阅读说明：本技术 一种多级孔炭材料及其制备方法和应用 (Hierarchical porous carbon material and preparation method and application thereof ) 是由 潘力 喻乐意 李星 于 2021-08-20 设计创作，主要内容包括：本发明公开一种多级孔炭材料及其制备方法和应用,涉及生物质炭吸附剂制备的技术领域。本发明将啤酒糟作为底物,运用黑曲霉产酶的特点,对啤酒糟进行微生物预处理,得到比表面积最高达1689m～(2)/g,以及具备多级孔结构的炭材料。该炭材料具备高比表面积,以及微孔、介孔、大孔多孔径结构的特征,可有效提高炭材料的吸附性能。同时,该炭材料对甲苯具有很好的吸附性能,最高吸附量为0.399g/g。本发明中的底物啤酒糟和黑曲霉均为无毒无害的前体物质,制备工艺简单,绿色环保,成本低廉,可实现工业化；可广泛应用于吸附领域,也可应用于环保、催化、医药等其他领域；在吸附剂的开发以及空气的净化领域具有较大的应用前景。(The invention discloses a hierarchical porous carbon material and a preparation method and application thereof, and relates to the technical field of preparation of biomass carbon adsorbents. The invention takes the beer lees as the substrate, and uses the characteristics of Aspergillus niger enzyme production to carry out microbial pretreatment on the beer lees to obtain the beer lees with the highest specific surface area of 1689m 2 And/g, and a carbon material having a hierarchical pore structure. The carbon material has the characteristics of high specific surface area and microporous, mesoporous and macroporous porous structures, and can effectively improve the adsorption performance of the carbon material. Meanwhile, the carbon material has good adsorption performance on toluene, and the maximum adsorption capacity is 0.399 g/g. The substrate brewer's grains and aspergillus niger in the invention are nontoxic and harmless precursor substances, the preparation process is simple, green and environment-friendly, the cost is low, and industrialization can be realized; can be widely applied to the field of adsorption, and can also be applied to environmental protection and catalysisAnd other fields such as medicine; has wide application prospect in the fields of development of adsorbents and air purification.)

1. A method for preparing a hierarchical porous carbon material by pretreating brewer's grains with Aspergillus niger is characterized by comprising the following steps: the method comprises the following steps:

(1) dewatering and drying the waste biomass brewer's grain: firstly, filtering and dewatering the brewer's grains by four layers of gauze, and cleaning for three times by ultrapure water; then placing the beer lees dewatered and washed by gauze in a room at normal temperature, and naturally drying in the air;

(2) aspergillus niger pretreatment of brewer's grains: simultaneously placing the seed liquid of the aspergillus niger and the washed and dried brewer's grain into a fermentation medium, and carrying out constant-temperature shaking culture; after fermentation is finished, collecting brewer's grains treated by aspergillus niger; washing and drying to obtain a beer lees carbonized precursor;

(3) carbonization and activation of the precursor: firstly, carrying out high-temperature carbonization treatment on a beer lees carbonization precursor in a nitrogen atmosphere to obtain a primary carbonized substance; then, further performing high-temperature activation treatment on the primary carbide in a nitrogen atmosphere to obtain a carbide;

(4) acid washing of carbide: and stirring the carbide obtained by activation with hydrochloric acid solution at room temperature, centrifuging to remove water, and drying to obtain the hierarchical porous carbon material.

2. The method of claim 1, wherein:

the Aspergillus niger in the step (2) is at least one of a spore-forming Aspergillus niger and a non-spore-forming Aspergillus niger.

3. The method of claim 2, wherein:

the Aspergillus niger capable of producing spores is Aspergillus niger capable of producing spores (Aspergillus niger CBS513.88), and the Aspergillus niger capable of not producing spores is Aspergillus niger capable of not producing spores (Aspergillus niger SH 2).

4. The method of claim 3, wherein:

the seed solutions in the step (2) are respectively a spore-producing Aspergillus niger (Aspergillus niger CBS513.88) inoculated in a potato glucose agar culture medium, a spore solution collected by culturing at 24-30 ℃ for 5-10 days, and a spore-producing Aspergillus niger (Aspergillus niger SH2) inoculated in a liquid CD culture medium, a hypha solution cultured at 24-30 ℃ for 3-8 days;

the inoculation amounts of the seed solutions in the step (2) are respectively that the inoculation amount of the Aspergillus niger (Aspergillus niger CBS513.88) producing spores is 1-3% v: v, the concentration of the spores is 0.5-1.5 multiplied by 10⁷cfu/mL; the inoculum size of the Aspergillus niger (Aspergillus niger SH2) is 2-5% v: v, OD₆₀₀＝1.0～2.0；

The fermentation medium is a potato glucose fermentation medium and has the following formula: 5g/L of potato starch, 20g/L of anhydrous glucose, 5g/L of monopotassium phosphate and 0.5g/L of magnesium sulfate heptahydrate;

the addition amount of the dried brewer's grains is 2-4% w: v.

5. The method according to any one of claims 1 to 4, wherein:

in the step (3), the high-temperature carbonization treatment is carried out for 90-120 minutes at the temperature of 350-500 ℃;

in the step (3), the high-temperature activation treatment is carried out for 90-120 minutes at the temperature of 750-900 ℃.

6. The method of claim 5, wherein:

in the step (3), the high-temperature carbonization treatment is carried out for 90 minutes at the temperature of 500 ℃;

in the step (3), the high-temperature activation treatment is carried out for 90 minutes at 800 ℃.

7. The method according to any one of claims 1 to 4, wherein:

in the step (2), the constant-temperature shaking culture conditions are 24-34 ℃, and the constant-temperature shaking culture is carried out at 200-250 rpm for 7-10 days;

in the step (2), the drying temperature is 40-80 ℃;

in the step (4), the hydrochloric acid solution is 1.5-2.5 mol/L hydrochloric acid solution; the stirring time is 2-4 h;

in the step (4), the drying temperature is 50-80 ℃;

the temperature of the room temperature is 15-35 ℃.

8. A hierarchical porous carbon material is characterized in that: prepared by the method of any one of claims 1 to 7.

9. Use of the hierarchical porous carbon material according to claim 8 or the carbon material prepared by the method according to any one of claims 1 to 7 without Aspergillus niger pretreatment for adsorbing volatile organic compounds.

10. Use according to claim 9, characterized in that:

the volatile organic compound is toluene.

Technical Field

The invention relates to the technical field of biomass charcoal adsorbent preparation, in particular to a method for preparing a hierarchical porous charcoal material by utilizing Aspergillus niger to pretreat brewer's grains and application of the prepared charcoal material, and provides a safe and reliable material for adsorption treatment of pollutants such as Volatile Organic Compounds (VOCs).

Background

The beer lees is a main byproduct in the beer production process, and is residue obtained by repeatedly fermenting refined barley serving as a raw material by yeast. According to statistics, about 0.25 ton of beer lees is produced per 1 ton of beer, the annual output of the beer lees in China reaches more than 1000 million tons, and the production is continuously increased. The main components of brewer's grains are husk, leaf bud, insoluble protein, hemicellulose, fat, ash and small amount of undecomposed starch. The brewer's grain is a biomass with rich sources and various components, can be used for preparing carbon materials only by simple dehydration, and is beneficial to preparing a large amount of high-performance carbon materials at low cost. On the other hand, inspired by the natural decomposition process, fungi can decompose plant biomass, forming the biomass into a precursor with a loose structure, facilitating the construction of rich porous materials through subsequent carbonization and activation. Aspergillus niger has a rich enzyme secretion system, is often used as an efficient cell factory, and is widely applied to the bio-manufacturing industry.

With the rapid development of industry, Volatile Organic Compounds (VOCs) are released into the atmosphere in large quantities, which causes environmental problems such as greenhouse effect and photochemical smog, and seriously harms human health. The adsorption method is widely applied to controlling the diffusion of volatile organic compounds, can fix the volatile organic compounds in the atmosphere and effectively purify the air. The core element in the adsorption process is an adsorbent, and the most commonly used adsorbent is a porous carbon material. The production cost of the porous carbon material is relatively low, and the porous carbon material produced by the method is mostly waste plant biomass, such as shaddock peel, corn straw and the like. However, the pretreatment cost of the biomass is high, the method for preparing the porous carbon material is complex, secondary pollution is easy to cause, and large-scale production and application cannot be realized. Meanwhile, the prepared porous carbon material has limited adsorption performance on volatile organic compounds due to the limitation of properties such as specific surface area, micropores and the like. Therefore, there is a need to develop an economical porous carbon material with high specific surface area and good adsorption performance.

Disclosure of Invention

In order to overcome the defects of the prior art of the carbonaceous VOCs adsorbent, the invention mainly aims to provide a method for preparing a multi-level porous carbon material by pretreating brewer's grains with Aspergillus niger. According to the method, the Aspergillus niger decomposition pretreatment is adopted, so that the pore structure of the biomass raw material brewer's grain can be enriched and adjusted, and the carbonaceous VOCs adsorbent with a hierarchical pore structure is obtained. According to the method, the carbon material with large specific surface area and multistage pore size structure distribution can be prepared. The prepared carbon material has good adsorption performance and larger adsorption capacity.

The invention also aims to provide the hierarchical porous carbon material prepared by the method.

The invention further aims to provide application of the hierarchical porous carbon material. The carbon material with high specific surface area and a multistage pore size structure is used for adsorbing volatile organic compounds.

The purpose of the invention is realized by the following technical scheme:

the invention provides a method for preparing a hierarchical porous carbon material by pretreating brewer's grains with aspergillus niger, which comprises the following steps:

(1) dewatering and drying the waste biomass brewer's grain: firstly, filtering and dewatering the brewer's grains by four layers of gauze, and cleaning for three times by ultrapure water; then placing the beer lees dewatered and washed by gauze in a room at normal temperature, and naturally drying in the air;

(2) aspergillus niger pretreatment of brewer's grains: simultaneously placing the seed liquid of the aspergillus niger and the washed and dried brewer's grain into a fermentation medium, and carrying out constant-temperature shaking culture; after fermentation is finished, collecting brewer's grains treated by aspergillus niger; washing and drying to obtain a beer lees carbonized precursor;

(3) carbonization and activation of the precursor: firstly, carrying out high-temperature carbonization treatment on a beer lees carbonization precursor in a nitrogen atmosphere to obtain a primary carbonized substance; then, further performing high-temperature activation treatment on the primary carbide in a nitrogen atmosphere to obtain a carbide;

(4) acid washing of carbide: and stirring the carbide obtained by activation with hydrochloric acid solution at room temperature, centrifuging to remove water, and drying to obtain the hierarchical porous carbon material.

The Aspergillus niger in the step (2) is at least one of a spore-forming Aspergillus niger and a non-spore-forming Aspergillus niger;

preferably, the spore-forming A.niger is Aspergillus niger (Aspergillus niger CBS513.88) and the non-spore-forming A.niger is Aspergillus niger (Aspergillus niger SH 2).

The seed solutions in the step (2) are respectively spore-producing Aspergillus niger (Aspergillus niger CBS513.88) inoculated in a potato glucose agar culture medium (PDA) and collected spore solution after 5-10 days of culture at 24-30 ℃, and spore-non-producing Aspergillus niger (Aspergillus niger SH2) inoculated in a liquid CD culture medium and mycelium solution after 3-8 days of culture at 24-30 ℃.

Further, the seed solutions in the step (2) are respectively a hypha solution obtained by inoculating Aspergillus niger (Aspergillus niger CBS513.88) producing spores in a Potato Dextrose Agar (PDA) culture medium and culturing the spores at 30 ℃ for 7 days for collection, and inoculating Aspergillus niger (Aspergillus niger SH2) not producing spores in a liquid CD culture medium and culturing the hypha solution at 30 ℃ for 5 days.

The inoculation amounts of the seed solutions in the step (2) are respectively that the inoculation amount of the Aspergillus niger (Aspergillus niger CBS513.88) producing spores is 1-3% (v: v, the spore concentration is 0.5-1.5 multiplied by 10)⁷cfu/mL), the inoculum size of the non-sporulating Aspergillus niger (Aspergillus niger SH2) is 2-5% (v: v, OD₆₀₀1.0 to 2.0). The fermentation medium is a potato glucose fermentation medium and has the following formula: 5g/L of potato starch, 20g/L of anhydrous glucose, 5g/L of monopotassium phosphate and 0.5g/L of magnesium sulfate heptahydrate. The addition amount of the dried brewer's grains is 2-4% (w: v).

Further, the seed liquid inoculation amounts in the step (2) are respectively that the inoculation amount of the Aspergillus niger (Aspergillus niger CBS513.88) for producing spores is 2% (v: v, the spore concentration is 10)⁷cfu/mL), the inoculum size of the spore-forming Aspergillus niger (Aspergillus niger SH2) was 3% (v: v, OD₆₀₀1.0). The amount of dry brewer's grains added was 3% (w: v).

In the step (2), the constant-temperature shaking culture conditions are 24-34 ℃, and the constant-temperature shaking culture is carried out at 200-250 rpm for 7-10 days; further culturing for 10 days at 30 ℃ and constant temperature shaking at 200 rpm;

in the step (2), the drying temperature is 40-80 ℃; further 80 ℃.

In the step (3), the high-temperature carbonization treatment is carried out for 90-120 minutes at the temperature of 350-500 ℃; further carrying out high-temperature carbonization treatment at 500 ℃ for 90 minutes;

in the step (3), the high-temperature activation treatment is carried out for 90-120 minutes at the temperature of 750-900 ℃; further activating treatment for 90 minutes at 800 ℃;

the high-temperature activation treatment comprises direct high-temperature activation treatment or high-temperature activation treatment after adding an activating agent; the activating agent is potassium hydroxide.

In the step (4), the hydrochloric acid solution is 1.5-2.5 mol/L hydrochloric acid solution; the stirring time is 2-4 h;

further, in the step (4), the hydrochloric acid solution is 2mol/L hydrochloric acid solution; the stirring time is 2 hours;

in the step (4), the drying temperature is 50-80 ℃; further 80 ℃.

The temperature of the room temperature is 15-35 ℃.

A hierarchical porous carbon material is prepared by the method.

The specific surface area of the carbon material prepared by the method is 1246-1689 m²/g。

The carbon material prepared by the method has a multi-stage pore diameter structure, and the specific surface area of the microporous structure is 1156-1575 m²/g。

The hierarchical porous carbon material prepared by the method is applied to the field of adsorption. The adsorbent can be used for adsorbing volatile organic compounds such as toluene, and the adsorption capacity of the toluene is up to 300-400 mg/g; further 346-399 mg/g.

The carbon material prepared by the method without Aspergillus niger pretreatment can also be applied to the field of adsorption. Can be used for adsorbing volatile organic compounds such as toluene and the like, and the adsorption capacity of the toluene can reach 288 mg/g.

Compared with the prior art, the invention has the following advantages and effects:

a. the original biomass of the carbon material is the waste brewer's grain in the brewery industry, the source is rich, the pretreatment process is simple, the production cost is basically not high, and the biological resource recycling can be realized. The substrate brewer's grains and aspergillus niger in the invention are nontoxic and harmless precursor substances, the process for preparing the carbon material is simple, green and environment-friendly, and the carbon material has a wide application prospect in the fields of development of adsorbents and air purification.

b. The invention uses cheap and easily obtained beer lees as the original biomass of the carbon material, and uses the Aspergillus niger with rich enzyme secretion system to pretreat the beer lees, so that the beer lees form a carbon precursor with a loose structure, particularly the Aspergillus niger with rapid growth and rich sporulation, and the pore diameter structure of the carbon material can be effectively adjusted. The method is efficient and simple, has low cost and can realize industrialization.

c. The invention takes the beer lees as the substrate, and uses the characteristics of Aspergillus niger enzyme production to carry out microbial pretreatment on the beer lees to obtain the beer lees with the highest specific surface area of 1689m²And/g, and a biomass charcoal material with a hierarchical pore structure. Meanwhile, the prepared carbon material has good adsorption performance on toluene, and the highest adsorption capacity is 0.399 g/g. In particular, the carbon material prepared by pretreating aspergillus niger rich in spores has higher specific surface area and stronger adsorption performance on VOCs.

d. The method provided by the invention is simple and efficient by adopting a method combining microbial treatment and chemical treatment. The combination of biology and chemistry results in the prepared carbon material having high specific surface area and more micropore structures, so that the carbon material has high adsorption performance.

e. The invention relates to a method for effectively preparing a biomass charcoal material, and the prepared charcoal material has the characteristics of high specific surface area and microporous, mesoporous and macroporous porous structures, and can effectively improve the adsorption performance of the charcoal material. Meanwhile, the prepared carbon material has high adsorption performance on volatile organic compounds. The carbon material obtained by the invention is green and pollution-free, can be widely applied to the field of adsorption, and can also be applied to other fields such as environmental protection, catalysis, medicine and the like.

Drawings

FIG. 1 is a nitrogen adsorption and desorption isotherm (A), a pore size distribution diagram (B) and a toluene breakthrough curve diagram (C) of a multi-stage pore carbon material prepared by pretreating brewers grains with Aspergillus niger (CBS 513.88) of Sporotrichum-producing in example 1; wherein, CK is a carbon material prepared without adopting Aspergillus niger pretreatment, and CBS is a carbon material prepared by adopting Aspergillus niger (CBS 513.88) of spore-forming Aspergillus niger.

FIG. 2 is a nitrogen adsorption and desorption isotherm (A), a pore size distribution diagram (B) and a toluene breakthrough curve diagram (C) of a multi-stage pore carbon material prepared by pretreating brewers grains with Aspergillus niger SH2 (Aspergillus niger) in example 2; wherein CK is a carbon material prepared without adopting Aspergillus niger pretreatment, and SH2 is a carbon material prepared with Aspergillus niger SH2 without producing spores.

FIG. 3 is a scanning electron micrograph of the hierarchical porous carbon material prepared in examples 1 and 2; wherein A is CK: carbon material prepared without aspergillus niger pretreatment, B is CBS: the carbon material prepared by adopting Aspergillus niger (Aspergillus niger CBS513.88) for pretreatment has the following formula that C is SH 2: the charcoal material prepared was pretreated with Aspergillus niger SH 2.

Detailed Description

The present invention will be described in further detail with reference to examples and drawings, but the present invention is not limited thereto.

The invention relates to a strain, a raw material, a reagent and an instrument: aspergillus niger (Aspergillus niger CBS513.88) which is a conventional commercially available product, and Aspergillus niger (Aspergillus niger SH2) which is not a spore producer, are both disclosed in the literature "Huangliang, transcriptional regulatory mechanism study at the Aspergillus niger genome level [ D ]. southern China university of technology", and are also materials deposited in this laboratory; the brewer's grains are from Qingdao beer (san shui) limited of Buddha mountain city; the purity of the nitrogen related to the invention is 99.999 percent (Foshan Drimezier gas Co., Ltd.), the purity of the toluene standard gas is 99.999 percent (Foshan Drimezier gas Co., Ltd.), and other chemical reagent medicines are made in China or imported with the purity level of analysis and above; the invention relates to main instruments and equipment: an autoclave (MLS-3750, SANYO, Japan), a mold incubator (SHP-450D, Shanghai Sensin laboratory instruments Co., Ltd.), a constant temperature air bath shaker (Suzhou peying laboratory instruments Co., Ltd.), an ultra clean bench (SW-CJ-1FD, Suzhou purification Co., Ltd.), an ultra pure water instrument (Shanghai Toudder instruments Co., Ltd.), a high precision balance (Sidoris, Germany), an ultrasonic cleaner (Ningbo Xinzhi instruments Co., Ltd.), a vacuum pump (DOA-P70-BN, PALL., USA), a tube furnace (OTF-1200X, Synechol Crystal Material technology Co., Ltd.), a gas chromatograph (GC-2014C, Japan island, Japan), a high resolution field emission scanning electron microscope (Merlin, Germany Seitz), and an adsorption evaluation reaction apparatus made by oneself.

The application comprises the following steps: the adsorption capacity of the hierarchical porous carbon material prepared in the embodiment 1-2 is evaluated by adopting toluene which is a typical substance for dynamically adsorbing VOCs. The experimental device consists of a gas distribution system, an adsorption system and an analysis system. The carrier gas, toluene vapor and air were mixed uniformly in a mixer. The toluene concentration in the gas stream before entry into the adsorption column was 100 ppm. The toluene concentration was analyzed by Gas Chromatography (GC). Accurately weighing 0.05g of a carbon material sample to be detected, loading the carbon material sample into an adsorption column, and connecting the adsorption column into a gas path. And when the peak area of the toluene is stable in GC (gas chromatography), opening the gas path of the adsorption column, closing the gas path without the adsorption column, performing dynamic adsorption evaluation, and when the peak area of the toluene is not changed any more, determining that the gas path reaches an adsorption saturation state, closing the gas path of the adsorption column, and switching to the gas path without the adsorption column. And finally analyzing the adsorption capacity of the carbon material to toluene.

Example 1

A method for preparing a multi-level pore carbon material by pretreating beer grains by Aspergillus niger (CBS 513.88) comprises the following steps:

(1) the brewery spent grains with high water content obtained from the brewery are filtered and dewatered by four layers of gauze, and are washed for three times by ultrapure water. Then placing the beer lees dewatered and washed by gauze in a room at normal temperature, and naturally drying for later use;

(2) the glycerol-deposited strain of Aspergillus niger (Aspergillus niger CBS513.88) producing spores was plated on potato dextrose agar medium (PDA), PDA medium: 200g/L of potato powder, 20g/L of glucose, 20g/L of agar and 5.6 of pH. Culturing at 30 deg.C for 7 days, collecting spore as inoculation liquid;

(3) inoculating the spore liquid prepared in the step (2) into 500mL of potato glucose fermentation medium, and adding 15g of the beer lees naturally air-dried in the step (1). The inoculation amount of the spores is 2 percent (v: v, the concentration of the spores is 10)⁷cfu/mL). Fermenting and culturing at 30 deg.C and 200rpm for 10 days. After the fermentation is finished, the three layers of gauzes are dehydrated and the treated brewer's grains are collected and washed three times by ultrapure water. Cleaning, drying at 80 deg.C to obtain brewery mash pretreated by Aspergillus niger (CBS 513.88).

(4) And (4) placing the beer lees pretreated by the microorganisms in the step (3) in a tube furnace, and carrying out high-temperature carbonization treatment at 500 ℃ for 90 minutes under the nitrogen atmosphere. Then, the resultant was activated at 800 ℃ for 90 minutes (potassium hydroxide as an activating agent) under a nitrogen atmosphere to obtain a carbide. And finally, stirring the carbide obtained by activation for 2 hours at room temperature by using 20mL of 2mol/L hydrochloric acid solution, centrifugally removing water, and then placing the carbide in an oven at 80 ℃ for drying to obtain the hierarchical porous carbon material.

The pore size distribution, performance test and surface morphology of the multi-stage pore carbon material prepared by pretreating brewer's grains with Aspergillus niger (CBS 513.88) of Aspergillus sporulation of this example are shown in FIGS. 1 and 3A, B. In FIG. 1, A is a nitrogen adsorption and desorption isotherm, B is a pore size distribution diagram, and C is a toluene penetration curve; wherein CK is a carbon material prepared without adopting Aspergillus niger pretreatment, and CBS is a carbon material prepared by adopting Aspergillus niger (Aspergillus niger CBS513.88) pretreatment. In FIG. 3, A is CK and B is a scanning electron micrograph of CBS.

The specific surface area of the carbon material prepared in this example was 1689m²Per g, specific surface area of micropores 1575m²(ii)/g, the specific surface area of the mesopores and macropores is 114m²(ii)/g, average pore diameter was 2.21nm, and adsorption capacity of toluene was 0.399 g/g.

The specific surface area of the carbon material (CK) prepared without Aspergillus niger pretreatment is 1489m²Per g, specific micropore surface area of 1336m²(ii)/g, the mesopore and macropore specific surface area is 153m²Per g, average pore diameter of 2.32nm, absorption of tolueneThe attached capacity was 0.288 g/g.

Example 2

A method for preparing a multi-level pore carbon material by pretreating beer lees by Aspergillus niger SH2 comprises the following steps:

(1) the brewery spent grains with high water content obtained from the brewery are filtered and dewatered by four layers of gauze, and are washed for three times by ultrapure water. Then placing the beer lees dewatered and washed by gauze in a room at normal temperature, and naturally drying for later use;

(2) the glycerol-deposited strain of aspergillus niger not producing spores (aspergillus niger SH2) was inoculated into liquid CD medium, CD medium: 20g/L of glucose, 2g/L of potassium chloride, 0.5g/L of magnesium sulfate heptahydrate, 1g/L of potassium dihydrogen phosphate, 0.01g/L of ferrous sulfate heptahydrate, 3g/L of sodium nitrate and 0.05% of agar. Culturing at 30 deg.C for 5 days;

(3) inoculating the mycelium liquid prepared in the step (2) into 500mL of potato glucose fermentation medium, and adding 15g of the beer lees naturally air-dried in the step (1). The inoculation amount is 3% (v: v, OD)₆₀₀1). Fermenting and culturing at 30 deg.C and 200rpm for 10 days. After the fermentation is finished, the three layers of gauzes are dehydrated and the treated brewer's grains are collected and washed three times by ultrapure water. Cleaning, drying at 80 deg.C to obtain brewery mash pretreated by Aspergillus niger SH 2.

(4) And (4) placing the beer lees pretreated by the microorganisms in the step (3) in a tube furnace, and carrying out high-temperature carbonization treatment at 500 ℃ for 90 minutes under the nitrogen atmosphere. Then, the resultant was activated at 800 ℃ for 90 minutes (potassium hydroxide as an activating agent) under a nitrogen atmosphere to obtain a carbide. And finally, stirring the carbide obtained by activation for 2 hours at room temperature by using 20mL of 2mol/L hydrochloric acid solution, centrifugally removing water, and then placing the carbide in an oven at 80 ℃ for drying to obtain the hierarchical porous carbon material.

The pore size distribution, performance test and surface morphology of the multi-stage pore carbon material prepared by pretreating brewer's grains with Aspergillus niger SH2 (Aspergillus niger) are shown in FIGS. 2 and 3A, C. In FIG. 2, A is a nitrogen adsorption and desorption isotherm, B is a pore size distribution diagram, and C is a toluene penetration curve; wherein CK is a carbon material prepared without adopting Aspergillus niger pretreatment, and SH2 is a carbon material prepared by adopting Aspergillus niger SH 2. In FIG. 3, A is CK and C is SH 2.

The specific surface area of the carbon material prepared in the embodiment is 1246m²Per g, specific micropore surface area of 1156m²The specific surface area of the mesopores and the macropores is 90m²(ii)/g, the average pore diameter was 2.46nm, and the adsorption capacity for toluene was 0.346 g/g.

The conclusions drawn from fig. 1, 2 and 3 are as follows:

the carbon material prepared in example 1 has a higher specific surface area and higher adsorption capacity for toluene than the carbon material prepared in example 2. The carbon material prepared in example 1 and the carbon material prepared in example 2 both have a multi-stage pore size structure, and the microporous structure is the largest. The carbon material prepared in example 1 and the carbon material prepared in example 2 both have higher adsorption capacity for toluene than the carbon material prepared from brewer's grains which are not pretreated by microorganisms. The carbon material prepared by the Aspergillus niger pretreatment has higher adsorption performance to toluene.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.