Nanometer zero-valent iron-loaded modified sulfo-based biochar catalyst as well as preparation method and application thereof

Abstract

The invention discloses a nano zero-valent iron loaded modified sulfonic acid-based biochar catalyst and a preparation method and application thereof, and belongs to the technical field of sewage treatment. The surface of the prepared biochar catalyst contains an active sulfonic acid group and a tert-butyl phenyl group; the catalyst prepared by the method provided by the invention has abundant hydrogenation hydrolysis sites, and the surface of the catalyst contains a tert-butylbenzene hydrophobic group, so that the limiting effect of byproduct water on the reaction is effectively reduced, the catalytic efficiency is improved, and the ring opening of a furan ring is promoted; according to the catalyst prepared by the method disclosed by the invention, the nano zero-valent iron is fully dispersed on the surface layer of the carrier, so that the agglomeration phenomenon of the nano zero-valent iron is effectively avoided, the reducing capacity of the nano zero-valent iron is fully exerted, and the degradation of halogenated furan ring substances is promoted.

Description

Technical Field

[0001] The present invention belongs to the technical field of sewage treatment, and in particular relates to a modified sulfonic acid-based biochar catalyst loaded with nanometer zero-valent iron, and a preparation method and application thereof. Background Art

[0002] Activated carbon is one of the most widely used carbon-based materials. With the emergence of coal and oil and the rapid development of modern industry, different types of activated carbon have emerged. Traditional mineral activated carbon and wood activated carbon are widely used in wastewater treatment, catalysis, decolorization and medical and health fields, but they have large pore sizes that are not conducive to adsorption. At the same time, because they contain high impurities, improper use can easily cause environmental pollution. For example, the coal-based activated carbon prepared by hydrothermal or solvent thermal method and its preparation method and application disclosed in patent CN115520863A, the raw coal used in the preparation of activated carbon in the invention has a high content of sulfur, which can easily cause environmental pollution if used improperly.

[0003] The intensive and large-scale development of modern agriculture has broken the waste recycling model of traditional agriculture, which has led to the accumulation of a large amount of agricultural waste, causing serious environmental problems and waste of resources. The use of biomass as raw material to prepare activated carbon has implemented the concept of waste utilization and resource utilization. This move has made great contributions to energy conservation and environmental protection through waste recycling and is increasingly recognized. Biomass materials are renewable, widely available, and inexpensive. The adsorbents prepared with them as raw materials have the advantages of high selectivity, high removal rate, developed pore structure and good adsorption performance, and are used in many fields.

[0004] Nano zero-valent iron materials are more reactive than traditional iron powder or iron filings because of their larger specific surface area and possible nanoscale effects. They are one of the most widely studied nanomaterials in the fields of wastewater treatment, soil and groundwater remediation, and can effectively transform, degrade and remove pollutants in water. Although nano zero-valent iron can effectively transform, degrade and remove pollutants in water, it has the problems of easy agglomeration and easy passivation, which reduces the reaction activity and has an adverse effect on the effective surface area and catalyst performance. In order to solve the related problems, Chinese patent CN118122264A discloses a carbon-loaded nano zero-valent iron material and its preparation and application. The invention uses the wire electric explosion method to load nano zero-valent iron on carbon material to obtain a carbon-loaded nano zero-valent iron material powder, which effectively solves the problem of easy agglomeration of nano zero-valent iron. Although a solution is proposed for the problem of easy agglomeration of nano zero-valent iron, there are problems such as harsh preparation conditions and insufficient reaction stability.

[0005] For catalytic reactions, high catalytic activity is very important. Sulfonic acid catalysts are a type of catalyst containing sulfonic acid groups. Sulfonic acid catalysts stand out among many catalysts due to their catalytic activity advantages. Sulfonic acid catalysts can catalyze esterification, acetalization, etherification, transesterification and ring-opening reactions, etc., and play an important role in the field of acid catalysis. Chinese patent CN114570389A discloses a sulfonic acid carbon catalyst and its preparation method and application. The invention ball-mills the mask under the conditions of 5-sulfosalicylic acid and aluminum sulfate to crack the main component of the mask, polyacrylate, and then promotes its carbonization reaction during the heat treatment process, and forms sulfonic acid catalytic sites on it, and then oxidizes the catalyst to enrich oxygen-containing functional groups, thereby obtaining a sulfonic acid carbon catalyst. The sulfonic acid carbon catalyst prepared by the invention can catalyze the efficient conversion of fructose to 5-hydroxymethylfurfural, but due to the presence of by-product water, the yield of the catalytic product 5-hydroxymethylfurfural is not high, and the catalytic performance of the sulfonic acid catalyst is not fully exerted. At present, the synthesis methods of sulfonic acid catalysts can be roughly divided into two types: direct synthesis and post-modification. The byproduct water produced by these two synthesis methods is easy to cause local deactivation, resulting in reduced catalytic activity of the acid site. Currently, research on exposing more acid sites to further enhance the catalytic performance of sulfonic acid catalysts is also widely underway. Summary of the invention

[0006] The present invention provides a modified sulfonic acid biochar catalyst loaded with nano zero-valent iron, and a preparation method and application thereof. The prepared biochar catalyst has both adsorption capacity and reduction capacity and catalytic performance, can separate halogen elements from furan rings, and can catalyze the opening of furan rings, thereby effectively improving the degradation capacity of halogenated furan ring substances.

[0007] To achieve the above objectives, the present invention adopts the following technical solutions:

[0008] A method for preparing a modified sulfonic acid biochar catalyst loaded with nano zero-valent iron comprises the following steps:

[0009] S1: Add coconut shell to KOH solution, heat at 120℃ for 1h, crush tea oil shell into powder, mix with ZnCl2 in a mass ratio of 1:3 to form an aqueous solution, dry at 110℃ for 2h, add high-temperature activated coconut shell to the mixed solution, place in a tube furnace and heat to 550℃ under N2 atmosphere and keep for 1h, disperse the obtained biochar sample in hydrochloric acid solution, heat at 70℃ for 1h, wash with deionized water until pH reaches 7.0, and place the obtained biochar sample in a vacuum oven and dry at 80℃ for 12h;

[0010] S2: Heat a mixture of biochar, NaOH, 4-aminobenzenesulfonic acid and water in a mass ratio of 2:1:(3-11) to 70°C under stirring, neutralize the sulfonic acid with NaOH, and then add an amount of NaNO2 equal to that of 4-aminobenzenesulfonic acid to the mixed solution;

[0011] S3: Slowly add 8 ml of 4 mol / L hydrochloric acid to the mixed solution, complete the grafting reaction at room temperature, wash with water and acetone until the pH of the filtrate reaches 7.0, and then dry at 80-100°C for 12 hours to obtain sulfonated biochar;

[0012] S4: A mixture of sulfonated biochar, NaOH, tert-butylaniline and an appropriate amount of ethanol and water in a mass ratio of 2:1:(0.2-1) is heated to 70°C under stirring, and after the sulfonic acid is neutralized with NaOH, an amount of NaNO2 equal to that of tert-butylaniline is added to the mixed solution;

[0013] S5: Slowly add 8 ml of 4 mol / L hydrochloric acid to the mixed solution, complete the grafting reaction at room temperature, wash with water and acetone until the pH of the filtrate reaches 7.0, and then dry at 80-100°C for 12 hours to obtain a hydrophobic acidic biochar catalyst;

[0014] S6: Place the biochar catalyst prepared by the above method in 100 ml of 0.1 mol / L FeSO4 aqueous solution, stir evenly under nitrogen, then add 0.2 mol / L NaBH4 solution dropwise at a uniform rate until no bubbles are generated in the mixed solution, stir and let stand for a period of time to obtain a post-reaction solution;

[0015] S7: The post-reaction solution is subjected to solid-liquid separation, ethanol washing, deionized water washing, and drying treatment to obtain a modified sulfonic acid biochar catalyst loaded with nano zero-valent iron.

[0016] The reaction among the mixtures in S1, S2 and S3 is carried out under stirring, and the stirring rate is 120-150 r / min.

[0017] In S6, nitrogen is passed through the mixed solution of biochar catalyst and FeSO4 for 20 to 25 minutes, and then NaBH4 solution is added dropwise at a uniform rate until the reaction is completed. After stirring, the mixture is allowed to stand for 2 to 3 hours.

[0018] The hydrophilicity and hydrophobicity of the biochar catalyst prepared above can be regulated by the amount of 4-aminobenzenesulfonic acid and tert-butylaniline added.

[0019] The biochar catalyst product prepared above is in powder form, and its specific surface area is greater than 1300m 2 / g, and the surface contains active sulfonic acid groups and tert-butylphenyl groups.

[0020] Beneficial effects: The present invention provides a modified sulfonic acid biochar catalyst loaded with nano zero-valent iron and a preparation method and application thereof, which has the following advantages over the prior art:

[0021] (1) The surface of the biochar catalyst of the present invention has both sulfonic acid groups and tert-butylphenyl groups. The sulfonic acid groups have good catalytic performance and can catalyze the furan ring opening. At the same time, the presence of tert-butylphenyl groups can regulate the hydrophilicity and hydrophobicity of the surface of the biochar catalyst, reduce the interference of byproduct water on the catalytic efficiency of the sulfonic acid group, and enable the catalytic ability of the sulfonic acid catalyst to be fully exerted;

[0022] (2) The surface of the biochar catalyst in the present invention is loaded with nano-zero-valent iron. The catalyst prepared by the method of the present invention allows the nano-zero-valent iron to be fully dispersed on the surface of the carrier, effectively avoiding the agglomeration of the nano-zero-valent iron, giving full play to its reducing ability, and promoting the degradation of halogenated furan ring substances; the nano-zero-valent iron has a larger specific surface area and possible nano-scale effects, and is therefore more reactive than traditional iron powder or iron filings. The nano-zero-valent iron can efficiently reduce the halogenated groups in the halogenated furan ring substances, further improving the degradation rate of the halogenated furan ring substances;

[0023] (3) The catalyst material prepared by the present invention has a strong adsorption and catalytic degradation ability for halogenated furan ring substances; at the same time, since the raw materials of the reaction, such as NaOH, tert-butylaniline, NaNO2 and ethanol, are mature industrial raw materials, the method of the present invention has the advantages of simple preparation, low cost, good dispersion of nano zero-valent iron particles, and high degradation efficiency;

[0024] (4) The biochar in the present invention is made of coconut shells, which is a process of converting biomass into high value-added products. Biomass materials are renewable, widely available, and inexpensive. The biochar products made from them have outstanding advantages and effectively solve the problems of low raw material utilization and high production costs in the process of biomass utilization. At the same time, the preparation of activated carbon using biomass as raw material implements the concept of waste utilization and resource utilization, and contributes to energy conservation and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a diagram of the preparation process of a modified sulfonic acid biochar catalyst loaded with nano zero-valent iron in an embodiment of the present invention;

[0026] Figure 2 Schematic diagram of the catalytic conversion rate of 2-chloromethylfuran by the biochar catalyst prepared in Examples 1 to 3 of the present invention and Comparative Example 1. DETAILED DESCRIPTION

[0027] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments:

[0028] Example 1

[0029] like Figure 1 As shown, a method for preparing a modified sulfonic acid biochar catalyst loaded with nanometer zero-valent iron comprises the following steps:

[0030] Add 2g of coconut shell to 100ml of 1mol / L KOH solution and heat at 120℃ for 1h. Crush 0.5g of camellia oleifera shell into powder, mix with 1.5g of ZnCl2 to make 100ml of aqueous solution, and dry in an oven at 110℃ for 2h. Add high-temperature activated coconut shell to the mixed solution of camellia oleifera shell and ZnCl2, place in a tubular furnace and heat to 550℃ under N2 atmosphere and keep for 1h. Disperse the obtained biochar sample in 100ml of 1mol / L hydrochloric acid solution, heat at 70℃ for 1h, and wash with deionized water until the pH reaches 7.0. Place the obtained biochar sample in a vacuum oven and dry at 80℃ for 12h;

[0031] A mixture of 1g biochar, 0.5g NaOH, 1.5g 4-aminobenzenesulfonic acid and water was heated to 70°C at a stirring rate of 150r / min. After the sulfonic acid was neutralized with NaOH, an amount of NaNO2 equal to that of 4-aminobenzenesulfonic acid was added to the mixed solution.

[0032] Slowly add 8 ml of 4 mol / L hydrochloric acid to the mixed solution, complete the grafting reaction at room temperature, wash with water and acetone until the pH of the filtrate reaches 7.0, and then dry at 80°C for 12 hours to obtain a sulfonated biochar catalyst;

[0033] A mixture of 1 g sulfonated biochar, 0.5 g NaOH, 0.1 g tert-butylaniline, an appropriate amount of ethanol and water was heated to 70 °C at a stirring rate of 150 r / min. After the sulfonic acid was neutralized with NaOH, an amount of NaNO2 equal to that of tert-butylaniline was added to the mixed solution.

[0034] Slowly add 8 ml of 4 mol / L hydrochloric acid to the mixed solution, complete the grafting reaction at room temperature, wash with water and acetone until the pH of the filtrate reaches 7.0, and then dry at 80°C for 12 hours to obtain a hydrophobic acidic biochar catalyst;

[0035] The biochar catalyst prepared above was placed in 100 ml of 0.1 mol / L FeSO4 aqueous solution and stirred evenly under nitrogen for 20 min. Then, 0.2 mol / L NaBH4 solution was added dropwise at a uniform rate until no bubbles were generated in the mixed solution. After stirring, the mixture was allowed to stand for 2 h to obtain a post-reaction solution.

[0036] The post-reaction solution is subjected to solid-liquid separation, ethanol washing, deionized water washing, and drying treatment to obtain a modified sulfonic acid biochar catalyst loaded with nano zero-valent iron.

[0037] Example 2

[0038] like Figure 1 As shown, a method for preparing a modified sulfonic acid biochar catalyst loaded with nanometer zero-valent iron comprises the following steps:

[0039] Add 2g of coconut shell to 100ml of 1mol / L KOH solution and heat at 120℃ for 1h. Crush 0.6g of camellia oleifera shell into powder, mix with 1.8g of ZnCl2 to make 100ml of aqueous solution, and dry in an oven at 110℃ for 2h. Add high-temperature activated coconut shell to the mixed solution of camellia oleifera shell and ZnCl2, place in a tubular furnace and heat to 550℃ under N2 atmosphere and keep for 1h. Disperse the obtained biochar sample in 100ml of 1mol / L hydrochloric acid solution, heat at 70℃ for 1h, and wash with deionized water until the pH reaches 7.0. Place the obtained biochar sample in a vacuum oven and dry at 80℃ for 12h;

[0040] A mixture of 1 g of biochar, 0.5 g of NaOH, 3.5 g of 4-aminobenzenesulfonic acid and water was heated to 70°C at a stirring rate of 150 r / min. After the sulfonic acid was neutralized with NaOH, an amount of NaNO2 equal to that of 4-aminobenzenesulfonic acid was added to the mixed solution.

[0041] 8 ml of 4 mol / L hydrochloric acid was slowly added to the mixed solution, and the grafting reaction was completed at room temperature. The filtrate was washed with water and acetone until the pH of the filtrate reached 7.0, and then dried at 90°C for 12 hours to obtain a sulfonated biochar catalyst.

[0042] A mixture of 1 g sulfonated biochar, 0.5 g NaOH, 0.3 g tert-butylaniline, an appropriate amount of ethanol and water was heated to 70 °C at a stirring rate of 150 r / min. After the sulfonic acid was neutralized with NaOH, an amount of NaNO2 equal to that of tert-butylaniline was added to the mixed solution.

[0043] 8 ml of 4 mol / L hydrochloric acid was slowly added to the mixed solution, and the grafting reaction was completed at room temperature. The filtrate was washed with water and acetone until the pH of the filtrate reached 7.0, and then dried at 90°C for 12 hours to obtain a hydrophobic acidic biochar catalyst.

[0044] The biochar catalyst prepared by the above method was placed in 100 ml of 0.1 mol / L FeSO4 aqueous solution and stirred evenly under nitrogen for 22 min. Then, 0.2 mol / L NaBH4 solution was added dropwise at a uniform rate until no bubbles were generated in the mixed solution. After stirring, it was allowed to stand for 2.5 h to obtain a post-reaction solution.

[0045] The post-reaction solution is subjected to solid-liquid separation, ethanol washing, deionized water washing, and drying treatment to obtain a modified sulfonic acid biochar catalyst loaded with nano zero-valent iron.

[0046] Example 3

[0047] like Figure 1 As shown, a method for preparing a modified sulfonic acid biochar catalyst loaded with nanometer zero-valent iron comprises the following steps:

[0048] Add 2g of coconut shell to 100ml of 1mol / L KOH solution and heat at 120℃ for 1h. Crush 0.7g of camellia oleifera shell into powder, mix with 2.1g of ZnCl2 to make 100ml of aqueous solution, and dry in an oven at 110℃ for 2h. Add high-temperature activated coconut shell to the mixed solution of camellia oleifera shell and ZnCl2, place in a tubular furnace and heat to 550℃ under N2 atmosphere and keep for 1h. Disperse the obtained biochar sample in 100ml of 1mol / L hydrochloric acid solution, heat at 70℃ for 1h, and wash with deionized water until the pH reaches 7.0. Place the obtained biochar sample in a vacuum oven and dry at 80℃ for 12h;

[0049] A mixture of 1 g of biochar, 0.5 g of NaOH, 5.5 g of 4-aminobenzenesulfonic acid and water was heated to 70°C at a stirring rate of 150 r / min. After the sulfonic acid was neutralized with NaOH, an amount of NaNO2 equal to that of 4-aminobenzenesulfonic acid was added to the mixed solution.

[0050] 8 ml of 4 mol / L hydrochloric acid was slowly added to the mixed solution, and the grafting reaction was completed at room temperature. The filtrate was washed with water and acetone until the pH of the filtrate reached 7.0, and then dried at 100°C for 12 hours to obtain a sulfonated biochar catalyst.

[0051] A mixture of 1 g sulfonated biochar, 0.5 g NaOH, 0.5 g tert-butylaniline, an appropriate amount of ethanol and water was heated to 70 °C at a stirring rate of 150 r / min. After the sulfonic acid was neutralized with NaOH, an amount of NaNO2 equal to that of tert-butylaniline was added to the mixed solution.

[0052] 8 ml of 4 mol / L hydrochloric acid was slowly added to the mixed solution, and the grafting reaction was completed at room temperature. The filtrate was washed with water and acetone until the pH of the filtrate reached 7.0, and then dried at 100°C for 12 hours to obtain a hydrophobic acidic biochar catalyst.

[0053] The biochar catalyst prepared by the above method was placed in 100 ml of 0.1 mol / L FeSO4 aqueous solution and stirred evenly under nitrogen flow for 25 min. Then, 0.2 mol / L NaBH4 solution was added dropwise at a uniform rate. After stirring, the mixture was allowed to stand for 3 h to obtain a post-reaction solution.

[0054] The post-reaction solution is subjected to solid-liquid separation, ethanol washing, deionized water washing, and drying treatment to obtain a modified sulfonic acid biochar catalyst loaded with nano zero-valent iron.

[0055] The mechanism diagram of preparing the biochar catalyst loaded with nano zero-valent iron in Examples 1 to 3 is as follows Figure 1 As shown. The biochar product made of coconut shell raw materials and subjected to a two-step activation process is mixed with NaOH, 4-aminobenzenesulfonic acid and hydrochloric acid to react, and active benzenesulfonic acid groups are grafted on the surface of the biochar. Then, the sulfonated biochar is mixed with NaOH, tert-butylaniline and hydrochloric acid to react, and tert-butylphenyl groups are further grafted on the surface of the biochar. The hydrophilicity and hydrophobicity of the prepared biochar catalyst can be regulated by the amount of the added sulfonation reagent (4-aminobenzenesulfonic acid) and hydrophobic reagent (tert-butylaniline). Finally, the biochar catalyst prepared according to the above steps is reacted with FeSO4 aqueous solution and NaBH4 solution under nitrogen flow, and nano zero-valent iron is loaded on the surface of the biochar catalyst by liquid phase reduction method, that is, a modified sulfonic acid biochar catalyst product loaded with nano zero-valent iron is obtained.

[0056] Comparative Example 1

[0057] Add 2g of coconut shell to 100ml of 1mol / L KOH solution and heat at 120℃ for 1h. Crush 0.7g of camellia oleifera shell into powder, mix with 2.1g of ZnCl2 to make 100ml of aqueous solution, and dry in an oven at 110℃ for 2h. Add high-temperature activated coconut shell to the mixed solution of camellia oleifera shell and ZnCl2, place in a tubular furnace and heat to 550℃ under N2 atmosphere and keep for 1h. Disperse the obtained biochar sample in 100ml of 1mol / L hydrochloric acid solution, heat at 70℃ for 1h, and wash with deionized water until the pH reaches 7.0. Place the obtained biochar sample in a vacuum oven and dry at 80℃ for 12h;

[0058] A mixture of 1 g of biochar, 0.5 g of NaOH, 5.5 g of 4-aminobenzenesulfonic acid and water was heated to 70°C at a stirring rate of 150 r / min. After the sulfonic acid was neutralized with NaOH, an amount of NaNO2 equal to that of 4-aminobenzenesulfonic acid was added to the mixed solution.

[0059] 8 ml of 4 mol / L hydrochloric acid was slowly added to the mixed solution, and the grafting reaction was completed at room temperature. The filtrate was washed with water and acetone until the pH of the filtrate reached 7.0, and then dried at 100°C for 12 hours to obtain a sulfonated biochar catalyst.

[0060] Test Case

[0061] The modified sulfonic acid biochar catalyst loaded with nano zero-valent iron prepared in Examples 1 to 3 and Comparative Example 1 was placed in a 200 ml conical flask, and 100 ml of a properly prepared 2000 mg / L 2-chloromethylfuran solution was added in sequence. The reaction was carried out at 130° C. for 0.5 h. The residual concentration of 2-chloromethylfuran in the solution after the reaction was measured by a gas chromatograph. The catalytic conversion rate of the prepared biochar catalyst to 2-chloromethylfuran was calculated based on the difference between the initial concentration and the residual concentration. The specific catalytic conversion rate of 2-chloromethylfuran is shown in Table 1. In Tables 1 and Figure 2 , Example 1 is represented by E1, Example 2 is represented by E2, Example 3 is represented by E3, and Comparative Example 1 is represented by F1.

[0062] Table 1 Catalytic conversion rate of 2-chloromethylfuran by biochar catalyst prepared in Examples 1 to 3

[0063]

[0064] From Table 1 and Figure 2It can be seen that the modified sulfonic acid biochar catalyst loaded with nano zero-valent iron prepared by the present invention can achieve efficient catalytic conversion of 2-chloromethylfuran in a relatively short time. Under the reaction conditions of 130°C and 0.5h of reaction time, the catalytic conversion rate is above 90%. In contrast, the catalytic conversion rate of 2-chloromethylfuran under the same conditions of the ordinary sulfonated biochar catalyst is less than 60%, indicating that the modified sulfonic acid biochar catalyst loaded with nano zero-valent iron provided by the present invention has excellent catalytic conversion performance of halogenated furan ring substances.

[0065] The above are only preferred embodiments of the present invention, which will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be pointed out that for those skilled in the art, without departing from the concept of the present invention, several modifications and improvements made are all protected by the present invention.

Claims

1. A method for preparing a modified sulfonic acid biochar catalyst loaded with nano zero-valent iron, characterized in that: The following steps are involved: S1: Heat a mixture of biochar, NaOH, 4-aminobenzenesulfonic acid and water under stirring, neutralize the sulfonic acid with NaOH, and then add an amount of NaNO2 equal to that of 4-aminobenzenesulfonic acid to the mixed solution; S2: slowly adding hydrochloric acid to the above mixed solution, completing the grafting reaction, washing until the pH of the filtrate reaches 7.0, and drying to obtain sulfonated biochar; S3: The mixture of sulfonated biochar, NaOH, tert-butylaniline, ethanol and water is heated under stirring, and after the sulfonic acid is neutralized with NaOH, an amount of NaNO2 equal to that of tert-butylaniline is added to the mixed solution; S4: slowly adding hydrochloric acid to the mixed solution to complete the grafting reaction, washing until the pH of the filtrate reaches 7.0, and drying to obtain a hydrophobic acidic biochar catalyst; S5: placing the biochar catalyst prepared above in an FeSO4 aqueous solution, stirring it evenly under nitrogen flow, then adding NaBH4 solution dropwise at a uniform rate until no bubbles are generated in the mixed solution, stirring and then letting it stand; After solid-liquid separation, washing and drying, a modified sulfonic acid biochar catalyst loaded with nano zero-valent iron is obtained.

2. The method for preparing the modified sulfonic acid biochar catalyst loaded with nano zero-valent iron according to claim 1, characterized in that: The preparation method of biochar in S1 is as follows: adding coconut shell to KOH solution, heating at 120°C for 1 hour, crushing tea oil shell into powder, mixing with ZnCl2 in a mass ratio of 1:3 to form an aqueous solution, drying at 110°C for 2 hours, adding high-temperature activated coconut shell to the mixed solution, heating to 550°C under N2 atmosphere and maintaining for 1 hour, dispersing the obtained biochar sample in hydrochloric acid solution, heating at 70°C for 1 hour, washing with deionized water until the pH reaches 7.0, and placing the obtained biochar sample in a vacuum oven at 80°C for 12 hours for use.

3. The method for preparing the modified sulfonic acid biochar catalyst loaded with nano zero-valent iron according to claim 2, characterized in that: The mass ratio of the biochar, NaOH and 4-aminobenzenesulfonic acid is 2:1:(3-11).

4. The method for preparing the modified sulfonic acid biochar catalyst loaded with nano zero-valent iron according to claim 1, characterized in that: The stirring rate is 120-150 r / min.

5. The method for preparing the modified sulfonic acid biochar catalyst loaded with nano zero-valent iron according to claim 1, characterized in that: In S5, nitrogen is passed through the mixed solution of biochar catalyst and FeSO4 for 20 to 25 minutes.

6. The method for preparing the modified sulfonic acid biochar catalyst loaded with nano zero-valent iron according to claim 1, characterized in that: After stirring, let stand for 1 to 2 hours.

7. The method for preparing the modified sulfonic acid biochar catalyst loaded with nano zero-valent iron according to claim 1, characterized in that: The hydrophilicity and hydrophobicity of the prepared biochar catalyst were regulated by the amount of 4-aminobenzenesulfonic acid and tert-butylaniline.

8. The modified sulfonic acid biochar catalyst loaded with nano zero-valent iron prepared by the method according to any one of claims 1 to 7, characterized in that: The surface of the biochar catalyst contains active sulfonic acid groups and tert-butylphenyl groups.

9. The modified sulfonic acid biochar catalyst loaded with nano zero-valent iron according to claim 8, characterized in that: The biochar catalyst is in powder form with a specific surface area greater than 1300m 2 / g.

10. The use of the modified sulfonic acid biochar catalyst loaded with nano zero-valent iron according to any one of claims 8 to 9, characterized in that: The biochar catalyst is used for the degradation of halogenated furan ring substances.

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