Preparation method and application of micro-nano manganese ferrite anchored biochar
By alkaline activation and hydrothermal anchoring of manganese ferrite on biochar, the method addresses the limitations of traditional biochar, achieving high catalytic activity and stability for pollutant degradation.
Patent Information
- Application Number
- CN202411160094.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-22
- Publication Date
- 2024-12-10
AI Technical Summary
Existing biochar materials exhibit weak adsorption capacity and poor regeneration performance, and the preparation of manganese ferrite/biochar composites faces challenges such as complex processes, low yield, and low saturation magnetization, necessitating the development of micro-nano catalysts with higher specific surface area and catalytic activity.
A method involving alkaline activation of peanut shells to remove endogenous minerals, followed by mixing with ethylene glycol and ultrasonic dispersion, then a hydrothermal reaction to anchor micro-nano manganese ferrite on biochar, enhancing its specific surface area and catalytic activity.
The prepared micro-nano manganese ferrite anchored biochar demonstrates high catalytic activity, stability, and ease of recovery, effectively degrading organic pollutants like bisphenol A under various environmental conditions.
Smart Images
Figure CN119098185A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of new material preparation, and specifically relates to a preparation method and application of micro-nano manganese ferrite anchored biochar. Background Art
[0002] my country's annual output of agricultural waste (such as straw, peanut shells, etc.) is as high as more than 4 billion tons. As a clean, large, cheap and renewable biomass resource, turning it into biochar material is one of the high-value applications. However, endogenous minerals (such as silicates and carbonates) in biomass such as straw and peanut shells can regulate the decomposition temperature of the main carbon skeleton during pyrolysis, making the carbon structure of biochar more disordered and prone to lattice defects, thereby reducing its structural stability. If these endogenous minerals are removed, the stability of biochar will be significantly improved.
[0003] Slow pyrolysis is the most widely used technology for preparing biochar. It mainly regulates the physical and chemical properties of biochar by changing the process conditions. This technology can obtain biochar with a relatively high yield. In the process of preparing biochar by slow pyrolysis of biomass, the use of strong alkali pretreatment and subsequent roasting can remove endogenous minerals (such as silicates and carbonates) in the biomass. First, the high temperature and alkaline environment cause some organic matter in the biomass to undergo dehydration, decarboxylation and cracking reactions, exposing the minerals embedded in the organic structure. Under high temperature conditions, strong alkali (such as KOH, NaOH) catalyzes the hydrolysis reaction of silicate minerals in the biomass with water molecules to generate soluble silicates and oxides. Soluble silicates react with strong alkali to generate water-soluble silicates, which are removed by washing with water. Strong alkali can not only change the pore structure of biochar, increase its specific surface area and pore volume, but also change the surface chemical properties of biochar, increase the types and number of oxygen-containing functional groups, and enhance the catalytic activity of biochar. In addition, alkali metals can promote the conversion of organic matter in biomass into biochar, thereby increasing the yield of biochar.
[0004] However, biochar has disadvantages such as weak adsorption capacity and poor regeneration performance in adsorption / catalysis, and needs to be modified. In recent years, there have been many studies on metal-loaded biochar, and spinel bimetallic oxides have higher catalytic activity and thermal stability than traditional single metal oxides. Common techniques for preparing spinel bimetallic oxides include hydrothermal reaction method, sol-gel method and coprecipitation method. Patents CN114768819A and CN116351392A disclose the preparation of manganese ferrite / biochar composite materials by sol-gel method and coprecipitation method, respectively, and confirm that the materials have good effects in removing organic pollutants and heavy metals. However, both have the disadvantages of complex material preparation process, low yield, large amount of reagents used, low degradation rate and low saturation magnetization. In view of this, micro-nano catalysts have higher specific surface area and more active sites, which are 3 to 4 orders of magnitude higher than the specific surface area of traditional catalysts, and have faster reaction rate and higher catalytic activity. In addition, the catalyst can still maintain high catalytic activity and be easy to separate and recycle in harsh and complex chemical environments. The hydrothermal reaction method can prepare micro-nanostructured catalysts at relatively low temperatures and under normal conditions, and utilizes hydrothermal synthesis agents to effectively enhance the binding force between the metal and the carrier through hydrogen bonding, coordination, etc., thereby achieving efficient anchoring of the metal on the carrier surface and intact retention of the active components on the carrier surface.
[0005] Therefore, obtaining a highly active and highly stable micro-nano metal-based biochar composite material is a technical problem that needs to be urgently solved in this field. Summary of the invention
[0006] To achieve the above objectives, the present invention provides the following technical solutions:
[0007] The first aspect of the present invention provides a method for preparing micro-nano manganese ferrite anchored biochar, comprising the following steps:
[0008] S1: Mix peanut shells and strong alkali in a certain mass ratio, add appropriate amount of deionized water to immerse, continue stirring, then dry, and then place at a high temperature in an inert atmosphere for roasting, and obtain peanut shell-based biochar after roasting;
[0009] S2: The peanut shell-based biochar is mixed with ethylene glycol and ultrasonically dispersed, and then a certain proportion of metal iron salt and manganese salt solution is added to continue ultrasonic dispersion, and then a hydrothermal synthesis agent is added, stirred at room temperature, and then a hydrothermal reaction is carried out, washed and dried to obtain micro-nano manganese ferrite anchored biochar;
[0010] Furthermore, in S1, the mass ratio of the peanut shell to the strong base is 1:1 to 1:5;
[0011] Further, in S1, the strong base is potassium hydroxide or sodium hydroxide;
[0012] Further, in S1, the stirring time is 6 to 48 hours; preferably, in S1, the stirring time is 24 hours;
[0013] Further, in S1, the stirring rate is 400-800 r / min; preferably, in S1, the stirring rate is 500 r / min;
[0014] Further, in S1, the high temperature calcination under an inert atmosphere specifically includes: calcination under a N2 atmosphere at 600 to 800°C for 30 to 120 minutes;
[0015] Further, in S2, the mass ratio of the peanut shell-based biochar to ethylene glycol is 1:120-250;
[0016] Further, in S2, the peanut shell-based biochar is mixed with ethylene glycol and ultrasonically dispersed for 8 to 15 minutes;
[0017] Further, in S2, the mass ratio of the peanut shell-based biochar to the metal iron salt and manganese salt is 1:3-5:1.5-2; further preferably, in S2, the mass ratio of the peanut shell-based biochar to the metal iron salt and manganese salt is 1:4:1.504;
[0018] Further, in S2, the metal iron salt is FeCl3·6H2O;
[0019] Further, in S2, the manganese salt is MnCl2·4H2O;
[0020] Furthermore, in S2, the duration of continuing ultrasonic dispersion is 2 to 4 hours;
[0021] Further, in S2, the hydrothermal synthesis agent is polyethylene glycol and sodium acetate;
[0022] Further, in S2, the mass ratio of the peanut shell-based biochar: sodium acetate: polyethylene glycol is 1:8-12:2; further preferably, in S2, in S2, the mass ratio of the peanut shell-based biochar: sodium acetate: polyethylene glycol is 1:10:2;
[0023] Further, in S2, the hydrothermal synthesis agent is added and stirred at room temperature for 0.5 to 2 h;
[0024] Furthermore, the hydrothermal reaction temperature ranges from 160 to 240° C. and the time ranges from 12 to 36 hours;
[0025] The second aspect of the present invention provides micro-nano manganese ferrite anchored biochar, which is prepared by any of the above methods;
[0026] The third aspect of the present invention provides the use of the above-mentioned micro-nano manganese ferrite anchored biochar in activating persulfate to degrade phenolic organic pollutant preparations;
[0027] Furthermore, the application comprises the following steps:
[0028] (1) At a concentration of 20 to 50 mg·L -1 To the bisphenol A solution, 1-10 mmol / L potassium permonosulfate (abbreviated as PMS) in an amount of 300-400 times the mass of bisphenol A is added, and then 4-20 times the mass of bisphenol A is added to the above-mentioned micro-nano manganese ferrite anchored biochar, and the degradation reaction starts timing;
[0029] (2) Sampling was performed using a disposable syringe at time intervals of 2, 5, 10, 20, 30, 60 and 90 minutes, respectively. Each time, quantitative sampling was performed, and the sample was added to an appropriate amount of brown chromatographic bottle after filtering through a polyethersulfone (abbreviated as PES) filter head. Methanol was added to the chromatographic bottle in advance to terminate the free radical reaction still in progress in the sample, and the quantitative sampling volume: the volume of the brown chromatographic bottle was 1:2-5, and the quantitative sampling volume: the amount of methanol was 1:0.4-1;
[0030] (3) The terminated reaction solution in the chromatographic bottle is filtered to obtain the micro-nano manganese ferrite anchored biochar after the reaction, which is dispersed in an appropriate amount of ethanol, and ultrasonicated for 30 to 60 minutes to eliminate the effect of adsorption on the degradation and removal rate of bisphenol A (BPA), and the BPA concentration in the solution is measured by liquid chromatography to obtain the concentration of BPA adsorbed by the catalyst; BRIEF DESCRIPTION OF THE DRAWINGS
[0031] Figure 1 These are the SEM images of (1a) manganese ferrite, (1b) peanut shell-based biochar and (1c) micro-nano manganese ferrite-anchored biochar used in Example 1, (1d) TEM images of manganese ferrite and (1e) micro-nano manganese ferrite-anchored biochar, and (1f) VSM images of manganese ferrite and micro-nano manganese ferrite-anchored biochar.
[0032] Figure 2 Effects of different dosages on the degradation of BPA by PMS activated by micro-nano manganese ferrite anchored biochar and K obs .
[0033] Figure 3 Effects of different PMS dosages on the degradation of BPA by PMS activated by micro-nano manganese ferrite anchored biochar and K obs .
[0034] Figure 4 Effects of different BPA concentrations on the degradation of BPA by PMS activated by micro-nano manganese ferrite anchored biochar and K obs .
[0035] Figure 5 Effects of different pH values on the degradation of BPA by PMS activated by micro-nano manganese ferrite anchored biochar and the K obs .
[0036] Figure 6 The effects of different coexisting anions on the degradation of BPA by PMS activated by micro-nano manganese ferrite anchored biochar and K obs .
[0037] Beneficial Effects
[0038] First, the method for preparing micro-nano manganese ferrite anchored biochar of the present invention has the following advantages: (1) the present invention uses peanut shells as raw materials, which realizes the environmental protection demand of waste recycling; (2) before preparing peanut shell-based biochar by slow pyrolysis method, the method of the present invention performs alkaline activation pretreatment on peanut shells, removes endogenous minerals (such as silicates and carbonates) in peanut shell biomass, and improves its specific surface area and chemical activity, making the reaction faster and more complete; (2) before using the hydrothermal reaction method to load manganese ferrite, the peanut shell-based biochar is first mixed with ethylene glycol to improve the dispersion and loading amount of the loaded metal;
[0039] Secondly, the micro-nano manganese ferrite anchored biochar prepared by the present invention has the following advantages: (1) the prepared micro-nano manganese ferrite anchored biochar has a high specific surface area, high metal dispersion and high metal loading rate, and exhibits excellent bisphenol A degradation performance; (2) the micro-nano manganese ferrite anchored biochar prepared by the present invention can better adapt to the complex conditions of wastewater, and exhibits ultra-high catalytic degradation activity for a variety of pollutants under different anion interferences and different environmental conditions; (3) the micro-nano manganese ferrite anchored biochar prepared by the present invention has the advantages of small dosage, high efficiency, low cost, simple process, easy recovery, high stability and the like in terms of degrading organic matter. DETAILED DESCRIPTION
[0040] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.
[0041] The instruments and equipment used in the following examples, unless otherwise specified, are all conventional laboratory instruments and equipment; the experimental materials used in the following examples, unless otherwise specified, are all purchased from conventional biochemical reagent stores.
[0042] (I) Embodiment
[0043] Example 1
[0044] A preparation method of micro-nano manganese ferrite anchored biochar, comprising the following steps: S1: 10g peanut shell powder is mixed with 20g sodium hydroxide, and deionized water is added to immerse, and the mixture is continuously stirred at a stirring speed of 400r / min, and then dried after immersion for 20h. Then the dried mixture is placed in an inert atmosphere and roasted at 800°C for 1h. After the roasting is completed, the mixture is washed with deionized water and dried to obtain peanut shell-based biochar (referred to as BC); S2: 0.5g of the above peanut shell-based biochar (BC) and 100mL of ethylene glycol are placed in a beaker for ultrasonic dispersion for 15min, 2g FeCl3·6H2O and 0.752g MnCl2·4H2O are added to the above solution, and then ultrasonic dispersion is performed for 3h to mix evenly, and then 5g NaAC and 1g polyethylene glycol (MW6000) are added to the above solution and stirred for 2h at room temperature. The mixture was transferred to a hydrothermal reactor and reacted at 200°C for 24 hours, cooled to room temperature, washed with ethanol and deionized water in turn, and dried to obtain micro-nano manganese ferrite anchored biochar.
[0045] Example 2
[0046] A preparation method of micro-nano manganese ferrite anchored biochar, comprising the following steps: S1: 10g of peanut shell powder is mixed with 50g of sodium hydroxide, and deionized water is added to immerse it, and the mixture is continuously stirred at a stirring speed of 800r / min, and then dried after stirring for 30h. Then the dried mixture is placed in an inert atmosphere and roasted at 600°C for 2h. After the roasting is completed, the mixture is washed with deionized water and dried to obtain peanut shell-based biochar (referred to as BC); S2: 1g of the above peanut shell-based biochar (BC) and 100mL of ethylene glycol are placed in a beaker for ultrasonic dispersion for 15min, 4g of FeCl3·6H2O and 1.508g of MnCl2·4H2O are added to the above solution, and then ultrasonic dispersion is performed for 3h to mix evenly, and then 10g of NaAC and 2g of polyethylene glycol (MW6000) are added to the above solution and stirred at room temperature for 40min. The mixture was transferred to a hydrothermal reactor and reacted at 160°C for 36 hours, cooled to room temperature, washed with ethanol and deionized water in sequence, and dried to obtain micro-nano manganese ferrite anchored biochar.
[0047] Example 3
[0048] A preparation method of micro-nano manganese ferrite anchored biochar, comprising the following steps: S1: 10g peanut shell powder is mixed with 30g sodium hydroxide, and deionized water is added to immerse, and the mixture is continuously stirred at a stirring speed of 500r / min, and then dried after immersion for 24h. Then the dried mixture is placed in an inert atmosphere and roasted at 600°C for 1h. After the roasting is completed, the mixture is washed with deionized water and dried to obtain peanut shell-based biochar (referred to as BC); S2: 0.5g of the above peanut shell-based biochar (BC) and 70mL of ethylene glycol are placed in a beaker and ultrasonically dispersed for 10min, 2g FeCl3·6H2O and 0.752g MnCl2·4H2O are added to the above solution, and then ultrasonically dispersed for 3h to mix evenly, and then 5g NaAC and 1g polyethylene glycol (MW6000) are added to the above solution and stirred at room temperature for 1h. The mixture was transferred to a hydrothermal reactor and reacted at 180°C for 24 hours, cooled to room temperature, washed with ethanol and deionized water in turn, and dried to obtain micro-nano manganese ferrite anchored biochar.
[0049] (II) Experimental Examples
[0050] 2.1 Experiment on degradation of phenolic organic pollutants by activated PMS
[0051] The above-prepared micro-nano manganese ferrite anchored biochar was used to activate PMS to degrade phenolic organic pollutants, which specifically included the following steps:
[0052] (1) Add 100 mL of the prepared 20 mg·L -1 654 mg of PMS was added to the BPA solution, the PMS concentration was 10 mmol / L, and then 30 mg of the above-mentioned micro-nano manganese ferrite anchored biochar was added, and the degradation reaction started timing.
[0053] (2) 1 mL of sample was taken at time intervals of 2, 5, 10, 20, 30, 60, and 90 min using a disposable syringe. The sample was filtered through a 0.22 μm PES filter and added to a 2 mL brown chromatographic bottle. 0.5 mL of methanol was added to the chromatographic bottle in advance to terminate the free radical reaction in the sample.
[0054] (3) After the free radical reaction is terminated, the terminated reaction solution in the chromatographic bottle is filtered to obtain the micro-nano manganese ferrite anchored biochar after the reaction, which is dispersed in 100 mL of ethanol and ultrasonicated for 45 min to eliminate the effect of adsorption on the degradation and removal rate of BPA. The BPA concentration in the solution is measured by liquid chromatography to obtain the concentration of BPA adsorbed by the catalyst, that is, the concentration of the BPA is obtained.
[0055] The micro-nano manganese ferrite anchored biochar prepared by the present invention is used to activate PMS to degrade phenolic organic pollutants. The SEM image of the manganese ferrite used ( Figure 1 a) and TEM images ( Figure 1 d) shows a spherical cluster structure, and the prepared peanut shell-based biochar has a highly developed pore structure ( Figure 1 b), the manganese ferrite of the prepared micro-nano manganese ferrite anchored biochar is micro-nanoscale ( Figure 1 e), and are evenly distributed on the biochar surface with a large loading ( Figure 1 c); VSM diagram of manganese ferrite and micro-nano manganese ferrite anchored biochar ( Figure 1 f).
[0056] 2.2 Investigate the effect of different catalyst dosages on BPA removal rate in wastewater
[0057] The effects of different catalyst dosages on the removal rate of BPA in wastewater were investigated. Except for the different catalyst dosages, the other steps and methods were the same as those in Example 3, and the preparation of micro-nano manganese ferrite anchored biochar was consistent with the preparation method in Example 3. The experimental results are shown in Figure 2 As shown, Figure 2 a represents the effect of different catalyst dosages, Figure 2 b represents K at different catalyst dosages obs The results showed that as the amount of micro-nano manganese ferrite anchored biochar increased from 0.20 g / L to 0.40 g / L, the complete degradation time of BPA was shortened from 90 min to 30 min, and the reaction kinetic constant K obs From 0.0248min -1 Increased to 0.2238min -1 , which increased by nearly 10 times. This is mainly because the increase in the amount of catalyst increased the catalytic active sites and the enrichment of PMS and pollutants, prompting the rapid decomposition of PMS to produce more reactive oxygen species (ROS, such as OH and SO4 ·- ). However, excessive catalyst can also lead to self-quenching of ROS in the reaction system (·OH+SO4· - →HSO5 - ; SO4· - +SO4 - →S2O8 2- ), thereby reducing the reaction rate.
[0058] 2.3 Investigate the effect of different PMS dosage on BPA removal rate in wastewater
[0059] The effect of different PMS dosages on the removal rate of bisphenol A in wastewater was investigated. Except for the different PMS dosages, the other steps and methods were the same as those in Example 3, and the preparation method of micro-nano manganese ferrite anchored biochar was consistent with that in Example 3. The experimental results are shown in Figure 3 As shown, Figure 3a represents the influence of different PMS dosages, Figure 3 b represents K at different PMS dosages obs The results showed that when the dosage of PMS increased from 5.0mM to 7.5mM, the complete degradation time of BPA was shortened by half (90min→45min), and Kobs increased from 0.0945min to 1.545min. -1 Increased to 0.1463min -1 , increased by nearly 2 times, continued to increase PMS usage, K obs The increase was not significant. This is mainly because, on the one hand, the increase of PMS can quickly produce ROS to oxidize and degrade BPA, and on the other hand, the ROS produced by PMS activation can react with HSO5 - Reaction (HSO5 - + OH → H2O + HSO4 - ;HSO5 - +SO4 ·- →SO5 - +HSO4 - ), thereby inhibiting the degradation of BPA.
[0060] 2.4 Effects of different initial BPA concentrations on the activation of PMS by micro-nano manganese ferrite anchored biochar
[0061] The effect of different initial BPA concentrations on the activation of PMS by micro-nano manganese ferrite anchored biochar was investigated. Except for the different initial BPA concentrations, the other steps and methods were the same as those in Example 3, wherein the preparation of micro-nano manganese ferrite anchored biochar was consistent with the preparation method in Example 3. The experimental results are shown in Figure 4 As shown, Figure 4 a represents the effect of different BPA concentrations, Figure 4 b represents the K of different BPA concentrations obs The results show that when the amount of catalyst and oxidant is constant, as the concentration of target pollutant BPA increases (10 mg / L→30 mg / L), the system reaction rate constant K obs Then it decreased (0.4633min -1 →0.0834min -1 ). This is mainly because the amount of ROS generated by the activation of PMS by micro-nano manganese ferrite anchored biochar in the system is constant, and with the increase of BPA molecules, the ROS in the system is not enough to react with BPA, resulting in a decrease in the degradation reaction rate of BPA.
[0062] 2.5 Investigating the effect of different initial pH in water on BPA removal rate in wastewater
[0063] The effect of different initial pH values in water on the removal rate of BPA in wastewater was investigated. Except for the different initial pH values in water, the other steps and methods were the same as those in Example 3, and the preparation of micro-nano manganese ferrite anchored biochar was consistent with the preparation method in Example 3. The experimental results are shown in Figure 5 As shown, Figure 5 a represents the effect of different pH values, Figure 5 b represents K at different pH values obs ; The results showed that BPA exhibited a high degradation efficiency (complete degradation within 30 minutes) under acidic, alkaline and neutral conditions, which also means that the micro-nano manganese ferrite anchored biochar / PMS reaction system has a wide pH adaptability.
[0064] 2.6 Investigating the effect of anions in actual water on the removal rate of BPA in wastewater
[0065] The effect of anions in actual water on the removal rate of BPA in wastewater was investigated. Except for the difference in anions in the water, the other steps and methods were the same as those in Example 3, and the preparation of micro-nano manganese ferrite anchored biochar was consistent with the preparation method in Example 3. Figure 6 As shown, Figure 6 a represents the influence of different coexisting anions, Figure 6 b represents the K of different coexisting anions obs ; The results showed: Cl - The degradation of BPA was inhibited, but BPA was almost completely degraded within 30 min. - Interference conditions had almost no significant effect; CO3 2- 、HCO3 - 、SO4 2- Plasma has a certain promoting effect on the degradation of BPA. It can be seen that the micro-nano manganese ferrite anchored biochar / PMS system still shows a high degradation efficiency for phenolic organic pollutants under the conditions of different anions, which also means the feasibility of the application of this reaction system in actual water bodies.
[0066] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of protection of the technical solution of the present invention.
Claims
1. A method for preparing micro-nano manganese ferrite anchored biochar, characterized in that: The following steps are involved: S1: Mix peanut shells and strong alkali in a certain mass ratio, add appropriate amount of deionized water to immerse, continue stirring, then dry, and then place at a high temperature in an inert atmosphere for roasting, and obtain peanut shell-based biochar after roasting; S2: The peanut shell-based biochar is mixed with ethylene glycol and ultrasonically dispersed, and then a certain proportion of metal iron salt and manganese salt solution is added to continue ultrasonic dispersion, and then a hydrothermal synthesis agent is added, stirred at room temperature, and then a hydrothermal reaction is carried out, washed and dried to obtain micro-nano manganese ferrite anchored biochar.
2. The method for preparing micro-nano manganese ferrite anchored biochar according to claim 1, characterized in that: In S1, the mass ratio of the peanut shell to the strong base is 1:1 to 1:
5.
3. The method for preparing micro-nano manganese ferrite anchored biochar according to claim 1, characterized in that: In S1, the strong base is potassium hydroxide or sodium hydroxide.
4. The method for preparing micro-nano manganese ferrite anchored biochar according to claim 1, characterized in that: In S1, the stirring time is 6 to 48 hours; preferably, in S1, the stirring time is 24 hours.
5. The method for preparing micro-nano manganese ferrite anchored biochar according to claim 1, characterized in that: In S1, the stirring rate is 400-800 r / min; preferably, in S1, the stirring rate is 500 r / min.
6. The method for preparing micro-nano manganese ferrite anchored biochar according to claim 1, characterized in that: In S1, the high temperature calcination under an inert atmosphere specifically includes: calcination under a N2 atmosphere at 600-800°C for 30-120 min.
7. The method for preparing micro-nano manganese ferrite anchored biochar according to claim 1, characterized in that: In S2, the mass ratio of the peanut shell-based biochar to ethylene glycol is 1:120-250.
8. The method for preparing micro-nano manganese ferrite anchored biochar according to claim 1, characterized in that: In S2, the peanut shell-based biochar is mixed with ethylene glycol and ultrasonically dispersed for 8 to 15 minutes.
9. The method for preparing micro-nano manganese ferrite anchored biochar according to claim 1, characterized in that: In S2, the mass ratio of the peanut shell-based biochar to the metal iron salt and manganese salt is 1:3-5:1.5-2; further preferably, in S2, the mass ratio of the peanut shell-based biochar to the metal iron salt and manganese salt is 1:4:1.
504.
10. The method for preparing micro-nano manganese ferrite anchored biochar according to claim 1, characterized in that: In S2, the metallic iron salt is FeCl3·6H2O.
11. The method for preparing micro-nano manganese ferrite anchored biochar according to claim 1, characterized in that: In S2, the manganese salt is MnCl2·4H2O.
12. The method for preparing micro-nano manganese ferrite anchored biochar according to claim 1, characterized in that: In S2, the ultrasonic dispersion is continued for 2 to 4 hours.
13. The method for preparing micro-nano manganese ferrite anchored biochar according to claim 1, characterized in that: In S2, the hydrothermal synthesis agent is polyethylene glycol and sodium acetate.
14. According to the method for preparing micro-nano manganese ferrite anchored biochar according to claim 1, in S2, the mass ratio of the peanut shell-based biochar: sodium acetate: polyethylene glycol is 1:8-12:2; further preferably, in S2, in S2, the mass ratio of the peanut shell-based biochar: sodium acetate: polyethylene glycol is 1:10:
2.
15. The method for preparing micro-nano manganese ferrite anchored biochar according to claim 1, wherein in S2, the hydrothermal synthesis agent is added and stirred at room temperature for 0.5 to 2 hours.
16. According to the method for preparing micro-nano manganese ferrite anchored biochar as claimed in claim 1, the hydrothermal reaction temperature ranges from 160 to 240°C and the reaction time is from 12 to 36 hours.
17. A micro-nano manganese ferrite anchored biochar, characterized in that: Prepared by the preparation method according to any one of claims 1 to 16.
18. Use of the micro-nano manganese ferrite anchored biochar according to claim 17 in activating persulfate to degrade phenolic organic pollutants.
19. The use according to claim 18, characterized in that The application comprises the following steps: (1) At a concentration of 20 to 50 mg·L -1 To the bisphenol A solution, 1-10 mmol / L potassium permonosulfate (abbreviated as PMS) in an amount of 300-400 times the mass of bisphenol A is added, and then 4-20 times the mass of bisphenol A is added to the above-mentioned micro-nano manganese ferrite anchored biochar, and the degradation reaction starts timing; (2) Sampling was performed using a disposable syringe at time intervals of 2, 5, 10, 20, 30, 60 and 90 minutes, respectively. Each time, quantitative sampling was performed, and the sample was added to an appropriate amount of brown chromatographic bottle after filtering through a polyethersulfone (abbreviated as PES) filter head. Methanol was added to the chromatographic bottle in advance to terminate the free radical reaction still in progress in the sample, and the quantitative sampling volume: the volume of the brown chromatographic bottle was 1:2-5, and the quantitative sampling volume: the amount of methanol was 1:0.4-1; (3) The terminated reaction solution in the chromatographic bottle was filtered to obtain the micro-nano manganese ferrite anchored biochar after the reaction, which was dispersed in an appropriate amount of ethanol. After ultrasonic treatment for 30 to 60 minutes, the effect of adsorption on the degradation and removal rate of bisphenol A (BPA) was eliminated, and the BPA concentration in the solution was determined by liquid chromatography to obtain the concentration of BPA adsorbed by the catalyst.