Activated edible fungus residue biochar as well as preparation method and application thereof

Abstract

The invention discloses activated edible fungus residue biochar as well as a preparation method and application thereof, and aims to provide activated edible fungus residue biochar which is obtained by taking edible fungus residues as a carbon source, pre-carbonizing materials, performing alkali activation and then performing high-temperature carbonization, and the preparation method is simple and convenient to operate and low in cost; the activated edible fungus residue biochar realizes degradation of 4-chlorophenol and tetracycline in water by peroxydisulfate with a very small amount, solves the problems of low catalytic efficiency and large addition amount of a current transition metal catalyst, and belongs to the field of environmental governance.

Description

Technical Field

[0001] The present invention belongs to the technical field of advanced oxidation, and specifically relates to a carbon material and a biochar catalyst, and also relates to a preparation method and application of the catalyst, belonging to the technical field of environmental governance. Background Art

[0002] Phenolic compounds (R-OH) refer to compounds formed by substituting hydrogen atoms on the benzene ring of aromatic hydrocarbons with other groups, and are widely used in fields such as petrochemical industry, printing and dyeing, food processing, and chemical production. However, during the manufacturing and use processes, if the treatment and operation are improper, the leaked phenolic compounds will degrade to produce phenolic pollutants, which will penetrate into the water source through the soil, posing a non-negligible hazard to the health of animals and humans.

[0003] Currently, the removal of phenolic compounds in water usually adopts adsorption method, photo-Fenton method, and oxidation processes (AOPs) based on sulfate radical technology. Although the adsorption method can effectively remove phenolic compounds in water, the regeneration and treatment problems of the adsorbent are relatively complex. In addition, the removal effect on some phenolic compounds is poor, and during the treatment process of the adsorption method, there may be a chemical reaction between the adsorbent and the target pollutant, resulting in a decrease in the treatment effect. The photo-Fenton method requires specific light conditions, has high requirements for equipment, and high operating costs. The advanced oxidation process based on persulfate (PS-AOPs) uses persulfate (such as potassium persulfate, sodium persulfate, etc.) to generate strongly oxidizing reactive radicals (such as hydroxyl radicals, sulfate radicals, etc.) under the action of oxidants (such as ozone, hydrogen peroxide, etc.), thereby realizing the degradation of phenolic pollutants in water. At the same time, it has been experimentally verified that it can also effectively degrade tetracycline. It has the characteristics of high efficiency, greenness, and environmental protection, and has received extensive attention from scholars.

[0004] Biochar (BC) is a carbon-rich solid substance produced by the pyrolysis of biomass under limited oxygen or anaerobic conditions. It has a special porous structure and physicochemical properties, good surface characteristics, and wide adaptability, and has become a new type of inorganic and organic pollutant adsorption material. However, due to the large differences in the properties of raw materials during the preparation of biochar and the limited types of surface functional groups, it is restricted in the adsorption of different types of pollutants. Therefore, in order to improve the adsorption capacity of biochar for specific pollutants, researchers have begun to explore different raw materials and modification methods. For example, using agricultural waste as raw materials can not only reduce production costs but also realize the resource utilization of waste.

[0005] The spent mushroom substrate of edible fungi is a common type of agricultural waste. Research shows that for every 1 kg of edible fungi produced, approximately 5 kg of spent mushroom substrate is generated. With the rapid development of the edible fungi industry, the output of spent mushroom substrate has been increasing year by year. Since there is currently no reasonable method for utilizing spent mushroom substrate, a large amount of it is directly discarded or burned, not only causing waste of resources but also resulting in certain environmental pollution.

[0006] Therefore, through the research on the spent mushroom substrate of edible fungi, the preparation of biochar with a rich pore structure and good degradation performance has important environmental significance and application value. Summary of the Invention

[0007] In view of the above deficiencies, the present invention provides an activated spent mushroom substrate biochar with a rich pore structure and good adsorption performance, effectively solving the problem of poor adsorption performance of traditional biochar.

[0008] The second object of the present invention is to provide a preparation method of activated spent mushroom substrate biochar. This method uses spent mushroom substrate to prepare biochar and utilizes alkali activation to modify the biochar. The raw material source is extensive and the preparation method is simple.

[0009] The third object of the present invention is to provide the application of the above biochar in activating PDS to degrade 4-chlorophenol and tetracycline in water. The modified biochar can achieve the degradation of chlorophenol and tetracycline in water with a very small dosage of persulfate, so as to solve the problems of low catalytic efficiency and large dosage in current transition metal catalysts.

[0010] To achieve the above objects, the present invention provides the following technical solutions:

[0011] A preparation method of activated spent mushroom substrate biochar successively includes the following steps:

[0012] (1) Wash, dry, and pulverize the spent mushroom substrate to obtain mushroom residue powder;

[0013] (2) After drying the mushroom residue powder in step (1), heat it to 200 - 300 °C in a nitrogen atmosphere and maintain it for 1 - 3 h. After the reaction ends, cool it to room temperature under nitrogen protection and grind it into powder to obtain pre-carbonized spent mushroom substrate biochar;

[0014] (3) According to the mass ratio of 1∶(6 - 8), weigh the pre-carbonized spent mushroom substrate biochar prepared in step (2) and NaOH, add water and mix evenly. Continuously stir vigorously at 70 - 90 °C until it becomes a gel-like state and then dry and pulverize it into powder to obtain the modified activated mushroom residue powder;

[0015] (4) Heat the activated mushroom residue powder prepared in step (3) to 700 - 900 °C in a nitrogen atmosphere and keep it at a constant temperature for 1 - 3 h. After the reaction ends, cool it to room temperature under nitrogen protection and grind it into powder to obtain crude biochar;

[0016] (5) Wash the crude biochar prepared in step (4) thoroughly with freshly prepared hydrochloric acid; then wash it with excessive deionized water until neutral and grind it into powder to obtain activated edible mushroom residue biochar.

[0017] Furthermore, in the above preparation method of the modified residue biochar, the mass of water in step (3) is 4 - 5 times the total mass of the mixture.

[0018] Furthermore, in the above preparation method of the modified residue biochar, the heating in step (2) is carried out by heating at a heating rate of 10 °C / min to 200 - 300 °C.

[0019] Furthermore, in the above preparation method of the modified residue biochar, the heating in step (2) is carried out by heating at a heating rate of 5 °C / min to 700 - 900 °C.

[0020] Furthermore, in the above preparation method of the modified residue biochar, the concentration of hydrochloric acid in step (4) is 2 - 4 M;

[0021] The second technical solution of the present invention is to provide an activated edible mushroom residue biochar prepared by the method described in the first technical solution.

[0022] Another technical solution of the present invention is the application of the activated edible mushroom residue biochar described in the second technical solution in catalyzing the degradation of 4-chlorophenol and / or tetracycline in water by persulfate.

[0023] Compared with the prior art, the technical solution provided by the present invention has the following technical advantages:

[0024] 1. In the solution proposed by the present invention, waste edible mushroom residues are used as raw materials for biochar, and activated edible mushroom residue biochar is prepared through high-temperature heating carbonization technology. In this technical solution, the biochar modified by alkali activation and high-temperature heating significantly enhances the degradation ability of pollutants. At the same time, using agricultural waste - edible mushroom residues as raw materials not only has a wide source but also realizes the recycling of waste, achieving the effect of turning waste into useful materials. In addition, the preparation process of the modified biochar is simple and safe.

[0025] 2. In the present invention, during the high-temperature synthesis process of edible mushroom residue biochar, due to the overflow of heteroatoms, a variety of vacancies are formed, thus endowing the biochar with more microscopic defects. These defects are beneficial to activating PDS to generate O 2 - , SO4· - and ·OH and other free radicals, which further oxidize and degrade organic pollutants in water. At the same time, the surface of the biochar material can adsorb a variety of pollutants, promoting their in-situ degradation on the biochar surface, thereby improving the overall degradation efficiency.

[0026] 3. The biochar prepared by the proposed solution of the present invention has significant porous structure characteristics on its surface. Its specific surface area is increased by more than 20 times compared with unmodified biochar, and the pore volume is increased to more than 10 times that of unmodified biochar. The porous structure characteristics exhibited by the modified biochar are significantly different from those of unmodified biochar. This characteristic significantly enhances its adsorption capacity for pollutants and promotes the diffusion of pollutants in the biochar pores, effectively shortening the time required for pollutant degradation. Description of the Drawings

[0027] Figure 1 is a physical picture of the activated edible mushroom residue biochar prepared in Example 1 of the present invention;

[0028] Figure 2 is the SEM image of the activated edible mushroom residue biochar (a-BC-800) and unactivated biochar (a-BC) prepared in Example 1 of the present invention;

[0029] Figure 3 is the Raman image of the activated edible mushroom residue biochar (a-BC-800) and unactivated biochar (a-BC) prepared in Example 1 of the present invention;

[0030] Figure 4 is the FTIR image of the activated edible mushroom residue biochar (a-BC-800) and unactivated biochar (a-BC) prepared in Example 1 of the present invention;

[0031] Figure 5 is the XRD image of the activated edible mushroom residue biochar (a-BC-800) and unactivated biochar (a-BC) prepared in Example 1 of the present invention;

[0032] Figure 6 is the XPS image of the activated edible mushroom residue biochar (a-BC-800) and unactivated biochar (a-BC) prepared in Example 1 of the present invention;

[0033] Figure 7 is the comparison chart of the degradation effect of 4-CP by the activated edible mushroom residue biochar prepared in Example 1 of the present invention at different concentrations;

[0034] Figure 8 is the comparison chart of the degradation effect of 4-CP by the activated edible mushroom residue biochar prepared in Example 1 of the present invention at different PDS concentrations;

[0035] Figure 9 is the comparison chart of the degradation effect of the activated edible mushroom residue biochar prepared in the examples of the present invention at different 4-CP concentrations;

[0036] Figure 10It is a comparison chart of the effect of activated edible mushroom residue biochar prepared in the examples of the present invention on degrading 4-CP at different pH values;

[0037] Figure 11 It is a comparison chart of the effect of activated edible mushroom residue biochar prepared in Example 1 of the present invention on degrading 4-CP at different temperatures;

[0038] Figure 12 It is a comparison chart of the effect of activated edible mushroom residue biochar prepared in the examples of the present invention on degrading 4-CP under different inorganic salt ion conditions;

[0039] Figure 13 It is a comparison chart of the effect of activated edible mushroom residue biochar prepared in the examples of the present invention on catalyzing the degradation of 4-chlorophenol by persulfate;

[0040] Figure 14 It is a comparison chart of the effect of activated edible mushroom residue biochar prepared in the examples of the present invention on degrading TC at different concentrations. Detailed implementation manners

[0041] The following further describes the detailed implementation manners of the present invention in conjunction with the accompanying drawings and specific examples. It should be noted here that the description of these implementation manners is for helping to understand the present invention. The reagents in this example are all commercially available products, but this does not constitute a limitation to the present invention. In addition, the technical features involved in the various implementation manners of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0042] The edible mushroom residue mentioned below refers to the edible mushrooms being Lentinula edodes and Auricularia auricula (mass ratio 1:1) as described.

[0043] Example 1

[0044] A preparation method of activated edible mushroom residue biochar provided in this example is prepared successively by the following methods:

[0045] (1) Pretreatment of crude biochar of mushroom residue

[0046] After crushing the edible mushroom residue, it is repeatedly rinsed with deionized water and ethanol, then baked in an oven at 65 °C for 2 h. The dried edible mushroom residue fragments are put into a tube furnace, heated to 300 °C at a rate of 10 °C / min and kept at a constant temperature for 2 h. At the same time, nitrogen is introduced to ensure that the tube is filled with nitrogen, the furnace tube pressure is kept below 0.02 MPa, and the inlet pressure is controlled at 0 - 0.05 MPa. After cooling, the sample is taken out, ground into fine powder, and the soluble impurities of the material are repeatedly rinsed with deionized water and ethanol. Finally, the solid material is filtered out and dried at 80 °C to obtain crude biochar of mushroom residue.

[0047] (2) Activation treatment of crude biochar of mushroom residue

[0048] Mix the pre-carbonized crude biochar of mushroom residue from step (1) with NaOH at a mass ratio of 1:6 in a container, add deionized water 4 times the mass of the solid, continue to stir vigorously at 70 °C, and keep the rotation speed at 600 - 700 rpm until a gel-like mucus is formed. Then place it in an oven and dry at 80 °C for later use (a-BC).

[0049] (3) Synthesis of activated mushroom residue biochar

[0050] Grind the activated mushroom residue biochar from step (2) into powder, transfer it to a special porcelain boat for a tube furnace, and then transfer it to the tube furnace. React at a constant temperature of 800 °C for 2 h, take it out after cooling, wash it thoroughly with 3M hydrochloric acid for 12 h, then repeatedly wash it with deionized water until neutral and filter it by suction, dry it, and finally grind the biochar until it can pass through a 200-mesh sieve. The obtained product is the activated mushroom residue biochar (a-BC-800).

[0051] To prove the physicochemical properties of the activated mushroom residue biochar provided in this application, the following gives the detection chromatogram of the activated mushroom residue biochar prepared in Example 1: Among them: The physical picture of the activated mushroom residue biochar prepared in Example 1 is referred to Figure 1 ; Through Figure 1 it can be seen that the biochar is a black powdery solid and the particles are relatively small; The SEM images of the activated mushroom residue biochar (a-BC-800) and the unactivated biochar (a-BC) prepared in Example 1 are referred to Figure 2 ; Among them, the activated biochar refers to Figure 2 the left two pictures in; The unactivated biochar refers to Figure 2 the right two pictures in, through Figure 2 it can be seen that the surface of the activated biochar has a loose porous structure, while the surface of the unactivated biochar hardly has such a structure; The Raman images of the activated mushroom residue biochar (a-BC-800) and the unactivated biochar (a-BC) prepared in Example 1 are referred to Figure 3 ; Through Figure 3 it can be seen that the activated biochar has an obvious carbon absorption peak at a Raman wavelength of 1500 nm, while the unactivated biochar has no absorption peak at this peak value; The FTIR images of the activated mushroom residue biochar (a-BC-800) and the unactivated biochar (a-BC) prepared in Example 1 are referred to Figure 4 ; Through Figure 4 it can be seen that both of them have functional group peaks at wavelengths of 3425, 1579, and 654 cm -1 which belong to O-H, COO-, and C-X signals respectively, but the contents of each functional group of the activated biochar are higher than those of the unactivated biochar; The XRD spectra of the activated mushroom residue biochar (a-BC-800) and the unactivated biochar (a-BC) prepared in Example 1 are referred toFigure 5 ;pass Figure 5 It can be seen that the XRD peak positions of the two materials are slightly different, but the broad peak at 2θ=21.54° corresponds to the crystalline carbon (002) crystal plane and the narrow peak at 2θ=26.35° corresponds to the crystal plane (100); the XPS spectrum of the activated edible fungus residue biochar prepared in Example 1 is shown in Figure 6 ;pass Figure 6 It can be seen that the surface elements of the biochar are mainly composed of C, H, and O, with higher C and O contents, lower N content, and a small amount of impurity peaks;

[0052] Example 2

[0053] The present embodiment provides a method for preparing activated edible fungus residue biochar, which is prepared by the following methods in sequence:

[0054] (1) Pretreatment of crude biochar from fungus residue

[0055] The edible fungus residue was crushed and rinsed repeatedly with deionized water and ethanol, and then baked in an oven at 65°C for 2h. The dried edible fungus residue pieces were placed in a tubular furnace, heated to 250°C at 10°C / min and kept at a constant temperature for 2h. Nitrogen was introduced to ensure that the tube was filled with nitrogen, so that the furnace tube pressure was maintained below 0.02MPa, and the air inlet pressure was controlled at 0-0.05MPa. After cooling, the sample was taken out and ground into fine powder. The soluble impurities of the material were repeatedly rinsed with deionized water and ethanol. Finally, the solid material was filtered out and dried at 80°C to obtain crude biochar from the fungus residue.

[0056] (2) Activation treatment of crude biochar from fungus residue

[0057] The crude biochar material of the mushroom residue pre-carbonized in step (1) is mixed with NaOH in a mass ratio of 1:8 and placed in a container, and deionized water 4 times the solid mass is added, and continued to be vigorously stirred at 80°C, with the rotation speed maintained at 600-700rpm until a gel-like mucus is formed, and then placed in an oven at 80°C for drying for standby use.

[0058] (3) Synthesis of activated edible fungus residue biochar

[0059] The activated mushroom residue biochar in step (2) is ground into powder, transferred to a special porcelain ark for a tube furnace, and then transferred to a tube furnace, reacted at 700°C for 2h, taken out after cooling, washed with 3M hydrochloric acid for 12h, repeatedly washed with deionized water until neutral, filtered, dried, and finally ground to pass through a 200-mesh sieve. The obtained product is the activated edible mushroom residue biochar (a-BC-800).

[0060] Example 3

[0061] A preparation method of activated edible mushroom residue biochar provided by this embodiment is prepared successively by the following methods:

[0062] (1) Pretreatment of crude biochar from mushroom residue

[0063] The edible mushroom residue is crushed and repeatedly rinsed with deionized water and ethanol, then baked in an oven at 65 °C for 2 h. The dried edible mushroom residue chunks are put into a tubular furnace, heated to 250 °C at a rate of 10 °C / min and kept at a constant temperature for 3 h. At the same time, nitrogen is introduced to ensure that the inside of the tube is filled with nitrogen, the pressure in the furnace tube is kept below 0.02 MPa, and the inlet pressure is controlled at 0 - 0.05 MPa. After cooling, the sample is taken out, ground into fine powder, and the soluble impurities of the material are repeatedly rinsed with deionized water and ethanol. Finally, the solid material is filtered out and dried at 70 °C to obtain the crude biochar from mushroom residue.

[0064] (2) Activation treatment of crude biochar from mushroom residue

[0065] The crude biochar material from mushroom residue after pre-carbonization in step (1) is mixed with NaOH in a mass ratio of 1:8 and put into a container. Deionized water 5 times the mass of the solid is added, and it is continuously stirred vigorously at 80 °C, with the rotation speed maintained at 600 - 700 rpm until a gel-like mucus is formed, and then it is placed in an oven and dried at 80 °C for later use.

[0066] (3) Synthesis of activated edible mushroom residue biochar

[0067] The activated biochar from mushroom residue in step (2) is ground into powder, transferred to a special porcelain boat in the tubular furnace, and then transferred to the tubular furnace. It is kept at a constant temperature of 800 °C for 3 h, taken out after cooling, washed thoroughly with 3M hydrochloric acid for 12 h, repeatedly washed with deionized water until neutral and filtered, dried, and finally the biochar is ground to pass through a 200-mesh sieve. The obtained product is the activated edible mushroom residue biochar (a-BC-800).

[0068] To better use the technical solution provided by this application, the following specific application examples of the edible mushroom residue biochar catalyst provided by this application are given.

[0069] Application Example 1 Influence of a-BC-800 with different concentrations on the catalytic degradation of 4-CP by edible mushroom residue biochar

[0070] At room temperature, prepare 3 portions (50 mL each) of 4-CP aqueous solution with a concentration of 20 mg / L. Take three 100-mL glass beakers and place them on a magnetic stirrer (with a 2-cm conical stir bar placed inside the glass beaker). Add 50 mL of the prepared 4-CP aqueous solution to each flask. Then, add the activated edible mushroom residue biochar (a-BC-800) prepared in Example 2 to the glass beakers such that the biochar concentrations in the three 100-mL glass beakers are 0.1 g / L, 0.2 g / L, and 0.3 g / L, respectively. At the same time, add 30 mg of PDS to each beaker, turn on the magnetic stirrer (350 rpm), and stir thoroughly for 40 min under non-illuminated conditions. After the reaction is completed, use a high-performance liquid chromatograph (HPLC) to quantitatively test the 4-CP concentration in each reaction system, record and analyze the experimental results. The analysis results are as Figure 7 shown. It can be seen from Figure 7 that the higher the content of biochar in the reaction system, the faster the reaction rate. The degradation effect shows a gradually narrowing gap over time, but it is still related to the biochar concentration. At a reaction time of 20 min, the two groups with higher biochar concentrations have been basically completely degraded.

[0071] Effect of edible mushroom residue biochar catalyzing PDS to degrade 4-CP at different PDS concentrations in Application Example 2

[0072] At room temperature, prepare 4 portions (50 mL each) of 4-CP aqueous solution with a concentration of 20 mg / L. Take four 100-mL glass beakers and place them on a magnetic stirrer (with a 2-cm conical stir bar placed inside the glass beaker). Add 50 mL of the prepared 4-CP aqueous solution to each flask. Then, add 10 mg of the activated edible mushroom residue biochar (a-BC-800) prepared in Example 2 to each 100-mL glass beaker. At the same time, add different amounts of PDS to each glass beaker such that the PDS concentrations in the four 100-mL glass beakers are 0.2 g / L, 0.4 g / L, 0.6 g / L, and 0.8 g / L, respectively. Turn on the magnetic stirrer (350 rpm), and stir thoroughly for 40 min under non-illuminated conditions. After the reaction is completed, use a high-performance liquid chromatograph (HPLC) to quantitatively test the 4-CP concentration in each reaction system, record and analyze the experimental results. The analysis results are as Figure 8 shown. It can be seen from Figure 8 that as the content of PDS in the reaction system increases, the reaction rate and degradation effect increase slightly, but overall, the concentration of PDS has little effect on the reaction rate and degradation effect.

[0073] Effect of edible mushroom residue biochar catalyzing PDS to degrade 4-CP at different 4-CP concentrations in Application Example 3

[0074] At room temperature, prepare one portion (50 mL each) of 4-CP aqueous solutions with concentrations of 10 mg / L, 20 mg / L, 30 mg / L, and 40 mg / L respectively. Take four 100-mL glass beakers and place them on a magnetic stirrer (with a 2-cm conical stir bar placed inside the glass beaker). Add the 50-mL prepared 4-CP aqueous solutions with different concentrations into different glass beakers respectively (each 100-mL glass beaker corresponds to a 4-CP aqueous solution with a certain concentration). Then, add 10 mg of the activated edible mushroom residue biochar (a-BC-800) prepared in Example 2 into each 100-mL glass beaker. At the same time, add 30 mg of PDS into each beaker. Turn on the magnetic stirrer (350 rpm) and stir thoroughly for 40 min under non-illuminated conditions. After the reaction is completed, use a high-performance liquid chromatograph (HPLC) to quantitatively test the 4-CP concentration in each reaction system, record and analyze the experimental results. The analysis results are as Figure 9 shown. Through Figure 9 it can be seen that as the content of 4-CP in the reaction system increases, with other conditions remaining unchanged, the reaction rate is inversely proportional to the concentration of 4-CP in the system. The higher the 4-CP concentration, the slower the reaction rate. When the 4-CP concentration is relatively low, the reaction is basically completely degraded after 20 min of reaction time. The degradation effects of each group will gradually narrow with the passage of time, but are still related to the 4-CP concentration in the system. Therefore, when the 4-CP content increases, to ensure the improvement of the degradation rate, the concentration of biochar needs to be increased.

[0075] Application Example 4: Influence of Edible Mushroom Residue Biochar on Catalyzing the Degradation of 4-CP by PDS at Different pH Values

[0076] At room temperature, prepare 5 portions (50 mL each) of 4-CP aqueous solutions with a concentration of 20 mg / L. Use 1 mol / L hydrochloric acid or 1 mol / L sodium hydroxide solution to adjust the pH values of the 4-CP aqueous solutions to different values under the measurement of a pH meter, specifically 3, 5, 7, 9, and 11 respectively. Take five 100-mL glass beakers and place them on a magnetic stirrer (with a 2-cm conical stir bar placed inside the glass beaker). Add the 50-mL prepared 4-CP aqueous solutions with different pH values into different glass beakers respectively (each 100-mL glass beaker corresponds to a 4-CP aqueous solution with a certain pH value). Then, add 10 mg of the activated edible mushroom residue biochar (a-BC-800) prepared in Example 2 into the glass beakers. At the same time, add 30 mg of PDS into each beaker. Turn on the magnetic stirrer (350 rpm) and stir thoroughly for 40 min under non-illuminated conditions. After the reaction is completed, use a high-performance liquid chromatograph (HPLC) to quantitatively test the 4-CP concentration in each reaction system, record and analyze the experimental results. The analysis results are as Figure 10 shown. Through Figure 10It can be seen that with the increase of the pH value in the reaction system, under the condition that other conditions remain unchanged, the reaction rate and degradation effect do not increase with the increase of the pH value. Both overly acidic and overly alkaline conditions will cause the reaction rate and degradation effect to decline, while weak acidic or weak alkaline conditions have a promoting effect on the reaction.

[0077] Application Example 5: Influence of Edible Mushroom Residue Biochar Catalyzed PDS Degradation of 4-CP at Different Temperatures

[0078] At room temperature, prepare 3 portions (each 50 mL) of 4-CP aqueous solution with a concentration of 20 mg / L. Take three 100-mL glass beakers and place them on three magnetic stirrers (a 2-cm conical stir bar is placed inside the glass beaker). Add the prepared 50-mL 4-CP aqueous solution into different glass beakers respectively. Turn on the heating button of the heating device of the magnetic stirrer to keep the temperature of the liquid in the 3 beakers at 25 °C, 35 °C, and 45 °C respectively (each glass beaker corresponds to one temperature). Then add 10 mg of the activated edible mushroom residue biochar (a-BC-800) prepared in Example 2 into the glass beakers respectively. At the same time, add 10 mg of PDS into each beaker. Turn on the magnetic stirrer (350 rpm) of the heating device of the magnetic stirrer and stir well for 40 min under non-illuminated conditions. After the reaction is completed, use a high-performance liquid chromatograph (HPLC) to quantitatively test the 4-CP concentration in each reaction system, record and analyze the experimental results. The analysis results are as Figure 11 shown. Through Figure 11 It can be seen that within a certain temperature range, the reaction rate and degradation effect will increase with the increase of temperature. Bath heating the reaction system and controlling the temperature are beneficial for the reaction to proceed more rapidly and achieve a better degradation effect.

[0079] Application Example 6: Influence of Edible Mushroom Residue Biochar Catalyzed PDS Degradation of 4-CP under Different Ion Conditions

[0080] At room temperature, prepare 5 portions (each 50 mL) of 4-CP aqueous solution with a concentration of 20 mg / L. Add 30 mg of an inorganic salt powder, which is one of sodium chloride, sodium bicarbonate, disodium hydrogen phosphate, and sodium nitrate (i.e., add one of sodium chloride, sodium bicarbonate, disodium hydrogen phosphate, and sodium nitrate to each 4-CP aqueous solution), to 4 of the 4-CP aqueous solutions. Do not add the inorganic salt powder to the remaining 4-CP aqueous solution. Stir with a glass rod until it is completely dissolved. Place five 100-mL glass beakers on a magnetic stirrer (a 2-cm conical stir bar is placed inside the glass beaker), and add 50 mL of the prepared 4-CP aqueous solution dissolved with the inorganic salt powder to different glass beakers. Then add 10 mg of the activated edible mushroom residue biochar (a-BC-800) prepared in Example 2 to each glass beaker. At the same time, add 30 mg of PDS to each beaker. Turn on the magnetic stirrer (350 rpm) and stir well for 40 min under non-light conditions. After the reaction is completed, use a high-performance liquid chromatograph (HPLC) to quantitatively test the 4-CP concentration in each reaction system, record and analyze the experimental results. The analysis results are as Figure 12 shown. It can be seen from Figure 12 that the presence of NO 3 - and HPO 4 2- in the reaction system will have an obvious inhibitory effect on the reaction, while HCO 3 - and Cl - will not cause much interference to the reaction system. This may be because the catalytic degradation performance of this biochar material itself is good, and even if some ions that are beneficial to the forward progress of the catalytic reaction are added, there will be no obvious rate increase.

[0081] Application Example 7: Degradation of 4-chlorophenol by edible mushroom residue biochar-catalyzed persulfate (PDS)

[0082] At room temperature, prepare 3 portions (50 mL each) of 4-chlorophenol (4-CP) aqueous solution with a concentration of 20 mg / L and pH 7.5. Take 3 100-mL glass beakers and place them on a magnetic stirrer (with a 2-cm conical stir bar placed inside the glass beaker). Add 50 mL of the prepared 4-chlorophenol (4-CP) aqueous solution to different glass beakers respectively. Then, add 10 mg and 20 mg of PDS prepared in Example 3 and activated edible mushroom residue biochar (a-BC-800) to one of the glass beakers, add only 20 mg of PDS to another glass beaker as Control Group 1, and add only 10 mg of the activated edible mushroom residue biochar (a-BC-800) prepared in Example 3 to the other as Control Group 2. Turn on the magnetic stirrer (350 rpm) and stir thoroughly for 40 min under non-light conditions. After the reaction is completed, use a high-performance liquid chromatograph (HPLC) to quantitatively test the 4-CP concentration in each reaction system.

[0083] Repeat the above operation three times, take the average value, record and analyze the experimental results. The analysis results are as Figure 13 shown. It can be seen from Figure 13 that when only PDS is present, the removal rate is below 10%. When only the activated biochar is present, the removal rate is only 20 - 30%. However, in the activated biochar / PDS system, the removal rate of 4-chlorophenol reaches over 90% within 10 min, indicating that this activated biochar has a good effect on catalyzing the degradation of 4-chlorophenol pollutants by PDS.

[0084] Application Example 8: Degradation of Tetracycline by Edible Mushroom Residue Biochar Catalyzing PDS

[0085] At room temperature, prepare a tetracycline (TC) aqueous solution with a concentration of 50 mg / L and pH = 8.5, and then divide it into 3 portions (50 mL each). Take 3 100-mL glass beakers and place them on a magnetic stirrer (with a 2-cm conical stir bar placed inside the glass beaker). Add 50 mL of the prepared tetracycline (TC) aqueous solution to different glass beakers respectively. Then, add different masses (10 mg, 20 mg, or 30 mg) of the activated edible mushroom residue biochar (a-BC-800) prepared in Example 3 to different glass beakers, so that the concentrations of biochar in different beakers are 0.2 g / L, 0.4 g / L, and 0.6 g / L respectively. At the same time, add 50 mg of PDS to each beaker. Turn on the magnetic stirrer (350 rpm) and stir thoroughly for 60 min under non-light conditions. After the reaction is completed, use an ultraviolet spectrophotometer (UV-3600Plus) to measure the absorbance at a wavelength of 357 nm for each reaction group, and make 3 replicates for each group.

[0086] Use the obtained absorbance to calculate the absorbance value / initial absorbance value at each time point. With the reaction time as the abscissa, C t / C0 Taking [ordinate value] as the ordinate, a comparison chart of the degradation effect of activated edible mushroom residue biochar on TC at different concentrations was drawn, and the analysis results are as follows Figure 14 shown. By Figure 14 It can be seen that taking the reaction time as the abscissa and the absorbance at this moment / initial absorbance as the ordinate, with the continuous increase of the biochar concentration, the removal rate of tetracycline pollutants shows a gradually increasing trend. It is worth noting that even when the biochar concentration is 0.2 g / L, its removal rate has reached nearly 80%, and when the biochar concentration reaches 0.4 g / L, its removal rate has reached more than 90%, achieving trace amounts and high efficiency. Its removal effect, like that of 4-CP, can reach a high removal rate in a short time.

Claims

1. A method for preparing activated edible fungus residue biochar, characterized in that: The steps are as follows: (1) washing, drying and crushing edible mushroom residue to obtain mushroom residue powder; (2) drying the mushroom residue powder in step (1), heating it to 200-300° C. in a nitrogen atmosphere and maintaining it for 1-3 hours, cooling it to room temperature under nitrogen protection after the reaction is completed, and grinding it into powder to obtain pre-carbonized edible mushroom residue biochar; (3) Weigh the pre-carbonized edible mushroom residue biochar and NaOH prepared in step (2) in a mass ratio of 1:(6-8), add water and mix evenly, continue to vigorously stir at 70-90° C. until it becomes a gel-like state, dry and grind into powder to obtain modified active mushroom residue powder; (4) heating the active bacterial residue powder prepared in step (3) to 700-900° C. in a nitrogen atmosphere and maintaining the constant temperature for 1-3 h. After the reaction is completed, cooling to room temperature under nitrogen protection, grinding into powder to obtain crude biochar; (5) The crude biochar prepared in step (4) is fully washed with current hydrochloric acid; then washed with excess deionized water until neutral and ground into powder to obtain activated edible fungus residue biochar.

2. The method for preparing modified fungus residue biochar according to claim 1, characterized in that: The mass of water in step (3) is 4 to 5 times the total mass of the mixture.

3. The method for preparing activated edible fungus residue biochar according to claim 1, characterized in that: The heating described in step (2) is to increase the temperature to 200-300°C at a heating rate of 10°C / min.

4. The method for preparing activated edible fungus residue biochar according to claim 1, characterized in that: The heating described in step (2) is to increase the temperature to 700-900°C at a heating rate of 5°C / min.

5. The method for preparing activated edible fungus residue biochar according to claim 1, characterized in that: The concentration of the hydrochloric acid in step (4) is 2-4M.

6. An activated edible fungus residue biochar, characterized in that: Prepared by the method described in any one of claims 1 to 5.

7. Use of the activated edible fungus residue biochar according to claim 6 for catalyzing the degradation of 4-chlorophenol and / or tetracycline in water by peroxydisulfate.

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