Amino acid-hydrated zirconium oxide hybrid material, and preparation method and application thereof

Abstract

This invention discloses an amino acid-hydrated zirconium oxide hybrid material, its preparation method, and its application, belonging to the field of water treatment. The specific preparation method of this hybrid material is as follows: amino acids are dissolved in deionized water, and a zirconium ammonium carbonate solution is added dropwise while stirring at room temperature to obtain a transparent mixed solution; the transparent mixed solution is dried at a constant temperature to obtain a white solid, which is then soaked, washed, and filtered to obtain a white precipitate; the white precipitate is dried at a constant temperature to obtain the product. The Arg-HZO prepared by this invention exhibits adsorption capacities for Cr(VI) and phosphate approximately 14 and 12 times that of blank HZO, respectively, while the Lys-HZO also achieves adsorption capacities for Cr(VI) and phosphate approximately 15 and 10 times that of blank HZO. Even in the presence of competing ions in the solution, Arg-HZO and Lys-HZO still demonstrate excellent adsorption capacity for Cr(VI) and phosphate, exhibiting good anti-interference capabilities. The Arg-HZO and Lys-HZO prepared in this invention have the advantages of being environmentally friendly, highly efficient, having good selectivity for Cr(VI) and phosphate, and having high mechanical stability. They are promising adsorbents for removing Cr(VI) and phosphate from wastewater.

Description

Technical Field

[0001] This invention belongs to the field of water treatment, specifically relating to an amino acid-hydrated zirconium oxide hybrid material, its preparation method, and its application. Background Technology

[0002] In today's rapidly evolving human society, industrialization is advancing, industrial and agricultural production are booming, and the population is steadily growing. While these changes have brought convenience to our lives, they have also triggered a series of environmental problems, especially Cr(VI) and phosphate pollution. Cr(VI) is a highly toxic heavy metal that remains stable in the environment and is easily migrated, entering organisms through the food chain and posing a serious threat to human health. Phosphate is an essential nutrient for plant growth, but excessive discharge leads to eutrophication of water bodies, affecting the survival of other aquatic organisms. Furthermore, phosphate can also enter the human body through the food chain, causing harm to human health. Currently, various technologies for removing Cr(VI) and phosphate have been developed, including biological methods, chemical methods, and adsorption methods. However, biological treatment and chemical precipitation methods have drawbacks to varying degrees, including high production costs, secondary pollution, and demanding operating conditions. In contrast, adsorption methods are widely used in wastewater treatment due to their flexible preparation and separation, high efficiency, environmental friendliness, and recyclability.

[0003] Currently, various adsorbent materials have been reported to remove Cr(VI) and phosphate from water, such as biochar, hydrated metal oxides, metal-organic frameworks (MOFs), and biopolymers. Despite some progress in Cr(VI) and phosphate removal, most prepared adsorbents may have drawbacks affecting their practical application, including high cost, non-recyclability, poor adsorption capacity, and low adsorption rate. Therefore, it is essential to develop a highly efficient, environmentally friendly, and sustainable adsorbent for the removal of Cr(VI) and phosphate.

[0004] Hydrated zirconium oxide (HZO) is an adsorbent material renowned for its abundant hydroxyl functional groups, wide availability, non-toxicity, environmental friendliness, and resistance to oxidants, acids, and alkalis. It can remove heavy metal ions through ion exchange and coordination complexation, and selectively adsorb anions such as phosphate and fluoride ions. Therefore, HZO shows great potential in treating Cr(VI) and phosphorus-containing wastewater. However, HZO also suffers from problems such as dense surface, compact internal structure, and poor dispersibility, which limit the effective utilization of its internal adsorption sites and thus hinder the full realization of its high adsorption capacity. Therefore, overcoming the limitations of HZO and fully exploring its adsorption potential is a key issue that urgently needs to be addressed. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the present invention provides an amino acid-hydrated zirconium oxide hybrid material and its preparation method, so as to make effective use of the internal adsorption sites of the hybrid material and to achieve high adsorption capacity for heavy metals and phosphates.

[0006] The present invention is achieved through the following technical solutions.

[0007] This invention provides a method for preparing an amino acid-hydrated zirconium oxide hybrid material, specifically comprising the following steps:

[0008] (1) Dissolve the amino acids in deionized water, then add zirconium ammonium carbonate solution dropwise, and then stir at room temperature to obtain a transparent mixed solution;

[0009] The mass ratio of the amino acid, ammonium zirconium carbonate, and deionized water is 1:3.33-20:4-29.

[0010] (2) After drying the transparent mixed solution at a constant temperature, a white solid is obtained. Then, after soaking, washing and filtering, a white precipitate is obtained.

[0011] (3) The white precipitate was dried at a constant temperature to obtain the amino acid-hydrated zirconium oxide hybrid material.

[0012] Furthermore, the amino acid mentioned in step (1) is arginine or lysine.

[0013] Furthermore, the stirring time in step (1) is 1 hour.

[0014] Furthermore, the drying temperature in step (2) is 120°C and the drying time is 12 hours.

[0015] Furthermore, the drying temperature in step (3) is 70°C and the drying time is 12 hours.

[0016] The amino acid-hydrated zirconium oxide hybrid material prepared by the above method.

[0017] This invention also provides the application of the above-mentioned amino acid-hydrated zirconium oxide hybrid material in the adsorption of Cr(VI) and phosphate.

[0018] In the above applications, as an optimization, the amino acid-hydrated zirconium oxide hybrid material is used at a pH of 2 to 10 for the adsorption of Cr(VI) and phosphate.

[0019] In the above applications, as an optimization, the amount of the amino acid-hydrated zirconium oxide hybrid material added for the adsorption of Cr(VI) and phosphate is 0.25-3 g / L.

[0020] In the above applications, as an optimization, the amino acid-hydrated zirconium oxide hybrid material has an adsorption temperature of 298–318 K for the adsorption of Cr(VI) and phosphate.

[0021] Compared with the prior art, the present invention has the following technical effects:

[0022] 1. This invention uses arginine (Arg) and lysine (Lys) to hybridize hydrated zirconium oxide (HZO), obtaining Arg-HZO and Lys-HZO organic-inorganic molecular-level hybrid materials via a simple sol-gel method for adsorbing Cr(VI) and phosphate in aqueous solutions. The carboxyl groups on the Arg and Lys chains interact with the hydroxyl groups on the HZO molecular chains, achieving bottom-up fusion from the molecular level to the overall material, thus realizing a complementary fusion from structure to performance. The hydrophilic organic fragments introduced by Arg and Lys are expected to form numerous water channels penetrating the Arg-HZO and Lys-HZO hybrid materials, fully utilizing the adsorption sites inside and outside HZO. Simultaneously, it increases the types and number of active adsorption sites (hydroxyl, amino, and guanidinyl groups), thereby enhancing the adsorption potential of HZO, Arg, and Lys for Cr(VI) and phosphate.

[0023] 2. Under the same reaction conditions, the adsorption capacity of Arg-HZO for Cr(VI) and phosphate is about 14 and 12 times that of blank HZO, respectively, and the adsorption capacity of Lys-HZO for Cr(VI) and phosphate can also reach about 15 and 10 times that of blank HZO.

[0024] 3. Competitive ion experiments show that even in the presence of competing ions in the solution, Arg-HZO and Lys-HZO still exhibit excellent adsorption capacity for Cr(VI) and phosphate, demonstrating good anti-interference ability. More importantly, in fixed-bed column experiments, despite the presence of other competing ions in the solution, Arg-HZO and Lys-HZO can still effectively treat large quantities of phosphate-containing wastewater, showcasing the great potential of these two materials in practical applications.

[0025] 4. Cyclic adsorption experiments showed that Arg-HZO and Lys-HZO maintained good adsorption performance for Cr(VI) and phosphate after multiple cycles.

[0026] 5. The Arg-HZO and Lys-HZO prepared by this invention have the advantages of being environmentally friendly, highly efficient, having good selectivity for Cr(VI) and phosphate, and having high mechanical stability. They are promising adsorbents for removing Cr(VI) and phosphate from wastewater. Attached Figure Description

[0027] Figure 1The graph shows the effect of the Arg ratio in the hybrid material of this invention on the adsorption capacity of Cr(VI) and phosphate (wherein, Figure 1 (a) shows the effect of Cr(VI) adsorption capacity. Figure 1 (b) shows the effect of phosphate adsorption capacity.

[0028] Figure 2 Characterization diagram of the hybrid material prepared in Example 1 of the present invention (wherein, Figure 2 (a) is the FESEM plot of Arg-HZO. Figure 2 (b) is a TEM image. Figure 2 (c) is the HAADF-STEM image. Figure 2 (d) is the EDX element mapping diagram.

[0029] Figure 3 This is a SEM image of the HZO of this invention.

[0030] Figure 4 The images show the FTIR spectra of Arg, HZO, and Arg-HZO from this invention.

[0031] Figure 5 The images show the XRD patterns of Arg, HZO, and Arg-HZO from this invention.

[0032] Figure 6 The thermogravimetric curves of Arg-HZO and HZO of this invention are shown.

[0033] Figure 7 The graph shows the effect of the initial pH value of the solution on the adsorption of Cr(VI) and phosphate by Arg-HZO and HZO.

[0034] Figure 8 This is a graph showing the effect of Arg-HZO dosage on the adsorption capacity of Cr(VI) and phosphate in this invention.

[0035] Figure 9 This is a graph showing the effect of adsorption time on the adsorption of Cr(VI) and phosphate by Arg-HZO according to the present invention.

[0036] Figure 10 This is a graph showing the adsorption capacity of Arg-HZO for different Cr(VI) and phosphate concentrations at three different temperatures (298, 308 and 318 K) according to the present invention.

[0037] Figure 11 This is a diagram showing the cyclic regeneration performance of Arg-HZO according to the present invention.

[0038] Figure 12 The figure shows the effect of competing ions on the adsorption of phosphate by Arg-HZO in this invention.

[0039] Figure 13This is an experimental diagram of the fixed bed column of Arg-HZO of the present invention.

[0040] Figure 14 This figure shows the effect of the proportion of Lys in AZC in the hybrid material of this invention on the adsorption capacity of Cr(VI) and phosphate.

[0041] Figure 15 The infrared spectra of Lys, HZO, and Lys-HZO of this invention are shown.

[0042] Figure 16 The images show the XRD patterns of Lys, HZO, and Lys-HZO from this invention.

[0043] Figure 17 The thermogravimetric curves of HZO and Lys-HZO of this invention are shown.

[0044] Figure 18 The graph shows the effect of Lys-HZO dosage on the adsorption of Cr(VI) and phosphate in this invention.

[0045] Figure 19 The graph shows the effect of the initial pH value of the solution on the adsorption of Cr(VI) and phosphate by Lys-HZO and HZO.

[0046] Figure 20 This is a graph showing the effect of adsorption time on the adsorption of Cr(VI) and phosphate by Lys-HZO according to the present invention.

[0047] Figure 21 This is a graph showing the adsorption capacity of Lys-HZO for different Cr(VI) and phosphate concentrations at three different temperatures (298, 308 and 318 K).

[0048] Figure 22 The diagram shows the effect of competing ions on the adsorption of Cr(VI) and phosphate by Lys-HZO in this invention. Detailed Implementation

[0049] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0050] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0051] Unless otherwise specified, all raw materials used in the embodiments of this invention are commercially available.

[0052] Example 1

[0053] 3.2 g of arginine was dissolved in 20.8 g of deionized water, and then added dropwise to 16 g of ammonium zirconium carbonate solution while stirring. The mass of AZC was fixed at 40% of the total solution, and Arg at 20% of the AZC mass. The mixture was stirred at room temperature for 1 h to obtain a transparent mixed solution. The mixed solution was then dried in a constant temperature drying oven at 120 °C for 12 h. The resulting white solid was thoroughly soaked and washed with deionized water. Subsequently, it was filtered multiple times using filter paper with a thickness of ≥800 nm. The resulting precipitate was dried in a constant temperature drying oven at 70 °C for 12 h to obtain an Arg-HZO organic-inorganic molecular-level hybrid material as an adsorbent.

[0054] Example 2

[0055] The difference from Example 1 is that Arg accounts for 5% of the mass of AZC.

[0056] Example 3

[0057] The difference from Example 1 is that Arg accounts for 10% of the mass of AZC.

[0058] Example 4

[0059] The difference from Example 1 is that Arg accounts for 30% of the mass of AZC.

[0060] Comparative Example 1

[0061] The difference from Example 1 is that Arg is not added. Instead, the AZC solution (prepared by slowly adding 16g of AZC to 24g of deionized water) is directly dried in a constant temperature drying oven at 120°C for 12h to obtain the control sample hydrated zirconium oxide (HZO) as the adsorbent.

[0062] Example 5

[0063] Figure 1 (ab) shows the effect of the proportion of Arg in AZC in the hybrid material on the adsorption capacity of Cr(VI) and phosphate.

[0064] Experimental conditions: Cr(VI) solution: pH=2, CO=150mg / L, adsorbent dosage=1g / L, t=12h, T=25℃; phosphate solution: pH=2, CO=60mg / L, adsorbent dosage=0.5g / L, t=12h, T=25℃.

[0065] It can be seen that the adsorption capacities of both Cr(VI) and phosphate show a trend of first increasing and then slowly decreasing with the increase of Arg dosage. Therefore, the composite adsorbent prepared with an Arg dosage of 20% of the mass of AZC was selected for subsequent experiments and denoted as Arg-HZO.

[0066] The surface morphology of the samples was analyzed by FESEM. Figure 2 (a) shows that Arg-HZO exhibits a dense stacked structure, which is significantly different from the varying particle morphology of HZO. Figure 3 TEM was used to further characterize the internal morphology of the hybrid material. Figure 2 (b) It was observed that no HZO nanoparticles were present in the Arg-HZO hybrid material. HAADF-STEM image ( Figure 2 (c) also shows that HZO nanoparticles are not present in the hybrid material. Figure 2 (d) shows the elemental mapping of Arg-HZO, revealing the presence of four elements: C, N, O, and Zr. C and N belong to Arg, while O and Zr originate from HZO. Notably, the uniform distribution of N and Zr indicates that the hybridization of Arg and HZO is uniform.

[0067] FTIR spectroscopy was used to analyze the changes in functional groups resulting from Arg and HZO hybridization. For example... Figure 4 As shown, the peak of C=O starts from 1678 cm⁻¹. -1 Redshifted to 1631cm -1 This reflects the interaction between the carboxyl group in Arg and the hydroxyl group in HZO. FTIR spectroscopy analysis shows that Arg successfully hybridizes with HZO through intermolecular interactions. HZO retains its original adsorption sites and introduces other functional groups (amino and guanidine groups), which can serve as new active adsorption sites.

[0068] The crystal structure of the hybrid material can be understood by analyzing the XRD patterns of Arg, HZO, and Arg-HZO. Figure 5 Clearly, both Arg-HZO and HZO exist in an amorphous phase, which is quite different from the crystal structure of Arg. The hybridization of Arg and HZO is uniform and compact, which leads to the destruction of the crystallinity of Arg. Arg-HZO is an amorphous or crystal-poor hybrid material.

[0069] Figure 6 The thermogravimetric curves for Arg, HZO, and Arg-HZO are shown. It can be observed that HZO decomposes completely at approximately 500 °C, while Arg-HZO requires a higher temperature to decompose completely, indicating that the hybrid material has better thermal stability.

[0070] Example 6

[0071] This embodiment investigates the effect of the initial pH value of the solution on the adsorption of Cr(VI) and phosphate by Arg-HZO and HZO.

[0072] Experimental conditions: Cr(VI) solution: pH = 2-10, CO = 150 mg / L, adsorbent dosage = 1 g / L, t = 12 h, T = 25 ℃; phosphate solution: pH = 2-10, CO = 60 mg / L, adsorbent dosage = 1 g / L, t = 12 h, T = 25 ℃.

[0073] The results are as follows Figure 7 As shown, (a) is the adsorption diagram for Cr(VI), and (b) is the adsorption diagram for phosphate. It can be seen that the adsorption capacities of Arg-HZO and HZO for Cr(VI) and phosphate reach their maximum at pH = 2, and then decrease rapidly with increasing pH. However, it is noteworthy that at any pH value, the adsorption capacity of Arg-HZO for Cr(VI) and phosphate is higher than that of HZO, confirming that Arg-HZO has better adsorption performance.

[0074] Example 7

[0075] This embodiment investigates the effect of Arg-HZO dosage on the adsorption of Cr(VI) and phosphate.

[0076] Experimental conditions: Cr(VI) solution: adsorbent dosage = 0.5-2.5 g / L, CO = 100 mg / L, pH = 2, t = 12 h, T = 25 ℃; phosphate solution: adsorbent dosage = 0.25-1.25 g / L, CO = 60 mg / L, pH = 2, t = 12 h, T = 25 ℃.

[0077] The results are as follows Figure 8 As shown, (a) is the adsorption diagram for Cr(VI), and (b) is the adsorption diagram for phosphate. With increasing adsorbent dosage, the adsorption capacity of Arg-HZO for Cr(VI) and phosphate significantly increases. However, when the dosage exceeds a certain value, the adsorption capacity remains almost constant. This is because excessive adsorbent leads to overlapping adsorption sites and a decrease in the ratio of Cr(VI) and phosphate to active adsorption sites.

[0078] Example 8

[0079] This embodiment investigates the effect of adsorption time on the adsorption of Cr(VI) and phosphate by Arg-HZO.

[0080] Experimental conditions: Cr(VI) solution: t = 0-400 min, CO = 100 mg / L, pH = 2, adsorbent dosage = 1 g / L, T = 25℃; phosphate solution: t = 0-1000 min, CO = 40-60 mg / L, pH = 2, adsorbent dosage = 0.5 g / L, T = 25℃.

[0081] The results are as follows Figure 9As shown, (a) is the adsorption diagram for Cr(VI), and (b) is the adsorption diagram for phosphate. The adsorption rate is rapid in the early stages of adsorption, gradually slowing down with increasing reaction time until adsorption equilibrium is reached. This change in adsorption trend can be attributed to: in the initial stage of adsorption, a large number of available adsorption sites exist on the adsorbent; in addition, the high concentrations of Cr(VI) and phosphate in the solution at this time create a large concentration difference at the solid-liquid interface, which is conducive to increasing the adsorption rate of Cr(VI) and phosphate. In the later stage of adsorption, most adsorption sites are occupied, resulting in a reduction in effective adsorption sites. In addition, the concentrations of Cr(VI) and phosphate in the solution decrease, causing the adsorption rate to gradually slow down until adsorption equilibrium is reached.

[0082] Example 9

[0083] This embodiment investigates the adsorption capacity of Arg-HZO for different Cr(VI) and phosphate concentrations at three different temperatures (298, 308 and 318 K).

[0084] Experimental conditions: Cr(VI) solution: T = 298-318K, CO = 75-200mg / L, pH = 2, adsorbent dosage = 1g / L, t = 10h; phosphate solution: T = 298-318K, CO = 40-80mg / L, pH = 2, adsorbent dosage = 0.5g / L, t = 16h.

[0085] The results are as follows Figure 10 As shown, (a) is the adsorption diagram for Cr(VI), and (b) is the adsorption diagram for phosphate. It can be seen that the adsorption capacity of Arg-HZO increases with increasing initial concentration. Simultaneously, the adsorption capacity also increases slightly with increasing temperature, indicating that higher temperature favors adsorption, and the adsorption of Cr(VI) and phosphate by Arg-HZO is an endothermic reaction.

[0086] Example 10

[0087] Tables 1 and 2 compare the adsorption of Cr(VI) and phosphate by other zirconium-based adsorbents and Arg-HZO adsorbents:

[0088] It can be seen that Arg-HZO has a higher adsorption capacity for Cr(VI) and phosphate than most zirconium-based adsorbents in the literature, indicating that Arg-HZO has great research value in the removal of Cr(VI) and phosphate.

[0089] Other zirconium-based adsorbents listed in Table 1 are polypyrrole-modified zirconium α-phosphate nanocomposite material (PPy-ZrPO4), zirconium oxide intercalated sodium montmorillonite composite material (ZrO2-NaMMT@700), zirconium metal-organic framework modified by Nitrosomonas, and zirconium-loaded mesoscopic silica nanoparticles (Zr / MSN). Among them, the polypyrrole-modified zirconium α-phosphate nanocomposite material (PPy-ZrPO4) is from the literature "Materials Chemistry and Physics, 2022, 290:126540", the zirconium oxide intercalated sodium montmorillonite composite material (ZrO2-NaMMT@700) is from the literature "Journal of Environmental Chemical Engineering, 2021, 9(5):106053", and the zirconium metal-organic framework modified by Nitrosomonas is from the literature "Chemical Engineering". Journal, 2019, 360: 879-889; Zirconium-loaded mesostructured silica nanoparticles (Zr / MSN) are from the literature "Industrial & Engineering Chemistry Research, 2018, 58(2): 704-712".

[0090] Table 1 Comparison of Cr(VI) removal capabilities with other zirconium-based adsorbents

[0091]

[0092] Other zirconium-based adsorbents listed in Table 2 are zirconium-modified magnesium-aluminum layered double hydroxide (Zr-LDH), La-Zr bimetallic modified magnetic adsorbent (La-Zr@Fe3O4), Fe3O4 / ZrO2 composite material (Fe3O4 / ZrO2), and polyethylene glycol modified alginate-Zr. 4+ Interpenetrating network beaded adsorbents with PNIPAM (PEG-modified PNIPAM / SA-Zr hydrogel bead), including zirconium-modified magnesium aluminum layered double hydroxide (Zr-LDH) from the literature "Environmental Progress & Sustainable Energy, 2021, 41(2):e13744", La-Zr bimetallic modified magnetic adsorbent (La-Zr@Fe3O4) from the literature "Chemical Engineering Journal, 2021, 413:127530", Fe3O4 / ZrO2 composite material (Fe3O4 / ZrO2) from the literature "Chemical Engineering Journal, 2023, 451:139817", and polyethylene glycol modified alginate-Zr4+ The PNIPAM interpenetrating network bead adsorbent (PEG-modified PNIPAM / SA-Zr hydrogel bead) is from the literature "International Journal of Biological Macromolecules, 2019, 126: 1133-1144".

[0093] Table 2 Comparison of phosphate removal capabilities with other zirconium-based adsorbents

[0094]

[0095] Example 11

[0096] This embodiment investigates the cyclic regeneration performance of Arg-HZO.

[0097] Experimental conditions: Cr(VI) solution: CO = 100 mg / L, pH = 2, adsorbent dosage = 1 g / L, t = 10 h, T = 25 ℃, NaOH = 0.1 M; phosphate solution: CO = 40 mg / L, pH = 2, adsorbent dosage = 0.5 g / L, t = 16 h, T = 25 ℃, NaOH = 0.1 M.

[0098] The results are as follows Figure 11 As shown in the figure, (a) is the adsorption diagram for Cr(VI), and (b) is the adsorption diagram for phosphate. It can be seen from the figure that after five cycles of adsorption experiments, Arg-HZO still exhibits good adsorption performance for Cr(VI) and phosphate. Therefore, Arg-HZO has good regenerability and reusability, making it a highly efficient adsorbent for treating Cr(VI) and phosphate ions.

[0099] Example 12

[0100] This embodiment investigates the effect of competing ions on the adsorption of phosphate by Arg-HZO.

[0101] Experimental conditions: CO = 40 mg / L, pH = 2, adsorbent dosage = 0.5 g / L, t = 16 h, T = 25 °C, Cl - SO4 2- and NO3 - =0.01-0.1mol / L.

[0102] The results are as follows Figure 12 As shown. Cl - and NO3 - The presence of SO4 has a negligible effect on the phosphate adsorption capacity, while SO4 2- This is not conducive to phosphate removal. This may be due to the difference in the hydration radius and negative charge of the ions, SO42-2- Divalent anions compete for adsorption sites with phosphate ions due to their similar hydration radius. Therefore, compared to monovalent anions, divalent anions reduce the adsorption performance of Arg-HZO. Nevertheless, Arg-HZO still exhibits good anti-interference capabilities and shows great promise for phosphate adsorption.

[0103] Example 13

[0104] This embodiment explores the fixed bed column experiment of Arg-HZO.

[0105] Experimental conditions: Adsorbent weight = 4.7 g, bed height = 3.3 cm, bed volume = 5.08 mL, phosphate concentration = 5 mg / L, Cl - =6mg / L, NO3 - =1 mg / L, SO4 2- =10mg / L, pH=2, flow rate=10BV / h exhaustion point (C t / C0) = 90%.

[0106] The results are as follows Figure 13 As shown. It can be seen that although coexisting ions (Cl...) exist... - NO3 - and SO4 2- Despite interference from other sources, Arg-HZO can effectively treat 15.30 L of phosphate wastewater, maintaining the effluent concentration below 0.3 mg / L. Furthermore, Arg-HZO can treat a maximum of 71.40 L of synthetic wastewater even at its depletion point. In conclusion, Arg-HZO demonstrates excellent capabilities for the deep treatment of phosphate-containing wastewater and is an adsorbent material with broad practical application potential.

[0107] Example 14

[0108] Weigh 1.75 g of lysine (Lys) into 68.25 g of deionized water and stir at room temperature. After the Lys is completely dissolved, slowly add 30 g of ammonium zirconium carbonate (AZC) solution dropwise while stirring continuously, and then stir at room temperature for 1 hour. The mixture is then transferred to a petri dish and dried in a 120°C oven for 12 hours. The resulting block sample is then repeatedly soaked and washed with deionized water. The soaked sample is then filtered repeatedly at least three times using filter paper with a thickness of ≥800 nm. Finally, the resulting powder is dried in a 70°C oven for 12 hours. This yields the Lys-HZO adsorbent.

[0109] Example 15

[0110] The difference from Example 14 is that Lys accounts for 1.67% of the mass of AZC.

[0111] Example 16

[0112] The difference from Example 14 is that Lys accounts for 3.33% of the mass of AZC.

[0113] Example 17

[0114] The difference from Example 14 is that Lys accounts for 5% of the mass of AZC.

[0115] Example 18

[0116] The difference from Example 14 is that Lys accounts for 6.67% of the mass of AZC.

[0117] Example 19

[0118] Figure 14 (ab) shows the effect of the proportion of Lys in AZC in the hybrid material on the adsorption capacity of Cr(VI) and phosphate.

[0119] Experimental conditions: Cr(VI) solution: pH=2, CO=100mg / L, adsorbent dosage=1g / L, t=16h, T=25℃; phosphate solution: pH=2, CO=60mg / L, adsorbent dosage=0.5g / L, t=16h, T=25℃.

[0120] It can be seen that the adsorption capacity of both Cr(VI) and phosphate increases with the increase of Lys dosage. However, when the proportion of Lys in AZC reaches 6.67%, the filtration process becomes more difficult due to the strong hydrophilicity of the hybrid material. Therefore, the composite adsorbent prepared with a Lys dosage of 5.83% of the AZC mass was selected for subsequent experiments and denoted as Lys-HZO.

[0121] Figure 15 These are the infrared spectra of Lys, HZO, and Lys-HZO. The figures show that Lys-HZO contains characteristic functional groups of both Lys and HZO, indicating that they have successfully hybridized.

[0122] Figure 16 The images show the XRD patterns of Lys, HZO, and Lys-HZO. It can be seen that Lys has a crystalline structure, while HZO and Lys-HZO have amorphous structures. Therefore, it can be inferred that during the hybridization process of Lys with HZO, the crystalline structure is gradually destroyed, eventually resulting in a uniform and compact hybridization with HZO to form an amorphous molecular-level organic-inorganic hybrid material (Lys-HZO).

[0123] Figure 17These are the thermogravimetric curves of Lys-HZO and HZO. As can be seen from the figure, HZO decomposes almost completely at around 600℃, while Lys-HZO only decomposes completely around 700℃. This demonstrates that the introduction of Lys enhances the thermal stability of the material.

[0124] Example 20

[0125] This embodiment investigates the effect of Lys-HZO dosage on the adsorption of Cr(VI) and phosphate.

[0126] Experimental conditions: Cr(VI) solution: adsorbent dosage = 0.5-3 g / L, CO = 150 mg / L, pH = 2, t = 16 h, T = 25 ℃; phosphate solution: adsorbent dosage = 0.25-1.5 g / L, CO = 60 mg / L, pH = 2, t = 16 h, T = 25 ℃.

[0127] The results are as follows Figure 18 As shown in the figure, (a) is the adsorption diagram for Cr(VI), and (b) is the adsorption diagram for phosphate. It can be seen from the figures that with the increase of the dosage, the removal rates of Cr(VI) and phosphate by the adsorbent gradually increase and slowly approach equilibrium. The figures also show that the unit adsorption capacity of Lys-HZO generally shows a gradual decreasing trend with the increase of the dosage.

[0128] Example 21

[0129] This embodiment investigates the effect of the initial pH value of the solution on the adsorption of Cr(VI) and phosphate by Lys-HZO and HZO.

[0130] Experimental conditions: Cr(VI) solution: pH = 2-10, CO = 100 mg / L, t = 16 h, T = 25 ℃, adsorbent dosage = 1 g / L; phosphate solution: pH = 2-10, CO = 60 mg / L, t = 16 h, T = 25 ℃, adsorbent dosage = 0.5 g / L.

[0131] The results are as follows Figure 19 As shown, (a) is the adsorption diagram for Cr(VI), and (b) is the adsorption diagram for phosphate. The adsorption capacities of Lys-HZO and HZO for both Cr(VI) and phosphate are maximum at pH = 2, after which the adsorption capacity decreases rapidly with increasing solution pH. However, it is evident that Lys-HZO exhibits greater adsorption performance than HZO within the tested pH range, indicating that the introduction of Lys enhances the adsorption effect of the adsorbent.

[0132] Example 22

[0133] This embodiment investigates the effect of adsorption time on the adsorption of Cr(VI) and phosphate by Lys-HZO.

[0134] Experimental conditions: Cr(VI) solution: t = 0-1440 min, CO = 100 mg / L, pH = 2, T = 25 ℃, adsorbent dosage = 1 g / L; phosphate solution: t = 0-1440 min, CO = 60 mg / L, pH = 2, T = 25 ℃, adsorbent dosage = 0.5 g / L.

[0135] The results are as follows Figure 20 As shown, (a) is the adsorption diagram for Cr(VI), and (b) is the adsorption diagram for phosphate. Initially, the adsorption rate of Lys-HZO is relatively fast, then the adsorption rate begins to slow down until adsorption equilibrium is reached. This is because in the initial stage of adsorption, there are a large number of available adsorption sites on the adsorbent surface, and at the same time, there are a large number of Cr(VI) and phosphate ions in the solution, which allows Lys-HZO to perform rapid adsorption. However, as time goes on, the adsorption sites on the material surface are gradually occupied, and the Cr(VI) and phosphate in the solution gradually decrease, thus the adsorption rate gradually slows down, eventually reaching adsorption equilibrium.

[0136] Example 23

[0137] This embodiment investigates the adsorption capacity of Lys-HZO for different Cr(VI) and phosphate concentrations at three different temperatures (298, 308 and 318 K).

[0138] Experimental conditions: Cr(VI) solution: T = 298-318K, CO = 75-200mg / L, pH = 2, adsorbent dosage = 1g / L, t = 24h; phosphate solution: T = 298-318K, CO = 20-60mg / L, pH = 2, adsorbent dosage = 0.5g / L, t = 24h.

[0139] The results are as follows Figure 21 As shown, (a) is the adsorption diagram for Cr(VI), and (b) is the adsorption diagram for phosphate. The adsorption capacity of Lys-HZO increases with increasing initial solution concentration and gradually approaches equilibrium. This may be because when the solution concentration is low, the number of adsorption sites on the adsorbent is greater than the number of Cr(VI) and phosphate ions in the solution. However, as the solution concentration increases, the adsorption sites are gradually occupied, eventually reaching saturation. It was also found that the adsorption capacity slightly increases with increasing temperature, indicating that higher temperature favors adsorption, and the adsorption of Cr(VI) and phosphate by Lys-HZO is an endothermic reaction.

[0140] Example 24

[0141] This embodiment investigates the effect of competing ions on the adsorption of Cr(VI) and phosphate by Lys-HZO.

[0142] Experimental conditions: Cr(VI) solution: pH = 2, CO = 100 mg / L, t = 16 h, T = 25 °C, adsorbent dosage = 1 g / L, Cl - SO4 2- and NO3 - =0-200mg / L; Phosphate solution: pH=2, CO=60mg / L, t=16h, T=25℃, adsorbent dosage=0.5g / L, Cl - SO4 2- and NO3 - =0-200mg / L.

[0143] The results are as follows Figure 22 As shown, (a) is the adsorption diagram for Cr(VI), and (b) is the adsorption diagram for phosphate. In Cl... - and NO3 - In the presence of SO42-, the adsorption capacity of Lys-HZO for Cr(VI) and phosphate did not change significantly with increasing ion concentration. Conversely, with increasing SO42-, the adsorption capacity increased. 2- As the concentration of Cr(VI) increases, the adsorption capacity of the adsorbent for Cr(VI) and phosphate gradually decreases, causing significant interference. However, despite this, Lys-HZO still exhibits good anti-interference capabilities and shows great promise for the adsorption of Cr(VI) and phosphate.

Claims

1. A method for preparing an amino acid-hydrated zirconium oxide hybrid material, characterized in that... Includes the following steps: (1) Dissolve the amino acids in deionized water, then add zirconium ammonium carbonate solution dropwise, and then stir at room temperature to obtain a transparent mixed solution; The mass ratio of the amino acid, ammonium zirconium carbonate, and deionized water is 1:3.33-20:4-29. (2) After drying the transparent mixed solution at a constant temperature, a white solid is obtained. Then, after soaking, washing and filtering, a white precipitate is obtained. (3) The white precipitate was dried at a constant temperature to obtain the amino acid-hydrated zirconium oxide hybrid material.

2. The method for preparing the amino acid-hydrated zirconium oxide hybrid material as described in claim 1, characterized in that, The amino acid mentioned in step (1) is arginine or lysine.

3. The method for preparing the amino acid-hydrated zirconium oxide hybrid material as described in claim 1, characterized in that, The stirring time in step (1) is 1 hour.

4. The method for preparing the amino acid-hydrated zirconium oxide hybrid material as described in claim 1, characterized in that, The drying temperature in step (2) is 120℃ and the drying time is 12h.

5. The method for preparing the amino acid-hydrated zirconium oxide hybrid material as described in claim 1, characterized in that, The drying temperature in step (3) is 70°C and the drying time is 12 hours.

6. The amino acid-hydrated zirconium oxide hybrid material prepared by the preparation method according to claims 1 to 5.

7. The application of the amino acid-hydrated zirconium oxide hybrid material as described in claim 6 in the adsorption of Cr(VI) and phosphate.

8. The application as described in claim 7, characterized in that: The amino acid-hydrated zirconium oxide hybrid material is used in the adsorption of Cr(VI) and phosphate at pH 2 to 10.

9. The application as described in claim 7, characterized in that: The amino acid-hydrated zirconium oxide hybrid material is added at an amount of 0.25–3 g / L for the adsorption of Cr(VI) and phosphate.

10. The application as described in claim 7, characterized in that: The amino acid-hydrated zirconium oxide hybrid material exhibits an adsorption temperature of 298–318 K for the adsorption of Cr(VI) and phosphate.

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