CN115041137B - Preparation and application of a recyclable humic acid biomass carbon material - Google Patents

Abstract

A preparation method of a recyclable humic acid biomass carbon material comprises the steps of preparing and regenerating the carbon material, wherein the carbon material is prepared by soaking humic acid in a sodium carbonate aqueous solution under ultraviolet light, adding hydrogen peroxide into the treated humic acid, mixing, carrying out first high-temperature treatment to obtain humic acid carbon, treating the humic acid carbon by using potassium hydroxide and sodium hydroxide as composite activators, carrying out second high-temperature treatment, carrying out acid pickling and drying, and the mass ratio of black humic acid in the humic acid is more than 85%. The humic acid biomass carbon material prepared by the invention has excellent physicochemical properties, and the specific surface area reaches 2376m ² G, pore volume up to 2.27cm ³ The adsorption capacity of the humic acid biomass carbon material to malachite green and tetracycline hydrochloride reaches 1059.4mg/g and 872.3mg/g, and after the humic acid biomass carbon material is recycled for 5 times, the removal rate of the humic acid biomass carbon material to malachite green and tetracycline hydrochloride still reaches 69.7% and 58.6%, and the humic acid biomass carbon material has excellent cycle stability.

Description

Preparation and application of a recyclable humic acid biomass carbon material

technical field

The invention relates to the technical field of organic wastewater treatment, in particular to the preparation and application of a recyclable humic acid biomass carbon material.

Background technique

In recent years, due to the rapid development of society, water pollution has become an increasingly serious problem, and dyes and antibiotics are one of the main sources of wastewater pollution. The adsorption and degradation of organic dyes and antibiotics in wastewater has become a research hotspot. Common methods for treating water pollution include chemical flocculation, membrane filtration, reverse osmosis, ion exchange, adsorption, and electrochemical processes, etc. Among them, the adsorption method has the advantages of simple operation, low cost, and high efficiency, and has become a popular wastewater treatment method. .

Malachite green has been widely used to prevent and treat diseases such as saprolegniasis, gill mold and melon worms of various aquatic animals. It is also used as a dye for silk, leather and paper, but malachite green has potential carcinogenicity. , teratogenic and mutagenic effects, and the state explicitly prohibits adding it in the field of pollution-free aquaculture.

Tetracyclic antibiotics are broad-spectrum antibiotics that can inhibit the synthesis of bacterial proteins and are widely used in the pharmaceutical industry, animal husbandry and aquaculture. However, tetracyclic antibiotics are difficult to be completely degraded, and their degradation intermediates often have very Large toxicity, and the general residue will cause the enrichment of drug-resistant bacteria and the production of resistance genes. When using biomass carbon adsorption to treat tetracycline hydrochloride, there are often technical problems such as low adsorption capacity, agglomeration, and separation difficulties, which hinder the application of this method in the adsorption of tetracycline hydrochloride.

Humic acid has strong ion exchange capacity, adsorption capacity and ability to remove impurities, so it is widely used in the field of wastewater treatment. It can be used as a cationic dye decolorizer to treat cationic printing and dyeing wastewater. In the prior art, humic acid is directly used to adsorb and degrade malachite green and tetracycline hydrochloride, but the degradation efficiency is not high and the stability is poor. It has been reported in the literature that after high-temperature carbonization of fulvic acid and sodium hydroxide as an activator, the biomass carbon prepared by high-temperature activation has a specific surface area of 2922m ² /g, and the adsorption capacity of bright green and sulfadiazine sodium salt is respectively 2250mg/g and 941mg/g. However, the biomass carbon prepared by this method has poor adsorption performance when used to treat malachite green and tetracycline hydrochloride. Based on this, further improvement is needed to prepare humic acid biomass with excellent adsorption performance for malachite green and tetracycline hydrochloride. carbon material.

Contents of the invention

The purpose of the present invention is to provide a method for preparing a recyclable humic acid biomass carbon material.

Another object of the present invention is to provide the application of the humic acid biomass carbon material.

The object of the invention is achieved through the following technical solutions:

A kind of preparation method of recyclable humic acid biomass carbon material, it is characterized in that: comprise the preparation of carbon material and regeneration treatment, described carbon material preparation is that humic acid is added in sodium carbonate aqueous solution, ultrasonic treatment, in The treated humic acid is mixed with hydrogen peroxide, and the first high-temperature treatment is carried out to obtain humic acid carbon. The humic acid carbon is treated with potassium hydroxide and sodium hydroxide as a composite activator, and then the second high-temperature treatment is carried out. Pickling and drying are then carried out, and the mass ratio of black humic acid in the humic acid is more than 85%.

Further, the concentration of the above sodium carbonate aqueous solution is 0.6-1mmol/L, and the power of the ultrasonic treatment is 60-100W.

Black humic acid has a large molecular weight and low activity. If it is directly carbonized at high temperature and then activated, the physical and chemical properties of the prepared biochar are poor, and the overall adsorption performance is not ideal.

The present invention uses sodium carbonate combined with ultrasound for pretreatment, activates sodium carbonate through ultrasound, removes a small amount of black humic acid, and achieves the effect of loosening the stable structure of black humic acid, and then adds hydrogen peroxide, through the oxidation of hydrogen peroxide, in the structure of black humic acid On the basis of loosening, the molecular chain of black humic acid is further broken. In the first high-temperature treatment process, sodium carbonate acts as an activator to activate pore-forming effect on humic acid after hydrogen peroxide oxidation treatment, increasing the carbon material surface. The active group of the active group, followed by potassium hydroxide and sodium hydroxide, on the basis of the first activation of pore-forming, further adjusted the activation degree of humic acid carbon, and adjusted the change trend of its surface functional groups, thus preparing A biomass carbon material with high adsorption performance for malachite green and tetracycline hydrochloride and excellent adsorption stability.

Preferably, the concentration of the above-mentioned sodium carbonate aqueous solution is 0.8mmol/L, and the power of the ultrasonic treatment is 80W.

Further, the mass fraction of the above-mentioned hydrogen peroxide is 20%, and the dosage relationship of humic acid, sodium carbonate aqueous solution and hydrogen peroxide is 10g: 15-20mL: 4-5mL.

Furthermore, the above first high temperature treatment is specifically to place the pretreated humic acid under nitrogen protection, raise the temperature to 550-600°C at 2-3°C/min, and keep it warm for 40-50min to obtain humic acid carbon.

Further, in the above second high temperature treatment, the humic acid carbon and the composite activator are mixed and ground according to the mass ratio of 1:2-3, and then placed in a tube furnace, and the temperature is raised to 600-650°C at 6-8°C/min , keep warm for 60min; after the keep warm, wash with hydrochloric acid, then wash with deionized water until neutral.

Further, the mass ratio of potassium hydroxide and sodium hydroxide in the above composite activator is 1:1.

In the preparation process, sodium hydroxide was used as an activator for activation. Although the specific surface area and pore volume of the biomass carbon material can be improved, the adsorption of the prepared biomass carbon to malachite green and tetracycline hydrochloride is relatively low. Poor, while the biomass carbon material prepared by the combined activation of sodium hydroxide and potassium hydroxide has a significant improvement in the adsorption performance of malachite green and tetracycline hydrochloride.

A kind of preparation method of humic acid biomass carbon material is characterized in that, carries out as follows:

Step 1: Preprocessing

Add a sodium carbonate aqueous solution with a concentration of 0.6-1mmol/L to the powder, and ultrasonically treat it for 40-60min at a power of 60-100W. The proportion of black humic acid in humic acid is 85%, and the dosage ratio of humic acid, sodium carbonate aqueous solution and hydrogen peroxide is 10g: 15-20mL: 4-5mL;

Step 2: First High Temperature

Put the pretreated humic acid in a tube furnace, and under the protection of nitrogen, raise the temperature to 550-600°C at 2-3°C/min, and keep it warm for 40-50min to obtain humic acid carbon;

Step 3: Second High Temperature

The humic acid carbon and the composite activator are mixed and ground according to the mass ratio of 1:2-3, then placed in a tube furnace, heated to 600-650°C at 6-8°C/min, and kept for 60 minutes; after the heat preservation is completed, After washing with hydrochloric acid, and then washing with deionized water until neutral, the composite activator is composed of KOH and NaOH in a mass ratio of 1:1.

The regeneration treatment is to centrifuge the above-mentioned humic acid biomass charcoal from the waste water after the pollutants are adsorbed, put it in a tube furnace after drying, and raise the temperature to 550-600°C at 2-3°C/min , keep warm for 40-50min.

The application of the above-mentioned humic acid biomass carbon material is used to adsorb organic dyes and antibiotics.

Specifically, the humic acid biomass carbon material is used to adsorb malachite green and tetracycline hydrochloride.

The present invention has following technical effect:

The humic acid biomass carbon material prepared by the invention has excellent physical and chemical properties, the specific surface area reaches 2376m ² /g, the pore volume reaches 2.27cm ³ /g, the surface has abundant active groups, and the adsorption capacity for malachite green and tetracycline hydrochloride Reaching 1059.4mg/g and 872.3mg/g, after 5 times of recycling, the removal rate of humic acid biomass carbon material for malachite green and tetracycline hydrochloride still reached 69.7% and 58.6%, which has excellent cycle stability.

Description of drawings

Fig. 1: scanning electron micrograph of humic acid raw material, carbonized humic acid carbon and humic acid biomass carbon material finished product in the present invention.

Detailed ways

The present invention is specifically described by the following examples. It is necessary to point out that the following examples are only used to further illustrate the present invention, and cannot be interpreted as limiting the protection scope of the present invention. Those skilled in the art can according to the above-mentioned description SUMMARY OF THE INVENTION Some non-essential improvements and adjustments are made to the present invention.

According to the protocol recorded in the document "Preparation of biomass carbon material based on fulvic acid and its application in dye and antibiotic treatments, Xu Qiao, etc.", the specific surface area of fulvic acid biomass carbon is 2250m ² /g, and the pore volume is 1.8cm ³ / g, when the pH is 3, the maximum adsorption capacity for sulfadiazine sodium salt is 941 mg/g, and the maximum adsorption capacity for bright green is 2250 mg/g when the pH is 9, but the fulvic acid biomass carbon is used for adsorption For malachite green and tetracycline hydrochloride, the adsorption performance is not high, only 388.4mg/g and 363.5mg/g, and after 5 cycles of recycling, the removal rate of malachite green and tetracycline hydrochloride is only 31.4% of the first time and 27.9%.

Example 1

A preparation method of humic acid biomass carbon material, carried out as follows:

Step 1: Preprocessing

Add a sodium carbonate aqueous solution with a concentration of 0.8mmol/L to the powder, and ultrasonically treat it for 60min at a power of 80W. The proportion of acid is 85%, and the dosage ratio of humic acid, sodium carbonate aqueous solution and hydrogen peroxide is 10g: 20mL: 5mL;

Step 2: First High Temperature

Put the pretreated humic acid in a tube furnace, and under the protection of nitrogen, raise the temperature to 600°C at 2°C/min and keep it warm for 40min to obtain humic acid carbon;

Step 3: Second High Temperature

The humic acid carbon and the composite activator are mixed and ground according to the mass ratio of 1:2, and then placed in a tube furnace, heated to 650°C at 8°C/min, and kept for 60min; Hydrochloric acid washing, and then washing with deionized water to neutrality, the composite activator is composed of KOH and NaOH according to the mass ratio of 1:1.

Example 2

A preparation method of humic acid biomass carbon material, carried out as follows:

Step 1: Preprocessing

Add a sodium carbonate aqueous solution with a concentration of 1mmol/L to the powder, and ultrasonically treat it for 40min at a power of 60W. After filtering, add hydrogen peroxide with a mass fraction of 20% in the solid component and stir and mix. Among the humic acids, black humic acid The proportion is 85%, and the dosage ratio of humic acid, sodium carbonate aqueous solution and hydrogen peroxide is 10g: 15mL: 4mL;

Step 2: First High Temperature

Put the pretreated humic acid in a tube furnace, and under the protection of nitrogen, raise the temperature to 550°C at 3°C/min and keep it warm for 50min to obtain humic acid carbon;

Step 3: Second High Temperature

Mix and grind the humic acid carbon and the composite activator according to the mass ratio of 1:3, then place it in a tube furnace, raise the temperature to 600°C at 6°C/min, and keep it warm for 60 minutes; Hydrochloric acid washing, and then washing with deionized water to neutrality, the composite activator is composed of KOH and NaOH according to the mass ratio of 1:1.

Example 3

A preparation method of humic acid biomass carbon material, carried out as follows:

Step 1: Preprocessing

Add a sodium carbonate aqueous solution with a concentration of 0.6mmol/L to the powder, and ultrasonically treat it for 50min at a power of 100W. The proportion of acid is 85%, and the dosage ratio of humic acid, sodium carbonate aqueous solution and hydrogen peroxide is 10g: 16mL: 4mL;

Step 2: First High Temperature

Put the pretreated humic acid in a tube furnace, and under the protection of nitrogen, raise the temperature to 580°C at 2°C/min and keep it warm for 45min to obtain humic acid carbon;

Step 3: Second High Temperature

Mix and grind the humic acid carbon and the composite activator according to the mass ratio of 1:2.5, then place it in a tube furnace, raise the temperature to 620°C at 7°C/min, and keep it warm for 60 minutes; Hydrochloric acid washing, and then washing with deionized water to neutrality, the composite activator is composed of KOH and NaOH according to the mass ratio of 1:1.

The humic acid biomass carbon prepared by each embodiment of the present invention has the adsorption performance and cycle stability of malachite green and tetracycline hydrochloride as shown in Table 1.

Table 1:

The humic acid biomass carbon prepared by the present invention has excellent adsorption performance for malachite green and tetracycline hydrochloride, and the removal rate reaches 90.7% and 88.2% respectively during the first adsorption, and can still be maintained at 58.4% and above 50.5%, with excellent cycle stability.

Comparative example 1

The difference from Example 1 is that after the humic acid in Example 1 is soaked in sodium carbonate, hydrogen peroxide is added to carry out the first high-temperature treatment, and the activator is NaOH, and the rest of the steps are the same as in Example 1.

Comparative example 2

The difference from Example 1 is that after the first high-temperature treatment, the activator is NaOH, and then a second high-temperature treatment is performed under the same parameters, and the rest of the steps are the same as in Example 1.

Comparative example 3

The difference from Example 1 is that the humic acid in Example 1 is treated in sodium carbonate solution, and then directly subjected to high temperature treatment after external light treatment, and the rest of the steps are the same as in Example 1.

Comparative example 4

Humic acid with a proportion of fulvic acid of 90% is used as a raw material and prepared according to the method of the invention.

The adsorption properties of the biomass carbon prepared in each comparative example for malachite green and tetracycline hydrochloride are shown in Table 2.

Table 2:

Since black humic acid with a relatively large molecular weight was used as raw material in Comparative Example 1, soaking humic acid in sodium carbonate alone did not change the structure of humic acid before carbonization. The oxidation of stable black humic acid is weak, the activity of black humic acid is low, the specific surface area and pore volume of the prepared biomass carbon are not high, and the adsorption capacity for malachite rate and tetracycline hydrochloride is limited. However, after soaking in sodium carbonate combined with ultrasonic treatment, a very small amount of black humic acid in humic acid is degraded, loosening the solid overall structure of black humic acid. During the high-temperature carbonization process, sodium carbonate is used as the first activator to activate simultaneously Pore making, followed by secondary pore making with compound alkali, the specific surface area and pore volume of the prepared biomass carbon have been significantly improved, and the surface functional groups have also changed, making it more effective for the adsorption of malachite green and tetracycline. Get a certain improvement. And on the basis of the present invention, the humic acid based on black humic acid is replaced by the humic acid based on fulvic acid with a smaller molecular weight, soaked in sodium carbonate under ultraviolet light, the degradation of fulvic acid The degree is uncontrollable, leading to the destruction of its original structure. When hydrogen peroxide is added later, the strong oxidation of hydrogen peroxide destroys the internal structure of fulvic acid again, resulting in a downward trend in the specific surface area and pore volume of the final prepared biomass carbon. Extremely poor, in the process of cyclic adsorption, the adsorption performance also decays seriously.

Claims (11)

1. A preparation method of a humic acid biomass carbon material capable of being recycled is characterized by comprising the following steps: the method comprises the steps of preparing a carbon material and performing regeneration treatment, wherein the carbon material is prepared by adding humic acid into a sodium carbonate aqueous solution, performing ultrasonic treatment, adding hydrogen peroxide into the treated humic acid, mixing, performing first high-temperature treatment to obtain humic acid carbon, treating the humic acid carbon by using potassium hydroxide and sodium hydroxide as composite activators, performing second high-temperature treatment, and performing acid pickling and drying, wherein the mass ratio of the humic acid to the black humic acid is more than 85%.

2. The method for preparing the humic acid biomass carbon material capable of being recycled according to claim 1, wherein: the concentration of the sodium carbonate aqueous solution is 0.6-1mmol/L, and the power of ultrasonic treatment is 60-100W.

3. The method for preparing the humic acid biomass carbon material capable of being recycled according to claim 2, wherein: the mass fraction of the hydrogen peroxide is 20%, and the dosage relationship of the humic acid, the sodium carbonate aqueous solution and the hydrogen peroxide is 10g:15-20mL:4-5mL.

4. A method for preparing a humic acid biomass carbon material capable of being recycled according to any one of claims 1 to 3, wherein: the first high-temperature treatment is to put the pretreated humic acid under the protection of nitrogen, raise the temperature to 550-600 ℃ at the speed of 2-3 ℃/min, and preserve the temperature for 40-50min to obtain humic acid carbon.

5. A method for preparing a humic acid biomass carbon material capable of being recycled according to any one of claims 1 to 3, wherein: in the second high-temperature treatment, the humic acid carbon and the composite activator are mixed and ground according to the mass ratio of 1:2-3, then the mixture is placed in a tubular furnace, the temperature is raised to 600-650 ℃ according to the speed of 6-8 ℃/min, and the temperature is kept for 60min; after the heat preservation is finished, washing the mixture by hydrochloric acid and then washing the mixture by deionized water until the mixture is neutral.

6. The method for preparing the humic acid biomass carbon material capable of being recycled according to claim 4, wherein: mixing and grinding humic acid carbon and a composite activator according to the mass ratio of 1:2-3, then placing the mixture into a tubular furnace, heating to 600-650 ℃ at the speed of 6-8 ℃/min, and keeping the temperature for 60min; after the heat preservation is finished, washing the mixture by hydrochloric acid and then washing the mixture by deionized water until the mixture is neutral.

7. The method for preparing the humic acid biomass carbon material capable of being recycled according to claim 6, wherein: the mass ratio of potassium hydroxide to sodium hydroxide in the composite activator is 1:1.

8. The method for preparing the humic acid biomass carbon material capable of being recycled according to claim 7, wherein the step of preparing the carbon material is as follows; and the regeneration treatment is to perform centrifugal separation from the wastewater after the humic acid biomass carbon material adsorbs pollutants, dry the wastewater and place the wastewater in a tubular furnace, heat the wastewater to 550-600 ℃ at a speed of 2-3 ℃/min, and preserve the temperature for 40-50min.

9. The preparation method of the humic acid biomass carbon material is characterized by comprising the following steps of:

step 1: pretreatment of

Adding a sodium carbonate aqueous solution with the concentration of 0.6-1mmol/L into humic acid powder, carrying out ultrasonic treatment for 40-60min under the power of 60-100W, adding hydrogen peroxide with the mass fraction of 20% into solid components after filtering, stirring and mixing, wherein the content of the humic acid is 85%, and the dosage ratio of the humic acid, the sodium carbonate aqueous solution and the hydrogen peroxide is 10g:15-20mL:4-5mL;

step 2: first high temperature

Placing the pretreated humic acid in a tubular furnace, heating to 550-600 ℃ at a speed of 2-3 ℃/min under the protection of nitrogen, and preserving heat for 40-50min to obtain humic acid carbon;

and 3, step 3: second high temperature

Mixing and grinding humic acid carbon and a composite activator according to a mass ratio of 1:2-3, then placing the mixture in a tube furnace, heating to 600-650 ℃ at a speed of 6-8 ℃/min, and preserving heat for 60min; after the heat preservation is finished, washing the mixture by hydrochloric acid, and then washing the mixture by deionized water to be neutral, wherein the composite activating agent is composed of KOH and NaOH according to the mass ratio of 1:1.

10. Use of humic acid biomass carbon material prepared by the process of claim 9 wherein: used for adsorbing organic dyes and antibiotics.

11. Use of humic acid biomass carbon material according to claim 10 wherein: the humic acid biomass carbon material is used for adsorbing malachite green and tetracycline hydrochloride.

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