A cobalt polysulfide fenton catalyst supported by biochar, a preparation method and application thereof
By using biochar-supported cobalt polysulfide Fenton catalysts, the problems of poor antibiotic degradation and cobalt ion leaching in traditional water treatment methods have been solved, achieving efficient and stable antibiotic degradation and demonstrating potential for industrial application.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- YUNNAN UNIV
- Filing Date
- 2023-09-18
- Publication Date
- 2026-06-16
Smart Images
Figure HDA0004454411310000011 
Figure HDA0004454411310000012 
Figure HDA0004454411310000021
Abstract
Description
Technical Field
[0001] This invention belongs to the field of organic pollutant treatment, specifically, it relates to a biochar-supported cobalt polysulfide Fenton catalyst, its preparation method, and its application. Background Technology
[0002] For over 60 years, antibiotics have been produced and used on a large scale in medicine and agriculture, greatly promoting global public health and agricultural development. However, the large-scale use and even abuse of antibiotics has resulted in a significant amount of antibiotics being released into the environment through households, hospitals, pharmaceutical factories, and wastewater treatment plants. This poses an immeasurable threat to ecological security and human health. Currently, traditional water treatment methods are generally ineffective at degrading antibiotics, while advanced oxidation technologies (AOPs) have attracted widespread attention from water pollution treatment researchers both domestically and internationally due to their high degradation efficiency and broad applicability to various pollutants.
[0003] Persulfate oxidation, a type of advanced oxidation process, exhibits excellent degradation performance for recalcitrant organic pollutants, including antibiotics. Its principle involves using catalysts to catalyze persulfate to generate highly reactive species with high redox potentials. These species possess strong oxidizing capabilities, reacting with pollutants to mineralize them into smaller organic molecules and CO2. Therefore, selecting a suitable catalyst is crucial in this technology.
[0004] Metal sulfides are a class of materials with strong oxygen resistance and good electrical conductivity. Therefore, they have been widely used in water treatment in recent years. Among the many metal sulfides, cobalt polysulfide is an excellent choice. In persulfate decontamination applications, the multiple valence states of cobalt and the synergistic effect between cobalt ions and sulfur ions give it strong catalytic activity. However, in practical applications, some drawbacks exist, such as secondary pollution caused by the leaching of cobalt ions and the deactivation of cobalt sulfide by oxidation in water. Summary of the Invention
[0005] To overcome the problems existing in the background technology, this invention proposes a biochar-supported cobalt polysulfide Fenton catalyst. Biochar is an excellent support; by loading cobalt polysulfide onto biochar, the dissolution of metal ions during catalyst use can be reduced. Simultaneously, the adsorption effect of biochar allows the degradation reaction to occur on the biochar surface, providing more active sites for cobalt polysulfide and thus improving its catalytic performance. Furthermore, compared with other biochar and cobalt polysulfide composite methods, the preparation method proposed in this invention has lower process requirements and costs, is safe, simple, and easy to implement. The application of the biochar-cobalt polysulfide composite in the degradation of antibiotics has shown good results and has the potential for industrial production.
[0006] To achieve the above objectives, the present invention is implemented through the following technical solution:
[0007] A biochar-supported cobalt polysulfide Fenton catalyst is a biochar cobalt polysulfide composite prepared from lignocellulose biomass, ammonium sulfate, and cobalt sulfate complex salt cobalt ammonium sulfate ((NH4)2Co(SO4)2).
[0008] Preferably, the lignocellulosic biomass is one or more of rice straw, wheat straw, sorghum straw, corn cob, corn stalk, sugarcane bagasse, pine wood, eucalyptus wood, cypress wood, jute, etc.
[0009] The specific preparation steps for biochar-supported cobalt polysulfide Fenton catalysts are as follows:
[0010] 1) Wash and soak the biomass three times with deionized water, then dry it for later use;
[0011] 2) Weigh out the biomass and ammonium cobalt sulfate separately according to the proportion. Dissolve the ammonium cobalt sulfate in 150-250ml of deionized water to prepare an ammonium cobalt sulfate solution. Then soak the biomass in the prepared ammonium cobalt sulfate solution and stir to ensure that the biomass and ammonium cobalt sulfate solution are fully mixed.
[0012] 3) After mixing the biomass with the cobalt ammonium sulfate solution evenly, let it stand, and then put it into a drying oven and dry it at a temperature of 60°C to completely remove the solvent and allow the cobalt ammonium sulfate to crystallize on the surface of the biomass.
[0013] 4) Place the dried cobalt ammonium sulfate and biomass mixture into a box furnace, heat it under nitrogen protection, and calcine it. After calcine, filter the obtained sample through a 100-mesh sieve to obtain the biochar cobalt polysulfide composite (CoSn / BC).
[0014] Further, in step 2), the mass ratio of biomass to ammonium cobalt sulfate is 1:0.25-1; the concentration of the ammonium cobalt sulfate solution is 0.1-0.4 g / ml; and the amount of ammonium cobalt sulfate used is 2.5-10 g.
[0015] Furthermore, in step 2), the stirring rate is 800-1000 rpm; the stirring time is 3-6 h.
[0016] Furthermore, in step 3), the standing soaking time is 18-24 hours; the drying time is 48-36 hours.
[0017] Furthermore, in step 4), the heating temperature is 650-850℃, the heating rate is 5℃ per minute, and the calcination time is 1-2 hours.
[0018] The above-mentioned biochar-supported cobalt polysulfide Fenton catalyst was applied to the treatment of antibiotic-contaminated water.
[0019] The beneficial effects of this invention are:
[0020] (1) The preparation method of the present invention can prepare CoSn / BC composite material by impregnation and pyrolysis. Compared with other composite methods of biochar and polysulfides, this method is simple, reliable and low cost.
[0021] (2) The CoSn / BC composite material prepared by the method of the present invention can reduce the leaching of cobalt ions in the use of cobalt polysulfide and avoid secondary pollution caused by the large amount of cobalt ions dissolved during the degradation process.
[0022] (3) In the preparation method proposed in this invention, when cobalt ammonium sulfate is mixed with biomass for pyrolysis, the ammonia gas and sulfur dioxide gas produced not only activate the biochar, but also dope the biochar with N and S, thereby improving the catalytic activity of the biochar itself.
[0023] (4) The CoSn / BC composite material prepared by the method of the present invention can effectively activate persulfate to produce highly oxidizing active species and has good degradation performance on antibiotics including sulfamethoxazole and tetracycline.
[0024] (5) The CoSn / BC composite material prepared by the method of the present invention can regain its properties after being used for antibiotic degradation multiple times by simple reheating. Attached Figure Description
[0025] Figure 1 The XRD patterns are of the CoSn / BC composite materials prepared by different mass ratios in Examples 1-3.
[0026] Figure 2 The XRD patterns of CoSn / BC composite materials prepared at different calcination temperatures in Examples 1 and 4-5 are shown.
[0027] Figure 3 The image shows a scanning electron microscope (SEM) image of the CoSn / BC composite material prepared in Example 1.
[0028] Figure 4 The image shows a transmission electron microscope (TEM) image of the CoSn / BC composite material prepared in Example 1.
[0029] Figure 5 The Raman spectrum of the CoSn / BC composite material prepared in Example 1 is shown below.
[0030] Figure 6 The graphs show the tetracycline degradation performance of the CoSn / BC composite materials prepared at different mass ratios in Examples 1-3.
[0031] Figure 7The graphs show the tetracycline degradation performance of the CoSn / BC composite materials prepared at different calcination temperatures in Examples 1 and 4-5.
[0032] Figure 8 The graph shows the tetracycline degradation performance of the CoSn / BC composite material prepared in Example 1 during recycling.
[0033] Figure 9 The graph shows the tetracycline degradation performance of the CoSn / BC composite material prepared in Example 1 after high-temperature regeneration. Detailed Implementation
[0034] The present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the content described.
[0035] Example 1
[0036] A biochar-supported cobalt polysulfide Fenton catalyst, the specific preparation steps are as follows:
[0037] 1) Cleaning of biomass:
[0038] Soak 50g of cypress wood chips in 1L of deionized water and stir for 15 minutes. Discard the suspension containing impurities on the surface of the solution. Repeat this operation 3 times. Then, place the cleaned biomass in an oven and dry it at 60℃ for later use.
[0039] 2) Mixed impregnation of biomass and ammonium cobalt sulfate:
[0040] Weigh 10g of biomass and 2.5g of cobalt ammonium sulfate. Dissolve the weighed cobalt ammonium sulfate in 250ml of deionized water and stir for 10 minutes to prepare a cobalt ammonium sulfate solution. Then, pour the weighed biomass into the prepared cobalt ammonium sulfate solution, with a biomass to cobalt ammonium sulfate mass ratio of 1:0.25. Stir the above biomass and cobalt ammonium sulfate mixture at 1000rpm for 3 hours to ensure thorough mixing of the biomass and cobalt ammonium sulfate.
[0041] 3) Solvent removal from a mixed solution of biomass and ammonium cobalt sulfate:
[0042] The mixed biomass and cobalt ammonium sulfate solution were left to stand for 24 hours, and then placed in an oven and dried at 60°C for 48 hours to remove the solvent from the mixed solution of biomass and cobalt ammonium sulfate, so that the cobalt ammonium sulfate crystallized on the biomass.
[0043] 4) Calcination of a mixture of biomass and ammonium cobalt sulfate:
[0044] The mixture of biomass and cobalt ammonium sulfate was transferred to a crucible and placed in a box furnace for calcination. After evacuation, nitrogen was introduced as a protective atmosphere. The temperature control program was set as follows: calcination temperature of 850℃, heating rate of 5℃ / min, and calcination time of 2h. After calcination, the sample was taken out, ground twice, and filtered through a 100-mesh sieve. The black powder obtained was the biomass cobalt polysulfide composite.
[0045] The CoSn / BC material obtained by the aforementioned method was scanned by electron microscopy, and the results are as follows: Figure 3 As shown, cobalt sulfide particles are loaded onto biochar; under transmission electron microscopy, as... Figure 4 As shown, the interplanar spacings of the (311), (222), and (440) crystal planes of Co9S8 are 0.293 nm, 0.288 nm, and 0.177 nm, respectively. The Raman spectra of the CoSn / BC material obtained by the aforementioned method are shown below. Figure 5 As shown, this indicates that the CoSn / BC material has a high degree of graphitization, I D / I G =0.99.
[0046] Example 2
[0047] A biochar-supported cobalt polysulfide Fenton catalyst, the specific preparation steps are as follows:
[0048] 1) Cleaning of biomass:
[0049] Soak 50g of cypress wood chips in 1L of deionized water and stir for 15 minutes. Discard the suspension containing impurities on the surface of the solution. Repeat this operation 3 times. Then, place the cleaned biomass in an oven and dry it at 60℃ for later use.
[0050] 2) Mixed impregnation of biomass and ammonium cobalt sulfate:
[0051] Weigh 10g of biomass and 5g of cobalt ammonium sulfate; dissolve the weighed cobalt ammonium sulfate in 250ml of deionized water and stir for 10 minutes to prepare a cobalt ammonium sulfate solution; then pour the weighed biomass into the prepared cobalt ammonium sulfate solution, with a biomass to cobalt ammonium sulfate mass ratio of 1:0.5; stir the above biomass and cobalt ammonium sulfate mixture at 1000rpm for 3 hours to ensure thorough mixing of biomass and cobalt ammonium sulfate.
[0052] 3) Solvent removal from a mixed solution of biomass and ammonium cobalt sulfate:
[0053] The mixed biomass and cobalt ammonium sulfate solution were left to stand for 24 hours, and then placed in an oven and dried at 60°C for 48 hours to remove the solvent from the mixed solution of biomass and cobalt ammonium sulfate, so that the cobalt ammonium sulfate crystallized on the biomass.
[0054] 4) Calcination of a mixture of biomass and ammonium cobalt sulfate:
[0055] The mixture of biomass and cobalt ammonium sulfate was transferred to a crucible and placed in a box furnace for calcination. After evacuation, nitrogen was introduced as a protective atmosphere. The temperature control program was set as follows: calcination temperature of 850℃, heating rate of 5℃ / min, and calcination time of 2h. After calcination, the sample was taken out, ground twice, and filtered through a 100-mesh sieve. The black powder obtained was the biomass cobalt polysulfide composite.
[0056] Example 3
[0057] A biochar-supported cobalt polysulfide Fenton catalyst, the specific preparation steps are as follows:
[0058] 1) Cleaning of biomass:
[0059] Soak 50g of cypress wood chips in 1L of deionized water and stir for 15 minutes. Discard the suspension containing impurities on the surface of the solution. Repeat this operation 3 times. Then, place the cleaned biomass in an oven and dry it at 60℃ for later use.
[0060] 2) Mixed impregnation of biomass and ammonium cobalt sulfate:
[0061] Weigh 10g of biomass and 10g of cobalt ammonium sulfate; dissolve the weighed cobalt ammonium sulfate in 250ml of deionized water and stir for 10 minutes to prepare a cobalt ammonium sulfate solution; then pour the weighed biomass into the prepared cobalt ammonium sulfate solution, with a biomass to cobalt ammonium sulfate mass ratio of 1:1; stir the above biomass and cobalt ammonium sulfate mixture at 1000rpm for 3 hours to ensure thorough mixing of biomass and cobalt ammonium sulfate.
[0062] 3) Solvent removal from a mixed solution of biomass and ammonium cobalt sulfate:
[0063] The mixed biomass and cobalt ammonium sulfate solution were left to stand for 24 hours, and then placed in an oven and dried at 60°C for 48 hours to remove the solvent from the mixed solution of biomass and cobalt ammonium sulfate, so that the cobalt ammonium sulfate crystallized on the biomass.
[0064] 4) Calcination of a mixture of biomass and ammonium cobalt sulfate:
[0065] The mixture of biomass and cobalt ammonium sulfate was transferred to a crucible and placed in a box furnace for calcination. After evacuation, nitrogen was introduced as a protective atmosphere. The temperature control program was set as follows: calcination temperature of 850℃, heating rate of 5℃ / min, and calcination time of 2h. After calcination, the sample was taken out, ground twice, and filtered through a 100-mesh sieve. The black powder obtained was the biomass cobalt polysulfide composite.
[0066] Example 4
[0067] Based on the preparation method in Example 1, the calcination temperature was adjusted to 750°C, while other steps remained unchanged, to prepare a biomass cobalt polysulfide composite.
[0068] Example 5
[0069] Based on the preparation method in Example 1, the calcination temperature was adjusted to 650°C, while other steps remained unchanged, to prepare a biomass cobalt polysulfide composite.
[0070] Example 6
[0071] The biomass cobalt polysulfide complexes prepared in Examples 1-5 were used as catalysts to effectively activate persulfate to produce highly oxidizing active species. When applied to the treatment of antibiotic-contaminated water, they showed good degradation performance for antibiotics.
[0072] Experimental Analysis
[0073] I. Effect of different biomass-to-cobalt ammonium sulfate mass ratios on the degradation of tetracycline hydrochloride
[0074] (1) Preparation of tetracycline hydrochloride solution:
[0075] Dissolve 1g of tetracycline hydrochloride in 1L of deionized water and stir for 10min to prepare a 1g / L tetracycline hydrochloride solution. Then take 10ml of the 1g / L tetracycline hydrochloride solution and use a 200ml volumetric flask to prepare a 50mg / L tetracycline hydrochloride test solution.
[0076] (2) Tests for the degradation of tetracycline hydrochloride:
[0077] Three portions of 0.3693 g potassium persulfate were weighed and added to three portions of 50 mg / L tetracycline hydrochloride test solution, respectively. Then, 0.06 g of CoSn / BC (mass ratios of 1:1, 1:0.5, and 1:0.25) prepared in Examples 1-3 were weighed and added to 50 mg / L tetracycline hydrochloride test solution to initiate the degradation reaction.
[0078] Every 5 minutes, 10 ml of the test solution was sampled using a syringe, filtered through a 0.45 μm polyethersulfone membrane, and the concentration was immediately measured using a UV-Vis spectrophotometer.
[0079] like Figure 1 As shown, the CoSn / BC phase structures prepared by different biomass-to-ammonium cobalt sulfate mass ratios are identical, indicating that different mass ratios do not affect the phase structure of the material.
[0080] Test results are as follows Figure 6As shown, the degradation effects of CoSn / BC with different mass ratios on tetracycline hydrochloride vary. The CoSn / BC composite material prepared with a mass ratio of biomass to cobalt ammonium sulfate of 1:0.25 has the best effect, with a degradation rate of about 99.6%.
[0081] II. Effect of CoSn / BC prepared at different calcination temperatures on the degradation of tetracycline hydrochloride
[0082] (1) Preparation of tetracycline hydrochloride solution:
[0083] Dissolve 1g of tetracycline hydrochloride in 1L of deionized water and stir for 10min to prepare a 1g / L tetracycline hydrochloride solution. Then take 10ml of the 1g / L tetracycline hydrochloride solution and use a 200ml volumetric flask to prepare a 50mg / L tetracycline hydrochloride test solution.
[0084] (2) Tests for the degradation of tetracycline hydrochloride:
[0085] Three 0.3693g portions of potassium persulfate were weighed and added to three 50mg / L tetracycline hydrochloride test solutions. Then, 0.06g of CoSn / BC prepared in Examples 1, 4, and 5 (calcined at 850℃, 750℃, and 650℃) were weighed and added to the 50mg / L tetracycline hydrochloride test solutions to initiate the degradation reaction.
[0086] Every 5 minutes, 10 ml of the test solution was sampled using a syringe, filtered through a 0.45 μm polyethersulfone membrane, and the concentration was immediately measured using a UV-Vis spectrophotometer.
[0087] like Figure 2 As shown, different calcination temperatures affect the phase structure of the prepared CoSn / BC material. When the temperature reaches 850℃, the phase of the material is Co9S8.
[0088] Test results are as follows Figure 7 As shown, the CoSn / BC materials prepared at different calcination temperatures exhibit different degradation effects on tetracycline hydrochloride. Among them, the CoSn / BC material prepared at a calcination temperature of 850℃ shows the best effect, with a degradation rate of approximately 99.6%.
[0089] III. Cyclic Performance Testing of CoSn / BC
[0090] (1) Preparation of tetracycline hydrochloride solution:
[0091] Dissolve 1g of tetracycline hydrochloride in 1L of deionized water and stir for 10 minutes to prepare a 1g / L tetracycline hydrochloride solution. Then take 50ml of the 1g / L tetracycline hydrochloride solution and use a 1L volumetric flask to prepare a 50mg / L tetracycline hydrochloride test solution.
[0092] (2) Tests for the degradation of tetracycline hydrochloride:
[0093] Two 1.8465g portions of potassium persulfate were weighed and added to two 1L portions of 50mg / L tetracycline hydrochloride test solution; then two 0.3g portions of the CoSn / BC composite material prepared in Example 1 were weighed and added to the 50mg / L tetracycline hydrochloride test solution to initiate the degradation reaction.
[0094] Every 5 minutes, 10 ml of the test solution was sampled using a syringe, filtered through a 0.45 μm polyethersulfone membrane, and the concentration was immediately measured using a UV-Vis spectrophotometer.
[0095] After the test, the tetracycline hydrochloride solution was filtered out using a vacuum filtration device. The remaining CoSn / BC was washed three times with deionized water and ethanol, and then transferred to an oven to dry at 60°C. The dried CoSn / BC was then subjected to the same steps as above to degrade the tetracycline hydrochloride solution.
[0096] Test results are as follows Figure 8 As shown, the CoSn / BC material exhibits poor cycling performance; after three cycles, the removal rate of tetracycline hydrochloride at 60 min decreased from 99.6% to 64.4%.
[0097] IV. Performance Testing of CoSn / BC After Thermal Regeneration
[0098] The CoSn / BC material, after multiple cycles in Experiment 3, was calcined in a tube furnace to restore its catalytic activity. The calcination temperatures were 400℃, 600℃, and 800℃, respectively. The temperature program was set at 5℃ / min, and the calcination time was 2 hours. The thermally regenerated CoSn / BC material was then reused in the tetracycline hydrochloride degradation test. The test procedures and conditions were similar to those for the CoSn / BC cycle performance test in Experiment 3, except that the CoSn / BC used in the test was thermally regenerated.
[0099] Test results are as follows Figure 9 As shown, the catalytic performance of CoSn / BC was restored after thermal regeneration at 800℃, and the removal rate of tetracyclic hydrochloride at 30 min recovered from 47.9% to 92.5%.
Claims
1. A biochar-supported cobalt polysulfide Fenton catalyst, characterized in that: The biochar-supported cobalt polysulfide Fenton catalyst is a biochar cobalt polysulfide composite prepared from lignocellulose biomass, ammonium sulfate, and cobalt sulfate (a double salt of cobalt sulfate). The specific preparation steps are as follows: 1) Wash and soak the biomass three times with deionized water, then dry it for later use; 2) Weigh out the biomass and cobalt ammonium sulfate separately according to a mass ratio of 1:0.25-1. Dissolve the cobalt ammonium sulfate with a concentration of 0.1-0.4 g / ml in 150-250 ml of deionized water to prepare a cobalt ammonium sulfate solution. Then soak the biomass in the prepared cobalt ammonium sulfate solution, using 2.5-10 g of cobalt ammonium sulfate, and stir at a stirring speed of 800-1000 rpm for 3-6 hours to ensure that the biomass and cobalt ammonium sulfate solution are fully mixed and homogeneous. 3) After mixing the biomass with the cobalt ammonium sulfate solution evenly, let it stand for 18-24 hours, and then put it into a drying oven and dry it at 60°C for 36-48 hours to completely remove the solvent and allow the cobalt ammonium sulfate to crystallize on the surface of the biomass. 4) Place the dried cobalt ammonium sulfate and biomass mixture into a box furnace, heat it under nitrogen protection at a temperature of 650-850℃, a heating rate of 5℃ per minute, and calcine for 1-2 hours. After calcination, filter the obtained sample through a 100-mesh sieve to obtain the cobalt polysulfide biochar composite.
2. The biochar-supported cobalt polysulfide Fenton catalyst according to claim 1, characterized in that: The lignocellulose biomass mentioned is one or more of rice straw, wheat straw, sorghum straw, corn cob, corn stalk, sugarcane bagasse, pine wood, eucalyptus wood, cypress wood, and jute.
3. The application of the biochar-supported cobalt polysulfide Fenton catalyst as described in claim 1 in the treatment of antibiotic-contaminated water.