Co modified biochar material as well as preparation method and application thereof
Through the preparation of cobalt modified biochar material, the sulfite is activated using its high surface area and active sites to achieve efficient degradation of tetracycline, solving the problem of insufficient degradation efficiency and stability of existing catalysts in tetracycline, reaching 92% Removal rate.
Patent Information
- Application Number
- CN202411516467.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-29
- Publication Date
- 2024-12-10
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
The degradation efficiency of existing catalysts in tetracycline in wastewater is not high, and the reactivity and stability are insufficient, which hinders its large-scale application.
Co-modified biochar material with high surface area and abundant active sites was prepared by mixing, drying and pyrolyzing with cobalt salt solution for activation of sulfite degradation tetracycline.
The tetracycline removal rate reached more than 92% within five minutes, providing a low-cost, high-activity and stability catalyst, solving the problem of insufficient tetracycline degradation efficiency and stability of existing catalysts.
Smart Images
Figure CN119098172A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of multifunctional water treatment and purification materials, and in particular to a Co-modified biochar material and a preparation method and application thereof. Background Art
[0002] Antibiotics are difficult to metabolize in humans and animals, and the excrement and urine contain active chemicals that can enter sewage treatment plants with wastewater. Studies have found that the concentrations of antibiotics in the inlet and outlet water of my country's sewage treatment plants are tens of nanograms to tens of micrograms per liter, and it is difficult to completely remove antibiotics with conventional sewage treatment processes. Residual antibiotics enter natural water bodies and accumulate in the water environment, resulting in tetracycline, ciprofloxacin, norfloxacin, ofloxacin and clarithromycin being frequently detected in rivers, with concentrations as high as several micrograms per liter. The concentration of tetracycline in wastewater discharged from aquaculture and livestock and poultry farming, agricultural production, medical treatment and industry ranges from hundreds of ng / L to μg / L. Among the many methods for tetracycline degradation, sulfite advanced oxidation has the advantages of being green, efficient, environmentally friendly and simple to operate, and has attracted widespread attention.
[0003] It is particularly important to develop sulfite catalysts with high activity and specificity. At present, there are few studies on the activation of sulfite by heterogeneous catalysts such as metal oxides and metal-loaded carbon materials. There is no significant effect on the degradation of tetracycline by sulfite activation using biochar materials as catalysts. However, transition metal ions (such as Co(II), Fe(III), Mn(II) and Cr(VI)) have a better effect on sulfite activation, but the toxicity of transition metal ions and the potential cost of secondary treatment hinder their large-scale application. In view of this, it is necessary to develop a cobalt-modified biochar heterogeneous catalyst with good reaction activity and stability, easy separation, and low metal leaching rate to activate sulfite. Summary of the invention
[0004] The object of the present invention is to provide a Co-modified biochar material and a preparation method and application thereof, so as to solve the technical problems that the degradation efficiency of existing catalysts for tetracycline in sewage is low and the stability of catalyst reaction activity is low.
[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:
[0006] The present invention provides a method for preparing a Co-modified biochar material, comprising the following steps:
[0007] 1) mixing biochar with a cobalt salt solution and then drying to obtain a precipitate;
[0008] 2) pyrolyzing the precipitate to obtain a Co-modified biochar material;
[0009] The temperature of the pyrolysis treatment is 500-800°C.
[0010] Furthermore, the molar concentration of the cobalt salt solution is 20-25 mM, and the cobalt salt in the cobalt salt solution comprises cobalt chloride.
[0011] Furthermore, the mass volume ratio of the biochar and the cobalt salt solution is 1-3 g: 50-150 mL.
[0012] Furthermore, the mixing is carried out under stirring, and the stirring time is 20 to 26 hours.
[0013] Furthermore, the drying temperature is 100-110° C., and the drying time is 10-14 hours.
[0014] Furthermore, the pyrolysis time is 1 to 3 hours.
[0015] The invention provides a Co-modified biochar material.
[0016] The present invention also provides an application of a Co-modified biochar material in activating sulfite to degrade tetracycline.
[0017] Beneficial effects of the present invention:
[0018] (1) The Co-modified biochar material obtained by the present invention has a large specific surface area and abundant active sites.
[0019] (2) The cobalt-modified biochar materials prepared by the present invention at different temperatures can activate sulfite to produce active oxidative species with different compositions (such as 1 O2, · OH and SO4 ·- ).
[0020] (3) The Co-modified biochar material activated sulfite, and the removal rate of tetracycline reached over 92% in 5 min. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 This is the XRD pattern of the Co-modified biochar material prepared in the embodiment of the present invention;
[0022] Figure 2 This is an XPS graph of the Co-modified biochar material prepared in an embodiment of the present invention;
[0023] Figure 3 This is a graph showing the degradation performance of tetracycline by Co-modified biochar materials at different pyrolysis temperatures. DETAILED DESCRIPTION
[0024] The present invention provides a method for preparing a Co-modified biochar material, comprising the following steps:
[0025] 1) mixing biochar with a cobalt salt solution and then drying to obtain a precipitate;
[0026] 2) pyrolyzing the precipitate to obtain a Co-modified biochar material;
[0027] The temperature of the pyrolysis treatment is 500-800°C.
[0028] In the present invention, the temperature of the pyrolysis treatment is preferably 600-700°C.
[0029] In the present invention, the molar concentration of the cobalt salt solution is 20-25 mM, preferably 21-24 mM, and more preferably 22-23 mM; the cobalt salt in the cobalt salt solution is preferably cobalt chloride.
[0030] In the present invention, the mass volume ratio of the biochar to the cobalt salt solution is 1-3 g:50-150 mL, preferably 2 g:100 mL.
[0031] In the present invention, the mixing is performed under stirring, and the stirring time is 20 to 26 hours, preferably 24 hours.
[0032] In the present invention, the drying temperature is 100-110° C., preferably 105° C.; the drying time is 10-14 h, preferably 12 h.
[0033] In the present invention, the pyrolysis time is 1 to 3 hours, preferably 2 hours.
[0034] The invention provides a Co-modified biochar material.
[0035] The present invention also provides an application of a Co-modified biochar material in activating sulfite to degrade tetracycline.
[0036] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.
[0037] Example 1
[0038] Preparation of Co-modified biochar material: 0.5948 g of cobalt chloride hexahydrate (CoCl2·6H2O) was dissolved in a beaker containing 100 mL of deionized water to obtain a cobalt chloride solution with a concentration of 25 mM. 2 g of biochar was added to the cobalt chloride solution and stirred on a magnetic stirrer for 24 hours. After stirring, it was transferred to an oven and maintained at 105°C for 12 hours to be fully dried to remove the moisture. The dried precipitate was placed in a tubular furnace for pyrolysis (pyrolysis temperature of 500°C, pyrolysis time of 2 hours, heating rate = 10°C / min), and the modified biochar powder was prepared after the tubular furnace was naturally cooled to room temperature. Co-BC500 was obtained.
[0039] Co modified biochar material activated sulfite to degrade tetracycline: At 25±1℃, 100mL 1 mg / L TC solution was added to a 250mL conical flask, and then 0.01g modified biochar powder was added. After ultrasonic dispersion of the modified biochar, the sample was taken after stirring for 30min to reach adsorption equilibrium at a speed of 300r / min and a reaction temperature of 25℃. The sample was filtered through a 0.22μm polyethersulfone filter membrane and a certain volume of 0.1M hydroxylamine was added and then placed in a liquid phase vial. After adsorption equilibrium, 1mL of 10mM S(IV) solution was added, and stirring was continued under the same conditions. Samples were taken at 1, 2, 3, 4, and 5min, respectively, and passed through a 0.22μm polyethersulfone filter membrane. A certain volume of 0.1M hydroxylamine was added to terminate the reaction and then placed in a liquid phase vial for testing.
[0040] Example 2
[0041] Preparation of Co-modified biochar material: 0.5948 g of cobalt chloride hexahydrate (CoCl2·6H2O) was dissolved in a beaker containing 100 mL of deionized water to obtain a cobalt chloride solution with a concentration of 25 mM. 2 g of biochar was added to the cobalt chloride solution and stirred on a magnetic stirrer for 24 hours. After stirring, it was transferred to an oven and maintained at 105°C for 12 hours to be fully dried to remove the moisture. The dried precipitate was placed in a tubular furnace for pyrolysis (pyrolysis temperature of 600°C, pyrolysis time of 2 hours, heating rate = 10°C / min), and the modified biochar powder was prepared after the tubular furnace was naturally cooled to room temperature. Co-BC600 was obtained.
[0042] Co modified biochar material activated sulfite to degrade tetracycline: At 25±1℃, 100mL of 1 mg / L TC solution was added to a 250mL conical flask, and then 0.02g of modified biochar powder was added. After ultrasonic dispersion of the modified biochar, the sample was sampled after stirring for 30min to reach adsorption equilibrium at a speed of 300r / min and a reaction temperature of 25℃. The sample was filtered through a 0.22μm polyethersulfone filter membrane and a certain volume of 0.1M hydroxylamine was added and then placed in a liquid phase vial. After adsorption equilibrium, 1mL of 50mM S(IV) solution was added, and stirring was continued under the same conditions. Samples were taken at 1, 2, 3, 4, and 5min, respectively, and passed through a 0.22μm polyethersulfone filter membrane. A certain volume of 0.1M hydroxylamine was added to terminate the reaction and then placed in a liquid phase vial for testing.
[0043] Example 3
[0044] Preparation of Co-modified biochar material: 0.5948 g of cobalt chloride hexahydrate (CoCl2·6H2O) was dissolved in a beaker containing 100 mL of deionized water to obtain a cobalt chloride solution with a concentration of 25 mM. 2 g of biochar was added to the cobalt chloride solution and stirred on a magnetic stirrer for 24 hours. After stirring, it was transferred to an oven and maintained at 105°C for 12 hours to be fully dried to remove the moisture. The dried precipitate was placed in a tubular furnace for pyrolysis (pyrolysis temperature of 700°C, pyrolysis time of 2 hours, heating rate = 10°C / min), and the modified biochar powder was prepared after the tubular furnace was naturally cooled to room temperature. Co-BC700 was obtained.
[0045] Co modified biochar material activated sulfite to degrade tetracycline: At 25±1℃, 100mL of 1 mg / L TC solution was added to a 250mL conical flask, and then 0.01g of modified biochar powder was added. After ultrasonic dispersion of the modified biochar, the sample was taken after stirring for 30min to reach adsorption equilibrium at a speed of 300r / min and a reaction temperature of 25℃. The sample was filtered through a 0.22μm polyethersulfone filter membrane and a certain volume of 0.1M hydroxylamine was added and then placed in a liquid phase vial. After adsorption equilibrium, 1mL of 100mM S(IV) solution was added, and stirring was continued under the same conditions. Samples were taken at 1, 2, 3, 4, and 5min, respectively, and passed through a 0.22μm polyethersulfone filter membrane. A certain volume of 0.1M hydroxylamine was added to terminate the reaction and then placed in a liquid phase vial for testing.
[0046] Example 4
[0047] Preparation of Co-modified biochar material: 0.5948 g of cobalt chloride hexahydrate (CoCl2·6H2O) was dissolved in a beaker containing 100 mL of deionized water to obtain a cobalt chloride solution with a concentration of 25 mM. 2 g of biochar was added to the cobalt chloride solution and stirred on a magnetic stirrer for 24 hours. After stirring, it was transferred to an oven and maintained at 105°C for 12 hours to be fully dried to remove the moisture. The dried precipitate was placed in a tubular furnace for pyrolysis (pyrolysis temperature of 800°C, pyrolysis time of 2 hours, heating rate = 10°C / min), and the modified biochar powder was prepared after the tubular furnace was naturally cooled to room temperature. Co-BC800 was obtained.
[0048] Co modified biochar material activated sulfite to degrade tetracycline: At 25±1℃, 100mL of 1 mg / L TC solution was added to a 250mL conical flask, and then 0.02g of modified biochar powder was added. After ultrasonic dispersion of the modified biochar, the sample was sampled after stirring for 30min to reach adsorption equilibrium at a speed of 300r / min and a reaction temperature of 25℃. The sample was filtered through a 0.22μm polyethersulfone filter membrane and a certain volume of 0.1M hydroxylamine was added and then placed in a liquid phase vial. After adsorption equilibrium, 1mL of 100mM S(IV) solution was added, and stirring was continued under the same conditions. Samples were taken at 1, 2, 3, 4, and 5min, respectively, and passed through a 0.22μm polyethersulfone filter membrane. A certain volume of 0.1M hydroxylamine was added to terminate the reaction and then placed in a liquid phase vial for testing.
[0049] Figure 1 The XRD patterns of biochar BC, Co-BC500, Co-BC600, Co-BC700, and Co-BC800 show that BC has a diffraction peak at 20°-30°, which can be attributed to amorphous carbon. According to the standard card JCPDS (46-1045), 2θ=26.6° corresponds to crystalline SiO2, which further shows that SiO2 has the highest content in biochar. The characteristic peaks at 44.28°, 51.33°, and 75.85° in the XRD pattern of Co-BC correspond to the (111), (200), and (220) crystal planes of Co, respectively (PDF#15-0806), which shows that the metal Co on the surface of biochar is mainly in the form of Co 0 It can be seen from the figure that with the increase of the pyrolysis temperature of the modified biochar, the characteristic peak of cobalt element begins to appear and the intensity gradually increases, which further proves that Co in the composite material 0 existence.
[0050] Figure 2The XPS spectra of Co-BC500, Co-BC600, Co-BC700 and Co-BC800 show obvious characteristic peaks of Co 2p, O1s, C 1s and Si 2p (Fig. Figure 2 As shown). The Co contents of Co-BC500, Co-BC600, Co-BC700, and Co-BC800 are 2.49%, 1.01%, 0.90%, and 0.84%, respectively. The higher the Co content of the catalyst material, the higher the intensity of the Co 2p characteristic peak. In addition, the full spectra of the four catalyst materials Co-BC500, Co-BC600, Co-BC700, and Co-BC800 show characteristic peaks of C1s, O1s, Si 2p, and Co 2p, indicating that the catalyst material contains three elements: C, O, and Co.
[0051] Figure 3 The comparison chart of the degradation performance of Co-modified biochar materials on tetracycline at different pyrolysis temperatures is shown in Figure 2. Figure 3 As shown in the figure, for a TC solution with an initial concentration of 1 mg / L, when only 0.1 g / L Co-BC was added, 27.3% of TC was removed within 35 minutes; when only 1 mL of 50 mM S(IV) was added, the TC removal rate within 35 minutes was 21.07%. It can be seen that the removal effect of TC by adding Co-BC alone and S(IV) alone is very limited. However, when 0.1 g / L Co-BC500 and Co-BC600 were added respectively, the TC removal rate within 5 minutes only reached 39.8% and 59.6%, and when 0.1 g / L Co-BC700 was added, the removal rate reached 92%.
[0052] It can be seen from the above embodiments that the present invention provides a Co-modified biochar material and a preparation method and application thereof. The present invention provides a low-cost, highly active and stable catalyst material for activating sulfite to degrade tetracycline. Biochar is used as a raw material and is modified by metal impregnation. By simultaneously regulating the preparation temperature and impregnation concentration, the surface properties and structure of the biochar material are changed, the active sites of the biochar material are regulated, and an efficient sulfite system is constructed to promote efficient activation of sulfite, thereby improving the removal rate of tetracycline. The Co-modified biochar material of the present invention activates sulfite, and the tetracycline removal rate reaches more than 92% in 5 minutes.
[0053] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.
Claims
1. A method for preparing a Co-modified biochar material, characterized in that: The following steps are involved: 1) mixing biochar with a cobalt salt solution and then drying to obtain a precipitate; 2) pyrolyzing the precipitate to obtain a Co-modified biochar material; The temperature of the pyrolysis treatment is 500-800°C.
2. The preparation method according to claim 1, characterized in that: The molar concentration of the cobalt salt solution is 20-25 mM, and the cobalt salt in the cobalt salt solution comprises cobalt chloride.
3. The preparation method according to claim 1 or 2, characterized in that: The mass volume ratio of the biochar and the cobalt salt solution is 1-3 g: 50-150 mL.
4. The preparation method according to claim 1, characterized in that: The mixing is carried out under stirring, and the stirring time is 20 to 26 hours.
5. The preparation method according to claim 3, characterized in that: The drying temperature is 100-110° C., and the drying time is 10-14 hours.
6. The preparation method according to claim 1, 2, 4 or 5, characterized in that: The pyrolysis time is 1 to 3 hours.
7. The Co-modified biochar material prepared by the preparation method according to any one of claims 1 to 6.
8. Use of the Co-modified biochar material according to claim 7 in activating sulfite to degrade tetracycline.