Bismuth phosphate as well as preparation method and application thereof
By combining bismuth-containing compounds with phosphate ions in phosphorus-containing wastewater, bismuth phosphate with a hollow nanotube-shaped structure is formed, which solves the problem of difficulty in efficiently removing and recovering phosphorus in phosphorus-containing wastewater in the prior art, and achieves efficient removal and degradation of organic pollutants. The process is simple and cost-effective.
Patent Information
- Application Number
- CN202510148989.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-11
- Publication Date
- 2025-04-25
AI Technical Summary
The prior art is difficult to efficiently remove phosphorus in phosphorus-containing wastewater and realize the recycling and value-added utilization of phosphorus. The traditional methods are cumbersome and costly.
By dispersing the bismuth-containing compound in the phosphorus-containing wastewater, bismuth ions and phosphate ions form bismuth phosphate in situ, using the high specific surface area and photocatalytic activity of the hollow nanotube-shaped structure therein, efficient removal of phosphorus and degradation of organic pollutants are achieved.
It realizes efficient removal and recycling of phosphorus in phosphorus-containing wastewater, degradation of organic pollutants, simple process, low cost, and no cumbersome desorption process is required.
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Figure CN119873773A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the fields of environmental protection and resource recycling, and in particular to bismuth phosphate and a preparation method and application thereof. Background Art
[0002] Phosphorus is not only an essential element for all living organisms, but also a valuable non-renewable mineral resource. The annual global output of ore remains at 200 million tons, equivalent to 21 million tons of phosphorus. However, due to human production activities, about 8.93 million tons of phosphorus are discharged into natural water bodies every year. Excessive phosphorus content in water bodies is the main cause of eutrophication. Recent studies have shown that nearly 93% of lakes in the world are affected by eutrophication to some extent. Therefore, the removal and recovery of phosphorus in wastewater is conducive to alleviating environmental pollution problems and promoting the sustainable utilization of phosphorus resources. However, the process of recovering phosphorus using traditional methods is relatively cumbersome, and it is difficult to achieve the recovery and value-added utilization of phosphorus. Therefore, there is an urgent need for a method for efficient phosphorus removal and recovery and value-added utilization of phosphorus. Summary of the invention
[0003] In view of this, in order to at least partially solve at least one of the above-mentioned technical problems, the present disclosure provides bismuth phosphate and a preparation method and application thereof.
[0004] According to one aspect of the present disclosure, a method for preparing bismuth phosphate is provided, comprising: dispersing a bismuth-containing compound in phosphorus-containing wastewater so that bismuth ions in the bismuth-containing compound and phosphate ions in the phosphorus-containing wastewater form a mixed solution containing bismuth phosphate in situ; and separating bismuth phosphate from the mixed solution; wherein the bismuth phosphate has a hollow nanotubular structure.
[0005] According to another aspect of the present disclosure, bismuth phosphate is provided.
[0006] According to yet another aspect of the present disclosure, there is provided a use of bismuth phosphate in degrading organic pollutants.
[0007] According to the embodiments of the present disclosure, since the bismuth ions in the bismuth-containing compound can be combined with the phosphate ions in the phosphorus-containing wastewater, the bismuth-containing compound can be used as an adsorbent to adsorb the phosphate in the phosphorus-containing wastewater, so that the concentration of phosphorus in the phosphorus-containing wastewater is lower than 0.5 ppm, thereby achieving efficient removal of phosphorus in the phosphorus-containing wastewater. In addition, since the bismuth ions and phosphate ions can form bismuth phosphate with a hollow nanotubular structure in situ, and the hollow nanotubular structure has a large specific surface area, it can expose more active sites, and has a high utilization rate of light. There is no need to perform cumbersome, time-consuming, and energy-consuming desorption of the adsorbed phosphorus. It has redox ability under light conditions and can efficiently degrade organic pollutants in water, thereby realizing the recovery and reuse of phosphorus in phosphorus-containing wastewater. In addition, the above method is used to prepare bismuth phosphate, and the process is relatively simple and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:
[0009] Figure 1 is a morphology diagram of Bi2(NO3)O2(OH) of Example 1 of the present disclosure;
[0010] Figure 2 is a graph showing the relationship between the amount of Bi2(NO3)O2(OH) added and the phosphorus concentration in Example 1 of the present disclosure;
[0011] Figure 3 is a morphology diagram of bismuth phosphate of Example 1 of the present disclosure;
[0012] Figure 4 is the X-ray diffraction pattern (XRD) of the bismuth phosphate of Example 1 of the present disclosure;
[0013] Figure 5 This is a morphology diagram of bismuth phosphate after thermal activation in Example 2 of the present disclosure;
[0014] Figure 6 is the XRD pattern of bismuth phosphate after thermal activation in Example 2 of the present disclosure;
[0015] Figure 7 is a morphology diagram of bismuth phosphate of Example 3 of the present disclosure;
[0016] Figure 8 is a morphology diagram of bismuth phosphate of Example 5 of the present disclosure;
[0017] Fig. 9 It is a schematic diagram of the rate of catalytic degradation of glyphosate in Example 6 of the present disclosure and Comparative Examples 2 to 4. DETAILED DESCRIPTION
[0018] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present disclosure. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.
[0019] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The term "comprising" used herein indicates the existence of features, steps, operations, but does not exclude the existence or addition of one or more other features.
[0020] In the case of using expressions such as "at least one of A, B, and C, etc.", it should generally be interpreted in accordance with the meaning of the expression generally understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.). In the case of using expressions such as "at least one of A, B, or C, etc.", it should generally be interpreted in accordance with the meaning of the expression generally understood by those skilled in the art (for example, "a system having at least one of A, B, or C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).
[0021] In the process of realizing the inventive concept of the present disclosure, it is found that in the related art, the methods commonly used to remove phosphorus from phosphorus-containing wastewater are solvent extraction, electrodialysis, crystallization, evaporation and precipitation neutralization. However, these technologies are mainly used to treat phosphorus-containing wastewater with high phosphorus concentration. When treating phosphorus-containing wastewater with low phosphorus concentration, the above methods often have disadvantages such as low removal efficiency and high recovery cost, and the recovered phosphorus is usually crude phosphoric acid or phosphate with low value. The use of bismuth-containing compounds to remove phosphates from phosphorus-containing wastewater can not only achieve efficient removal of phosphorus in phosphorus-containing wastewater, but also form a catalyst with higher value and practicality in situ, thereby achieving efficient removal, recovery and value-added reuse of phosphorus in phosphorus-containing wastewater.
[0022] Specifically, according to an embodiment of one aspect of the present disclosure, a method for preparing bismuth phosphate is provided, comprising: dispersing a bismuth-containing compound in phosphorus-containing wastewater so that the bismuth-containing compound and phosphate ions in the phosphorus-containing wastewater form a mixed solution containing bismuth phosphate in situ; and separating bismuth phosphate from the mixed solution; wherein the bismuth phosphate has a hollow nanotubular structure.
[0023] According to the embodiments of the present disclosure, by using a bismuth-containing compound as an adsorbent to adsorb phosphate in phosphorus-containing wastewater, the phosphorus concentration in the wastewater can be reduced to less than 0.5 ppm, thereby achieving efficient removal of phosphorus in sewage. Bismuth ions and phosphate ions can form bismuth phosphate with a hollow nanotube structure in situ, which can be used as a catalyst with high utilization rate, without the need for cumbersome, time-consuming, and energy-consuming desorption of the adsorbed phosphorus.
[0024] According to an embodiment of the present disclosure, the bismuth-containing compound is selected from at least one of Bi(OH)3, Bi2O2CO3, Bi2O3, BiOCl, BiOI, and Bi2(NO3)O2(OH).
[0025] According to the embodiments of the present disclosure, the removal rate of phosphorus in phosphorus-containing wastewater can be improved by selecting a suitable bismuth-containing compound.
[0026] According to an embodiment of the present disclosure, the molar ratio of the bismuth element in the bismuth-containing compound to the phosphorus element in the phosphorus-containing wastewater is 0.8-1.1, for example, 0.85, 0.9, 0.95, 1.0 and 1.05.
[0027] According to the embodiments of the present disclosure, if the molar ratio of the bismuth element in the bismuth-containing compound to the phosphorus element in the phosphorus-containing wastewater is lower than 0.8, it is not conducive to improving the removal rate of phosphorus in the phosphorus-containing wastewater; if the molar ratio of the bismuth element in the bismuth-containing compound to the phosphorus element in the phosphorus-containing wastewater is greater than 1.1, it will be not conducive to improving the catalytic effect of bismuth phosphate.
[0028] According to an embodiment of the present disclosure, the reaction time of the bismuth-containing compound and the phosphorus-containing wastewater is 1 to 48 h, for example, 2 h, 5 h, 10 h, 20 h, 30 h and 40 h.
[0029] According to the embodiments of the present disclosure, if the reaction time is too short, the removal rate of phosphorus in the phosphorus-containing wastewater and the generation rate of bismuth phosphate will be reduced. If the reaction time is too long, the removal rate of phosphorus in the phosphorus-containing wastewater and the generation rate of bismuth phosphate cannot be improved, and resources will be wasted.
[0030] According to an embodiment of the present disclosure, the length of the hollow nanotubular structure is 0.1~4 μm, for example, 0.5 μm, 1 μm, 1.5 μm, 2 μm, 3 μm, 3.5 μm and 4 μm, and the diameter is 50~800 nm, for example, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm and 700 nm.
[0031] According to an embodiment of the present disclosure, the concentration of phosphorus in the phosphorus-containing wastewater is <200 ppm, for example, 1 ppm, 2 ppm, 5 ppm, 10 ppm, 20 ppm, 50 ppm, 100 ppm and 150 ppm.
[0032] According to the embodiments of the present disclosure, if the concentration of phosphorus in the phosphorus-containing wastewater is too high, it is not conducive to improving the removal rate of phosphorus in the phosphorus-containing wastewater.
[0033] According to an embodiment of the present disclosure, the pH value of the phosphorus-containing wastewater is 0.5~3.5, for example, 1, 1.5, 2, 2.5 and 3.
[0034] According to the embodiments of the present disclosure, if the pH of phosphorus-containing wastewater is too high or too low, it is not conducive to improving the removal rate of phosphorus in the phosphorus-containing wastewater.
[0035] According to an embodiment of the present disclosure, the bismuth phosphate is further subjected to heat treatment.
[0036] According to the embodiments of the present disclosure, when heat-treating bismuth phosphate, the bismuth phosphate can be fully washed with deionized water, heated in an air atmosphere in a muffle furnace, and kept at 400° C. to 600° C. for 1 to 24 hours. The heat-treated bismuth phosphate can have higher photocatalytic activity.
[0037] According to an embodiment of another aspect of the present disclosure, there is provided bismuth phosphate prepared by the above preparation method.
[0038] According to an embodiment of yet another aspect of the present disclosure, there is provided an application of bismuth phosphate prepared by the above preparation method in degrading organic pollutants.
[0039] According to the embodiments of the present disclosure, bismuth phosphate with a hollow nanotubular structure has a large specific surface area due to its hollow structure, can expose more active sites, and has a higher light utilization rate, and can efficiently degrade organic pollutants in water.
[0040] According to the embodiments of the present disclosure, organic pollutants include organic pollutants in water, such as antibiotics, benzene, phenols, organophosphorus pesticides, organochlorine pesticides and polycyclic aromatic hydrocarbons. When degrading organic pollutants, the mass concentration of bismuth phosphate in water is 1-10 g·L -1 , for example 2 g·L -1 , 3 g·L -1 , 4 g·L -1 , 5 g·L -1 , 6 g·L -1 , 7 g·L -1 , 8 g·L -1 and 9g·L -1 , the pH of water is 3 to 11, such as 4, 5, 6, 7, 8, 9 and 10.
[0041] According to the embodiments of the present disclosure, if the mass concentration of bismuth phosphate in water is too low, the catalytic effect of bismuth phosphate on the degradation of organic pollutants will be reduced; if the bismuth phosphate content is too high, the catalytic effect of bismuth phosphate on the degradation of organic pollutants cannot be improved, and bismuth phosphate is wasted. If the pH of water is too high or too low, the catalytic effect of bismuth phosphate on the degradation of organic pollutants will be reduced.
[0042] The present disclosure will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0043] Example 1
[0044] 6.79 g of bismuth nitrate and 1.68 g of sodium hydroxide were dissolved in 40 mL of ethylene glycol respectively, the two solutions were fully mixed, the mixed solution was placed in a reactor, reacted at 90 ° C for 12 h, the solid was centrifuged, and washed alternately with deionized water and ethanol, and the washed solid was placed in a vacuum oven at 60 ° C for 24 h to obtain Bi2(NO3)O2(OH); phosphorus-containing wastewater with an initial pH of 2.76 and an initial phosphorus concentration of 58.8 mg P / L was provided, Bi2(NO3)O2(OH) as described above was added, and the reaction was stirred for 2 h, so that the phosphorus concentration in the phosphorus-containing wastewater was less than 0.5 ppm; the reacted material was centrifuged to obtain bismuth phosphate.
[0045] The morphology of Bi2(NO3)O2(OH) in Example 1 of the present disclosure was characterized by transmission electron microscopy. Figure 1 As shown, the generated Bi2(NO3)O2(OH) is in the form of nanosheets; different amounts of Bi2(NO3)O2(OH) were added and the phosphorus removal rate was tested at different Bi2(NO3)O2(OH) addition amounts, as shown in FIG. Figure 2 As shown in the figure, the red dotted line represents the discharge standard of Class A comprehensive wastewater. The higher the addition amount of Bi2(NO3)O2(OH), the higher the phosphorus removal rate. When the addition amount is 0.6 g·L -1 When the phosphorus concentration in the water is lower than 0.5 ppm, the phosphorus removal rate reaches 99.82%, which meets the first-level discharge standard in the comprehensive sewage discharge standard; the morphology of the bismuth phosphate generated in Example 1 of the present disclosure is characterized by transmission electron microscopy, as shown in FIG. Figure 3 As shown, the generated bismuth phosphate has a hollow nanotube structure, proving that the nanosheet-like Bi2(NO3)O2(OH) can form a bismuth phosphate having a hollow nanotube structure in situ after adsorbing phosphorus; the crystal structure of the bismuth phosphate generated in Example 1 of the present disclosure is characterized by XRD, as shown Figure 4 As shown, the XRD results show that the generated bismuth phosphate has an HP type structure.
[0046] Example 2
[0047] The bismuth phosphate obtained in Example 1 was transferred to a muffle furnace, heated to 500 °C in an air atmosphere and maintained at this temperature for 2 h to obtain thermally activated bismuth phosphate; an initial concentration of 50 mg·L -1 glyphosate solution at 1 mW·cm -2 Under ultraviolet light, a concentration of 1 g·L -1 After the bismuth phosphate was thermally activated as described above and the reaction continued, the degradation rate of glyphosate could reach 99.85% after 1 h.
[0048] The morphology of the thermally activated bismuth phosphate in Example 2 of the present disclosure was characterized by transmission electron microscopy. Figure 5 As shown, the thermally activated bismuth phosphate retains the original hollow nanotube structure; the crystal structure of the thermally activated bismuth phosphate in Example 2 of the present disclosure is characterized by XRD, as shown Figure 6 As shown, the XRD results show that the thermally activated bismuth phosphate is a mixed phase of HTMP structure and LTMP structure.
[0049] Comparative Example 1
[0050] Provide an initial concentration of 50 mg·L -1 glyphosate solution at 1 mW·cm -2 Under ultraviolet light, a concentration of 1 g·L -1 The bismuth phosphate obtained in Example 1 was used and the reaction was continued. After 1 h, the degradation rate of glyphosate was about 51.32%, which proved that thermal activation can significantly improve the catalytic performance of bismuth phosphate.
[0051] Example 3
[0052] Dissolve 3.88 g of bismuth nitrate in 8 ml of 1 mol·L -1 nitric acid solution to obtain solution A; 6.76 g of sodium carbonate and 0.8 g of hexadecyltrimethylammonium bromide were dissolved in 72 ml of deionized water to obtain solution B; solution A was added dropwise to solution B under vigorous stirring, and stirring was continued for 30 minutes; the solid was centrifuged and washed alternately with deionized water and ethanol, and the washed solid was placed in a vacuum oven at 60 ° C and dried for 24 h to obtain bismuth oxycarbonate; phosphorus-containing wastewater with an initial pH of 3.97 and an initial phosphorus concentration of 25.6 mg P / L was provided, nitric acid was added to adjust the pH of the phosphorus-containing wastewater to 3, the bismuth oxycarbonate as described above was added, and the reaction was stirred for 2 h, so that the phosphorus concentration in the phosphorus-containing wastewater was less than 0.5 ppm; the reacted material was centrifuged to obtain bismuth phosphate.
[0053] The morphology of the bismuth phosphate produced in Example 3 of the present disclosure was characterized by transmission electron microscopy. Figure 7 As shown, the generated bismuth phosphate has a hollow nanotubular structure, proving that bismuth oxycarbonate can in situ form bismuth phosphate with a hollow nanotubular structure after adsorbing phosphorus.
[0054] Example 4
[0055] The bismuth phosphate obtained in Example 3 was transferred to a muffle furnace, heated to 550 °C in an air atmosphere and maintained at this temperature for 3.5 h to obtain thermally activated bismuth phosphate; an initial concentration of 5 mg·L -1 glyphosate solution at 5 mW·cm -2Under ultraviolet light, a concentration of 2 g·L -1 After the bismuth phosphate was thermally activated as described above and continued to react, the degradation rate of glyphosate was about 99.96% after 4 minutes.
[0056] Example 5
[0057] Dissolve 3.88 g of bismuth nitrate in 8 ml of 1 mol·L -1 nitric acid solution to obtain solution A; 6.76 g of sodium carbonate and 0.8 g of hexadecyltrimethylammonium bromide were dissolved in 72 ml of deionized water to obtain solution B; solution A was added dropwise to solution B under vigorous stirring, and stirring was continued for 30 minutes; the solid was centrifuged, washed alternately with deionized water and ethanol, the washed solid was placed in a vacuum oven at 60 ° C and dried for 24 h, and placed in a muffle furnace and calcined at 400 ° C for 3.5 h to obtain bismuth oxide; phosphorus-containing wastewater with an initial pH of 0.4 and an initial phosphorus concentration of 185.1 mg P / L was provided, sodium hydroxide was added to adjust the pH of the phosphorus-containing wastewater to 0.5, the bismuth oxide as described above was added, and the reaction was stirred for 2 h, so that the phosphorus concentration in the phosphorus-containing wastewater was less than 0.5 ppm; the reacted material was centrifuged to obtain bismuth phosphate.
[0058] The morphology of the bismuth phosphate produced in Example 3 of the present disclosure was characterized by transmission electron microscopy. Figure 8 As shown, the generated bismuth phosphate has a hollow nanotubular structure, indicating that bismuth phosphate with a hollow nanotubular structure can be formed in situ after bismuth oxide adsorbs phosphorus.
[0059] Example 6
[0060] The bismuth phosphate obtained in Example 5 was transferred to a muffle furnace, heated to 600 °C in an air atmosphere and maintained at this temperature for 5 h to obtain thermally activated bismuth phosphate; an initial concentration of 0.2 mg·L -1 glyphosate solution at 2 mW·cm -2 Under ultraviolet light irradiation, a mass concentration of 1.5 g·L -1 As described above, after the thermal activation of bismuth phosphate, oxygen was introduced and the reaction continued. After 2 minutes, the degradation rate of glyphosate was about 99.98%.
[0061] Comparative Example 2
[0062] Dissolve 3.4 g of bismuth nitrate in 28 ml of 0.7 mol·L -1nitric acid solution to obtain solution A; 1.5 g ammonium phosphate was dissolved in 42 ml deionized water to obtain solution B; the above solution A and solution B were fully mixed and placed in a beaker with a capacity of 100 ml, and stirred vigorously for 1 h; the solid was centrifuged and thoroughly washed with deionized water, and the washed solid was placed in a vacuum oven at 60 °C for 24 h, and finally heated in a muffle furnace at 600 °C for 5 h to obtain solid nanorod bismuth phosphate; an initial concentration of 0.2 mg·L -1 glyphosate solution at 2 mW·cm -2 Under ultraviolet light irradiation, a mass concentration of 1.5 g·L -1 The solid nanorod bismuth phosphate as described above is introduced with oxygen and allowed to react continuously.
[0063] Comparative Example 3
[0064] The difference from Example 6 is that commercial bismuth phosphate is added to the glyphosate solution.
[0065] Comparative Example 4
[0066] The difference from Example 6 is that commercial titanium dioxide (P25-TiO2) is added to the glyphosate solution.
[0067] The degradation rate constant K of the catalyst for pollutants reflects the catalytic ability of the catalyst. The higher the K value, the better the performance of the catalyst. By calculating and comparing the degradation rate constants K in Example 6 of the present disclosure and Comparative Examples 2 to 4, as shown in FIG. Fig. 9 As shown, the degradation rate constant after thermal activation in Example 6 is 3.25 times that of the solid nanorod bismuth phosphate in Example 2, 4.73 times that of the commercial bismuth phosphate in Example 3, and 2.74 times that of the commercial titanium dioxide in Example 4, proving that the catalytic performance of hollow nanotubular bismuth phosphate on organic pollutants in water is better than that of solid bismuth phosphate, commercial bismuth phosphate and commercial titanium dioxide.
[0068] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above description is only a specific embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.
Claims
1. A method for preparing bismuth phosphate, comprising: Dispersing a bismuth-containing compound in phosphorus-containing wastewater so that bismuth ions in the bismuth-containing compound and phosphate ions in the phosphorus-containing wastewater form a mixed solution containing bismuth phosphate in situ; Separating the bismuth phosphate from the mixed solution; Wherein, the bismuth phosphate has a hollow nanotube structure.
2. The preparation method according to claim 1, wherein The bismuth-containing compound is selected from at least one of Bi(OH)3, Bi2O2CO3, Bi2O3, BiOCl, BiOI, and Bi2(NO3)O2(OH).
3. The preparation method according to claim 1, wherein The molar ratio of the bismuth element in the bismuth-containing compound to the phosphorus element in the phosphorus-containing wastewater is 0.8-1.1, and the reaction time of the bismuth-containing compound and the phosphorus-containing wastewater is 1-48 h.
4. The preparation method according to claim 1, wherein The hollow nanotube structure has a length of 0.1-4 μm and a diameter of 50-800 nm.
5. The preparation method according to claim 1, wherein The phosphorus concentration in the phosphorus-containing wastewater is <200 ppm.
6. The preparation method according to claim 1, wherein The pH of the phosphorus-containing wastewater is 0.5-3.
5.
7. The preparation method according to claim 1, further comprising: The bismuth phosphate is heat treated.
8. Bismuth phosphate prepared by the preparation method according to any one of claims 1 to 7.
9. Use of bismuth phosphate prepared by the preparation method according to any one of claims 1 to 7 in degrading organic pollutants.
10. The use according to claim 9, wherein: The organic pollutants include organic pollutants in water. When degrading the organic pollutants in the water, the mass concentration of the bismuth phosphate in the water is 1-10 g·L -1 , the pH of the water is 3~11.