Preparation method and application of biochar material for adsorbing 2, 4, 6-trinitrochlorobenzene

Abstract

The invention discloses a preparation method and application of a biochar material for adsorbing 2, 4, 6-trinitrochlorobenzene, and belongs to the technical field of environmental functional materials.The preparation method comprises the steps that hydrothermal carbon is prepared, specifically, straw is washed, dried, smashed and then sieved, a straw powder product a is obtained, the product a is put into a container, distilled water is added, after ultrasonic treatment is conducted, turbid liquid is obtained, and hydrothermal carbon is obtained; heating at a set temperature to obtain a product b; washing: centrifuging the obtained product b, washing with deionized water and ethanol, and carrying out vacuum drying to obtain a product c; activating: mixing the product c with a potassium hydroxide solid, and calcining in N2 atmosphere at a set temperature to obtain a product d; and neutralization: putting the product d into a hydrochloric acid solution for ultrasonic treatment, filtering to remove the hydrochloric acid solution, washing with distilled water, and drying to obtain a biochar product e adsorbing 2, 4, 6-trinitrochlorobenzene. According to the invention, cheap wastes are directly utilized to prepare the biochar adsorption material with excellent performance, and the biochar adsorption material can efficiently adsorb 2, 4, 6-trinitrochlorobenzene and has huge application value in industry.

Description

Technical Field

[0001] The present invention belongs to the technical field of environmental functional materials, and in particular, relates to a preparation method and application of a biochar material for adsorbing 2,4,6-trinitrochlorobenzene. Background Art

[0002] 2,4,6-Trinitrochlorobenzene (picryl chloride) is an explosive compound that can be used as a precursor for the synthesis of new explosives. It has high toxicity and has been shown to be mutagenic and carcinogenic to humans and animals. 2,4,6-Trinitrochlorobenzene is insoluble in water. In industry, ethanol or acetone is usually used as a reaction solvent. After the reaction, a condensation reaction waste solvent containing a large amount of 2,4,6-trinitrochlorobenzene will be produced. 2,4,6-Trinitrochlorobenzene waste solvent has the characteristics of poor biodegradability, high toxicity, difficulty in degradation, and high organic matter content. Direct discharge into the environment will cause serious water and soil pollution. Therefore, before 2,4,6-trinitrochlorobenzene waste solvent is released into the environment, it needs to be treated as necessary.

[0003] At present, the method used for 2,4,6-trinitrochlorobenzene waste solvent is distillation, and the ethanol and acetone in the waste solvent are recovered by distillation. However, the distillation method is costly, energy-intensive, and has great safety hazards, which can easily cause 2,4,6-trinitrochlorobenzene to explode at high temperatures. The premise of using the distillation method is to stabilize the waste solvent, but there is currently a lack of effective stabilization methods. Advanced oxidation methods can efficiently degrade difficult-to-degrade pollutants by producing ·OH (hydroxyl radicals), but in the solvent system, organic solvents such as ethanol can act as natural quenchers of free radicals, resulting in the inability of free radicals to react with 2,4,6-trinitrochlorobenzene, limiting the application of a series of advanced oxidation methods with ·OH as the core. The biological method is a mature and cost-effective technology that has a good removal effect on nitrogen-containing organic matter. However, this method also has some defects, such as the need for a high carbon-nitrogen ratio, suitable pH value and temperature to successfully enrich functional bacteria, and poor toxicity resistance.

[0004] Therefore, exploring a green, economical and efficient method for treating 2,4,6-trinitrochlorobenzene waste solvent is extremely important for the treatment of industrial wastes. Summary of the invention

[0005] In order to solve the deficiencies in the prior art, the present invention provides a process for effectively removing 2,4,6-trinitrochlorobenzene by using cheap biomass energy, which can treat 2,4,6-trinitrochlorobenzene in waste solvents generated in the production process of explosives.

[0006] The present invention adopts the following technical solution.

[0007] The first aspect of the present invention discloses a method for preparing a biochar material for adsorbing 2,4,6-trinitrochlorobenzene, comprising the following steps:

[0008] Preparation of hydrothermal charcoal: Wash and dry the straw, crush and sieve to obtain straw powder product A, put product A into a reaction container, add distilled water and ultrasonicate to obtain a suspension, and heat at a set temperature to obtain product B;

[0009] Washing: centrifuge the obtained product B, wash with deionized water and ethanol, and vacuum dry to obtain product C;

[0010] Activation: Mix product C with potassium hydroxide solid in a set mass ratio, put into a reaction container, and calcine at a set temperature in a N2 atmosphere to obtain product D;

[0011] Neutralization: Place product D in a hydrochloric acid solution and perform ultrasonic treatment. After filtering to remove the hydrochloric acid solution, wash with distilled water and dry to obtain product E of biochar that adsorbs 2,4,6-trinitrochlorobenzene.

[0012] Preferably, in the preparation of the hydrothermal carbon, product A is placed in a hydrothermal synthesis reactor, the suspension solution needs to be stirred during the ultrasonic process, and the suspension solution in the hydrothermal synthesis reactor does not exceed 3 / 4 of the volume of the reactor.

[0013] Preferably, the deionized water washing and ethanol washing of product B are as follows: product B is centrifuged to separate the solid, deionized water and ethanol are added for multiple centrifugal separation and washing, the supernatant is removed, and product C is obtained by vacuum drying and then ground into powder.

[0014] Preferably, the potassium hydroxide solid needs to be ground into powder, mixed and ground with the powdered product C, and calcined at a set temperature in a N2 atmosphere at a heating rate of 5°C / min.

[0015] Preferably, the set mass ratio of the C product to potassium hydroxide solid is 1:2, and the set temperature is 300-800°C.

[0016] Preferably, product D needs to be ground into powder, placed in a hydrochloric acid solution to remove residual potassium hydroxide, filtered to remove the hydrochloric acid solution, the filtered solid is washed, centrifuged several times, and the supernatant is removed until the washing liquid is neutral.

[0017] The second aspect of the present invention discloses an application of the biochar material prepared according to the method in the adsorption of 2,4,6-trinitrochlorobenzene.

[0018] Preferably, the biochar material is weighed into a reaction container, 2,4,6-trinitrochlorobenzene solution is added, and stirring is performed under set conditions to complete adsorption.

[0019] The second aspect of the present invention discloses an application of the biochar material prepared according to the method in adsorbing 2,4,6-trinitrochlorobenzene in organic wastewater.

[0020] Preferably, the biochar material is weighed into a reaction container, and a 2,4,6-trinitrochlorobenzene organic solution is added thereto, and the mixture is stirred under set conditions to complete the adsorption.

[0021] Compared with the prior art, the beneficial effects of the present invention include at least:

[0022] This method can directly utilize cheap waste to prepare biochar adsorption materials with excellent performance, which has a huge cost advantage.

[0023] The series of biochar materials synthesized in this method have excellent specific surface area when the activation temperature exceeds 500°C, and SBC700 has the largest adsorption performance, which can efficiently adsorb 2,4,6-trinitrochlorobenzene and remove 80.68% of 2,4,6-trinitrochlorobenzene within 30 minutes. In organic solvents, the synthesized biochar has excellent performance in organic wastewater and can maintain high adsorption performance in high-concentration organic solutions, which has great application value in industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The N2 adsorption-desorption isotherm of the prepared straw biochar, where the horizontal axis is the relative pressure, the unit is P / P0, and the vertical axis is the nitrogen adsorption under standard conditions, the unit is (cm 3 / g);

[0025] Figure 2 This is the infrared spectrum of the prepared straw biochar, where the horizontal axis is the wave number (Wavenumber), the unit is cm -1 ,The vertical axis is absorbance, which indicates the ability of the sample to absorb infrared light;

[0026] Figure 3 This is a kinetic diagram of the adsorption and removal of 2,4,6-trinitrochlorobenzene by the prepared straw biochar, where the horizontal axis is the adsorption time in min, and the vertical axis is the adsorption capacity of 2,4,6-trinitrochlorobenzene per unit mass of straw biochar in mg / g;

[0027] Figure 4 It is a three-dimensional effect diagram of the prepared straw biochar for adsorbing and removing 2,4,6-trinitrochlorobenzene from organic wastewater. The X-axis is the ratio of organic solution to aqueous solution, the Y-axis is the type of straw biochar, and the Z-axis is the adsorption capacity of 2,4,6-trinitrochlorobenzene per unit mass of straw biochar, and the unit is mg / g. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The embodiments described in this application are only embodiments of a part of the present invention, rather than all embodiments. Based on the spirit of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the protection scope of the present invention.

[0029] The inventors of the present invention realized that adsorption is a common method for treating industrial wastewater and waste solvents. Pollutants can be effectively removed by developing low-cost and high-efficiency adsorption materials. At the same time, straw, as a common biomass material, can be used to synthesize biochar materials with excellent performance.

[0030] Then, the synthesis of biochar using straw as raw material is low-cost, and the synthesized biochar still has high adsorption performance in organic solutions with high ethanol and acetone content. Therefore, the development of straw-based biochar materials has great application value in the treatment of 2,4,6-trinitrochlorobenzene waste solvent.

[0031] Embodiment 1 of the present invention provides a method for preparing a biochar adsorption material for removing 2,4,6-trinitrochlorobenzene from organic wastewater. Low-cost waste straw is used as a raw material to convert the straw biomass into biochar. Biochar has a high adsorption capacity for 2,4,6-trinitrochlorobenzene due to its special structural characteristics and functional groups, thereby achieving efficient and fast treatment of nitro compounds in organic wastewater.

[0032] The specific steps include:

[0033] Step A. Wash the straw with distilled water, dry it, crush it and sieve it to obtain straw powder product A, put product A into a hydrothermal synthesis reactor, add distilled water and perform ultrasound to obtain a suspension, and heat it at a set temperature to obtain product B;

[0034] Step A specifically comprises: taking a number of waste straws, washing them with distilled water and drying them, crushing them with a pulverizer, sieving out larger particles with a sieve to obtain straw powder product a, taking 24 g of product a, putting it into a hydrothermal synthesis reactor (polytetrafluoroethylene lining), adding 100 ml of distilled water, ultrasonicating for 5 minutes to obtain a suspension, and heating at 250° C. for 10 hours to obtain product b;

[0035] In a preferred but non-limiting embodiment of the present invention, in step A, the suspension solution needs to be stirred during the ultrasonic process to make the solution as uniform as possible, and the amount of solution placed in the hydrothermal synthesis reactor does not exceed 3 / 4 of the reactor volume.

[0036] The sieve is 50 mesh.

[0037] Step B. Washing: centrifuge the obtained product B, wash with deionized water and ethanol, and vacuum dry to obtain product C;

[0038] Step B specifically comprises: centrifuging the obtained product B, washing with deionized water and ethanol for 4 to 5 times, and vacuum drying at 120° C. for 8 to 16 hours to obtain product C;

[0039] In a preferred but non-limiting embodiment of the present invention, in step B, the specific operation of washing the sample with deionized water and ethanol is to first centrifuge the original solution to separate the solid, then add deionized water and ethanol for multiple centrifugation, and remove the supernatant.

[0040] Product C obtained by vacuum drying needs to be ground into powder using a mortar.

[0041] Step C. Activation: Mix product C with potassium hydroxide solid according to a set mass ratio, put into a reaction container, and calcine at a set temperature in a N2 atmosphere to obtain product D;

[0042] Step C specifically comprises: mixing product C with potassium hydroxide solid in a mass ratio of 1:2, placing the mixture into a quartz boat, placing the quartz boat into a tube furnace, and calcining the mixture at 300, 400, 500, 600, 700, and 800° C. in a N2 atmosphere for 2 h, respectively, to obtain product D;

[0043] In a preferred but non-limiting embodiment of the present invention, in step C, the blocky potassium hydroxide solid needs to be ground into powder in advance, and then mixed and ground with the powdery product C. During high-temperature calcination, the heating rate is 5°C / min, and biochar is generated during the high-temperature calcination process.

[0044] Step D. Neutralization: Place product D in a hydrochloric acid solution for ultrasonic treatment, filter out the hydrochloric acid solution, and then wash with distilled water and dry to obtain product E of biochar.

[0045] Step D specifically comprises: placing product d in a 1 mol / L hydrochloric acid solution and ultrasonicating for 30 minutes, filtering to remove the hydrochloric acid solution, washing the powder with distilled water, and drying at 120° C. to obtain biochar product e;

[0046] The biochar grades are named SBC300, SBC400, SBC500, SBC600, SBC700 and SBC800 corresponding to the temperatures.

[0047] In a preferred but non-limiting embodiment of the present invention, in step D, during neutralization, product D needs to be ground into powder using a mortar and then placed in a 1 mol / L hydrochloric acid solution to remove residual potassium hydroxide.

[0048] After filtering out the hydrochloric acid solution, the specific operation of washing the sample with distilled water is to wash the filtered solid with distilled water, centrifuge for multiple times, and remove the supernatant until the washing solution is neutral.

[0049] Product E needs to be ground into powder before use.

[0050] like Figure 1 As shown in the figure, the adsorption isotherms of the seven synthesized biochar materials are shown. In the figure, the N2 adsorption of SBC600 is the largest, reaching a maximum of 853.58 cm 3 / g, while the initial hydrolyzed carbon HC and SBC300 had the lowest N2 adsorption capacity.

[0051] In general, as the activation temperature increases, the N2 adsorption of the material also increases. However, the N2 adsorption of SBC800 and SBC700 is lower than that of SBC600, which may be related to the "hysteresis loop" of the two biochars. HC, SBC300-SBC600 show typical type II isotherm characteristics, while SBC700 and SBC800 show type IV isotherms. The results of BET model calculation show that the specific surface area of ​​HC is 20.257 cm 2 / g, and the specific surface areas of SBC300-SBC800 are 21.974cm 2 / g, 192.958cm 2 / g, 662.195cm 2 / g, 2477.076cm 2 / g, 890.253cm 2 / g, 970.278cm 2 / g. The results show that with the increase of activation temperature, the specific surface area of ​​biochar increases, among which SBC600 has the largest specific surface area. However, with the further increase of activation temperature, the specific surface areas of biochar SBC700 and SBC800 decrease relative to SBC600 due to the appearance of hysteresis loop.

[0052] like Figure 2 As shown, the infrared spectra of the seven synthesized biochar materials can be seen. -1 The peak at 2850-2930cm represents the OH group. As the temperature increases from 250℃ to 800℃, the intensity of the peak gradually decreases, indicating the dehydration process of lignin and cellulose in the straw. -1 The peak at 750-900cm is related to the CH stretching vibration in saturated aliphatic groups. As the activation temperature increases, the peak weakens. When the temperature rises to 400℃, the characteristic peak disappears, indicating the change of the carbon chain structure. -1 The peak shift between the wavenumber ranges indicates the enhancement of the out-of-plane vibration of the aromatic CH.

[0053] Embodiment 2 of the present invention provides a method for using a biochar material for removing 2,4,6-trinitrochlorobenzene, which specifically includes:

[0054] Weigh 50 mg of straw biochar (HC, SBC300-SBC800) respectively into a 150 ml beaker, add 100 mL of 250 mg / L 2,4,6-trinitrochlorobenzene solution, and stir at 300 rpm and 25 °C.

[0055] The preparation method of the 250 mg / L 2,4,6-trinitrochlorobenzene solution is as follows: accurately weigh 250 mg of 2,4,6-trinitrochlorobenzene solid, put it into 1000 mL of aqueous solution, ultrasonicate for 30 minutes, obtain a product, and put it into a volumetric flask for standby use.

[0056] like Figure 3 As shown in the figure, with the increase of synthesis temperature, the adsorption capacity of biochar increases. Biochar synthesized above 600℃ has a better adsorption effect. The equilibrium adsorption capacities of SBC600, SBC700 and SBC800 are 304, 403 and 341 mg / g respectively, and SBC700 has the best adsorption effect. For SBC700, its adsorption capacity quickly rises to 390 mg / g within 10 min, and the 2,4,6-trinitrochlorobenzene in the solution quickly drops from 250 to 55.2 mg / L. The adsorption equilibrium is reached in 30 min. At this time, the concentration of 2,4,6-trinitrochlorobenzene in the solution is 48.3 mg / L, and the removal efficiency is 80.68%.

[0057] Embodiment 3 of the present invention provides a method for using a biochar material for removing 2,4,6-trinitrochlorobenzene from organic wastewater, specifically comprising:

[0058] 50 mg of straw biochar (SBC300-SBC800) was weighed into a 150 ml beaker, and 100 mL of an organic solution containing 250 mg / L 2,4,6-trinitrochlorobenzene was added, and stirred at 300 rpm and 25 °C.

[0059] The method for preparing the organic solution containing 250 mg / L of 2,4,6-trinitrochlorobenzene is as follows: prepare a mixed organic solvent product g according to a volume ratio of ethanol to acetone of 1:1. Accurately weigh 250 mg of 2,4,6-trinitrochlorobenzene solid, put it into 1000 mL of product g, ultrasonicate for 30 minutes, obtain product h, and put it into a volumetric flask for standby use. Mix product h and product f at a volume ratio of 1:1, 1:3, 1:9, and 1:19, respectively, to obtain an organic solution containing 250 mg / L of 2,4,6-trinitrochlorobenzene.

[0060] like Figure 4As shown in the figure, it can be seen that as the ratio of organic solvent to water decreases from 1:1 to 1:19, the adsorption effect of straw biochar varies. The original hydrothermal char HC and SBC300 and SBC400 biochars have the best adsorption performance when the ratio of organic solvent to water is 1:3, and the adsorption effect becomes worse as the proportion of aqueous solution increases. This is because as the water phase increases, the biochar is not easy to enter the solution and the contact with the pollutants is not sufficient. The organic solvent has the same effect on the adsorption performance of SBC500-SBC800 biochars. As the water phase increases, the adsorption performance also improves. It is worth noting that the biochar with the best adsorption performance is SBC700. When the ratio of organic phase to water phase is 1:19, the adsorption effect is 402 mg / g, and when the ratio of organic phase to water phase is 1:1, the adsorption performance is 218 mg / g, indicating that biochar has a good adsorption effect on 2,4,6-trinitrochlorobenzene in organic solvents.

[0061] Example A

[0062] Take the waste straw, wash it, dry it, and crush it to get straw powder. Take 24g of straw powder and put it into a hydrothermal synthesis reactor (polytetrafluoroethylene lining), add 100ml of distilled water, ultrasonicate it for 5min to get a suspension, heat it at 250℃ for 10h, wash it, and dry it at 120℃ to get hydrothermal carbon HC. HC and potassium hydroxide solid are mixed in a mass ratio of 1:2, and calcined at 300, 400, 500, 600, 700, and 800℃ for 2h in N2 atmosphere to get SBC biochar (named SBC300, SBC400, SBC500, SBC600, SBC700, and SBC800, respectively).

[0063] Using biochar as adsorbent, 2,4,6-trinitrochlorobenzene was removed by adsorption. 50 mg of straw-based biochar (HC, SBC300-SBC800) was weighed and placed in a 150 ml beaker, and 100 mL of 250 mg / L 2,4,6-trinitrochlorobenzene solution was added, and stirred at 300 rpm and 25 °C. The results showed that biochar synthesized above 600 °C had a better adsorption effect, and the equilibrium adsorption capacities of SBC600, SBC700 and SBC800 were 304, 403 and 341 mg / g, respectively.

[0064] Example B

[0065] Take the waste straw, wash it, dry it, and crush it to get straw powder. Take 24g of straw powder and put it into a hydrothermal synthesis reactor (polytetrafluoroethylene lining), add 100ml of distilled water, ultrasonicate it for 5min to get a suspension, heat it at 250℃ for 10h, wash it, and dry it at 120℃ to get hydrothermal carbon HC. HC and potassium hydroxide solid are mixed in a mass ratio of 1:2, and calcined at 300, 400, 500, 600, 700, and 800℃ for 2h in N2 atmosphere to get SBC biochar (named SBC300, SBC400, SBC500, SBC600, SBC700, and SBC800, respectively).

[0066] Biochar was used as an adsorbent to remove 2,4,6-trinitrochlorobenzene from the organic solution. 50 mg of straw-based biochar (HC, SBC300-SBC800) was weighed and placed in a 150 ml beaker, and 100 mL of an organic solution containing 250 mg / L of 2,4,6-trinitrochlorobenzene was added, and stirred at 300 rpm and 25 °C. The biochar with the best adsorption performance was SBC700, with an adsorption effect of 402 mg / g when the ratio of organic phase to aqueous phase was 1:19, and an adsorption performance of 218 mg / g when the ratio of organic phase to aqueous phase was 1:1.

[0067] Compared with the prior art, the beneficial effects of the present invention include at least:

[0068] This method can directly utilize cheap waste to prepare biochar adsorption materials with excellent performance, which has great cost advantages. The series of biochar materials synthesized in this method have excellent specific surface area when the activation temperature exceeds 500°C, and SBC700 has the largest adsorption performance, which can efficiently adsorb 2,4,6-trinitrochlorobenzene and remove 80.68% of 2,4,6-trinitrochlorobenzene within 30 minutes. In organic solvents, the synthesized biochar has excellent performance in organic wastewater and can maintain high adsorption performance in high-concentration organic solutions, which has great application value in industry.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a biochar material for adsorbing 2,4,6-trinitrochlorobenzene, characterized in that: The following steps are involved: Preparation of hydrothermal charcoal: Wash and dry the straw, crush and sieve to obtain straw powder product A, put product A into a reaction container, add distilled water and ultrasonicate to obtain a suspension, and heat at a set temperature to obtain product B; Washing: centrifuge the obtained product B, wash with deionized water and ethanol, and vacuum dry to obtain product C; Activation: Mix product C with potassium hydroxide solid in a set mass ratio, put into a reaction container, and calcine at a set temperature in a N2 atmosphere to obtain product D; Neutralization: Place product D in a hydrochloric acid solution and perform ultrasonic treatment. After filtering to remove the hydrochloric acid solution, wash with distilled water and dry to obtain product E of biochar that adsorbs 2,4,6-trinitrochlorobenzene.

2. The method for preparing a biochar material for adsorbing 2,4,6-trinitrochlorobenzene according to claim 1, characterized in that: In the preparation of the hydrothermal carbon, product A is placed in a hydrothermal synthesis reactor, the suspension solution needs to be stirred during the ultrasonic process, and the suspension solution in the hydrothermal synthesis reactor does not exceed 3 / 4 of the reactor volume.

3. The method for preparing a biochar material for adsorbing 2,4,6-trinitrochlorobenzene according to claim 1, characterized in that: The deionized water washing and ethanol washing of product B are as follows: product B is centrifuged to separate the solid, deionized water and ethanol are added for multiple centrifugal separation and washing, the supernatant is removed, and product C is obtained by vacuum drying and then ground into powder.

4. The method for preparing a biochar material for adsorbing 2,4,6-trinitrochlorobenzene according to claim 1, characterized in that: The potassium hydroxide solid needs to be ground into powder, mixed and ground with the powdered product C, and calcined at a set temperature in a N2 atmosphere at a heating rate of 5°C / min.

5. The method for preparing a biochar material for adsorbing 2,4,6-trinitrochlorobenzene according to claim 4, characterized in that: The set mass ratio of the C product to potassium hydroxide solid is 1:2, and the set temperature is 300-800°C.

6. The method for preparing a biochar material for adsorbing 2,4,6-trinitrochlorobenzene according to claim 1, characterized in that: Product d needs to be ground into powder, placed in a hydrochloric acid solution to remove residual potassium hydroxide, filtered to remove the hydrochloric acid solution, the filtered solid is washed, centrifuged several times, the supernatant is removed, and washed until the washing solution is neutral.

7. Use of the biochar material prepared according to the method according to any one of claims 1 to 6 in the adsorption of 2,4,6-trinitrochlorobenzene.

8. The use according to claim 7, characterized in that: The biochar material was weighed into a reaction container, 2,4,6-trinitrochlorobenzene solution was added, and the mixture was stirred under set conditions to complete the adsorption.

9. Use of the biochar material prepared according to the method according to any one of claims 1 to 6 in adsorbing 2,4,6-trinitrochlorobenzene in organic wastewater.

10. The use according to claim 9, characterized in that: The biochar material was weighed into a reaction container, and 2,4,6-trinitrochlorobenzene organic solution was added, and stirred under set conditions to complete the adsorption.

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