Cobalt-doped biochar as well as preparation method and application thereof
By preparing cobalt-doped biochar CoxBC-T, the problem of insufficient catalytic performance of original biochar was solved, and the effect of efficiently removing tetracycline from water was achieved, especially at a pyrolysis temperature of 900℃.
Patent Information
- Application Number
- CN202411180747.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-27
- Publication Date
- 2026-03-06
AI Technical Summary
In existing technologies, the chemical inertness of the conjugated carbon structure of raw biochar results in insufficient catalytic performance, making it difficult to meet the demand for efficient removal of tetracycline antibiotics from water.
Cobalt-doped biochar CoxBC-T was prepared by impregnation and oxygen-limited pyrolysis using lignin as a biomass precursor. Cobalt doping was used to improve the catalytic activity of the biochar, and tetracycline was treated with PMS as an oxidant.
Cobalt-doped biochar significantly improves catalytic activity, enabling 100% removal of tetracycline within 10 minutes, which is superior to undoped biochar, and the optimal pyrolysis temperature is 900℃.
Smart Images
Figure CN121607149A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of advanced oxidation technology, specifically relating to a cobalt-doped biochar, its preparation method, and its application. Background Technology
[0002] Tetracycline antibiotics pose a serious threat to aquatic ecosystems and human health due to their toxicity, non-biodegradability, and the spread of antibiotic resistance genes in organisms. Therefore, removing antibiotics from aquatic environments has become an urgent task.
[0003] To efficiently remove tetracycline pollutants from the environment, researchers have explored various treatment technologies. Currently, conventional treatment technologies for tetracycline antibiotic wastewater are mainly divided into physical, chemical, and biological methods. Among them, advanced oxidation technologies based on sulfate radicals (SR-AOPs) can effectively degrade and remove organic compounds, chlorides, and antibiotics from water, and have been widely used for the removal of tetracycline antibiotics from water bodies. Many activation methods of advanced oxidation technologies, such as heat, ultrasound, ultraviolet light, electrolysis, and ionizing radiation, all have unavoidable drawbacks, such as high cost, high energy consumption, harsh reaction conditions, and low activation efficiency. In contrast, catalyst activation methods, due to their high efficiency, non-toxicity, and low cost, have great potential and application prospects among advanced oxidation technologies.
[0004] Among numerous catalysts, biochar can effectively activate persulfate (PMS) by accepting, transferring, and contributing electrons to the surrounding environment. Furthermore, compared to traditional carbon materials, biochar has attracted widespread attention due to its abundant porous structure and surface functional groups, its low cost, availability, and wide source. However, the chemical inertness of the conjugated carbon structure of raw biochar often results in its catalytic performance failing to meet practical application requirements. Therefore, many researchers have developed various modification methods to obtain higher-performance biochar. Common modification strategies include metal or metal oxide loading, heteroatom doping, and surface oxygen functionalization. With in-depth research on biochar doping modification, metal-doped biochar has been found to exhibit excellent persulfate activation performance. In particular, cobalt-doped biochar can increase the active sites of the reaction, thus exhibiting high reactivity, and is an effective means to improve the catalytic performance of biochar. Therefore, it is necessary to develop a method for preparing cobalt-doped biochar and further explore its application in water treatment. Summary of the Invention
[0005] To address the shortcomings of existing technologies, this invention provides a cobalt-doped biochar, its preparation method, and its applications. This invention uses lignin as a biomass precursor and cobalt acetate as the cobalt source to prepare cobalt-doped biochar (Co) through impregnation and oxygen-limited pyrolysis. x BC-T. Using PMS as the oxidant and tetracycline as the target pollutant, it provides Co... xThe application of BC-T in water treatment provides the technology for the directional preparation of metal-doped biochar and its application in practical water treatment.
[0006] The technical solution provided by this invention is as follows:
[0007] A method for preparing cobalt-doped biochar includes the following steps: using lignin as a biomass precursor, adding a cobalt source, and preparing cobalt-doped biochar by impregnation and oxygen-limited pyrolysis.
[0008] Based on the above technical solution, cobalt doping can significantly improve the catalytic activity of biochar compared to the original biochar.
[0009] Specifically, oxygen-limited pyrolysis is carried out in a nitrogen atmosphere.
[0010] Specifically, the preparation method of cobalt-doped biochar includes the following steps:
[0011] 1) Dissolve lignin in deionized water and form a black lignin solution by mechanical stirring;
[0012] 2) Add the cobalt source to the lignin solution and stir continuously;
[0013] 3) After static aging, the cobalt complex was obtained by centrifugation and then dried;
[0014] 4) The cobalt complex was heated to 540–550 °C in a tube furnace under a nitrogen atmosphere at a certain heating rate and held for 0.5–1.5 h, then heated to 800–1000 °C and held for 0.5–1.5 h to carry out pyrolysis.
[0015] 5) After cooling to room temperature, the material is washed alternately with deionized water and anhydrous ethanol, and then dried to obtain cobalt-doped biochar, which can be denoted as Co. x BC-T, where x represents the amount of Co source added and T represents the pyrolysis temperature.
[0016] Specifically, in step 1), the concentration of the lignin solution is 0.007–0.009 g / mL.
[0017] Specifically, in step 2):
[0018] The concentration of the cobalt source in the solution is 0–0.048 mmol / mL, and is not zero;
[0019] The cobalt source is cobalt acetate or cobalt nitrate.
[0020] Specifically, in step 3):
[0021] The aging time is 9–11 hours;
[0022] The drying temperature is 70-90℃, and the drying time is 11-13 hours.
[0023] Specifically, in step 4), the heating rate is 4.5–5.5 °C / min.
[0024] Preferably, in step 4), the pyrolysis temperature is 900℃.
[0025] Based on the above technical solutions, the optimal pyrolysis temperature is 900℃, and cobalt-doped biochar has the best removal effect on tetracycline.
[0026] Specifically, in step 5), the drying temperature is 50–70°C.
[0027] Preferably, the method for preparing cobalt-doped biochar specifically includes the following steps:
[0028] 1) Based on the amount of lignin, dissolve 4g of lignin in 500mL of deionized water and form a black lignin solution by mechanical stirring.
[0029] 2) Add 0–24 mmol of cobalt acetate to the lignin solution and stir continuously for 1 hour;
[0030] 3) After standing for 10 hours, the cobalt complex was obtained by centrifugation and dried at 80°C for 12 hours.
[0031] 4) The cobalt composite was heated to 550°C in a tube furnace under nitrogen atmosphere at a heating rate of 5°C / min and held for 1 hour, then heated to 800-1000°C and held for 1 hour.
[0032] 5) After cooling to room temperature, wash the material alternately with deionized water and anhydrous ethanol, and dry it in a 60°C oven for later use.
[0033] The present invention also provides cobalt-doped biochar prepared according to the above preparation method.
[0034] This invention also provides the application of cobalt-doped biochar, using the cobalt-doped biochar as a catalyst and potassium persulfate complex salt (PMS) as an oxidant to catalyze the treatment of tetracycline.
[0035] Specifically:
[0036] The concentration of cobalt-doped biochar was 0.09–0.11 g / L;
[0037] The concentration of potassium persulfate complex salt is 0.90–1.10 mmol / L;
[0038] The tetracycline concentration is 9.00–11.00 mg / L;
[0039] pH is 4.5–5.5;
[0040] The temperature is 25±1℃.
[0041] Preferred:
[0042] Co x The BC-T concentration was 0.10 g / L;
[0043] The PMS concentration was 1.00 mmol / L;
[0044] The tetracycline concentration was 10.00 mg / L; the pH was 5.
[0045] The temperature is 25±1℃.
[0046] The advantages and beneficial effects of this invention include:
[0047] 1. The prepared series of CoxBC-T showed good catalytic ability to degrade tetracycline by PMS in water treatment, with a removal rate of up to 100% within 10 min.
[0048] 2. Compared with the prepared original biochar, cobalt doping can significantly improve the catalytic activity of biochar.
[0049] 3. By comparing the application effects of CoxBC-T in water treatment, the optimal pyrolysis temperature was determined to be 900℃. Attached Figure Description
[0050] Figure 1 The graph shows the removal rate of tetracycline by CoxBC-800 prepared in this invention at 10 min.
[0051] Figure 2 The graph shows the removal rate of tetracycline by CoxBC-900 prepared in this invention at 10 min.
[0052] Figure 3 The graph shows the removal rate of tetracycline by CoxBC-1000 prepared in this invention at 10 min.
[0053] Figure 4 The graph shows the removal rate of tetracycline by the original biochar and cobalt-doped biochar with the best catalytic performance at different pyrolysis temperatures prepared in this invention at 10 min. Detailed Implementation
[0054] The principles and features of the present invention are described below. The embodiments given are for illustrative purposes only and are not intended to limit the scope of the invention. The specific embodiments described herein are for illustrative purposes only and to illustrate the principles of the examples. They are not intended to represent the only form of the present invention, nor do they imply any limitation.
[0055] Unless otherwise specified, the test methods used in the embodiments of the invention are conventional methods; unless otherwise specified, the materials and reagents used are commercially available.
[0056] Example 1:
[0057] A method for preparing cobalt-doped biochar:
[0058] The lignin was heated to 550°C in a tube furnace under nitrogen atmosphere at a heating rate of 5°C / min and held for 1 hour, then heated to 800°C and held for 1 hour.
[0059] After cooling to room temperature, the material was washed alternately with deionized water and anhydrous ethanol, and then dried in a 60°C oven for later use.
[0060] Example 2:
[0061] A method for preparing cobalt-doped biochar:
[0062] The lignin was heated to 550°C in a tube furnace under nitrogen atmosphere at a heating rate of 5°C / min and held for 1 hour, then heated to 900°C and held for 1 hour.
[0063] After cooling to room temperature, the material is washed alternately with deionized water and anhydrous ethanol, and then dried in a 60°C oven for later use.
[0064] Example 3:
[0065] A method for preparing cobalt-doped biochar:
[0066] Lignin was heated to 550°C in a tube furnace under nitrogen atmosphere at a heating rate of 5°C / min and held for 1 hour, then heated to 1000°C and held for 1 hour.
[0067] After cooling to room temperature, the material was washed alternately with deionized water and anhydrous ethanol, and then dried in a 60°C oven for later use.
[0068] Example 4:
[0069] A method for preparing cobalt-doped biochar:
[0070] Dissolve 4g of lignin in 500mL of deionized water and form a black lignin solution by mechanical stirring;
[0071] Add 8 mmol of cobalt acetate to the lignin solution and stir continuously for 1 hour;
[0072] After standing for 10 hours, the cobalt complex was obtained by centrifugation and dried at 80°C for 12 hours.
[0073] The cobalt composite was heated to 550°C in a tube furnace under nitrogen atmosphere at a heating rate of 5°C / min and held for 1 h, then heated to 800°C and held for 1 h.
[0074] After cooling to room temperature, the material was washed alternately with deionized water and anhydrous ethanol, and then dried in a 60°C oven for later use.
[0075] Example 5:
[0076] A method for preparing cobalt-doped biochar:
[0077] Dissolve 4g of lignin in 500mL of deionized water and form a black lignin solution by mechanical stirring;
[0078] Add 16 mmol of cobalt acetate to the lignin solution and stir continuously for 1 hour;
[0079] After standing for 10 hours, the cobalt complex was obtained by centrifugation and dried at 80°C for 12 hours.
[0080] The cobalt composite was heated to 550°C in a tube furnace under nitrogen atmosphere at a heating rate of 5°C / min and held for 1 h, then heated to 800°C and held for 1 h.
[0081] After cooling to room temperature, the material was washed alternately with deionized water and anhydrous ethanol, and then dried in a 60°C oven for later use.
[0082] Example 6:
[0083] A method for preparing cobalt-doped biochar:
[0084] Dissolve 4g of lignin in 500mL of deionized water and form a black lignin solution by mechanical stirring;
[0085] Add 24 mmol of cobalt acetate to the lignin solution and stir continuously for 1 hour;
[0086] After standing for 10 hours, the cobalt complex was obtained by centrifugation and dried at 80°C for 12 hours.
[0087] The cobalt composite was heated to 550°C in a tube furnace under nitrogen atmosphere at a heating rate of 5°C / min and held for 1 h, then heated to 800°C and held for 1 h.
[0088] After cooling to room temperature, the material was washed alternately with deionized water and anhydrous ethanol, and then dried in a 60°C oven for later use.
[0089] Example 7:
[0090] A method for preparing cobalt-doped biochar:
[0091] Dissolve 4g of lignin in 500mL of deionized water and form a black lignin solution by mechanical stirring;
[0092] Add 8 mmol of cobalt acetate to the lignin solution and stir continuously for 1 hour;
[0093] After standing for 10 hours, the cobalt complex was obtained by centrifugation and dried at 80°C for 12 hours.
[0094] The cobalt composite was heated to 550°C in a tube furnace under nitrogen atmosphere at a heating rate of 5°C / min and held for 1 h, then heated to 900°C and held for 1 h.
[0095] After cooling to room temperature, the material was washed alternately with deionized water and anhydrous ethanol, and then dried in a 60°C oven for later use.
[0096] Example 8:
[0097] A method for preparing cobalt-doped biochar:
[0098] Dissolve 4g of lignin in 500mL of deionized water and form a black lignin solution by mechanical stirring;
[0099] Add 16 mmol of cobalt acetate to the lignin solution and stir continuously for 1 hour;
[0100] After standing for 10 hours, the cobalt complex was obtained by centrifugation and dried at 80°C for 12 hours.
[0101] The cobalt composite was heated to 550°C in a tube furnace under nitrogen atmosphere at a heating rate of 5°C / min and held for 1 h, then heated to 900°C and held for 1 h.
[0102] After cooling to room temperature, the material was washed alternately with deionized water and anhydrous ethanol, and then dried in a 60°C oven for later use.
[0103] Example 9:
[0104] A method for preparing cobalt-doped biochar:
[0105] Dissolve 4g of lignin in 500mL of deionized water and form a black lignin solution by mechanical stirring;
[0106] Add 24 mmol of cobalt acetate to the lignin solution and stir continuously for 1 hour;
[0107] After standing for 10 hours, the cobalt complex was obtained by centrifugation and dried at 80°C for 12 hours.
[0108] The cobalt composite was heated to 550°C in a tube furnace under nitrogen atmosphere at a heating rate of 5°C / min and held for 1 h, then heated to 900°C and held for 1 h.
[0109] After cooling to room temperature, the material was washed alternately with deionized water and anhydrous ethanol, and then dried in a 60°C oven for later use.
[0110] Example 10:
[0111] A method for preparing cobalt-doped biochar:
[0112] Dissolve 4g of lignin in 500mL of deionized water and form a black lignin solution by mechanical stirring;
[0113] Add 8 mmol of cobalt acetate to the lignin solution and stir continuously for 1 hour;
[0114] After standing for 10 hours, the cobalt complex was obtained by centrifugation and dried at 80°C for 12 hours.
[0115] The cobalt composite was heated to 550°C in a tube furnace under nitrogen atmosphere at a heating rate of 5°C / min and held for 1 h, then heated to 1000°C and held for 1 h.
[0116] After cooling to room temperature, the material was washed alternately with deionized water and anhydrous ethanol, and then dried in a 60°C oven for later use.
[0117] Example 11:
[0118] A method for preparing cobalt-doped biochar:
[0119] Dissolve 4g of lignin in 500mL of deionized water and form a black lignin solution by mechanical stirring;
[0120] Add 16 mmol of cobalt acetate to the lignin solution and stir continuously for 1 hour;
[0121] After standing for 10 hours, the cobalt complex was obtained by centrifugation and dried at 80°C for 12 hours.
[0122] The cobalt composite was heated to 550°C in a tube furnace under nitrogen atmosphere at a heating rate of 5°C / min and held for 1 h, then heated to 1000°C and held for 1 h.
[0123] After cooling to room temperature, the material was washed alternately with deionized water and anhydrous ethanol, and then dried in a 60°C oven for later use.
[0124] Example 12:
[0125] A method for preparing cobalt-doped biochar:
[0126] Dissolve 4g of lignin in 500mL of deionized water and form a black lignin solution by mechanical stirring;
[0127] Add 24 mmol of cobalt acetate to the lignin solution and stir continuously for 1 hour;
[0128] After standing for 10 hours, the cobalt complex was obtained by centrifugation and dried at 80°C for 12 hours.
[0129] The cobalt composite was heated to 550°C in a tube furnace under nitrogen atmosphere at a heating rate of 5°C / min and held for 1 h, then heated to 1000°C and held for 1 h.
[0130] After cooling to room temperature, the material was washed alternately with deionized water and anhydrous ethanol, and then dried in a 60°C oven for later use.
[0131] Example 13:
[0132] An application of cobalt-doped biochar in water treatment:
[0133] Using PMS as the oxidant and tetracycline as the target pollutant, the study investigated the effects of PMS on Co. x The application of BC-T in water treatment is being implemented.
[0134] Example 14:
[0135] An application of cobalt-doped biochar in water treatment:
[0136] The experimental conditions for the degradation reaction are as follows: Co x The concentrations of BC-T and PMS were 0.10 g / L, 1.00 mmol / L, 10.00 mg / L, pH 5, and temperature 25 ± 1 °C.
[0137] Co x BC-T is Co8BC-800 from Example 4.
[0138] Example 15:
[0139] An application of cobalt-doped biochar in water treatment:
[0140] The experimental conditions for the degradation reaction are as follows: Co x The concentrations of BC-T and PMS were 0.10 g / L, 1.00 mmol / L, 10.00 mg / L, pH 5, and temperature 25 ± 1 °C.
[0141] Co x BC-T is Co from Example 5 16 BC-800.
[0142] Example 16:
[0143] An application of cobalt-doped biochar in water treatment:
[0144] The experimental conditions for the degradation reaction are as follows: Co x The concentrations of BC-T and PMS were 0.10 g / L, 1.00 mmol / L, 10.00 mg / L, pH 5, and temperature 25 ± 1 °C.
[0145] Co x BC-T is Co from Example 6 24 BC-800.
[0146] Example 17:
[0147] An application of cobalt-doped biochar in water treatment:
[0148] The experimental conditions for the degradation reaction are as follows: Co x The concentrations of BC-T and PMS were 0.10 g / L, 1.00 mmol / L, 10.00 mg / L, pH 5, and temperature 25 ± 1 °C.
[0149] Co x BC-T is Co8BC-900 from Example 7.
[0150] Example 18:
[0151] An application of cobalt-doped biochar in water treatment:
[0152] The experimental conditions for the degradation reaction are as follows: Co x The concentrations of BC-T and PMS were 0.10 g / L, 1.00 mmol / L, 10.00 mg / L, pH 5, and temperature 25 ± 1 °C.
[0153] Co x BC-T is Co from Example 8 16 BC-900.
[0154] Example 19:
[0155] An application of cobalt-doped biochar in water treatment:
[0156] The experimental conditions for the degradation reaction are as follows: Co x The concentrations of BC-T and PMS were 0.10 g / L, 1.00 mmol / L, 10.00 mg / L, pH 5, and temperature 25 ± 1 °C.
[0157] Co x BC-T is Co from Example 9 24BC-900.
[0158] Example 20:
[0159] An application of cobalt-doped biochar in water treatment:
[0160] The experimental conditions for the degradation reaction are as follows: Co x The concentrations of BC-T and PMS were 0.10 g / L, 1.00 mmol / L, 10.00 mg / L, pH 5, and temperature 25 ± 1 °C.
[0161] Co x BC-T is Co8BC-1000 from Example 10.
[0162] Example 21:
[0163] An application of cobalt-doped biochar in water treatment:
[0164] The experimental conditions for the degradation reaction are as follows: Co x The concentrations of BC-T and PMS were 0.10 g / L, 1.00 mmol / L, 10.00 mg / L, pH 5, and temperature 25 ± 1 °C.
[0165] Co x BC-T is Co from Example 11 16 BC-1000.
[0166] Example 22:
[0167] An application of cobalt-doped biochar in water treatment:
[0168] The experimental conditions for the degradation reaction are as follows: Co x The concentrations of BC-T and PMS were 0.10 g / L, 1.00 mmol / L, 10.00 mg / L, pH 5, and temperature 25 ± 1 °C.
[0169] Co x BC-T is Co from Example 12 24 BC-1000.
[0170] Comparative Example 1
[0171] Applications of biochar in water treatment:
[0172] The experimental conditions for the degradation reaction were as follows: BC-T concentration 0.10 g / L, PMS concentration 1.00 mmol / L, tetracycline concentration 10.00 mg / L, pH 5, and temperature 25 ± 1℃.
[0173] BC-T is BC-800 of Example 1.
[0174] Comparative Example 2
[0175] Applications of biochar in water treatment:
[0176] The experimental conditions for the degradation reaction were as follows: BC-T concentration of 0.10 g / L, PMS concentration of 1.00 mmol / L, tetracycline concentration of 10.00 mg / L, pH of 5, and temperature of 25 ± 1℃.
[0177] BC-T is BC-900 of Example 2.
[0178] Comparative Example 3
[0179] Applications of biochar in water treatment:
[0180] The experimental conditions for the degradation reaction were as follows: BC-T concentration of 0.10 g / L, PMS concentration of 1.00 mmol / L, tetracycline concentration of 10.00 mg / L, pH of 5, and temperature of 25 ± 1℃.
[0181] BC-T is BC-1000 of Example 3.
[0182] The obtained Co was tested according to the relevant tests shown in the attached figures. x BC-T draws the following conclusion: From Figures 1-3 A series of Co-related defects were observed in the tetracycline removal rate of the prepared product. x BC-T exhibits excellent catalytic ability to degrade tetracycline using PMS in water treatment applications, with a removal rate of up to 100% within 10 minutes. Compared to the prepared original biochar, cobalt doping can significantly improve the catalytic activity of the biochar. Figure 4 Comparison of Co x The application effect of BC-T in water treatment determined that the optimal pyrolysis temperature was 900℃.
[0183] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method of preparing cobalt-doped biochar, the method comprising: providing a biochar; and contacting the biochar with a cobalt source. The method comprises the following steps: The cobalt-doped biochar is prepared by adding a cobalt source to lignin as a biomass precursor through impregnation and limited oxygen pyrolysis.
2. The method of claim 1, wherein the cobalt-doped biochar is prepared by, The method comprises the following steps: 1) Dissolving lignin in deionized water to form a black lignin solution through mechanical stirring; 2) Adding a cobalt source to the lignin solution and continuously stirring; 3) After aging and standing, centrifugal separation is performed to obtain a cobalt complex, which is then dried; 4) The cobalt complex is heated to 540-550 DEG C at a certain heating rate in a nitrogen atmosphere tube furnace and kept for 0.5-1.5 h, then heated to 800-1000 DEG C and kept for 0.5-1.5 h to perform pyrolysis; 5) After cooling to room temperature, the material is washed with deionized water and anhydrous ethanol alternately, and then dried to obtain the cobalt-doped biochar.
3. The method of claim 2, wherein the cobalt-doped biochar is prepared by, In step 1), the concentration of the lignin solution is 0.007-0.009 g / mL.
4. The method of claim 2, wherein the cobalt-doped biochar is prepared by, In step 2), the concentration of the cobalt source in the solution is 0-0.048 mmol / mL; and the cobalt source is cobalt acetate or cobalt nitrate. In step 3), the aging time is 9-11 h; and the drying temperature is 70-90 DEG C and the drying time is 11-13 h. In step 4), the heating rate is 4.5-5.5 DEG C / min.
5. The method of claim 2, wherein the cobalt-doped biochar is prepared by, In step 4), the pyrolysis temperature is 900 DEG C.
8. The cobalt-doped biochar prepared by the preparation method according to any one of claims 1-7. The cobalt-doped biochar is used as a catalyst to catalytically treat tetracycline with a peroxymonosulfate composite salt as an oxidant.
6. The method of claim 2 to 5, wherein the cobalt-doped biochar is prepared by the method comprising the steps of:
10. The cobalt-doped biochar according to claim 9, characterized in that:
7. The method of claim 2 to 5, wherein the cobalt-doped biochar is prepared by, The concentration of the cobalt-doped biochar is 0.09-0.11 g / L; the concentration of the peroxymonosulfate composite salt is 0.90-1.10 mmol / L; the concentration of tetracycline is 9.00-11.00 mg / L; the pH is 4.5-5.5; and the temperature is 25±1 DEG C. 9. Use of the cobalt-doped biochar according to claim 8, characterized in that: