Lanthanum-doped metal-based new material and preparation method and application thereof

Abstract

The invention provides a lanthanum-doped metal-based novel material and a preparation method and application thereof, and relates to the technical field of materials, chemical engineering and environmental protection. The preparation method comprises the following steps: respectively preparing a metal salt solution, a lanthanum ion solution and an organic ligand solution; the preparation method comprises the following steps: mixing a metal salt solution, a lanthanum ion solution and an organic ligand solution to obtain a mixed solution; and adding an alkaline solution into the mixed solution, uniformly mixing, centrifuging, washing, centrifuging again, discarding the supernatant, and drying to obtain the lanthanum-doped metal-based organic new material. The preparation method is simple and easy to operate, the reaction can be rapidly completed at normal temperature, and the prepared lanthanum-doped metal-based organic new material has remarkable effects on inhibiting growth of blue-green algae and removing phosphorus.

Description

Technical Field

[0001] The present application relates to the fields of materials, chemical engineering and environmental protection technology, and in particular to a lanthanum-doped metal-based new material and a preparation method and application thereof. Background Art

[0002] Eutrophication has become a serious challenge facing the global aquatic environment (Hei et al., Crit. Rev. Environ. Sci. Technol. 2024), potentially triggering a series of severe negative impacts, including a significant decline in water quality, a dramatic reduction in biodiversity, and a complete breakdown of the self-regulating capacity of aquatic ecosystems (Wang et al., Process Saf. Environ. Protect. 2023). Nitrogen and phosphorus, as key nutrients, play crucial roles in this complex process. Phosphorus, in particular, is widely considered a core factor determining the productivity of lake ecosystems (Carpenter et al., Proc. Natl. Acad. Sci. USA 2022; Schindler et al., Environ. Sci. Technol. 2016). Microcystis blooms, a direct manifestation of water pollution, are rooted in the excessive accumulation of nutrients in source water, particularly a surge in phosphorus levels. This problem not only poses a major challenge to current water environment management, but also poses a serious threat to human and animal health (Wood et al., Environ. Int. 2016).

[0003] Currently, the treatment of phosphorus pollution and microcystis blooms is usually regarded as two independent processes, including the use of algaecides such as sodium percarbonate (solid hydrogen peroxide) and phosphorus lock agents such as Phoslock. However, using algaecides and phosphorus removers to treat phosphorus pollution and microcystis blooms separately will at least cause the following problems: (1) Complex operation process: Two different dosing systems and treatment processes need to be set up. From the storage and addition of the reagents to the subsequent reaction monitoring, they all need to be operated and managed separately, which increases the complexity of the operation and labor costs, and is also easy to affect the treatment effect due to operational errors. (2) Long treatment time: The two independent treatment processes need to be carried out in sequence, first algae removal treatment, then phosphorus removal treatment, or vice versa. This makes the entire water treatment process take a long time, reduces the efficiency of water treatment, and may not meet the requirements in some scenarios with requirements for treatment time. (3) The mutual influence between the phosphorus remover and the algaecide causes poor results. Summary of the Invention

[0004] The purpose of this application is to provide a method for preparing a lanthanum-doped metal-based new organic material and its application as a dual-effect algaecide and phosphorus removal agent in inhibiting the growth of cyanobacteria and controlling eutrophication of water bodies. The preparation method is simple and easy to operate, and the reaction can be completed quickly at room temperature. The prepared lanthanum-doped metal-based new organic material has significant effects in inhibiting the growth of cyanobacteria and removing phosphorus.

[0005] In order to solve the above technical problems, the technical solutions adopted in this application are:

[0006] In one aspect, the present application provides a method for preparing a lanthanum-doped metal-based new organic material, comprising the following steps:

[0007] S1. preparing a metal salt solution, a lanthanum ion solution and an organic ligand solution respectively;

[0008] S2, first mixing the metal salt solution, the lanthanum ion solution and the organic ligand solution to obtain a mixed solution;

[0009] S3. Adding alkaline solution to the mixed solution, mixing evenly, centrifuging, washing and centrifuging again, discarding the supernatant, and drying to obtain the lanthanum-doped metal-based organic new material.

[0010] On the other hand, the present application provides a lanthanum-doped metal-based new organic material prepared by the above method, and the apparent morphology of the lanthanum-doped metal-based new organic material after drying is a white powder.

[0011] On the other hand, the present application provides a lanthanum-doped metal-based new organic material for use as a simultaneous algaecide and phosphorus removal agent in the field of inhibiting cyanobacteria growth and eutrophication of water bodies. Specifically, the cyanobacteria are selected from at least one of Microcystis aeruginosa, Oscillatoria, Nostoc, Anabaena and Aphanizomenon, and the phosphorus content in the eutrophic water body is greater than 0.2 mg / L.

[0012] Compared with the prior art, the embodiments of the present application have at least the following advantages or beneficial effects:

[0013] 1. This application utilizes metal salts, lanthanum ion solutions, organic ligands, and alkaline solutions to prepare lanthanum-doped metal-based organic new materials. This method is convenient and easy to obtain reactants, has low cost, mild reaction conditions, and a safe and rapid reaction process, thus solving the problems of harsh conditions for the synthesis of metal-based organic new materials in the prior art.

[0014] 2. The lanthanum-doped metal-based organic material synthesized by the method of this application can bind to cyanobacteria cells through electrostatic interaction, inhibiting their photosynthesis and promoting the production of reactive oxygen species, ultimately leading to the death of the algae. Lanthanum ion doping can also effectively remove phosphorus from water. Therefore, this lanthanum-doped metal-based organic material can be used as a dual-action algaecide and phosphorus removal agent to effectively remove phosphorus from cyanobacteria and water bodies, with a removal effect that is superior to the widely used algaecide sodium percarbonate (SPC) and phosphorus removal agent Phoslock (LMB). In addition, this metal-based organic material is safe, efficient, and environmentally friendly, and has the potential to be used in the control of cyanobacterial blooms. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 X-ray powder diffraction patterns of the lanthanum-doped metal-based organic new materials LaM1 and LaM2 in Example 2;

[0017] Figure 2 This is a diagram showing the algae and phosphorus removal capabilities of LaM1, SPC, and LMB in Example 5. DETAILED DESCRIPTION

[0018] To make the purpose, technical solutions and advantages of the examples of the present application clearer, the technical solutions in the examples of the present application will be described clearly and completely below. Where specific conditions are not specified in the examples, conventional conditions or conditions recommended by the manufacturer are used. Where the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

[0019] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to specific embodiments.

[0020] A method for preparing a lanthanum-doped metal-based new organic material comprises the following steps:

[0021] S1. preparing a metal salt solution, a lanthanum ion solution and an organic ligand solution respectively;

[0022] S2, first mixing the metal salt solution, the lanthanum ion solution and the organic ligand solution to obtain a mixed solution;

[0023] S3. Adding alkaline solution to the mixed solution, mixing evenly, centrifuging, washing and centrifuging again, discarding the supernatant, and drying to obtain the lanthanum-doped metal-based organic new material.

[0024] In some embodiments of the present application, the metal salt in the above-mentioned step S1 is at least one of zinc salt, copper salt, cobalt salt and nickel salt, wherein the salt is one of chloride, acetate, sulfate, nitrate, gluconate, lactate and citrate; and the lanthanum ion solution is at least one of lanthanum nitrate, lanthanum chloride and lanthanum sulfate.

[0025] In some embodiments of the present application, the organic ligand in the above step S1 includes one or more of 1,2,4-triazolin-3-one, 5-methyl-1H-benzotriazole, 5-benzylthiotetrazole, 5-ethylthiotetrazole and their derivatives.

[0026] In some embodiments of the present application, the molar ratio of the metal salt solution, the lanthanum ion solution and the organic ligand solution in the above step S2 is 4:(1-4):(10-40).

[0027] In some embodiments of the present application, the alkaline solution in the above step S3 is one or more of sodium hydroxide solution, potassium hydroxide solution, ammonia solution, sodium carbonate solution and sodium bicarbonate solution.

[0028] In some embodiments of the present application, the volume ratio of the alkaline solution to the mixed solution in the above step S3 is (4-20):100.

[0029] In some embodiments of the present application, the mixing reaction time in the above-mentioned S3 step is 10-30 minutes, and the mixing stirring rate is 30-80 rpm; the centrifugation and re-centrifugation rates are both 5000-9000 rpm, and the time is 2-5 minutes; the drying temperature is 40-80°C, and the drying time is 24-72 hours.

[0030] A lanthanum-doped metal-based organic new material prepared by the method, wherein the apparent form of the metal-based organic new material is white powder.

[0031] A new lanthanum-doped metal-based organic material is used as a simultaneous algaecide and phosphorus removal agent in the fields of inhibiting cyanobacteria growth and eutrophication of water bodies.

[0032] In some embodiments of the present application, the cyanobacteria are selected from at least one of Microcystis aeruginosa, Oscillatoria, Nostoc, Anabaena and Aphanizomenon, and the phosphorus content in the eutrophic water body is greater than 0.2 mg / L.

[0033] The features and performance of the present application are further described in detail below with reference to the embodiments.

[0034] Example 1

[0035] In this example, the amount of lanthanum ion solution added was changed to synthesize products (M, LaM1, LaM2) with different lanthanum ion addition amounts:

[0036] Weigh three groups of 1.2 mmol zinc nitrate hexahydrate (357.0 mg) and 0, 0.6 mmol, and 1.2 mmol lanthanum nitrate hydrate (MW: 324.92) and dissolve them in 14.4 mL of secondary water (ddH2O) to obtain mixed solutions 1, 2, and 3, respectively;

[0037] Take about 3.6 mmol of 1,2,4-triazolin-3-one and dissolve it in 15 mL of ddH2O to obtain an organic ligand solution.

[0038] After mixing the mixed solution with the ligand solution, 0.32 mL of 25% aqueous ammonia was added. The mixture was shaken at 50 rpm on a horizontal rotary shaker at room temperature for 0.5 h. The precipitate was recovered by centrifugation at 6000 rpm for 5 min and washed twice with water. Finally, the mixture was dried at 60°C and ground to obtain the products M, LaM1, and LaM2 of this example, which were stored at room temperature.

[0039] The M, LaM1 and LaM2 prepared in this example were compared in phosphorus removal and algae removal, and the results are shown in Table 1.

[0040] Table 1M, LaM1, LaM2 production ratio and phosphorus removal and algae removal capacity

[0041] Product Name M LaM1 LaM2 Production ratio% 39 31 26 Algae removal rate% 65 72 67 Phosphorus removal rate% 42 84 63

[0042] In this example, LaM1 and LaM2 were synthesized by changing the doping amount of lanthanum ion solution. According to Table 1, the yield ranking is LaM>LaM, the algae removal effect is LaM1>LaM2, and the phosphorus removal effect is LaM1>LaM2. The XRD patterns of LaM1 and LaM2 are shown in Table 1. Figure 1 As shown, both LaMs (LaM1 and LaM2) produced obvious characteristic peaks.

[0043] Example 2

[0044] This example compares the phosphorus removal capabilities of M, LaM1, and LaM2 with the commercial phosphorus removal agent Phoslock (LMB).

[0045] Prepare a potassium dihydrogen phosphate solution containing 1 mg / L of the element L. Add M, LaM1, LaM2, and LMB to a final concentration of 30 mg / L. Mix thoroughly on a test tube shaker at 50 rpm for 4 hours. Determine the phosphorus concentration using the national standard "Water Quality—Determination of Total Phosphorus—Ammonium Molybdate Spectrophotometry." Calculate the phosphorus removal capacity and ratio of M, LaM1, LaM2, and LMB, as shown in Table 2.

[0046] Table 2 Phosphorus removal capacity and removal rate of M, LaM1, LaM2 and LMB

[0047] type <![CDATA[Phosphorus loading / mg·g -1 > Phosphorus removal rate% M 15.2±0.40 42.4±1.11 LaM1 30.2±0.40 84.0±1.11 LaM2 19.2±0.09 63.4±0.28 LMB 7.7±0.66 21.5±1.85

[0048] As can be seen from Table 2, LaM1 has the highest phosphorus loading and phosphorus removal capacity. For eutrophic water with a phosphorus content of 1 mg / L, its removal rate reaches 84.0±1.11%, which has great potential for controlling eutrophication of water bodies.

[0049] Example 3

[0050] This example tests the phosphorus removal capabilities of M, LaM1, LaM2, and LMB under different pH conditions.

[0051] A potassium dihydrogen phosphate solution containing 1 mg / L of phosphorus was prepared and the pH was adjusted to 3, 5, 7, 9, and 11. M, LaM1, LaM2, and LMB were added to a final concentration of 40 mg / L and mixed on a test tube shaker at 50 rpm for 4 hours. P concentration was determined using the national standard "Water Quality—Determination of Total Phosphorus—Ammonium Molybdate Spectrophotometry." The phosphorus removal capacities and ratios of LaMs (LaM1 and LaM2) and LMB were calculated. The results are shown in Table 3.

[0052] Table 3 Phosphorus removal capacity and removal rate of M, LaMs and LMB at different pH.

[0053]

[0054] As shown in Table 3, the phosphorus removal ability of the new metal-based materials without La doping is weak at different pH values, lower than that of the widely used commercial phosphorus removal agent LMB. However, LaMs synthesized by La doping significantly improved their phosphorus removal ability, significantly exceeding LMB, with LaM1 showing the strongest phosphorus removal efficiency. The phosphorus removal ability of LaM varied with pH, ​​reaching its highest at pH 5-7, its lowest at pH 3, and a removal rate of 74.1% at pH 5.

[0055] Example 4

[0056] This example tests the phosphorus removal capabilities of M, LaM1, LaM2, and LMB under different anion conditions.

[0057] Prepare a potassium dihydrogen phosphate solution containing 1 mg / L of the element. Add sulfate, nitrate, bicarbonate, chloride, and fluoride to the phosphorus solution to a final concentration of 10 mg / L. Then adjust the pH to between 7 and 8. Add M, LaM1, LaM2, and LMB to a final concentration of 40 mg / L and mix on a test tube shaker at 50 rpm for 4 hours. Determine phosphorus concentration using the national standard "Water Quality - Determination of Total Phosphorus - Ammonium Molybdate Spectrophotometry." Calculate the phosphorus removal capacity of LaMs (LaM1 and LaM2) and LMB. The results are shown in Table 4.

[0058] Table 4 Phosphorus removal capacity and removal rate of M, LaMs and LMB in the presence of different anions

[0059] <![CDATA[Phosphorus loading / mg·g -1 > M LaM1 LaM2 LMB Sulfate 8.2±1.26 23.0±0.21 19.9±1.26 5.5±0.27 Nitrate 5.5±0.75 22.3±0.21 20.5±0.23 4.2±1.87 bicarbonate 6.9±0.77 17.6±0.49 17.8±0.34 2.4±0.86 Chloride ions 5.6±1.07 21.2±1.91 20.0±0.41 6.7±1.02 Fluoride ion 5.1±0.98 19.0±0.78 16.8±0.28 5.2±0.75

[0060] As can be seen from Table 4, the phosphorus removal performance of the new metal-based materials without La doping does not change significantly in the presence of different anions; the phosphorus removal ability of LaM1 and LaM2 is slightly weakened in the presence of bicarbonate and fluoride ions; LMB is significantly inhibited in the presence of bicarbonate. Overall, LaMs (LaM1 and LaM2) still maintain high phosphorus removal performance in the presence of various anions, with the highest phosphorus loading reaching 23.0 mg·g -1 .

[0061] Example 5

[0062] This example tests the ability of LaM1 and LMB to simultaneously remove algae and phosphorus.

[0063] The natural water from Wuhan East Lake was used for a spiked experiment. BG11 culture medium was added at a ratio of 20%. At this time, the phosphorus content in the water was about 1 mg / L. Microcystis aeruginosa was added to simulate a heavy cyanobacterial bloom. LaM1, SPC (algaecide) and LMB (phosphorus remover) were added at a final concentration of 40 mg / L, and the water was cultured at room temperature for 5 days. A blank control group (Group C, without algaecide or phosphorus remover) was set up. During the process, the visual changes in the water body and the changes in phosphorus concentration were observed. The national standard method "Determination of total phosphorus in water quality - ammonium molybdate spectrophotometry" was used to determine the P concentration, and the phosphorus removal capabilities of LaM1, SPC and LMB were calculated. The results are as follows: Figure 2 shown.

[0064] from Figure 2As can be seen, LaM1 exhibited similar algae removal capabilities as SPC, while LMB had no significant algae removal effect. The phosphorus concentration in the blank control group slowly decreased due to natural water degradation. The SPC treatment group produced a large amount of phosphorus due to the massive death of cyanobacteria, which subsequently slowly degraded, but the phosphorus solubility was higher than the control group throughout the process. The phosphorus content in the LMB treatment group also slowly degraded, remaining slightly lower than the control group throughout the process. However, in the LaM1 treatment group, not only was the cyanobacteria effectively killed, but the phosphorus content also significantly decreased, falling below 0.1 mg / L on the fifth day. The phosphorus content in the water quality transitioned from extremely heavily contaminated to Class II surface water standards, demonstrating LaM1's excellent ability to simultaneously remove algae and phosphorus.

[0065] The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

Claims

1. A method for preparing a lanthanum-doped metal-based new organic material, characterized in that: The following steps are involved: S1. preparing a metal salt solution, a lanthanum ion solution and an organic ligand solution respectively; S2, first mixing the metal salt solution, the lanthanum ion solution and the organic ligand solution to obtain a mixed solution; S3. Adding alkaline solution to the mixed solution, mixing evenly, centrifuging, washing and centrifuging again, discarding the supernatant, and drying to obtain the lanthanum-doped metal-based new organic material.

2. The method for preparing a lanthanum-doped metal-based new organic material according to claim 1, characterized in that: In step S1, the metal salt is at least one of zinc salt, copper salt, cobalt salt and nickel salt, wherein the salt is one of chloride, acetate, sulfate, nitrate, gluconate, lactate and citrate; and the lanthanum ion solution is at least one of lanthanum nitrate, lanthanum chloride and lanthanum sulfate.

3. The method for preparing a lanthanum-doped metal-based new organic material according to claim 1, characterized in that: The organic ligand in step S1 includes one or more of 1,2,4-triazolin-3-one, 5-methyl-1H-benzotriazole, 5-benzylthiotetrazolyl, 5-ethylthiotetrazolyl and derivatives thereof.

4. The method for preparing a lanthanum-doped metal-based new organic material according to claim 1, characterized in that: In the step S2, the molar ratio of the metal salt solution, the lanthanum ion solution and the organic ligand solution is 4:(1-4):(10-40).

5. The method for preparing a lanthanum-doped metal-based new organic material according to claim 1, characterized in that: The alkaline solution in step S3 is one or more of sodium hydroxide solution, potassium hydroxide solution, ammonia solution, sodium carbonate solution and sodium bicarbonate solution.

6. The method for preparing a lanthanum-doped metal-based new organic material according to claim 3, characterized in that: In the step S3, the volume ratio of the alkaline solution to the mixed solution is (4-20):

100.

7. The method for preparing a lanthanum-doped metal-based new organic material according to claim 3, characterized in that: The mixing reaction time in step S3 is 10-30 minutes, and the mixing stirring rate is 30-80 rpm; the centrifugation and re-centrifugation rates are both 5000-9000 rpm, and the time is 2-5 minutes; the drying temperature is 40-80° C., and the drying time is 24-72 hours.

8. A lanthanum-doped metal-based new organic material prepared by the method according to any one of claims 1 to 7, characterized in that: The apparent form of the new metal-based organic material is white powder.

9. A lanthanum-doped metal-based new organic material as claimed in claim 8, wherein the lanthanum-doped metal-based new organic material is used as a simultaneous algaecide and phosphorus removal agent in the field of inhibiting the growth of cyanobacteria and eutrophication of water bodies.

10. The lanthanum-doped metal-based new organic material according to claim 9 is used as a simultaneous algaecide and phosphorus removal agent in the field of inhibiting the growth of cyanobacteria and eutrophication of water bodies, characterized in that: The cyanobacteria are selected from at least one of Microcystis aeruginosa, Oscillatoria, Nostoc, Anabaena and Aphanizomenon, and the phosphorus content in the eutrophic water body is greater than 0.2 mg / L.

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