Porous carbon composite material for degrading antibiotics through combination of photocatalysis and microorganisms and preparation method of porous carbon composite material
By combining modified titanium dioxide@porous carbon and microbial suspension, the problems of titanium dioxide's easy agglomeration and difficulty in recycling were solved, efficient degradation of antibiotics in water was achieved while avoiding secondary pollution, and the catalytic activity and physical adsorption capacity were enhanced.
Patent Information
- Application Number
- CN202510798276.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-16
- Publication Date
- 2025-10-03
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
In the existing technology, titanium dioxide photocatalysts are prone to agglomeration, resulting in reduced catalytic activity and difficulty in recovery. This may cause secondary pollution to water bodies and make it difficult to effectively degrade antibiotics in water bodies.
Magnetized titanium dioxide@porous carbon is obtained through modification and combined with microbial suspension to form a porous carbon composite material. Silane coupling agent is used to load ferrosoferric oxide to achieve magnetic separation and synergistic degradation of antibiotics.
The degradation ability of antibiotics is improved, secondary pollution is avoided, separation and recovery are easy, and catalytic activity and physical adsorption effects are enhanced.
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Abstract
Description
Technical Field
[0001] The present invention belongs to water treatment technology and catalyst development, and specifically relates to a porous carbon composite material that degrades antibiotics through the combined use of photocatalysis and microorganisms, and a preparation method thereof. Background Art
[0002] With the rapid development of modern medicine, antibiotics, as an important antimicrobial drug, are widely used in animal husbandry, aquaculture, and in the prevention and treatment of animal and human diseases. During antibiotic use, some of the drug that is not absorbed or metabolized by the body is excreted through urine and feces, ultimately entering the aquatic environment, leading to a gradual increase in antibiotic concentrations in water. This phenomenon has attracted global attention, as antibiotic contamination not only affects the balance of aquatic ecosystems but also poses a potential threat to human health. Conventional treatment processes for antibiotics in existing technologies primarily rely on coagulation, sedimentation, and filtration, resulting in low removal rates. Therefore, developing new methods to degrade antibiotics in water and mitigate their adverse environmental impacts is of great significance. Photocatalytic technology, as an advanced oxidation treatment technology, can generate electrons and holes through light irradiation with the help of semiconductor photocatalysts, which in turn generate hydroxyl radicals and superoxide anion radicals. These radicals can convert organic pollutants into carbon oxides and water, thereby destroying their structure. It offers advantages such as non-toxicity, high activity, low cost, and ease of use.
[0003] Patent CN111790388A discloses a photocatalyst, its preparation method and application. The invention uses a one-step calcination method to calcine cobalt ion-doped NH2-MIL-125 (Ti). By controlling the amount of cobalt ions added, a series of sponge-shaped three-dimensional CoTiO3 / C-TiO2 type II heterojunction photocatalysts are obtained. The obtained photocatalyst not only has a very large specific surface area, which can provide more reaction active sites for the catalytic reaction, but also introduces a carbon source to enhance its light absorption, so that the photogenerated charge transfer type of CoTiO3 / TiO2 is transformed from type I to type II, effectively inhibiting the recombination of photogenerated charges and greatly improving the photocatalytic degradation activity of titanium dioxide.
[0004] Although titanium dioxide has excellent photocatalytic degradation performance, it is extremely easy to agglomerate due to its small particle size. Agglomeration will lead to a decrease in specific surface area, which in turn affects the catalytic degradation activity of titanium dioxide. In addition, direct use of titanium dioxide is difficult to recycle and can easily cause secondary pollution.
[0005] Therefore, it is of great significance to utilize the photocatalytic activity of titanium dioxide to achieve the purpose of catalytic degradation of antibiotic pollution in water bodies while making titanium dioxide easy to separate and avoid secondary pollution of water bodies. Summary of the Invention
[0006] In view of the shortcomings of the prior art, the present invention obtains magnetized titanium dioxide @ porous carbon by reacting the modified titanium dioxide @ porous carbon with magnetic ferroferric oxide through a silane coupling agent, and then mixes the bacterial suspension with the magnetized titanium dioxide @ porous carbon to obtain a porous carbon composite material. While improving the degradation ability of antibiotics in water, it is easy to separate and avoid secondary pollution to the water body, thereby solving the technical problems raised in the background technology. Specifically, the technical solution of the present invention includes the following contents:
[0007] One of the purposes of the present invention is to provide a method for preparing a porous carbon composite material for degrading antibiotics by combined photocatalysis and microbial degradation, the preparation method comprising the following steps:
[0008] Titanium dioxide @ porous carbon, a silane coupling agent, ferrosoferric oxide powder, deionized water, and anhydrous ethanol are mixed and dispersed in a weight ratio of 1:1-1.5:0.8-1:5:50-60 to form a dispersion, and the dispersion is heated to 80° C. to 90° C. and reacted for 2 h to 3 h to obtain magnetized titanium dioxide @ porous carbon;
[0009] The magnetized titanium dioxide@porous carbon and the bacterial suspension are mixed in a weight ratio of 0.1 to 0.2:1, and then cultured by shaking to obtain a porous carbon composite material.
[0010] Furthermore, the preparation method of the titanium dioxide@porous carbon comprises the following steps:
[0011] An organic polyphosphonic acid chelating agent, an organic solvent and a halogenated alcohol are mixed to form a reaction solution, the reaction solution is adjusted to a pH of 8 to 9, and then heated to 70° C. to 80° C. for 13 to 15 hours to obtain a hydroxyl-modified quaternary ammonium chelating agent;
[0012] A hydroxy-modified quaternary ammonium chelating agent, levodopa, EDC hydrochloride, and 4-dimethylaminopyridine are mixed in a weight ratio of 1:2.5-3:2.5-3:0.25-0.3, and stirred at 25° C. under nitrogen protection for 24-30 hours to obtain modified levodopa;
[0013] Modified levodopa and titanium tetrachloride alcohol solution are mixed in a weight ratio of 1:10, heated to 40°C to 50°C, and stirred for 30 minutes to 40 minutes, and then the pH is adjusted to 8.0 to 9.0 and stirred for 10 hours to 14 hours to obtain titanium hydroxide@polylevodopa;
[0014] Titanium hydroxide@poly-L-dopa was pyrolyzed at high temperature to obtain titanium dioxide@porous carbon.
[0015] Furthermore, the organic polyphosphonic acid chelating agent includes aminotri(methylene)phosphonic acid.
[0016] Furthermore, the organic solvent includes isopropyl alcohol.
[0017] Furthermore, the halogenated alcohol includes 3-bromopropanol.
[0018] Furthermore, the molar ratio of the organic polyphosphonic acid chelating agent to the halogenated alcohol is 1:1 to 1.5.
[0019] Furthermore, the titanium tetrachloride alcohol solution is obtained by mixing and dispersing titanium tetrachloride and anhydrous ethanol in a weight ratio of 1:3 to 4.
[0020] Furthermore, the conditions for the high-temperature pyrolysis include a heating rate of 10°C / min, a pyrolysis temperature of 700°C to 800°C, and a pyrolysis time of 60min to 70min.
[0021] Furthermore, the silane coupling agent includes γ-aminopropyltrimethoxysilane.
[0022] Furthermore, the particle size of the ferrosoferric oxide powder is 40 nm to 50 nm.
[0023] Furthermore, the bacterial suspension has a concentration of 2.1×10 9 CFU / ml~2.5×10 9 CFU / ml of Microbacterium suspension.
[0024] Furthermore, the strain number of the Microbacterium is CICC 23615.
[0025] The second object of the present invention is to provide a porous carbon composite material prepared by a method for preparing a porous carbon composite material for degrading antibiotics through the combined use of photocatalysis and microorganisms.
[0026] Compared with the prior art, the present invention has the following beneficial effects:
[0027] The present invention utilizes an organic polyphosphonic acid chelating agent capable of chelating metal ions as a metal chelating agent for chelating titanium ions. A quaternization reaction occurs first through a nucleophilic substitution reaction between the nitrogen atom on the metal chelating agent structure and a halohydrin, and then a functional group hydroxyl group is introduced into the organic polyphosphonic acid chelating agent to obtain a hydroxyl-modified quaternized chelating agent. Then, the hydroxy-modified quaternary ammonium chelating agent is connected to levodopa through an esterification reaction to obtain modified levodopa. Taking advantage of the fact that levodopa can oxidatively self-polymerize in an alkaline environment, the modified levodopa is first chelated and adsorbed with titanium ions, and then placed in an alkaline environment for oxidative self-polymerization. In the alkaline environment, the titanium ions form a precipitate of titanium hydroxide while the modified levodopa self-polymerizes to form a wrapping of titanium hydroxide, thereby obtaining titanium hydroxide@polylevodopa. After high-temperature pyrolysis, the polylevodopa is carbonized to form a porous carbon material matrix, and the titanium hydroxide forms titanium oxide, thereby realizing the introduction of titanium dioxide with photocatalytic activity onto the porous carbon material to form titanium dioxide@porous carbon, effectively avoiding the defect that titanium dioxide is easy to agglomerate and thus leads to unstable catalytic activity and easy reduction. Subsequently, magnetic ferrosoferric oxide was loaded onto the surface of titanium dioxide@porous carbon via a silane coupling agent, resulting in magnetized titanium dioxide@porous carbon. This allows for magnetic separation of the porous carbon material containing the titanium dioxide from the water, avoiding the secondary contamination of the water caused by direct use of titanium dioxide. Finally, a bacterial suspension capable of degrading antibiotics was loaded onto the magnetized titanium dioxide@porous carbon via physical adsorption, resulting in a porous carbon composite material. This porous carbon composite material enhances its ability to degrade antibiotics in water through the synergistic effects of physical adsorption, photocatalytic degradation, and microbial degradation. DETAILED DESCRIPTION
[0028] The following will clearly and completely describe the technical solutions of the present invention through the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of the present invention.
[0029] Unless otherwise specified, the raw materials and reagents used in the present invention are commercially available or can be prepared by known methods.
[0030] Preparation Example 1:
[0031] The preparation method of the bacterial suspension specifically includes the following steps:
[0032] A sterilized inoculation loop was used to inoculate a microbacterium strain, numbered CICC 23615, into sterilized TSA solid medium. The culture was then incubated in a 27°C incubator for 24 hours. After activation, two loops of the same sterilized inoculation loop were inoculated into sterilized TSA liquid medium (without agar) and incubated in a 30°C incubator at 50 rpm until the bacterial concentration reached 2.1 × 10 9 CFU / ml, that is, a bacterial suspension containing Microbacterium spp. was obtained.
[0033] Preparation Example 2:
[0034] The preparation method of the bacterial suspension specifically includes the following steps:
[0035] A sterilized inoculation loop was used to inoculate a microbacterium strain, numbered CICC 23615, into sterilized TSA solid medium. The culture was then incubated in a 27°C incubator for 24 hours. After activation, two loops of the same sterilized inoculation loop were inoculated into sterilized TSA liquid medium (without agar) and incubated in a 30°C incubator at 50 rpm until the bacterial concentration reached 2.5 × 10 9 CFU / ml, that is, a bacterial suspension containing Microbacterium spp. was obtained.
[0036] Preparation Example 3:
[0037] The preparation method of the bacterial suspension specifically includes the following steps:
[0038] A sterilized inoculation loop was used to inoculate a microbacterium strain, numbered CICC 23615, into sterilized TSA solid medium. The culture was then incubated in a 27°C incubator for 24 hours. After activation, two loops of the culture were inoculated into sterilized TSA liquid medium (without agar) using a new sterilized inoculation loop. The culture was then incubated in a 30°C incubator at 50 rpm until the bacterial concentration reached 4.5 × 10 8 CFU / ml, that is, a bacterial suspension containing Microbacterium spp. was obtained.
[0039] Preparation Example 4:
[0040] The preparation method of the bacterial suspension specifically includes the following steps:
[0041] A sterilized inoculation loop was used to inoculate a microbacterium strain, numbered CICC 23615, into sterilized TSA solid medium. The culture was then incubated in a 27°C incubator for 24 hours. After activation, two loops of the same sterilized inoculation loop were inoculated into sterilized TSA liquid medium (without agar) and incubated in a 30°C incubator at 50 rpm until the bacterial concentration reached 1.8 × 10 10 CFU / ml, that is, a bacterial suspension containing Microbacterium spp. was obtained.
[0042] Preparation Example 5:
[0043] The preparation method of titanium dioxide@porous carbon specifically includes the following steps:
[0044] Weigh 1 mol of aminotri(methylenephosphonic acid) and 1 mol of 3-bromopropanol, mix and place in a flask, then add 800 ml of isopropanol and stir until completely dissolved and evenly dispersed to obtain a reaction solution. Use 0.01 mol / L sodium hydroxide solution to adjust the pH of the reaction solution to 8, then maintain the reaction solution at a speed of 200 r / min, heat to 70°C, and then time the reaction for 13 hours. After the reaction is completed, the obtained mixed solution is subjected to reduced pressure distillation on a rotary evaporator to remove isopropanol, then anhydrous acetone is added and stirred. After precipitation is completed, the precipitate is collected by filtration and dried to obtain hydroxy-modified quaternized aminotri(methylenephosphonic acid);
[0045] Weigh 2.5 parts by weight of levodopa and add it to 100ml of anhydrous dichloromethane. Then, use an ultrasonic disperser to disperse it at an ultrasonic power of 200W for 20 minutes. Then add 2.5 parts by weight of EDC hydrochloride and 0.25 parts by weight of 4-dimethylaminopyridine. Then place it in a temperature environment of 0°C and stir for pre-activation for 20 minutes. After the pre-activation treatment, add 1 part by weight of hydroxy-modified quaternized aminotrimethylphosphonic acid, mix and stir, and heat to 25°C. Then, introduce nitrogen as a protective gas. Stir and react at a speed of 200r / min in this temperature environment for 24 hours. After the reaction is completed, pour it into a dialysis bag with a molecular weight cutoff of 500Da, dialyze it repeatedly with deionized water for 2 days, and then freeze-dry the dialysate to obtain modified levodopa.
[0046] Weigh 1 part by weight of modified levodopa and 10 parts by weight of titanium tetrachloride alcohol solution (obtained by mixing and dispersing titanium tetrachloride and anhydrous ethanol in a weight ratio of 1:3) and stir until uniformly dispersed, then heat to 40°C and stir for 30 minutes for chelation reaction. After the chelation is completed, adjust the pH to 8.0 with ammonia water, and continue stirring and reacting at 40°C for 10 hours. After the reaction is completed, cool naturally to room temperature, and then separate and collect the precipitate by centrifugation at a speed of 4000r / min. Rinse the precipitate with ethanol and deionized water in sequence until the pH of the leaching water is neutral, and then place it in a vacuum drying oven at 50°C and dry it for 12 hours to obtain titanium hydroxide @ polylevodopa;
[0047] The obtained titanium hydroxide@poly-L-dopa was placed in a muffle furnace, then heated to 700°C at a heating rate of 10°C / min, and pyrolyzed at 700°C for 60 minutes. After the pyrolysis was completed, it was naturally cooled to room temperature to obtain titanium dioxide@porous carbon.
[0048] Preparation Example 6:
[0049] The preparation method of titanium dioxide@porous carbon specifically includes the following steps:
[0050] Weigh 1 mol of aminotri(methylenephosphonic acid) and 1.3 mol of 3-bromopropanol, mix and place in a flask, then add 900 ml of isopropanol and stir until completely dissolved and evenly dispersed to obtain a reaction solution. Use 0.01 mol / L sodium hydroxide solution to adjust the pH of the reaction solution to 8.5, then maintain the reaction solution at a speed of 200 r / min, heat to 75°C, and then time the reaction for 14 hours. After the reaction is completed, the obtained mixed solution is subjected to reduced pressure distillation on a rotary evaporator to remove isopropanol, then anhydrous acetone is added and stirred. After precipitation is completed, the precipitate is collected by filtration and dried to obtain hydroxy-modified quaternized aminotri(methylenephosphonic acid);
[0051] Weigh 2.7 parts by weight of levodopa and add it to 100ml of anhydrous dichloromethane. Then, use an ultrasonic disperser to disperse it at an ultrasonic power of 200W for 20 minutes. Then add 2.7 parts by weight of EDC hydrochloride and 0.27 parts by weight of 4-dimethylaminopyridine. Then place it in a temperature environment of 0°C and stir for pre-activation for 20 minutes. After the pre-activation treatment, add 1 part by weight of hydroxy-modified quaternized aminotrimethylphosphonic acid, mix and stir, and heat to 25°C. Then, introduce nitrogen as a protective gas. Stir and react at a speed of 200r / min in this temperature environment for 27 hours. After the reaction is completed, pour it into a dialysis bag with a molecular weight cutoff of 500Da, dialyze it repeatedly with deionized water for 2 days, and then freeze-dry the dialysate to obtain modified levodopa.
[0052] Weigh 1 part by weight of modified levodopa and 10 parts by weight of titanium tetrachloride alcohol solution (obtained by mixing and dispersing titanium tetrachloride and anhydrous ethanol in a weight ratio of 1:3) and stir until uniformly dispersed, then heat to 45°C and stir for 35 minutes for chelation reaction. After the chelation is completed, adjust the pH to 8.5 with ammonia water, and continue stirring and reacting at 45°C for 12 hours. After the reaction is completed, cool naturally to room temperature, and then separate and collect the precipitate by centrifugation at a speed of 4000r / min. Rinse the precipitate with ethanol and deionized water in sequence until the pH of the leaching water is neutral, and then place it in a vacuum drying oven at 50°C and dry it for 12 hours to obtain titanium hydroxide @ polylevodopa;
[0053] The obtained titanium hydroxide@poly-L-dopa was placed in a muffle furnace, then heated to 750°C at a heating rate of 10°C / min, and thermally decomposed at 750°C for 65 minutes. After the thermal decomposition was completed, it was naturally cooled to room temperature to obtain titanium dioxide@porous carbon.
[0054] Preparation Example 7:
[0055] The preparation method of titanium dioxide@porous carbon specifically includes the following steps:
[0056] Weigh 1 mol of aminotri(methylenephosphonic acid) and 1.5 mol of 3-bromopropanol, mix and place in a flask, then add 1000 ml of isopropanol and stir until completely dissolved and evenly dispersed to obtain a reaction solution. Use 0.01 mol / L sodium hydroxide solution to adjust the pH of the reaction solution to 9, then maintain the reaction solution at a speed of 200 r / min, heat to 80°C, and then time the reaction for 15 hours. After the reaction is completed, the obtained mixed solution is subjected to reduced pressure distillation on a rotary evaporator to remove isopropanol, then anhydrous acetone is added and stirred. After precipitation is completed, the precipitate is collected by filtration and dried to obtain hydroxy-modified quaternized aminotri(methylenephosphonic acid);
[0057] Weigh 3 parts by weight of levodopa and add it to 100ml of anhydrous dichloromethane. Then, use an ultrasonic disperser to disperse it at an ultrasonic power of 200W for 20 minutes. Then, add 3 parts by weight of EDC hydrochloride and 0.3 parts by weight of 4-dimethylaminopyridine. Then, place it in a temperature environment of 0°C and stir for pre-activation for 20 minutes. After the pre-activation treatment, add 1 part by weight of hydroxy-modified quaternized aminotrimethylphosphonic acid, mix and stir, and heat to 25°C. Then, introduce nitrogen as a protective gas. Stir and react at a speed of 200r / min in this temperature environment for 30 hours. After the reaction is completed, pour it into a dialysis bag with a molecular weight cutoff of 500Da, dialyze it repeatedly with deionized water for 2 days, and then freeze-dry the dialysate to obtain modified levodopa.
[0058] Weigh 1 part by weight of modified levodopa and 10 parts by weight of titanium tetrachloride alcohol solution (obtained by mixing and dispersing titanium tetrachloride and anhydrous ethanol in a weight ratio of 1:4) and stir until uniformly dispersed, then heat to 50°C and stir for 40 minutes for chelation reaction. After the chelation is completed, adjust the pH to 9.0 with ammonia water, and continue stirring and reacting at 50°C for 14 hours. After the reaction is completed, cool naturally to room temperature, and then separate and collect the precipitate by centrifugation at a speed of 5000r / min. Rinse the precipitate with ethanol and deionized water in sequence until the pH of the leaching water is neutral, and then place it in a vacuum drying oven at 50°C and dry it for 12 hours to obtain titanium hydroxide @ polylevodopa;
[0059] The obtained titanium hydroxide @ poly-L-dopa was placed in a muffle furnace, then heated to 800°C at a heating rate of 10°C / min, and pyrolyzed at 800°C for 70 minutes. After the pyrolysis was completed, it was naturally cooled to room temperature to obtain titanium dioxide @ porous carbon.
[0060] Preparation Example 8:
[0061] The preparation method of titanium dioxide@porous carbon specifically includes the following steps:
[0062] Weigh 1 part by weight of aminotrimethylphosphonic acid and 10 parts by weight of titanium tetrachloride alcohol solution (obtained by mixing and dispersing titanium tetrachloride and anhydrous ethanol in a weight ratio of 1:4) and stir until uniformly dispersed, then heat to 50°C and stir for 40 minutes for chelation reaction. After the chelation is completed, add 0.6 parts by weight of levodopa and stir and disperse, then adjust the pH to 9.0 with ammonia water, and continue stirring and reacting at 50°C for 14 hours. After the reaction is completed, cool naturally to room temperature, and then separate and collect the precipitate by centrifugation at a speed of 5000r / min. Rinse the precipitate with ethanol and deionized water in sequence until the pH of the rinse water is neutral, and then place it in a vacuum drying oven at 50°C and dry for 12 hours to obtain titanium hydroxide @ polylevodopa;
[0063] The obtained titanium hydroxide @ poly-L-dopa was placed in a muffle furnace, then heated to 800°C at a heating rate of 10°C / min, and pyrolyzed at 800°C for 70 minutes. After the pyrolysis was completed, it was naturally cooled to room temperature to obtain titanium dioxide @ porous carbon.
[0064] Preparation Example 9:
[0065] The preparation method of titanium dioxide@porous carbon specifically includes the following steps:
[0066] The pyrolysis temperature in Preparation Example 7 was lowered to 500° C., and the other conditions remained the same as in Preparation Example 7.
[0067] Preparation Example 10:
[0068] The preparation method of titanium dioxide@porous carbon specifically includes the following steps:
[0069] The pyrolysis temperature in Preparation Example 7 was increased to 900°C, the pyrolysis treatment time was extended to 90 min, and the other conditions remained the same as in Preparation Example 7.
[0070] Example 1:
[0071] A method for preparing a porous carbon composite material for degrading antibiotics by photocatalysis and microorganisms, specifically comprising the following steps:
[0072] Weigh 1 part by weight of the titanium dioxide @ porous carbon obtained in Preparation Example 5, 1 part by weight of γ-aminopropyltrimethoxysilane, 0.8 parts by weight of ferrosoferric oxide powder (particle size of 40 nm), 5 parts by weight of deionized water, and 50 parts by weight of anhydrous ethanol and add them together to the reactor. Dispersion treatment was performed at an ultrasonic power of 400 W for 10 minutes to form a dispersion, and then the dispersion was heated to 80°C for a timed reaction of 2 hours. After the reaction was completed, the solid obtained by filtration was rinsed with anhydrous ethanol and then with deionized water, and then dried in a vacuum drying oven at 50°C for 12 hours to obtain magnetized titanium dioxide @ porous carbon;
[0073] 0.1 parts by weight of magnetized titanium dioxide @ porous carbon was dispersed in 1 part by weight of the bacterial suspension obtained in Preparation Example 1, and then cultured in a constant temperature box at 25°C at a rotation speed of 100 r / min for 20 hours. After the culture, solid particles were filtered to obtain solid particles. The solid particles were rinsed three times with a phosphate buffer solution with a pH of 7.0, and then rinsed three times with sterile water, and then vacuum freeze-dried to obtain a porous carbon composite material.
[0074] Example 2:
[0075] A method for preparing a porous carbon composite material for degrading antibiotics by combined photocatalysis and microbial degradation, specifically comprising the following steps:
[0076] Weigh 1 part by weight of the titanium dioxide @ porous carbon obtained in Preparation Example 6, 13 parts by weight of γ-aminopropyltrimethoxysilane, 0.9 parts by weight of ferrosoferric oxide powder (particle size of 40 nm), 5 parts by weight of deionized water, and 55 parts by weight of anhydrous ethanol and add them together to the reactor. Dispersion is formed by ultrasonic dispersion treatment at 400 W power for 10 minutes, and then the dispersion is heated to 85 ° C for a timed reaction of 2.5 hours. After the reaction is completed, the solid obtained by filtration is rinsed with anhydrous ethanol and then with deionized water, and then placed in a vacuum drying oven at 50 ° C for 12 hours to obtain magnetized titanium dioxide @ porous carbon;
[0077] 0.15 parts by weight of magnetized titanium dioxide @ porous carbon was dispersed in 1 part by weight of the bacterial suspension obtained in Preparation Example 1, and then cultured in a constant temperature box at 25°C with an oscillation speed of 100 r / min for 20 hours. After the culture, solid particles were filtered to obtain solid particles. The solid particles were rinsed three times with a phosphate buffer solution with a pH of 7.0, and then rinsed three times with sterile water, and then vacuum freeze-dried to obtain a porous carbon composite material.
[0078] Example 3:
[0079] A method for preparing a porous carbon composite material for degrading antibiotics by combined photocatalysis and microbial degradation, specifically comprising the following steps:
[0080] Weigh 1 part by weight of the titanium dioxide @ porous carbon obtained in Preparation Example 7, 1.5 parts by weight of γ-aminopropyltrimethoxysilane, 1 part by weight of ferrosoferric oxide powder (particle size of 50 nm), 5 parts by weight of deionized water, and 60 parts by weight of anhydrous ethanol, and add them together to the reactor. Dispersion treatment was performed at an ultrasonic power of 400 W for 10 minutes to form a dispersion, and then the dispersion was heated to 90°C for a timed reaction of 3 hours. After the reaction was completed, the solid was filtered, rinsed with anhydrous ethanol, then rinsed with deionized water, and then dried in a vacuum drying oven at 50°C for 12 hours to obtain magnetized titanium dioxide @ porous carbon;
[0081] 0.2 parts by weight of magnetized titanium dioxide @ porous carbon was dispersed in 1 part by weight of the bacterial suspension obtained in Preparation Example 2, and then cultured in a constant temperature box at 25°C at a rotation speed of 100 r / min for 20 hours. After the culture, solid particles were filtered to obtain solid particles. The solid particles were rinsed three times with a phosphate buffer solution with a pH of 7.0, and then rinsed three times with sterile water, and then vacuum freeze-dried to obtain a porous carbon composite material.
[0082] Comparative Example 1:
[0083] A method for preparing a porous carbon composite material for degrading antibiotics by combined photocatalysis and microbial degradation, specifically comprising the following steps:
[0084] The bacterial suspension in Example 3 was replaced by the bacterial suspension obtained in Preparation Example 3, and the rest of the preparation process remained the same as in Example 3.
[0085] Comparative Example 2:
[0086] A method for preparing a porous carbon composite material for degrading antibiotics by combined photocatalysis and microbial degradation, specifically comprising the following steps:
[0087] The bacterial suspension in Example 3 was replaced by the bacterial suspension obtained in Preparation Example 4, and the rest of the preparation process remained the same as in Example 3.
[0088] Comparative Example 3:
[0089] A method for preparing a porous carbon composite material for degrading antibiotics by combined photocatalysis and microbial degradation, specifically comprising the following steps:
[0090] The titanium dioxide @ porous carbon in Example 3 was replaced by the titanium dioxide @ porous carbon obtained in Preparation Example 8, and the rest of the preparation process remained the same as in Example 3.
[0091] Comparative Example 4:
[0092] A method for preparing a porous carbon composite material for degrading antibiotics by combined photocatalysis and microbial degradation, specifically comprising the following steps:
[0093] The titanium dioxide @ porous carbon in Example 3 was replaced by the titanium dioxide @ porous carbon obtained in Preparation Example 9, and the rest of the preparation process was consistent with Example 3.
[0094] Comparative Example 5:
[0095] A method for preparing a porous carbon composite material for degrading antibiotics by combined photocatalysis and microbial degradation, specifically comprising the following steps:
[0096] The titanium dioxide @ porous carbon in Example 3 was replaced by the titanium dioxide @ porous carbon obtained in Preparation Example 10, and the rest of the preparation process was consistent with Example 3.
[0097] Comparative Example 6:
[0098] A method for preparing a porous carbon composite material for degrading antibiotics by combined photocatalysis and microbial degradation, specifically comprising the following steps:
[0099] The γ-aminopropyltrimethoxysilane in Example 3 was replaced by γ-aminopropyltriethoxysilane, and the rest of the preparation process was consistent with Example 3.
[0100] Comparative Example 7:
[0101] A method for preparing a porous carbon composite material for degrading antibiotics by combined photocatalysis and microbial degradation, specifically comprising the following steps:
[0102] Weigh 1 part by weight of the titanium dioxide @ porous carbon obtained in Preparation Example 7, 1.5 parts by weight of γ-aminopropyltrimethoxysilane, 1 part by weight of ferrosoferric oxide powder (particle size of 50 nm), 5 parts by weight of deionized water, and 60 parts by weight of anhydrous ethanol, and add them together to the reactor. Dispersion treatment was performed at an ultrasonic power of 400 W for 10 minutes to form a dispersion, and then the dispersion was heated to 90°C for a timed reaction of 4 hours. After the reaction was completed, the solid obtained by filtration was rinsed with anhydrous ethanol and then with deionized water, and then dried in a vacuum drying oven at 50°C for 12 hours to obtain magnetized titanium dioxide @ porous carbon;
[0103] 0.2 parts by weight of magnetized titanium dioxide @ porous carbon was dispersed in 1 part by weight of the bacterial suspension obtained in Preparation Example 2, and then cultured in a constant temperature box at 25°C at a rotation speed of 100 r / min for 20 hours. After the culture, solid particles were filtered to obtain solid particles. The solid particles were rinsed three times with a phosphate buffer solution with a pH of 7.0, and then rinsed three times with sterile water, and then vacuum freeze-dried to obtain a porous carbon composite material.
[0104] Comparative Example 8:
[0105] A method for preparing a porous carbon composite material for degrading antibiotics by combined photocatalysis and microbial degradation, specifically comprising the following steps:
[0106] The ferrosoferric oxide powder (particle size of 50 nm) in Example 3 was replaced with ferrosoferric oxide powder (particle size of 100 nm), and the rest of the preparation process remained the same as that of Example 3.
[0107] Specific surface area test:
[0108] The specific surface area and average pore size of the porous carbon composite materials obtained in Examples 1 to 3 and Comparative Examples 1 to 7 were measured by the BET method. The results are shown in Table 1 below.
[0109] Table 1 Specific surface area and average pore size results
[0110] Sources Specific surface area (m2 / g) Average pore size (nm) Example 1 452.74 247.58 Example 2 477.05 218.25 Example 3 481.19 213.11 Comparative Example 1 478.25 215.41 Comparative Example 2 472.28 223.09 Comparative Example 3 217.58 421.06 Comparative Example 4 231.49 405.77 Comparative Example 5 224.85 411.34 Comparative Example 6 475.64 220.37 Comparative Example 7 167.06 518.09 Comparative Example 8 135.74 546.09
[0111] Antibiotic degradation test:
[0112] 100 ml of 10 mg / L sulfamethoxazole solution, sulfadiazine solution and norfloxacin solution were prepared respectively, and then 80 mg of the porous carbon composite material obtained in Examples 1 to 3 and Comparative Examples 1 to 7 was added to the above antibiotic solution. After the addition was completed, it was placed in visible light with a wavelength of 420 nm and stirred at a speed of 400 r / min. After 60 minutes, the concentration after treatment was sampled and detected. The removal rate = (10 mg / L-concentration after treatment) / 10 mg / L×100%. The results are shown in Table 2 below.
[0113] Table 2 Antibiotic removal rate
[0114]
[0115] Split testing:
[0116] 80 mg of the porous carbon composite material obtained in Examples 1 to 3 and Comparative Examples 1 to 7 was added to 100 ml of a 10 mg / L sulfamethoxazole solution. After the addition was completed, it was placed in visible light with a wavelength of 420 nm and stirred at a speed of 400 r / min for 1 hour. It was then separated by magnetic adsorption for 10 minutes, and the solution was poured out. The remaining magnetically separated solid particles were placed in a vacuum oven at 60°C for drying, and the remaining weight was weighed using an electronic balance. The results are shown in Table 3 below.
[0117] Table 3 Residual weight of porous carbon composite materials
[0118] Sources Remaining weight (mg) Example 1 79.08 Example 2 79.21 Example 3 79.47 Comparative Example 1 77.62 Comparative Example 2 77.15 Comparative Example 3 75.48 Comparative Example 4 65.19 Comparative Example 5 68.72 Comparative Example 6 46.09 Comparative Example 7 57.03 Comparative Example 8 79.91
[0119] The following conclusions can be drawn from Tables 1 to 3 above:
[0120] (1) It can be found from Examples 1 to 3 that the porous carbon composite material prepared by the present invention has a good effect of degrading antibiotic pollution in water bodies, and can be separated from water bodies by magnetic separation to avoid secondary pollution of the water body.
[0121] (2) It can be found from Comparative Examples 1 and 2 that the prepared porous carbon composite material has a poor effect in degrading antibiotics in water. This may be because in this system, when loading the Microbacterium genus in the bacterial suspension, if the bacterial solution concentration is too low, the loading amount may be small, thereby affecting the degradation effect; if the bacterial solution concentration is too high, on the one hand, due to local aggregation of microorganisms, a high-density area may be formed, causing the microorganisms to be inactivated and die due to nutrient competition; on the other hand, due to excessive microorganisms clogging the pores, the physical adsorption capacity of the porous carbon composite material itself is weakened, resulting in the inability to enrich more antibiotics, hindering the contact between microorganisms and antibiotics, and thus weakening the effect of degrading antibiotics.
[0122] (3) Comparative Example 3 shows that if amino trimethylene phosphonic acid with chelated metal ions is directly mixed with titanium tetrachloride alcohol solution before adding levodopa, it is difficult for levodopa to form an esterified structure with amino trimethylene phosphonic acid in this system. When levodopa undergoes alkaline oxidation and self-polymerization, the amino trimethylene phosphonic acid that has chelated titanium ions may not be evenly dispersed in the polylevodopa structure, which may affect the pores of the porous carbon composite material obtained after high-temperature pyrolysis, resulting in a low specific surface area, which weakens its ability to enrich antibiotics and leads to poor performance in degradation of antibiotics in water.
[0123] (4) Comparative Examples 4 and 5 show that the prepared porous carbon composite material has a poor effect in degrading antibiotics in water. This may be because in this system, although high-temperature pyrolysis carbonization helps poly-levodopa form a porous carbon structure, the pyrolysis temperature is too low, which may cause the pore structure to fail to form fully, resulting in a small specific surface area and a weak adsorption capacity for enriching antibiotics, affecting the degradation of antibiotics; while the high-temperature pyrolysis temperature is too high, the pore structure may be over-sintered, the pore structure is destroyed, and the specific surface area is weakened, resulting in a weakened effect of degrading antibiotics.
[0124] (5) It can be found from Comparative Example 6 that the prepared porous carbon composite material has a poor effect of separating from water. This may be because γ-aminopropyltriethoxysilane has a longer carbon chain than γ-aminopropyltrimethoxysilane. The influence of steric hindrance may lead to poor connection effect of ferrosoferric oxide through silane coupling agent, thereby affecting the separation effect.
[0125] (6) Comparative Example 7 shows that the prepared porous carbon composite material has a poor effect in degrading antibiotics in water. This may be because in this system, when ferrosoferric oxide is loaded onto titanium dioxide@porous carbon using a silane coupling agent, if the treatment time is too long, the degree of self-polymerization of the silane coupling agent to form polysiloxane may be aggravated, and the excessive production of polysiloxane may cover up the pore structure of titanium dioxide@porous carbon, reduce the effective contact area, and result in a lower specific surface area, thereby weakening the effect of degrading antibiotics.
[0126] (7) Through comparative example 8, it can be found that the prepared porous carbon composite material has a poor effect in degrading antibiotics in water. This may be because in this system, although the use of magnetic ferroferric oxide with a larger particle size can improve the recovery and separation effect, the larger particle size of ferroferric oxide may easily clog the pore structure, thereby weakening the specific surface area and making the effect of degrading antibiotics weaker.
[0127] The embodiments described above provide a detailed description of the technical solutions and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and modifications fall within the scope of the present invention as claimed.
Claims
1. A method for preparing a porous carbon composite material for degrading antibiotics by combining photocatalysis and microorganisms, characterized in that: The preparation method comprises the following steps: Titanium dioxide @ porous carbon, a silane coupling agent, ferrosoferric oxide powder, deionized water, and anhydrous ethanol are mixed and dispersed in a weight ratio of 1:1-1.5:0.8-1:5:50-60 to form a dispersion, and the dispersion is heated to 80° C. to 90° C. and reacted for 2 h to 3 h to obtain magnetized titanium dioxide @ porous carbon; The magnetized titanium dioxide@porous carbon and the bacterial suspension are mixed in a weight ratio of 0.1 to 0.2:1, and then cultured by shaking to obtain a porous carbon composite material.
2. The preparation method according to claim 1, characterized in that The preparation method of the titanium dioxide@porous carbon comprises the following steps: An organic polyphosphonic acid chelating agent, an organic solvent and a halogenated alcohol are mixed to form a reaction solution, the reaction solution is adjusted to a pH of 8 to 9, and then heated to 70° C. to 80° C. and reacted for 13 to 15 hours to obtain a hydroxyl-modified quaternary ammonium chelating agent; A hydroxy-modified quaternary ammonium chelating agent, levodopa, EDC hydrochloride, and 4-dimethylaminopyridine are mixed in a weight ratio of 1:2.5-3:2.5-3:0.25-0.3, and stirred at 25° C. under nitrogen protection for 24-30 hours to obtain modified levodopa; Modified levodopa and titanium tetrachloride alcohol solution are mixed in a weight ratio of 1:10, heated to 40°C to 50°C, and stirred for 30 minutes to 40 minutes, and then the pH is adjusted to 8.0 to 9.0 and stirred for 10 hours to 14 hours to obtain titanium hydroxide@polylevodopa; Titanium hydroxide@poly-L-dopa was pyrolyzed at high temperature to obtain titanium dioxide@porous carbon.
3. The preparation method according to claim 2, characterized in that The organic polyphosphonic acid chelating agent includes aminotri(methylene)phosphonic acid.
4. The preparation method according to claim 2, characterized in that The halohydrin includes 3-bromopropanol.
5. The preparation method according to claim 2, characterized in that The molar ratio of the organic polyphosphonic acid chelating agent to the halogenated alcohol is 1:1 to 1.
5.
6. The preparation method according to claim 2, characterized in that The conditions for the high-temperature pyrolysis include a heating rate of 10° C. / min, a pyrolysis temperature of 700° C. to 800° C., and a pyrolysis time of 60 min to 70 min.
7. The preparation method according to claim 1, characterized in that The silane coupling agent includes γ-aminopropyltrimethoxysilane.
8. The preparation method according to claim 1, characterized in that The bacterial suspension has a concentration of 2.1×10 9 CFU / ml~2.5×10 9 CFU / ml of Microbacterium suspension.
9. A porous carbon composite material prepared by the method for preparing a porous carbon composite material for degrading antibiotics by combined photocatalysis and microorganisms as claimed in any one of claims 1 to 8.