Preparation method of carbon-based sewage adsorption carrier

Abstract

The application discloses a preparation method of a carbon-based sewage adsorption carrier and belongs to the field of sewage treatment. Carbon nanotubes are prepared through a chemical vapor deposition method, and a composite material with high specific surface area, good adsorption performance and chemical stability is prepared by combining the carbon nanotubes with activated carbon and bentonite. The material can not only effectively remove organic matters and heavy metal ions in rubber sewage, but also can be used as a catalyst to promote the degradation of pollutants. The application is suitable for adsorbing harmful substances in a large amount of sewage, and can also be used for removing pollutants in the form of electrocatalysis, photocatalysis and the like, so that water purification is realized, and an efficient and environment-friendly solution for sewage treatment is provided.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, specifically relating to a method for preparing a carbon-based wastewater adsorption carrier. Background Technology

[0002] With the rapid development of the national economy and the continuous growth of the population, rubber plays an increasingly important role in meeting various needs in our daily lives. Along with the high demand and rapid development of the rubber industry, it cannot be ignored that the rubber industry is a high-water-consuming sector. The production and preparation process of rubber generates a large amount of organic wastewater. Due to the complex composition of this wastewater, it is difficult to treat. How to effectively treat and dispose of this wastewater, while simultaneously achieving resource utilization, protecting the environment, reducing enterprise operating costs, and realizing sustainable development, has always been a challenging and pressing issue for the industry.

[0003] Nitrile butadiene rubber (NBR) is a synthetic rubber material copolymerized from butadiene and acrylonitrile, widely used in the manufacture of oil-resistant products. Its production process generates complex industrial wastewater, primarily containing pollutants such as organic matter, inorganic matter, and suspended solids. Organic matter includes unreacted monomers, solvents, and additives; these substances typically possess high chemical stability and biotoxicity, making them difficult for microorganisms to degrade. Inorganic matter mainly consists of salts, acids, alkalis, and metal ions generated from equipment corrosion used in production. Suspended solids include rubber particles, mineral oil, and solid impurities. Due to the complexity of these pollutants and the difficulty in their treatment, how to efficiently treat this type of wastewater, achieve resource utilization, reduce enterprise operating costs, and simultaneously protect the ecological environment has become a key and challenging issue for the industry. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing a carbon-based wastewater adsorbent carrier. The method employed is simple to operate, yields high output, achieves high purity, and allows for controllable structure. The prepared product possesses a large surface area, excellent adsorption capacity, and chemical stability. When applied to rubber wastewater treatment, it can not only act as an adsorbent to remove harmful substances from the water but also as a catalyst to promote the degradation of pollutants, thereby achieving effective treatment of rubber wastewater.

[0005] To achieve the above-mentioned objectives, the technical solution of this invention is as follows:

[0006] This invention provides a method for preparing a carbon-based wastewater adsorption carrier, comprising the following steps:

[0007] (1) Preparation of carbon nanotubes;

[0008] (2) Purify the carbon nanotubes obtained in step (1) to obtain pure carbon nanotubes;

[0009] (3) Preparation of activated carbon;

[0010] (4) Composite of carbon nanotubes with activated carbon;

[0011] (5) Combine the composite material obtained in step (4) with bentonite to obtain a new composite material;

[0012] (6) The composite material obtained in step (5) is ball-milled and granulated to obtain a granular water treatment material that can be applied.

[0013] Preferably, the preparation of the catalyst in step (1) of the carbon nanotube preparation is specifically as follows:

[0014] a. Prepare nickel or ruthenium nitrates;

[0015] b. Soak copper powder in deionized water, and add the nitrate from step a and the soaked copper powder to the deionized water in a certain proportion to obtain a nitrate solution.

[0016] c. Add sodium hydroxide solution to the solution obtained in step b until it is completely neutralized, and then wash, filter, dry and grind to obtain the corresponding catalyst precursor.

[0017] Preferably, the growth of carbon nanotubes in step (1) is carried out by chemical vapor deposition, specifically: a mixed reaction gas is introduced at a certain temperature to carry out a catalytic cracking reaction. During the process, the carbon source compound decomposes and diffuses on the surface of the catalyst and finally precipitates from the catalyst particles. After the gas is introduced, the carbon nanotubes are collected after cooling.

[0018] Preferably, the catalytic cracking reaction is carried out in a quartz tube furnace.

[0019] Preferably, the temperature is 600-800℃, for example, it can be 600℃, 650℃, 700℃, 750℃ or 800℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable. When carrying out catalytic cracking reaction, cracking temperature is a key process parameter affecting the yield and morphology of carbon nanotubes. Lower growth temperature and easily controllable parameters are beneficial to the control of carbon nanotube growth prepared by chemical vapor deposition.

[0020] Preferably, the mixed reaction gas includes a carbon source gas and a carrier gas.

[0021] Preferably, the purification of carbon nanotubes in step (2) is specifically as follows: the carbon nanotubes obtained in step (1) and the catalyst mixture are soaked in dilute acid to remove the catalyst and impurity carbon, and then the purified carbon nanotubes are obtained after washing.

[0022] Preferably, the dilute acid includes hydrochloric acid and nitric acid with a concentration of 0.1-3 mol / L.

[0023] Preferably, the preparation of activated carbon in step (3) specifically includes:

[0024] d. Preparation of activated carbon;

[0025] e. Modification of activated carbon.

[0026] Preferably, the preparation of activated carbon in step d specifically involves: grinding natural organic matter and adding it to a reaction furnace, calcining it under inert gas protection to achieve carbonization of the organic matter, and then further calcining it under oxygen conditions to generate pores and surface functional groups, thereby activating the activated carbon.

[0027] Preferably, the natural organic material includes sawdust, coconut shell, and straw;

[0028] Preferably, the reactor is a quartz tube furnace;

[0029] Preferably, the composite of carbon nanotubes and activated carbon in step (4) is specifically as follows: the prepared carbon nanotubes and activated carbon are mixed evenly, a certain amount of surfactant and stabilizer are added, and after stirring and mixing evenly, a carbonization reaction is carried out under high temperature to obtain carbon nanotube activated carbon composite material.

[0030] Preferably, the carbonization reaction temperature is 300-500℃, for example, 300℃, 350℃, 400℃, 450℃ or 500℃, but not limited to the listed values, and other unlisted values ​​within the range are also applicable; the carbonization time is 3-5h, for example, 3h, 3.5h, 4h, 4.5h or 5h, but not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0031] Preferably, in step (5), the carbon nanotube activated carbon obtained in step (4) is combined with bentonite using a solution mixing method to obtain a novel composite material. Specifically, the carbon nanotube activated carbon composite material is pretreated with a strong acid to improve its dispersibility by introducing surface functional groups. The pretreated composite material is then mixed with bentonite in an appropriate amount of solvent, stirred, and ultrasonically treated to disperse and fully mix the material. Finally, the novel composite material is obtained by centrifugation and filtration. This material combines the advantages of carbon nanotube activated carbon and bentonite, and has higher strength, toughness, and electron transport capacity. At the same time, its larger specific surface area and pore size distribution range give it better adsorption capacity, which helps to solve the problem of sewage treatment.

[0032] Preferably, the strong acid is concentrated nitric acid or concentrated sulfuric acid.

[0033] Preferably, in step (6), the composite material obtained in step (5) is ball-milled, dried, calcined, and granulated to obtain a granular water treatment material that can be used.

[0034] Preferably, the ball milling operation uses a planetary ball mill;

[0035] Preferably, the granulation is performed using a wet or dry granulation method.

Claims

1. A method for preparing a carbon-based wastewater adsorption carrier, characterized in that, The preparation method of the carbon-based wastewater adsorption carrier includes the following steps: (1) Preparation of carbon nanotubes; (2) Purify the carbon nanotubes obtained in step (1) to obtain pure carbon nanotubes; (3) Preparation of activated carbon; (4) Composite of carbon nanotubes with activated carbon; (5) Combine the composite material obtained in step (4) with bentonite to obtain a new composite material. (6) The composite material obtained in step (5) is ball-milled and granulated to obtain a granular water treatment material that can be applied.

2. The preparation method according to claim 1, characterized in that, In step (1), the catalyst used for the preparation of carbon nanotubes is nickel or ruthenium.

3. The preparation method according to claim 1, characterized in that, The preparation of the catalyst in step (1) is as follows: a. Using the corresponding nitrate of the noble metal catalyst as a precursor; b. React copper powder with the corresponding nitrate from step a to obtain the corresponding product; c. The product obtained in step b is washed, filtered, dried, and ground to prepare the catalyst of claim 1.

4. The preparation method according to claim 1, characterized in that, In step (1), the growth of carbon nanotubes is achieved through a catalytic pyrolysis reaction in a reactor, specifically as follows: A catalytic cracking reaction is carried out by introducing a mixed reaction gas at a certain temperature. During the process, the carbon source compound decomposes and diffuses on the catalyst surface and eventually precipitates from the catalyst particles. After the gas is introduced and cooled, carbon nanotubes are collected. The reactor for the catalytic cracking reaction is a quartz tube furnace; The temperature is 600-800℃; The mixed reaction gas includes a carbon source gas and a carrier gas.

5. The preparation method according to claim 4, characterized in that, The purification of carbon nanotubes in step (2) is as follows: The carbon nanotubes obtained in step (1) and the catalyst mixture were soaked in dilute acid to remove the catalyst and impurity carbon. After washing, pure carbon nanotubes were obtained.

6. The preparation method according to claim 1, characterized in that, The preparation of activated carbon in step (3) is as follows: d. Preparation of activated carbon; e. Modification of activated carbon.

7. The preparation method according to claim 1, characterized in that, The preparation of activated carbon in step d is as follows: Natural organic materials are ground and added to a reactor, and calcined under inert gas protection to achieve carbonization of the organic materials. Then, they are further calcined under oxygen conditions to produce pores and surface functional groups, thereby activating the activated carbon. The natural organic materials include wood chips, coconut shells, and straw; The reactor is a quartz tube furnace.

8. The preparation method according to claim 1, characterized in that, The composite of carbon nanotubes and activated carbon in step (4) is specifically as follows: The prepared carbon nanotubes and activated carbon are mixed evenly, a certain amount of surfactant and stabilizer are added, and after stirring and mixing evenly, a carbonization reaction is carried out under certain temperature conditions to obtain carbon nanotube activated carbon composite material. The carbonization reaction is carried out at a temperature of 300-500℃ for 3-5 hours.

9. The preparation method according to claim 1, characterized in that, In step (5), the carbon nanotube activated carbon obtained in step (4) is combined with bentonite using a solution mixing method to obtain a novel composite material, specifically: The carbon nanotube activated carbon composite material was pretreated with a strong acid to improve its dispersibility by introducing surface functional groups. The pretreated composite material was then mixed with bentonite in an appropriate solvent, stirred, and ultrasonically treated to ensure dispersion and thorough mixing. Finally, the material was centrifuged and filtered to obtain a novel composite material that combines the advantages of carbon nanotube activated carbon and bentonite. This material exhibits higher strength, toughness, and electron transport capacity, while its larger specific surface area and pore size distribution range give it better adsorption capacity, which is helpful in solving wastewater treatment problems.

10. The preparation method according to claim 1, characterized in that, In step (6), the composite material obtained in step (5) is ball-milled, dried, calcined, and granulated to obtain a granular water treatment material that can be used.