CN-121755165-B - Biochar for adsorbing hydrophobic organic pollutants as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of carbon adsorption, and provides biochar for adsorbing hydrophobic organic pollutants, and a preparation method and application thereof. The preparation method comprises the steps of preparing biomass raw materials, drying, crushing and sieving to obtain biomass powder, impregnating the biomass powder with composite chloride salt to obtain modified precursors, pyrolyzing the modified precursors in an inert gas environment to obtain pyrolysis products, replacing inert gas with carbon dioxide, raising pyrolysis temperature to activate, obtaining activated products, reacting the activated products with a hydrophobicizing modifier to obtain biochar for adsorbing hydrophobic organic pollutants, wherein the biochar can be used for efficiently treating the hydrophobic organic pollutants in wastewater, particularly dispersing purple and N, N-diethyl-3-acetamidine, and has good environmental protection and economical efficiency.

Inventors

• ZHANG RONG
• LIAO JIAQI
• QU CHENGDUN
• WANG BO
• YU TAO
• ZHAO JUNKAI

Assignees

• 西安石油大学

Dates

Publication Date

20260512

Application Date

20260305

Claims (8)

1. 1. A method for preparing biochar for adsorbing hydrophobic organic contaminants, comprising the steps of: s1, preparing a biomass raw material, drying, crushing and sieving to obtain biomass powder; S2, impregnating biomass powder with composite chloride salt to obtain a modified precursor, wherein the composite chloride salt is zinc chloride and potassium chloride in a molar ratio of 6:1; s3, pyrolyzing the modified precursor in an inert atmosphere environment to obtain a pyrolysis product; S4, after the pyrolysis in the step S3 is finished, directly replacing inert atmosphere with carbon dioxide without cooling, and raising the pyrolysis temperature for activation to obtain an activated product; S5, reacting the activated product with a hydrophobicizing modifier to obtain the biochar for adsorbing the hydrophobic organic pollutants, wherein the hydrophobicizing modifier is hexadecyltrimethoxysilane, and the dosage is 3% of the mass of the activated product.
2. 2. The method of preparing biochar for adsorbing hydrophobic organic contaminants according to claim 1, wherein the biomass feedstock is peanut shells.
3. 3. The method for preparing biochar for adsorbing hydrophobic organic pollutants according to claim 2, wherein step S2 comprises: S201, mixing biomass powder with composite chloride salt and adding ultrapure water; S202, completely soaking and standing for a preset time; s203, carrying out suction filtration, separation and drying to obtain modified precursor powder.
4. 4. A method for preparing biochar for adsorbing hydrophobic organic contaminants according to claim 3, characterized in that step S3 comprises: S301, preheating a modified precursor at 400 ℃ in a nitrogen environment; S302, raising the temperature to 600 ℃ at a rate of 5 ℃ per minute, and keeping for 60 minutes; S303, obtaining a pyrolysis product.
5. 5. The method for preparing biochar for adsorbing hydrophobic organic pollutants according to claim 1, wherein step S4 comprises: S401, replacing the inert atmosphere with carbon dioxide; s402, raising the temperature to 750 ℃ at a rate of 5 ℃ per minute, and keeping for 60 minutes; s403, obtaining an activated product.
6. 6. The biochar produced by the production method according to any one of claims 1 to 5.
7. 7. Use of the biochar according to claim 6 for the adsorption treatment of hydrophobic organic pollutants in wastewater.
8. 8. The use according to claim 7, wherein the hydrophobic organic contaminant is one or more of disperse violet and N, N-diethyl-3-acetamidine.

Description

Biochar for adsorbing hydrophobic organic pollutants as well as preparation method and application thereof Technical Field The invention relates to the technical field of carbon adsorption, in particular to biochar for adsorbing hydrophobic organic pollutants, and a preparation method and application thereof. Background Organic dyes are widely used in textile, printing and dyeing, pharmaceutical and fine chemical industries, but a large amount of industrial wastewater with high chromaticity and high toxicity is produced in the production and use processes. Wherein, the synthetic disperse violet dye and the key intermediate N, N-diethyl-3-acetamido aniline thereof have high biotoxicity and biodegradability due to the complex chemical structure, stable functional groups such as benzene ring, azo group, amino group and the like, larger molecular dynamics diameter and strong hydrophobicity. Therefore, the development of a technology for efficiently removing the hydrophobic organic dye and the intermediate thereof in the wastewater has urgent practical necessity for protecting water environment, ensuring ecological safety and public health. Currently, conventional treatment methods mainly include physical, chemical and biological methods for wastewater containing organic dyes. Physical methods such as adsorption and membrane separation are easy to operate, but the microporous structure of macromolecular dyes generally causes the problems of large diffusion mass transfer resistance, limited adsorption capacity, difficult regeneration of adsorbents, membrane pollution, high running cost and the like. Chemical methods such as advanced oxidation and coagulation precipitation can effectively degrade part of dye molecules, but have the limitations of large consumption of medicament, possibility of secondary pollution, poor treatment effect on high-concentration or specific-structure dye, and the like. The biological rule depends on the degradation of microorganisms, but the treatment period is long, and for dye molecules with high biotoxicity (such as disperse violet and N, N-diethyl-3-acetamidine), the activity of microorganisms is easy to be inhibited, and the treatment effect is unstable. Particularly, the existing activating method for preparing the biochar adopts one-step pyrolysis or single activating agent for activation, and the prepared material has a single pore structure, is difficult to consider a mesoporous channel with high specific surface area and suitable for macromolecular diffusion, and limits the efficient adsorption of macromolecular dye. Therefore, the prior art has the defects of cost, efficiency or environmental friendliness when treating the macromolecular organic dye wastewater with high concentration, high toxicity and difficult biodegradation. Therefore, how to develop a novel adsorption material capable of realizing efficient and rapid adsorption of hydrophobic organic dye and having good economical efficiency and environmental friendliness and a preparation technology thereof becomes a technical problem to be solved. Disclosure of Invention Aiming at the problems, the invention aims to provide the biochar for adsorbing the hydrophobic organic pollutants, and the preparation method and the application thereof, and the biochar for adsorbing the hydrophobic organic pollutants is obtained by the specially designed preparation method, so that the efficient adsorption of the hydrophobic organic dye is solved, and meanwhile, the biochar has good economical efficiency and environmental friendliness. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: a method for preparing biochar for adsorbing hydrophobic organic contaminants, comprising the steps of: s1, preparing a biomass raw material, drying, crushing and sieving to obtain biomass powder; S2, impregnating biomass powder with composite chloride to obtain a modified precursor, wherein the composite chloride is zinc chloride and potassium chloride; s3, pyrolyzing the modified precursor in an inert gas environment to obtain a pyrolysis product; s4, replacing inert gas with carbon dioxide, and raising the pyrolysis temperature to activate to obtain an activated product; s5, reacting the activated product with a hydrophobization modifier to obtain the biochar for adsorbing the hydrophobic organic pollutants. Further, the biomass raw material is peanut shells. Further, in step S2, the molar ratio of zinc chloride to potassium chloride is 6:1. Further, step S2 includes: S201, mixing biomass powder with composite chloride salt and adding ultrapure water; S202, completely soaking and standing for a preset time; s203, carrying out suction filtration, separation and drying to obtain modified precursor powder. Further, step S3 includes: S301, preheating a modified precursor at 400 ℃ in a nitrogen environment; S302, raising the temperature to 600 ℃ at a rate of 5 ℃ per minute, and keeping for 60 minutes; S30