CN-121974341-A - Modified biochar, preparation method and application thereof in treatment of organic wastewater

Abstract

The invention discloses modified biochar, a preparation method and application thereof in treating organic wastewater, and belongs to the technical field of material preparation. The invention adopts a one-step complete mixing method of microalgae powder, thiourea and sodium bicarbonate for modification, and then prepares the algae-based biochar by low-temperature drying and carbonization in an anaerobic high-temperature environment. The prepared modified biochar can activate a peroxymonosulfate system to rapidly degrade tetracycline pollutants in sewage, and the removal rate of the tetracycline pollutants can reach more than 94% within 40 min. The preparation method and the pollutant removal process have the advantages of simple steps, high performance, no addition of additional active metals, secondary pollution avoidance, good economic and environmental benefits and outstanding practical application value.

Inventors

• CHEN YI
• WANG JINWEN
• LI JUN

Assignees

• 重庆大学

Dates

Publication Date

20260505

Application Date

20260204

Claims (10)

1. 1. The preparation method of the modified biochar is characterized by comprising the following steps of: s1, dispersing microalgae powder, thiourea and sodium bicarbonate in water according to a mass ratio of 1.5-2.5:2-4:0.5-1.5, stirring at room temperature for reaction for 10-14h, and then drying to obtain a modified microalgae matrix; S2, placing the modified microalgae matrix in an inert atmosphere, carbonizing for 1.5-2.5 hours at 500-750 ℃, washing, and drying to obtain the modified biochar.
2. 2. The method for preparing modified biochar according to claim 1, wherein the mass ratio of the microalgae powder, thiourea and sodium bicarbonate is 2:3:1.
3. 3. The method for producing a modified biochar according to claim 1, wherein the microalgae is spirulina.
4. 4. The method for preparing modified biochar according to claim 1, wherein the drying temperature in S1 is 30-40 ℃, the drying time is 10-14h, the drying temperature in S2 is 60-70 ℃, and the drying time is 6-10h.
5. 5. The method for producing a modified biochar according to claim 1, wherein the gas used in the inert atmosphere is nitrogen.
6. 6. The method for producing a modified biochar according to claim 1, wherein the temperature rise rate upon carbonization of S2 is 3 to 7 ℃.
7. 7. A modified biochar produced by the production method according to any one of claims 1 to 6.
8. 8. The use of the modified biochar according to claim 7 for treating wastewater containing antibiotics.
9. 9. The method according to claim 8, wherein the modified biochar and the peroxymonosulfate are added to the wastewater to be treated in an amount of 0.3-0.6g/L and 0.05-0.3g/L, respectively, and the wastewater is degraded at room temperature for 20-60 min.
10. 10. The use according to claim 8, wherein the antibiotic is tetracycline.

Description

Modified biochar, preparation method and application thereof in treatment of organic wastewater Technical Field The invention belongs to the technical field of material preparation, and particularly relates to modified biochar, a preparation method and application thereof in treating organic wastewater. Background Antibiotics are used as core drugs in modern medical and aquaculture industry, the production and the use amount of the antibiotics are increasingly proliferated, and the antibiotics entering the water environment are continuously accumulated because the antibiotics are difficult to be completely removed by the traditional sewage treatment process. In particular to tetracycline antibiotics, which are typical emerging pollutants with high frequency and difficult degradation in the environment because of the wide application and stable chemical structure in aquatic and livestock breeding, the development of efficient and green advanced treatment technology is urgent. The advanced oxidation technology based on persulfate is paid attention to because the persulfate can generate strong oxidative free radicals, but the technology generally has the bottlenecks of complex catalyst preparation, need of adding a large amount of active metal components, easy secondary pollution generation, higher running cost and the like. The microalgae are regarded as a highly potential biochar precursor because of unique biological characteristics and chemical compositions, however, the biochar prepared by singly depending on the doping atoms of the microalgae is low in antibiotic sewage removal efficiency. Therefore, the preparation of a novel biochar for improving the degradation and removal efficiency of antibiotics in sewage is a main target of current research. Disclosure of Invention The invention aims to solve the technical problem of low removal rate of antibiotics in sewage by the existing biochar by providing a modified biochar, a preparation method and application thereof in treating organic wastewater. In order to achieve the aim, the technical scheme adopted by the invention is that the preparation method of the modified biochar comprises the following steps: s1, dispersing microalgae powder, thiourea and sodium bicarbonate in water according to a mass ratio of 1.5-2.5:2-4:0.5-1.5, stirring at room temperature for reaction for 10-14h, and then drying to obtain a modified microalgae matrix; S2, placing the modified microalgae matrix in an inert atmosphere, carbonizing for 1.5-2.5 hours at 500-750 ℃, washing, and drying to obtain the modified biochar. The microalgae protein content is high (for example, the spirulina protein content is 60-70%), and the biomass is naturally rich in N and other heteroatoms. The self-doped heteroatom modified carbon material can be directly formed after pyrolysis, and the self-doped heteroatom modified carbon material has excellent electron transfer capability and catalytic active sites without complex post-modification. And secondly, metal elements such as Fe, mg, ca, mn and the like can be enriched in the growth process of the microalgae. These endogenous metals are often highly dispersed in the carbon matrix in the form of nano oxides, carbonates or sulfides after pyrolysis, become natural, non-externally added catalytic active centers, and are particularly suitable for catalytic processes such as advanced oxidation. Based on the technical scheme, the invention can also be improved as follows: further, the mass ratio of the microalgae powder, thiourea and sodium bicarbonate is 2:3:1. Further, the microalgae are spirulina. Further, the drying temperature in S1 is 30-40 ℃, the drying time is 10-14h, the drying temperature in S2 is 60-70 ℃, and the drying time is 6-10h. Further, the inert atmosphere is nitrogen. Further, the temperature rising rate during S2 carbonization is 3-7 ℃ per minute. The invention also discloses modified biochar prepared by the preparation method. The invention also discloses application of the modified biochar in treating wastewater containing antibiotics. Based on the technical scheme, the invention can also be improved as follows: Further, adding the modified biochar and the peroxymonosulfate into the wastewater to be treated according to the addition amount of 0.3-0.6g/L and 0.05-0.3g/L respectively, and degrading for 20-60min at room temperature. Further, the antibiotic is tetracycline. The beneficial effects of the invention are as follows: 1. The invention has the advantages of low cost and easy acquisition of raw materials, less chemical reagents required in the modification synthesis process, simple synthesis steps, no use of any active transition metal for synthesis, no secondary environmental pollution caused by metal ion dissolution and the like. 2. The modified biochar prepared by the method is loose and porous, has an obvious spongy porous structure, uniform void distribution and greatly improved specific surface area, provides more reaction