CN112892478A - Preparation method and application of biomass dye adsorbent - Google Patents

Abstract

The invention discloses a preparation method and application of a biomass dye adsorbent. Firstly, biomass sugar is used as a carbon source, a hydrothermal method is adopted to prepare monodisperse carbon microspheres under an acidic condition, the carbon microspheres are added with an organic solvent to react with epoxy chloropropane and an amino functional compound in a certain proportion, and the prepared powder is washed by an alcohol-water solution and dried to obtain the amino modified carbon material. The carbon material modified by the amino group has a large specific surface area and a large number of active sites, has excellent adsorption performance on anionic dye, and can be applied to removal of dye in wastewater. The preparation method disclosed by the invention is simple and convenient in preparation process, green and environment-friendly in raw materials, controllable in thickness of the amino functional layer coated on the surface of the carbon microsphere, strong in adsorption effect on anionic dye, high in adsorption capacity and good in application prospect in treatment of dye-containing wastewater.

Description

Preparation method and application of biomass dye adsorbent

Technical Field

The invention belongs to the field of water environment protection, and particularly relates to a preparation method and application of a biomass dye adsorbent.

Background

In the last two decades, people are increasingly concerned about the treatment of dye wastewater in the dyeing industries such as textile, printing, paper making and the like. The dye has serious toxicity and carcinogenicity to water and human bodies, and threatens the survival of human beings. At present, the methods for removing the dye in water include an electrochemical method CN201710453504.2, an adsorption method CN201610972137.2, an electrolysis method CN201611079040.5, a membrane separation method CN201911171561.7 and an ion exchange method CN 201610635040.2. The adsorption method utilizes an adsorption material with a high specific surface area structure or special functional groups to adsorb the dye in water, has the characteristics of high efficiency, energy conservation, cyclic utilization, environmental protection and the like, and is considered to be the method with the greatest application prospect for removing the dye in water.

The biomass derivative is converted into a novel carbon-based material by a hydrothermal carbonization method, and the novel carbon-based material is green and friendly from a process and a raw material. The carbon material prepared by a hydrothermal method is used as a novel functional carbon material, has the characteristics of very good chemical stability, good heat and electricity conductivity, biocompatibility, low density, good monodispersity, easy surface functionalization and the like, and plays an extremely important role in the fields of catalysis, medical treatment, energy storage, drug carriers and the like at present. Phenolic resins have been used as carbon sources in the past, as in CN 201510569054.4: the phenolic resin polymer beads are synthesized by a hydrothermal method, but in the preparation process, the raw materials are toxic and can cause certain harm to human health. In the application aspect of the existing adsorbent, the carbon material synthesized by one step only through a hydrothermal method has small specific surface area and pore size and low adsorption capacity, and needs to be further removed from a template agent in an inert gas atmosphere to be roasted to form mesopores or macropores, such as CN201911287996.8, so that the preparation process is complicated and high in cost.

Therefore, a biological adsorbent which is simple in preparation process, low in cost, high in removal efficiency and environment-friendly and can effectively remove the dye in the water body by using the existing natural resources is urgently needed.

Disclosure of Invention

The invention aims to solve the problem of removing dye in wastewater, and provides a preparation method and application of a biomass dye adsorbent.

The idea of the invention is as follows: firstly, dehydrating and carbonizing a biomass carbon microsphere by a hydrothermal method, and then modifying the surface of the biomass carbon microsphere by an amino functional group to prepare an amino functionalized carbon material, wherein the carbon material is simple and convenient in preparation process, green and environment-friendly in raw materials and easy to prepare in batches; the carbon microsphere prepared by a hydrothermal method has a large specific surface area and good monodispersity, and the surface contains a large number of active oxygen-containing groups, so that amino functional modification is facilitated, and adsorption sites and selective active sites are increased, so that the carbon microsphere has excellent adsorption performance on anionic dye, and can be applied to removal of the anionic dye in wastewater.

The preparation method of the biomass dye adsorbent comprises the following specific steps:

(1) adding 5-20 g of carbon source and 0.05-5 g of acidic substance into deionized water, ultrasonically mixing uniformly, putting the mixture into a hydrothermal reaction kettle, reacting for 4-12 h at 160-200 ℃, cooling to room temperature, separating to obtain a first solid product, repeatedly washing the first solid product by using an alcohol-water solution with the volume ratio of absolute ethyl alcohol to deionized water being 1:1, and drying to obtain the carbon microsphere.

(2) Dispersing the carbon microspheres prepared in the step (1) in an organic solvent, adding 2-5 mL of epoxy chloropropane, placing the mixture in a constant-temperature oil bath kettle, stirring for 1-4 h at 80-100 ℃, dropwise adding an amino functional compound, continuing to react for 1-4 h, cooling to normal temperature after the reaction is finished, performing centrifugal separation to obtain a second solid product, and washing and drying to obtain an amino functional carbon material, namely the biomass dye adsorbent.

The carbon source in the step (1) is one or more selected from sucrose, glucose, maltose, lactose and fructose.

The acidic substance in the step (1) is one or more of oxalic acid, acetic acid and acrylic acid.

The mass ratio of the sum of the mass of the carbon source and the acidic substance to the mass of the deionized water in the step (1) is 5-25: 100.

The organic solvent in the step (2) is one or more selected from N, N-methylformamide, N-methylacetamide and N, N-dimethylformamide.

The amino functional compound in the step (2) is selected from one or more of ethylenediamine, diethylenetriamine, tetraethylenepentamine and triethylamine.

The volume ratio of the organic solvent, the epoxy chloropropane and the amino functional compound in the step (2) is 5-10: 1-3: 1.5-2.

The biomass dye adsorbent is applied to adsorbing anionic dye in wastewater.

The invention has the beneficial effects that:

(1) the adsorbent prepared by the invention takes low-cost biomass saccharides as a carbon source, has rich raw material sources, is environment-friendly, does not need special atmosphere protection in the preparation process, has simple preparation process and is easy for industrial production.

(2) The carbon microsphere prepared by a hydrothermal method is used as a matrix material, the particle size is controllable, the monodispersity is good, the formation of the carbon microsphere is promoted by adding an acid catalyst, and meanwhile, a large number of active oxygen-containing groups are added to the surface of the carbon microsphere, so that the surface modification of the carbon microsphere is facilitated.

(3) When the prepared adsorbent is used for removing an anionic dye solution, the provided amino functional groups can capture sulfonic acid groups in the solution, and the effects of rapid balance and high-capacity adsorption on the dye are achieved through ion exchange and electrostatic attraction. Has good economic and environmental benefits and wide market prospect in water treatment.

Drawings

FIG. 1 is an SEM photograph of the carbon microsphere obtained in example 1 of the present invention.

FIG. 2 is an SEM photograph of an amino-functionalized carbon material obtained in example 1 of the present invention.

Fig. 3 is a graph of the adsorption performance of the lemon yellow dye under different pH values in application example 1 of the present invention.

FIG. 4 is a graph showing the adsorption performance of the dye of example 1 at the same pH.

FIG. 5 is a graph showing the adsorption effect of the lemon yellow dye of the present invention in application example 1 on 10mL of the lemon yellow dye with an initial concentration of 1000mg/L under different contact time conditions.

Detailed Description

For further understanding of the present invention, the following detailed description of the embodiments of the present invention is provided in conjunction with the drawings and the technical solutions, but is not meant to limit the present invention in any way.

Example 1:

the preparation steps of the biomass dye adsorbent are as follows:

(1) adding 5g of glucose and 0.05g of oxalic acid into 100mL of deionized water, ultrasonically mixing uniformly, transferring the obtained solution into a hydrothermal reaction kettle, reacting for 12 hours at 160 ℃, and cooling to room temperature; separating to obtain a first solid product, washing the first solid product for 3 times by using an alcohol-water solution (the volume ratio of absolute ethyl alcohol to deionized water is 1: 1), and drying to obtain the carbon microsphere.

(2) And (2) adding 1.5g of the carbon microspheres obtained in the step (1) and 2mL of epoxy chloropropane into 50mL of dimethylformamide, stirring at 80 ℃ for reacting for 2h, then dropwise adding 2mL of diethylenetriamine, and continuing to react for 2 h. And after the reaction is finished, cooling to normal temperature, performing centrifugal separation to obtain a second solid product, and washing and drying to obtain the amino functionalized carbon material, namely the biomass dye adsorbent.

Example 2:

the preparation steps of the biomass dye adsorbent are as follows:

(1) adding 5g of glucose and 1g of oxalic acid into 100mL of deionized water, uniformly mixing by ultrasonic, putting the obtained solution into a hydrothermal reaction kettle, reacting for 8 hours at 160 ℃, and cooling to room temperature; and (3) separating to obtain a first solid product, repeatedly washing the first solid product by using an alcohol-water solution (the volume ratio of absolute ethyl alcohol to deionized water is 1: 1), and drying to obtain the carbon microsphere.

(2) Adding 2g of the carbon microspheres obtained in the step (1) and 3mL of epoxy chloropropane into 50mL of dimethylacetamide, stirring and reacting for 2h at 80 ℃, then respectively dropwise adding 1mL of ethylenediamine and 2mL of tetraethylenepentamine, and continuing to react for 2 h. And after the reaction is finished, cooling to normal temperature, performing centrifugal separation to obtain a second solid product, and washing and drying to obtain the amino functionalized carbon material, namely the biomass dye adsorbent.

Example 3:

the preparation steps of the biomass dye adsorbent are as follows:

(1) adding 5g of glucose and 0.05g of oxalic acid into 100mL of deionized water, uniformly mixing by ultrasonic, putting the obtained solution into a hydrothermal reaction kettle, reacting for 12 hours at 160 ℃, and cooling to room temperature; and (3) separating to obtain a first solid product, repeatedly washing the first solid product by using an alcohol-water solution (the volume ratio of absolute ethyl alcohol to deionized water is 1: 1), and drying to obtain the carbon microsphere.

(2) Adding 1.5g of the carbon microspheres obtained in the step (1) and 2mL of epoxy chloropropane into 50mL of dimethylformamide, stirring at 90 ℃ for reacting for 4h, then respectively dropwise adding 1mL of ethylenediamine and 2mL of triethylamine, and continuing to react for 4 h. And after the reaction is finished, cooling to normal temperature, performing centrifugal separation to obtain a second solid product, and washing and drying to obtain the amino functionalized carbon material, namely the biomass dye adsorbent.

Application example 1:

under different pH values, the adsorbent has influence on the adsorption performance of the dye: firstly, adjusting the pH value of 1500mg/L dye by using 0.1-5 mol/L HCl and 0.1-5 mol/L NaOH solution, wherein the volume of the solution is 10ml, respectively adjusting the pH value of the solution to 4-11, adding the adsorbent with a certain mass obtained in example 1, and testing the dye in the residual liquid after adsorbing for a period of time. The results show that the adsorption effect on the dye is the best when the pH value of the solution is 4, so that the adsorption performance of the adsorbent on the dye is better.

Application example 2:

under different dye conditions, the adsorbent has the following dye adsorption performance: and (3) adjusting the pH of 1500mg/L methyl orange, lemon yellow, methylene blue, methyl violet and carmine dye solution by using 0.1-5 mol/L HCl solution, wherein the volume of the solution is 10mL, the pH value of the solution is adjusted to 4, 10mg of the adsorbent obtained in example 1 is added, and the dye in the residual liquid is tested after being adsorbed for a period of time.

Application example 3:

under different time conditions, the adsorption performance of the adsorbent on the dye is as follows: and (3) adjusting the pH of the methyl orange solution by using 0.1-5 mol/L HCl solution, wherein the volume of the solution is 10mL, adjusting the pH value of the solution to be 4, adding 10mg of the adsorbent obtained in example 2, and oscillating and adsorbing for a period of time to test the dye in the residual liquid.

Claims (2)

1. A preparation method of a biomass dye adsorbent is characterized by comprising the following specific steps:

(1) adding 5-20 g of carbon source and 0.05-5 g of acidic substance into deionized water, ultrasonically mixing uniformly, putting the mixture into a hydrothermal reaction kettle, reacting for 4-12 h at 160-200 ℃, cooling to room temperature, separating to obtain a first solid product, repeatedly washing the first solid product by using an alcohol-water solution with the volume ratio of absolute ethyl alcohol to deionized water being 1:1, and drying to obtain carbon microspheres;

(2) dispersing the carbon microspheres prepared in the step (1) in an organic solvent, adding 2-5 mL of epoxy chloropropane, placing the mixture in a constant-temperature oil bath kettle, stirring for 1-4 h at 80-100 ℃, dropwise adding an amino functional compound, continuing to react for 1-4 h, cooling to normal temperature after the reaction is finished, performing centrifugal separation to obtain a second solid product, and washing and drying to obtain an amino functional carbon material, namely a biomass dye adsorbent;

the carbon source in the step (1) is selected from one or more of sucrose, glucose, maltose, lactose and fructose;

the acidic substance in the step (1) is one or more of oxalic acid, acetic acid and acrylic acid;

the mass ratio of the sum of the mass of the carbon source and the acidic substance in the step (1) to the mass of the deionized water is 5-25: 100;

the organic solvent in the step (2) is selected from one or more of N, N-methylformamide, N-methylacetamide and N, N-dimethylformamide;

the amino functional compound in the step (2) is selected from one or more of ethylenediamine, diethylenetriamine, tetraethylenepentamine and triethylamine;

the volume ratio of the organic solvent, the epoxy chloropropane and the amino functional compound in the step (2) is 5-10: 1-3: 1.5-2.

2. The application of the biomass dye adsorbent prepared by the preparation method of claim 1, wherein the biomass dye adsorbent is used for adsorbing anionic dye in wastewater.

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