradation reaction. The reaction lasted for 120 min to complete the degradation treatment of 2,4-dichlorophenol in the water body.
[0049] The control group PS: only add peroxodisulfate (PDS), do not add biochar material, and other conditions are the same. During the treatment, samples were taken at different treatment times to determine the concentration of 2,4-dichlorophenol, thereby obtaining the removal effect data of different biochar materials on 2,4-dichlorophenol, as shown in Table 1.
[0050] Table 1 Removal effect data of different biochar materials on 2,4-dichlorophenol
[0051] PDS A / PDS B / PDS C / PDS D / PDS Removal rate 8.9％ 98.5％ 62.7％ 56.3％ 74.1％
[0052] The removal effect of different biochar materials in Examples 1, Comparative Examples 1, 2 and 3 on the degradation of 2,4-dichlorophenol by activated persulfate is shown in Table 1. Figure 3
[0053] As can be seen from Table 1 and Figure 3 Compared with the peroxodisulfate (PDS) test alone and the control test of biochar (B, C and D) without hydrothermal-co-pyrolysis treatment, the removal rate of 2,4-dichlorophenol in water by activated peroxodisulfate in the co-pyrolysis biochar (S12F@HBC) in the present application is significantly better than that of single biochar material without hydrothermal or co-pyrolysis. Compared with biochar without hydrothermal treatment, hydrothermal pretreatment promotes the uniform combination of iron species and carbon matrix, forming a stable structure, significantly improving the density and stability of the catalytic active site; compared with single biochar without co-pyrolysis, the co-pyrolysis process, through the synergistic effect of sugarcane residue porous carbon skeleton and Fenton sludge iron species, maintains the catalytic activity while significantly inhibits the leaching of iron, thereby achieving efficient and persistent degradation of pollutants and effectively reducing the risk of 2,4-dichlorophenol pollutants to the ecosystem.
[0054] At the same time, as can be seen from Table 1, SHBC, FHBC and SFHBC in the three comparative examples cannot effectively activate peroxodisulfate to achieve effective degradation of 2,4-dichlorophenol, and the removal effect on 2,4-dichlorophenol in water is poor, especially the removal performance of biochar FHBC prepared from original Fenton sludge is poor, the fundamental reason of which is that the dense pore structure is difficult to adsorb pollutants, and at the same time, the iron species cannot be effectively combined, so as to be difficult to activate peroxodisulfate.
[0055] Experiment 2:
[0056] The application of the biochar-based sponge material in the present application in the degradation of organic pollutants in water by activated persulfate is specifically for treating 2,4-dichlorophenol wastewater, and the operation method comprises the following steps:
[0057] (1) Take 10 mg of the co-pyrolysis biochar S12F@HBC(A) after acid washing in Example 1 of the present application, and take 2 pieces of the biochar-based sponge material S12F@HBC·SS(B) prepared in Example 1 (length x width x height = 1 x 1 x 1 cm) and place them in a conical flask (250 mL) containing a 2,4-dichlorophenol solution with a volume of 50 mL and a pollutant concentration of 50 mg / L.
[0058] (2) Add 23.8 mg of peroxydisulfate (PDS) to the conical flask in step (1), i.e. the concentration of peroxydisulfate in the solution is 2 mM, to trigger the oxidative degradation reaction, and the reaction duration is 120 min to complete the degradation treatment of 2,4-dichlorophenol in the water body.
[0059] The 2,4-dichlorophenol removal effect data of the co-pyrolysis biochar material S12F@HBC and the biochar-based sponge material S12F@HBC·SS under the same conditions are shown in Table 2.
[0060] Table 2: 2,4-dichlorophenol removal effect data of two materials under the same conditions
[0061] S12F@HBC / PDS S12F@HBC·SS / PDS Removal rate 98.5％ 95.2％
[0062] As can be seen from Table 2, after loading the co-pyrolysis biochar on the sponge to form the biochar-based sponge material, it still exhibits good removal ability for 2,4-dichlorophenol. The reason is that the biochar-based sponge material S12F@HBC·SS enhances the adsorption and enrichment of pollutants through a three-dimensional porous structure, and the uniformly fixed active sites solve the problem of easy loss of powder materials while maintaining high-efficiency catalytic performance, making it more stable and operable in actual wastewater treatment.
[0063] Experiment 3:
[0064] The application of the biochar-based sponge material of the present application in the degradation of organic pollutants in different water bodies by activated peroxydisulfate, specifically the use of the biochar-based sponge material to treat 2,4-dichlorophenol in different water substrates, includes the following steps:
[0065] (1) Take 10 mg of the co-pyrolysis biochar S12F@HBC(A) after acid washing in Example 1, and take 2 pieces of the biochar-based sponge material S12F@HBC·SS(B) prepared in Example 1 (length x width x height = 1 x 1 x 1 cm) and place them in a conical flask (250 mL) containing a 2,4-dichlorophenol solution with a volume of 50 mL and a pollutant concentration of 50 mg / L in tap water, river water, and lake water as the water substrate.
[0066] (2) Add 23.8 mg of peroxydisulfate (PDS) to the conical flask in step (1), that is, the peroxydisulfate concentration in the solution is 2 mM, trigger the oxidative degradation reaction, the reaction duration is 120 min, complete the degradation treatment of 2,4-dichlorophenol in the water body.
[0067] The co-pyrolysis biochar S12F@HBC and the biochar-based sponge material S12F@HBC·SS were used to remove 2,4-dichlorophenol in different water bodies, and the results are shown in Figure 4
[0068] As can be seen from Figure 4 , the co-pyrolysis biochar (S12F@HBC) and the biochar-based sponge material (S12F@HBC·SS) can effectively degrade 2,4-dichlorophenol in tap water, river water and lake water and other different water matrices, among which the powder material shows excellent activity in low interference water samples, while the sponge material exhibits stronger anti-interference ability and stability in complex water bodies containing high concentrations of organic matter and coexisting ions due to its three-dimensional porous structure, and its mechanical strength also solves the engineering problem of easy loss of powder material, making it more suitable for actual wastewater treatment scenarios.
[0069] Experiment 4:
[0070] The application of the biochar-based sponge material in activating persulfate to degrade organic pollutants in water bodies, specifically the recycling ability test of the biochar-based sponge material in treating 2,4-dichlorophenol wastewater, includes the following steps:
[0071] (1) Take 2 pieces (length x width x height = 1 x 1 x 1 cm) of the biochar-based sponge material S12F@HBC·SS prepared in Example 1 and place them in conical flasks (250 mL) containing 50 mL of 2,4-dichlorophenol solution with a pollutant concentration of 50 mg / L.
[0072] (2) Add 23.8 mg of peroxydisulfate (PDS) to the conical flask in step (1), that is, the peroxydisulfate concentration in the solution is 2 mM, trigger the oxidative degradation reaction, the reaction duration is 120 min, complete the degradation treatment of 2,4-dichlorophenol in the water body.
[0073] (3) After the reaction in step (2) above, the biochar-based sponge material is washed with ethanol and ultrapure water alternately for three times, and after freeze-drying, the above steps (1) and (2) are repeated.
[0074] The removal effect data of 2,4-dichlorophenol by the biochar-based sponge material after multiple cycles under different time conditions are shown in Figure 5
[0075] After five cycles of use, the biochar-based sponge material S12F@HBC·SS still maintains a 2,4-dichlorophenol removal rate of more than 80%, which is due to its unique structure effectively inhibiting the leaching and oxidation of active iron species, and the three-dimensional porous network not only provides stable mechanical support, but also ensures efficient mass transfer of reactants and products. Experimental results show that the biochar-based sponge material successfully overcomes the defects of traditional powder catalysts, such as easy deactivation and difficult recovery, and its stable catalytic performance and good structural integrity provide reliable technical support for actual wastewater treatment projects, showing significant application potential and commercial value.
[0076] The above examples are only preferred embodiments of the present application, and the protection scope of the present application is not limited to the above examples. Any technical solutions falling within the concept of the present application shall fall within the protection scope of the present application. It should be pointed out that, for ordinary skilled persons in the art, improvements and refinements without departing from the principles of the present application shall also be considered as the protection scope of the present application.
Claims
1. A method of producing a biochar-based sponge material, characterized by, The method comprises the following operation steps: (1) The bagasse and Fenton sludge are dried and ground through a sieve, mixed according to a mass ratio of 1:2, then a chelating agent polyethylene glycol is added, the amount of the polyethylene glycol added is 20% of the total amount of the bagasse and Fenton sludge mixture, then the mixture is fully mixed and stirred in a hydrochloric acid solution with a pH value of 2 for 12 hours, the solid-liquid ratio in the mixture system is 1:10 (g / mL), then the mixed solution is transferred to a hydrothermal kettle, and reaction is carried out at 190 DEG C for 12 hours, and after filtration and drying, a hydrothermal biochar precursor in powder form is obtained; (2) The hydrothermal biochar precursor obtained in step (1) is placed in a tube furnace and pyrolyzed under a nitrogen atmosphere, the heating rate during pyrolysis is 5 DEG C / min, the temperature is kept at 900 DEG C for 2 hours after reaching 900 DEG C, then the temperature is naturally cooled to room temperature, and then the pyrolyzed biochar is obtained after acid washing in a hydrochloric acid solution with a pH value of 4, the solid-liquid ratio in the process is 1:200 (g / mL); (3) The pyrolyzed biochar obtained in step (2) is added to a sodium alginate aqueous solution with a mass concentration of 2%, the solid-liquid ratio in the mixture system is 1:100 (g / mL), after fully stirring, a uniformly dispersed suspension solution is formed, several pieces of polyurethane sponge are added and fully stirred to make the suspension completely loaded on the pores of the sponge, then the sponge is taken out and transferred to a calcium chloride solution with a concentration of 50 g / L for cross-linking and solidification, and after solidification, the biochar-based sponge material is obtained by freeze-drying.
2. The method of claim 1, wherein the biochar-based sponge material is prepared by the steps of: In step (1), the bagasse and Fenton sludge are dried and ground through a 100-mesh sieve.
3. The method of claim 1, wherein the biochar-based sponge material is prepared by the steps of: In step (1), the filtration is followed by drying at room temperature or 60 DEG C for 12 hours.
4. The method of claim 1 or 2, wherein the biochar-based sponge material is prepared by the steps of: In step (2), the acid washing time is 60 minutes.
5. The method of claim 1 or 2, wherein the biochar-based sponge material is prepared by the steps of: In step (3), the stirring time after adding the sodium alginate aqueous solution is 12 hours; the size of each piece of polyurethane sponge is 1 cm x 1 cm x 1 cm, and the stirring time after adding the polyurethane sponge is 30 minutes; 50 ml of the calcium chloride solution is required for each piece of polyurethane sponge; and the cross-linking and solidification time is 12 hours.
6. The method of claim 1 or 2, wherein the biochar-based sponge material is prepared by the steps of: In step (3), the freeze-drying refers to freeze-drying at-50 DEG C for 24 hours for shaping.
7. Use of the biochar-based sponge material according to claims 1 to 6, characterized in that The biochar-based sponge material is used for removing organic pollutants 2,4-dichlorophenol in water by catalytic oxidation of a persulfate salt.
8. Use of the biochar-based sponge material according to claim 7, characterized in that The persulfate salt is peroxodisulfate (PDS).