A composite adsorbent material, its preparation method, and its application in uranium adsorption.

Abstract

This invention discloses a composite adsorbent material, its preparation method, and its application in uranium adsorption, belonging to the field of materials technology. The method includes the following steps: S1: A raw material containing collagen fibers and a metal salt is subjected to reaction I to obtain a metal ion / collagen fiber composite; the metal is a transition metal; S2: A mixture containing the metal ion / collagen fiber composite from step S1, a sulfide, and a surfactant is subjected to reaction II to obtain a collagen fiber-based nano-metal sulfide composite adsorbent material. This invention combines collagen fibers with nano-metal sulfide materials, solving the problems of difficult recovery and low reusability of nano-metal sulfide materials when removing radioactive ions from water alone, while also overcoming the low adsorption capacity of collagen fibers alone. This composite material is a highly efficient remover of UO2 from aqueous solutions. 2+ A novel adsorbent material with a maximum adsorption capacity of 300–400 mg / g.

Description

Technical Field

[0001] This invention belongs to the field of materials technology, and particularly relates to a composite adsorbent material, its preparation method, and its application in adsorbing uranium. Background Technology

[0002] Nuclear power, as a clean energy source, can effectively alleviate the greenhouse effect and energy shortages. Uranium (U), a strategic resource, is the primary raw material used in the nuclear industry, and with the rapid development of nuclear power globally, the demand for uranium continues to increase. Uranium is often produced in the form of soluble UO2. 2+ Uranium exists in the form of radioactive nuclear wastewater and natural seawater. Due to its radioactivity, toxicity, and long half-life, uranium not only poses a serious threat to human health but also causes severe environmental pollution. Therefore, from the perspective of nuclear fuel resource utilization and human health, the adsorption of uranium from water bodies is crucial.

[0003] Currently, there are various methods for removing uranium from aqueous solutions, such as extraction, electrochemistry, photocatalysis, and adsorption (Abney et al., 2017). Among these methods, adsorption is widely considered an effective method due to its simplicity, low cost, low secondary pollution, and regenerable adsorbent (Manos and Kanatzidis., 2016; Mellah et al., 2006).

[0004] Traditional adsorbents are difficult to recover, have low reusability, and low adsorption capacity when removing radioactive ions from water; therefore, there is an urgent need to develop a method that can efficiently remove UO2 from aqueous solutions. 2+ A novel adsorbent material. Summary of the Invention

[0005] In view of this, the present invention provides a composite adsorbent material, its preparation method and its application in uranium adsorption, the main purpose of which is to solve the technical problems that the performance of uranium adsorbents needs to be improved and the types need to be expanded.

[0006] On the one hand, the present invention provides a method for preparing a composite adsorbent material, the method comprising the following steps:

[0007] S1: Raw materials containing collagen fibers and metal salts are reacted in reaction I to obtain a metal ion / collagen fiber complex; wherein the metal is a transition metal.

[0008] S2: A mixture containing the metal ion / collagen fiber complex, sulfide, and surfactant from step S1 is subjected to reaction II to obtain a collagen fiber-based nano-metal sulfide composite adsorbent material.

[0009] The metal salts selected in this invention can ionize into metal ions in aqueous solution.

[0010] The sulfides selected in this invention can serve as a sulfur source to provide sulfur and metal ions (such as Zn). 2+ The reaction produces sulfides (such as ZnS).

[0011] Optionally, in step S1, the transition metal is selected from at least one metallic element from Group IIB, Group VIB, and Group VIIB.

[0012] Optionally, in step S1, the metal is selected from at least one of zinc, molybdenum, tungsten, and manganese.

[0013] Optionally, the metal salt includes an organozinc salt.

[0014] Optionally, the organic zinc salt includes zinc acetate.

[0015] Optionally, the sulfide is selected from at least one of thioacetamide, thiourea, ammonium sulfide, L-cysteine, sodium thiosulfate, and thiols.

[0016] Optionally, the surfactant is selected from at least one of octadecylamine, sodium dodecyl sulfonate, ethylenediamine, sodium dodecylbenzene sulfonate, polyvinylpyrrolidone, and ethylenediaminetetraacetic acid.

[0017] Optionally, the collagen fibers described in step S1 are treated with alkali to obtain alkali-modified collagen fibers.

[0018] Optionally, the temperature of the alkali treatment is 40–60°C; preferably 50°C.

[0019] Optionally, the mixing ratio of the collagen fiber to the alkali is 1-5g:80-120mL; the alkali is selected from an aqueous solution of sodium hydroxide with a concentration of 0.025-0.1mol / L.

[0020] Optionally, the mixing ratio of the collagen fiber to the alkali is 2-4 g: 90-110 mL; the alkali is selected from an aqueous solution of sodium hydroxide with a concentration of 0.05-0.08 mol / L.

[0021] Optionally, the mixing ratio of the collagen fibers to the alkali is 3g:100mL; the alkali is selected from a sodium hydroxide aqueous solution with a concentration of 0.075mol / L.

[0022] Optionally, in step S1, the reaction I process includes: immersing the collagen fibers in a solution of the metal salt, heating to evaporate the solvent, replenishing the solution of the metal salt, repeating this process multiple times to obtain the metal ion / collagen fiber complex.

[0023] Optionally, the mixing ratio of the collagen fiber and the metal salt solution is 0.03-0.15g:2-10mL, and the concentration of the metal salt solution is 0.02-0.08mol / L.

[0024] Optionally, the mixing ratio of the collagen fiber and the zinc salt solution is 0.03–0.08 g: 2–5 mL, and the concentration of the zinc salt solution is 0.03–0.07 mmol / L.

[0025] Optionally, the mixing ratio of the collagen fiber and the zinc salt solution is 0.05 g: 3 mL, and the concentration of the zinc salt solution is 0.05 mmol / L.

[0026] Optionally, the temperature for heating and evaporating the solvent is 50–65°C, the time for heating and evaporating the solvent is 1.5–3.5 h, and the number of repetitions is 3–6.

[0027] The reaction I process in step S1 of the present invention is the process of heating and evaporating the solvent. The temperature of reaction I is 50-65°C and the reaction time is 1.5h-3.5h.

[0028] Optionally, the temperature for heating and evaporating the solvent is selected from any value of 50°C, 55°C, 60°C, 65°C, or a range between any two.

[0029] Optionally, the heating and evaporation time of the solvent is selected from any value of 1.5, 2.0, 2.5, 3.0, 3.5 or a range between any two.

[0030] The option is low, and the repeated times are selected from any value among 3, 4, 5, and 6 times or any range between two values.

[0031] Optionally, in step S2, the mixing ratio of the metal ion / collagen fiber complex, the sulfide, and the surfactant is (0.2–1.5) g: (0.5–5) mmol: (0.02–2) mmol.

[0032] Optionally, in step S2, the mixing ratio of the zinc ion / collagen fiber complex, the sulfide, and the surfactant is (0.3-1.0) g: (1-1.5) mmol: (0.05-1.5) mmol.

[0033] Optionally, in step S2, the mixing ratio of the zinc ion / collagen fiber complex, the sulfide, and the surfactant is (0.4-0.6) g: (1-1.5) mmol: (0.05-1.2) mmol.

[0034] Optionally, in step S2, the mixture further includes the same metal salt solution and water added again. The invention adds the same metal salt again in step S2 to make reaction II more complete.

[0035] Optionally, in step S2, the mixing ratio of the metal ion / collagen fiber complex, the ethanol solution of the sulfide, the ethanol solution of the surfactant, the same metal salt solution added again, and water is (0.2-1.5) g : (2-15) mL : (2-15) mL : (40-150) mL : 1 mL; the concentration of the ethanol solution of the sulfide is 200-300 mmol / L.

[0036] The concentration of the surfactant in the ethanol solution is 8–12 mmol / L;

[0037] The concentration of the same metal salt solution added again is 0.03–0.08 mol / L.

[0038] Optionally, in step S2, the mixing ratio of the metal ion / collagen fiber complex, the ethanol solution of the sulfide, the ethanol solution of the surfactant, the same metal salt added again, and water is (0.3-1.0) g: (2-10) mL: (2-10) mL: (40-100) mL: 1 mL.

[0039] Optionally, in step S2, the mixing ratio of the metal ion / collagen fiber complex, the ethanol solution of the sulfide, the ethanol solution of the surfactant, the same metal salt added again, and water is (0.4-0.8) g: (2-10) mL: (2-10) mL: (40-100) mL: 1 mL.

[0040] Optionally, in step S2, the reaction II process is carried out at room temperature, and the reaction time is 20-30 hours, preferably 24 hours.

[0041] Optionally, in step S2, the product after reaction II is washed and freeze-dried to obtain the collagen fiber-based nano-metal sulfide composite adsorbent material.

[0042] Secondly, the present invention provides a composite adsorbent material, which is prepared by the above method.

[0043] Optionally, the specific surface area of ​​the composite adsorbent material is 15–30 m². 2 / g; the metal sulfide nanoparticles on the surface of the composite adsorbent material have a particle size of 50-200 nm and a spherical morphology; the maximum adsorption capacity of the composite adsorbent material for uranyl ions is 300-400 mg / g.

[0044] Thirdly, the present invention provides the composite adsorbent material prepared by the above method or the application of the above composite adsorbent material in the adsorption treatment of uranium-containing wastewater.

[0045] Fourthly, the present invention provides a method for treating uranium-containing wastewater, the method comprising the following steps: contacting an adsorbent material with a uranium-containing solution, wherein the adsorbent material adsorbs uranyl ions in the uranium-containing solution, and separating the adsorbent material and the solution adsorbed with uranyl ions;

[0046] The adsorbent material includes the composite adsorbent material prepared by the above method or the above composite adsorbent material.

[0047] Optionally, the adsorption temperature is 25–60°C; the contact time is 6–12 h; the pH of the uranium-containing solution is 2–11; and the concentration of uranyl ions in the uranium-containing solution is 4.35–588 ppm.

[0048] Optionally, the adsorption temperature is selected from any value of 25, 30, 35, 40, 45, 50, 55, 60°C or a range between any two.

[0049] Optionally, the contact time is selected from any value of 6, 7, 8, 9, 10, 11, 12h or a range between any two.

[0050] Optionally, the pH of the uranium-containing solution is any value among 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11, or a range between any two; preferably 3-10.

[0051] Optionally, the uranium-containing solution flows through an adsorption column, the adsorption column being filled with the adsorption material, the adsorption material adsorbing and extracting uranyl ions from the uranium-containing solution.

[0052] The collagen fibers selected in this invention refer to renewable natural fibrous biomass materials extracted from animal skin. As a natural polymer, collagen fibers possess a unique structure and unparalleled reactivity. Structurally, collagen molecules consist of three helical peptide chains bonded together by hydrogen bonds. This structural feature also endows collagen fibers with good mechanical strength, which can be further enhanced through appropriate chemical cross-linking. In terms of properties, each polypeptide chain of a collagen molecule consists of approximately 1000 amino acids and contains a large number of functional groups, such as -OH, -CONH2, -COOH, and -NH2, which can act as reactive groups to bind ions or branch other compounds to achieve functional modification.

[0053] The metal sulfide nanomaterials selected in this invention possess excellent properties such as small particle size and large specific surface area. Sulfides can be strongly... (The sentence is incomplete and requires more context to translate accurately.) 2+ ···S 2- Bond interactions realize UO2 2+Capture. Although metal sulfide nanomaterials have good removal effects, they still have problems such as easy agglomeration, poor mechanical stability, and difficulty in recycling in practical applications.

[0054] To address the aforementioned problems, this invention combines collagen fibers with nano-zinc sulfide materials. This overcomes the drawbacks of nano-sulfide materials alone in removing radioactive ions from water, such as difficulty in recovery and low reusability, while also overcoming the low adsorption capacity of collagen fibers alone. The composite material prepared by this invention is capable of efficiently removing UO2 from aqueous solutions. 2+ A novel adsorbent material.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] 1) This invention is the first to load metal sulfides onto collagen fibers to form a composite adsorbent material. This composite material significantly improves the adsorption performance of collagen fibers for uranium while retaining the original mechanical toughness of the collagen fibers.

[0057] 2) The preparation method of collagen fiber-based nano zinc sulfide composite adsorbent material provided by the present invention is simple to operate, easy to repeat, and the raw materials are cheap and readily available, resulting in low cost.

[0058] 3) The synthesis reaction conditions of the collagen fiber-based nano-zinc sulfide composite adsorbent material prepared by this invention are mild, the equipment requirements are not high, and it belongs to a low-energy consumption process.

[0059] 4) The preparation method provided by the present invention can solve the problems of small powder particles, difficulty in recovery and recycling when using nano zinc sulfide as an ion adsorbent, and overcome the disadvantage of low adsorption capacity when using collagen fiber alone.

[0060] 5) This invention addresses UO2 2+ Ion adsorption experiments are applicable to aqueous solutions with a wide pH range.

[0061] 6) This invention utilizes the system's UO2 2+ Ion adsorption experiments, including kinetics, concentration dependence, acid and alkali resistance, and application of adsorption columns, confirmed that the prepared adsorbent is a highly efficient adsorbent for UO2. 2+ The material containing ions, after being irradiated with a high dose of gamma rays, has a uranium removal rate of no less than 93%, and has broad application prospects in the field of radioactive waste treatment. Attached Figure Description

[0062] Figure 1 The image is a scanning electron microscope (SEM) image of the collagen fiber-based nano-zinc sulfide composite adsorbent material provided in Example 1 of this invention.

[0063] Figure 2Comparison of X-ray powder diffraction patterns of nano-zinc sulfide and collagen fiber-based nano-zinc sulfide composite adsorbent materials provided in Example 1 of this invention;

[0064] Figure 3 The original collagen fibers, collagen fiber-based nano-zinc sulfide composite adsorbent material, and collagen fiber-based nano-zinc sulfide composite adsorbent material provided in Example 1 of this invention adsorb UO2. 2+ Comparison of infrared spectra after ionization;

[0065] Figure 4 The collagen fiber-based nano-zinc sulfide composite adsorbent material provided in Example 1 of this invention is used to remove UO2. 2+ Ion kinetic diagram;

[0066] Figure 5 The collagen fiber-based nano-zinc sulfide composite adsorbent material provided in Example 1 of this invention is used to remove UO2. 2+ Adsorption model diagram of ions;

[0067] Figure 6 The collagen fiber-based nano-zinc sulfide composite adsorbent provided in Example 1 of this invention exhibits good adsorption properties for UO2 over a wide pH range. 2+ Ion removal rate and partition coefficient diagram;

[0068] Figure 7 The removal of UO2 by the original and irradiated collagen fiber-based nano-zinc sulfide composite adsorbent materials provided in Example 1 of this invention. 2+ Ion effect diagram;

[0069] Figure 8 This is a data graph showing the collagen fiber-based nano-zinc sulfide composite adsorbent material sample provided in Example 1 of the present invention in an adsorption column experiment; wherein, Figure 8 a is the use of collagen fiber-based nano-zinc sulfide composite adsorbent material to adsorb UO2 in column experiments. 2 + Ion removal rate graph; Figure 8 b is a collagen fiber-based nano-zinc sulfide composite adsorbent material used as a column packing material for treating UO2-containing substances. 2+ The breakthrough curve of the aqueous solution, fitted by the Thomas model;

[0070] Figure 9 The graph shows the removal rate and partition coefficient of various ions in a simulated seawater solution for the collagen fiber-based nano-zinc sulfide composite adsorbent material sample provided in Example 1 of the present invention.

[0071] Figure 10 The collagen fiber-based nano-zinc sulfide composite adsorbent material provided in Example 1 of this invention adsorbs UO2. 2+ EDS plot;

[0072] Figure 11 SEM images of collagen fiber-based nano-sulfide composite adsorbent materials provided in Comparative Examples 1 and 2 of this invention at different resolutions; wherein, In2S3 / collagen fiber (ab), Sn2S3 / collagen fiber (cd).

[0073] Figure 12 The collagen fiber-based nano-sulfide composite adsorbent materials provided in Comparative Examples 1 and 2 of this invention adsorb UO2 2+ EDS diagrams; where In2S3 / collagen fiber (a) and Sn2S3 / collagen fiber F (b). Detailed Implementation

[0074] The present application is further illustrated below with reference to specific embodiments. The following descriptions are merely a few embodiments of the present application and are not intended to limit the present application in any way. Although the present application discloses preferred embodiments as follows, they are not intended to limit the present application. Any modifications or variations made by those skilled in the art without departing from the scope of the technical solution of the present application using the disclosed technical content are equivalent to equivalent implementation cases and all fall within the scope of the technical solution.

[0075] Unless otherwise specified, the raw materials used in the embodiments of this application are all purchased commercially and used directly without any special treatment.

[0076] Scanning electron microscopy (SEM) was performed on a JEOL JSM-6700F instrument.

[0077] Inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectroscopy (ICP-OES) were performed on XSerise II and Thermo 7400 devices, respectively.

[0078] X-ray powder diffraction (XRD) phase analysis was performed on a Rigaku Miniflex II X-ray diffractometer at 30 kV and 15 mA, with a Cu target and a Kα radiation source.

[0079] Energy dispersive X-ray spectroscopy (EDS) measurements were performed on a HITACHI FE-SEM SU8010 instrument.

[0080] Example 1 (Preparation of collagen fiber-based zinc sulfide nanocomposite adsorbent material)

[0081] (1) At room temperature, 3g of collagen fiber was soaked in distilled water for 12 hours. After soaking, the sample was filtered and dried at 50℃ for 24 hours. Then, the dried collagen fiber sample was immersed in 100mL of 0.075mol / L NaOH solution and shaken in a shaker at 50℃ for 5 hours. Subsequently, the collagen fiber sample was filtered and washed several times with deionized water to remove unreacted NaOH solution. After vacuum drying at 50℃ for 8 hours, alkali-modified collagen fiber was obtained.

[0082] (2) Divide 0.5g of alkali-modified collagen fiber into 10 equal parts, and add 3mL of 0.05mol / L zinc acetate solution to each part; then put these ten alkali-modified collagen fiber parts into an oven at 55℃ for 2.5 hours until the solvent is evaporated; then, add 3mL of 0.05mol / L zinc acetate solution to each part and evaporate again for 2.5 hours; repeat the "add solution-solvent evaporation" operation 6 times; put the collected ten samples into a 100mL glass bottle, and add 5mL of 10.8mmol / L octadecylamine ethanol solution, 1mL of distilled water, 50mL of 0.05mol / L zinc acetate aqueous solution and 5mL of 250mmol / L thioacetamide ethanol solution in sequence; shake the glass bottle at room temperature for 24 hours, centrifuge after complete reaction, collect the solid product, wash with deionized water and ethanol, and freeze dry for 24 hours; finally, collagen fiber-based nano zinc sulfide composite adsorbent material is obtained.

[0083] Comparative Example 1 (Preparation of Collagen Fiber-Based Indium Sulfide Nanocomposite Adsorbent Material)

[0084] The difference between Comparative Example 1 and Example 1 lies in step (2): First, 0.5g of unmodified collagen fibers were divided into 10 equal portions, and each portion was soaked in a quartz boat containing 3mL of 0.1mol / L indium acetate solution. Then, the boat was placed in an oven at 55°C for 2.5 hours until the solvent was evaporated. After one evaporation, 3mL of 0.1mol / L indium acetate solution was added and evaporation continued for 2.5 hours. This "addition-evaporation of solvent" operation was repeated 6 times. The collected product was In... 3+ / Collagen fibers. Then add 0.5 grams of In 3 + Collagen fibers were placed in a 100 mL glass bottle, and 5 mL of a 10.8 mmol / L octadecylamine ethanol solution, 1 mL of distilled water, and 50 mL of a 0.1 mol / L thioacetamide ethanol solution were added sequentially. The bottle was shaken at room temperature for 24 hours to allow the reactants to react completely. The solid product was collected by filtration, washed with deionized water and ethanol, and freeze-dried for 24 hours to obtain a gray-black, fibrous In2S3 / collagen fiber composite material.

[0085] Comparative Example 2 (Preparation of Collagen Fiber-Based Tin Sulfide Nanocomposite Adsorbent Material)

[0086] The difference between Comparative Example 2 and Example 1 lies in step (2): First, 0.5g of unmodified collagen fibers were divided into 10 equal portions. Each portion was soaked in a quartz boat containing 3mL of 0.1mol / L SnCl2·2H2O solution and placed in an oven at 55°C for 2.5 hours until the solvent evaporated. Subsequently, 3mL of 0.1mol / L SnCl2·2H2O solution was added to each portion, and evaporation continued for 2.5 hours. This "addition-evaporation of solvent" operation was repeated 6 times. The collected product was Sn 2+ Collagen fibers. Add 0.5 grams of Sn... 2+ Collagen fibers were placed in a 100 mL glass bottle. 5 mL of a 10.8 mmol / L octadecylamine ethanol solution, 1 mL of distilled water, and 20 mL of 0.1 mol / L Na₂S·9H₂O were added sequentially. The bottle was shaken at room temperature for 24 hours to allow the reactants to react completely. The solid product was collected by filtration, washed with deionized water and ethanol, and freeze-dried for 24 hours to obtain a grayish-black, fibrous Sn₂S₃ / collagen fiber composite material.

[0087] Comparative Example 3

[0088] WS2 nanosheets can reach U(VI) adsorption equilibrium within 30 minutes, with a maximum uranium adsorption capacity of 22.35 mg / g; published in the Journal of Radioanalytical and Nuclear Chemistry: Tungsten disulfide (WS2) nanosheets: synthesis, characterization, adsorption studies and application for remediation of groundwater samples with high prevalence of uranium from Faridkot district of SW Punjab. Received: 30 April 2021 / Accepted: 5 August 2021 Akadémiai Kiadó, Budapest, Hungary 2021.

[0089] Example 2 (Characteristics of collagen fiber-based nano-zinc sulfide composite adsorbent material)

[0090] The morphology of the samples prepared in Example 1 was analyzed using scanning electron microscopy (SEM). After in-situ growth of zinc sulfide nanoparticles, spherical particles with a size of 50–200 nm were uniformly distributed on the surface of the alkali-modified collagen fibers. Figure 1 a). Spherical zinc sulfide nanoparticles grow along the surface of collagen fibers, rather than diffusing in the interfiber spaces. Figure 1 b). Furthermore, no significant aggregation of zinc sulfide nanoparticles was observed. After successful loading of zinc sulfide nanoparticles, the specific surface area of ​​the material increased from 0.0121 m² to 21.3338 m². 2 The surface area was significantly increased by 1 g, resulting in a greater number of adsorption sites. This means that loading nano-zinc sulfide will facilitate the extraction of uranium from aqueous solutions.

[0091] Furthermore, in the powder diffraction pattern of the nano-zinc sulfide composite adsorbent material ( Figure 2 In the infrared spectroscopy, characteristic diffraction peaks corresponding to nano-zinc sulfide appeared, with additional peaks at 5-10° belonging to pure collagen fibers. Apart from these, no other diffraction peaks were found, further indicating that nano-zinc sulfide successfully bonded to collagen fibers without altering the two phases of collagen fibers and nano-zinc sulfide. Figure 3 The composite mechanism of zinc sulfide nanoparticles and collagen fibers was investigated. The results showed that the collagen fiber-based zinc sulfide nanoparticle composite adsorbent retained the same complete characteristic amide bands as the original collagen fibers, and the structure of the collagen fibers was not destroyed.

[0092] Example 3 (Adsorption kinetics of uranium on collagen fiber-based zinc sulfide nanomaterials)

[0093] The collagen fiber-based zinc sulfide nanocomposite adsorbent material prepared in Example 1 was mixed with a uranium solution of a certain initial concentration, and stirred at 50°C according to the condition V (solution volume): m (exchange resin mass) = 1000 mL / g. Small amounts of the supernatant were taken at regular intervals, and the ion concentration was determined by inductively coupled plasma mass spectrometry. The test results are as follows: Figure 4 As shown in Table 1, the adsorption of uranium by the collagen fiber-based nano-zinc sulfide composite adsorbent material can reach equilibrium within 150 minutes.

[0094] Table 1. Removal of UO2 by Collagen Fiber-Based Nano-Zinc Sulfide Adsorbent Material 2+ Ion kinetic test results

[0095] Time (min) <![CDATA[C e U (mg / L)]]> Removal rate (%) 0 24.00 0 2.5 17.75 26.04 6 14.85 38.13 11.5 10.50 56.25 15.17 9.36 61.00 20 7.40 69.19 30.5 4.28 82.17 60 1.58 93.44 150 0.54 97.75 300 0.32 98.69 450 0.27 98.88 600 0.26 98.92 720 0.23 99.04 1200 0.20 99.17

[0096] Example 4 (Isothermal adsorption model test of uranium on collagen fiber-based zinc sulfide nano-adsorbent material)

[0097] The collagen fiber-based zinc sulfide nanocomposite adsorbent prepared in Example 1 was mixed with aqueous solutions of different initial uranium concentrations. The pH of the uranium solution was adjusted to 4.2 with diluted sodium hydroxide solution to avoid excessive acidity or uranium precipitation. The mixture was stirred at 50°C for 12 h at a ratio of V (solution volume):m (exchange resin mass) = 1000 mL / g. After adsorption, the supernatant and the initial solution were collected, and the uranium concentration was determined by inductively coupled plasma mass spectrometry. The experimental results are as follows: Figure 5 As shown in Table 2, the experimental data conform to the Langmuir-Freundlich adsorption model. The calculated maximum adsorption capacity of the collagen fiber-based zinc sulfide nanocomposite adsorbent for uranium is as high as 359.72 mg / g, as shown in Table 3.

[0098] Table 2. Removal of UO2 by Collagen Fiber-Based Nano-Zinc Sulfide Composite Adsorbent Material 2+ Isothermal adsorption model test of ions

[0099] <![CDATA[C0(mg / L)]]> <![CDATA[C e (mg / L)]]> Adsorption capacity (mg / g) 4.35 1.90 2.45 7.15 4.10 3.05 12.75 1.40 11.35 25.40 1.50 23.90 41.50 2.05 39.45 68.60 5.30 63.30 144.00 34.70 109.30 286.00 119.00 167.00 588.00 357.00 231.00

[0100] Table 3. Fitting data for different isothermal adsorption models

[0101]

[0102] Example 5 (Testing the ability of composite adsorbent materials to enrich and recover uranium at different pH levels)

[0103] The collagen fiber-based zinc sulfide nanocomposite adsorbent prepared in Example 1 was mixed with uranium solutions of different pH values ​​and stirred at 50°C for 12 h under the condition of V (solution volume):m (exchange resin mass) = 1000 mL / g. After adsorption was complete, the supernatant and the initial solution were collected, and the concentration of uranium was determined by inductively coupled plasma mass spectrometry. The results are as follows: Figure 6 As shown in Table 4, the collagen fiber-based nano-zinc sulfide composite adsorbent material maintains its uranium removal activity within a pH range of 2 to 11; this indicates that the composite adsorbent material prepared in Example 1 of this invention has a strong uranium removal capacity over a wide pH activity range for enriching and recovering uranium from water.

[0104] Table 4. Test results of the ability of collagen fiber-based zinc sulfide nanoparticles to enrich and recover uranium at different pH values.

[0105]

[0106]

[0107] Example 6 (Test of uranium removal capability of collagen fiber-based nano-zinc sulfide adsorbent material after irradiation)

[0108] The collagen fiber-based zinc sulfide nanocomposite adsorbent material prepared in Example 1, after irradiation with 100 kGy and 200 kGy gamma rays, was mixed with a uranium solution and stirred at 50°C for 12 h under the condition of V (solution volume):m (exchange resin mass) = 1000 mL / g. After adsorption was complete, the supernatant and the initial solution were collected, and the uranium concentration was determined by inductively coupled plasma mass spectrometry. The test results are as follows: Figure 7 As shown, the collagen fiber-based nano-zinc sulfide composite adsorbent maintains a high partition coefficient and removal rate for uranium even after irradiation. This indicates that the adsorbent prepared in this invention has excellent radiation resistance and retains a strong uranium removal capacity even after high-intensity gamma-ray irradiation.

[0109] Example 7 (Simulated Ion Adsorption Column Application)

[0110] 70 mg of the collagen fiber-based zinc sulfide nanocomposite adsorbent material prepared in Example 1 was loaded into a 1 mL polyethylene column with an inner diameter of 0.56 cm and a column height of approximately 4.2 cm. To avoid loss of solid sample, a sieve plate with a pore size of 50 μm was placed at the bottom of the column. 120.5 mg / L UO2 2+ The solution was passed through the adsorption column at a flow rate of 1 mL / min. Fluid solution samples were collected in glass test tubes every 5 minutes using a peristaltic pump and an automatic collector, and the measured concentrations were close to the midpoint concentrations.

[0111] Test results are as follows Figure 8 A collagen fiber-based nano-zinc sulfide composite adsorption material sample simulated adsorption column for mixed UO2 2 + The breakthrough curve of the solution conforms to the Thomas model, and the maximum uranium adsorption capacity is 243.7 mg / g. Figure 8 b is the collagen fiber-based nano-zinc sulfide composite adsorbent sample's performance on UO2 in column experiments. 2+ The removal rate reaches a breakthrough point of over 80% at a bed volume of approximately 75.0, and can maintain a removal rate of over 99% up to a bed volume of 42.5. This demonstrates that the collagen fiber-based nano-zinc sulfide composite adsorbent prepared by this invention can be used as a column packing material in the application of UO2. 2+ Dynamic adsorption of ions; see Table 5 for specific data.

[0112] Table 5. Adsorption column treatment of UO2-containing materials using collagen fiber-based nano-zinc sulfide as column packing material. 2+ Results of ionic solutions

[0113] Time (min) <![CDATA[C t (mg / L)]]> <![CDATA[C t / C0]]> Removal rate (%) 0 0 0 0 2.5 0.43 0.0035 99.65 12.5 0.36 0.0030 99.70 22.5 0.36 0.0030 99.70 32.5 0.39 0.0032 99.68 42.5 0.87 0.0072 99.28 52.5 3.34 0.0277 97.23 62.5 8.20 0.0680 93.20 72.5 14.36 0.1192 88.08 97.5 40.09 0.3327 66.73 147.5 69.61 0.5777 42.23 197.5 98.80 0.819 18.01 257.5 111.95 0.9290 7.10 272.5 111.05 0.9216 7.84 287.5 107.34 0.8907 10.93 297.5 112.37 0.9325 6.75 322.5 108.91 0.9038 9.62

[0114] Example 8 (Simulated Seawater Application)

[0115] Artificial seawater was prepared according to Table 6, including various high concentrations of metal ions such as K. + Ca 2+ Na + and Mg 2+ and anions such as Cl - SO4 2- ,Br - and HCO3 - In situations where the competing ion concentration is extremely high, the target UO2... 2+ Even at extremely low ion concentrations, just 10 milligrams of collagen fiber-based zinc sulfide nanocomposite adsorbent can effectively adsorb UO2. 2+ The concentration was reduced to 5.5 μg / L. Figure 9 ).

[0116] The above demonstrates that the collagen fiber-based nano-zinc sulfide composite adsorbent prepared in the embodiments of the present invention is effective against ultra-low concentrations of UO2. 2+ It exhibits excellent adsorption capacity. After adsorption using the collagen fiber-based zinc sulfide nanocomposite adsorbent, the uranium concentration in simulated seawater meets the US drinking water standard (30 μg / L). This indicates that even under conditions of extremely high competing ion concentrations, the collagen fiber-based zinc sulfide nanocomposite adsorbent demonstrates stable uranium extraction capability.

[0117] Table 6. Composition and dosage of simulated seawater

[0118]

[0119]

[0120] The collagen fiber-based nano-zinc sulfide composite adsorbent material prepared in Example 1 of this invention involves in-situ growth of zinc sulfide onto the surface of collagen fibers. On one hand, zinc is readily bound to collagen fibers; on the other hand, sulfur and zinc can be converted into zinc sulfide through a low-temperature deposition-like process, and the zinc sulfide can be controlled to achieve a nanoscale size. Therefore, the synthesized material exhibits a favorable morphology, facilitating the adsorption of uranyl ions. Furthermore, the strong interaction between S ions and uranyl ions in the zinc sulfide leads to highly efficient adsorption of uranyl ions. Figure 10 As shown.

[0121] The morphologies of the In2S3 / collagen fiber composites and Sn2S3 / collagen fiber composites prepared in Comparative Examples 1 and 2 are as follows: Figure 11 As shown, the preparation method is the same as in the examples, but the sulfides used are different. The in-situ growth of indium with sulfur, tin, and sulfur on collagen fibers is not effective. For example... Figure 12As shown in the EDS diagrams, the products of the In2S3 / collagen fiber composite material of Comparative Example 1 and the Sn2S3 / collagen fiber composite material of Comparative Example 2 after being immersed in a uranium-containing solution do not contain uranyl ions, indicating that the composite adsorbent materials of Comparative Example 1 and Comparative Example 2 do not have the ability to adsorb uranyl ions.

[0122] The above comparison shows that Comparative Examples 1 and 2 are prepared using the same method as Example 1 of the present invention, but due to the different sulfur salts selected, the collagen fibers are not modified, resulting in different composite effects and different adsorption capacities for uranyl ions. This further illustrates that the zinc sulfide and collagen fiber composite adsorption material selected in the present invention has a better adsorption capacity for uranyl ions.

[0123] Comparative Example 3 describes a conventional technique that uses WS2 nanosheets to adsorb uranyl ions, achieving U(VI) adsorption equilibrium within 30 minutes, with a maximum uranium adsorption capacity of 22.35 mg / g. However, this adsorbent material has low adsorption capacity, is prone to aggregation in practical applications, exhibits poor mechanical stability, and is difficult to recover. In contrast, the zinc sulfide and collagen fiber composite adsorbent material prepared in this invention achieves a maximum uranyl ion adsorption capacity of approximately 359.72 mg / g, which is more than 10 times higher than the adsorption capacity of uranium by sulfides alone.

[0124] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for preparing a composite adsorbent material, characterized in that, The method includes the following steps: S1: Raw materials containing collagen fibers and organic zinc salts are reacted in reaction I to obtain a Zn ion / collagen fiber complex; S2: A mixture containing the Zn ion / collagen fiber complex, sulfide and surfactant from step S1 is subjected to reaction II to obtain a collagen fiber-based nano-metal sulfide composite adsorbent material. The collagen fiber mentioned in step S1 is an alkali-modified collagen fiber obtained by alkali treatment; The zinc sulfide nanoparticles on the surface of the composite adsorbent material have a particle size of 50-200 nm and a spherical morphology; the maximum adsorption capacity of the composite adsorbent material for uranyl ions is 300-400 mg / g.

2. The method for preparing a composite adsorbent material according to claim 1, characterized in that, The organic zinc salt includes zinc acetate.

3. The method for preparing a composite adsorbent material according to claim 1, characterized in that, The sulfide is selected from at least one of thioacetamide, thiourea, ammonium sulfide, L-cysteine, sodium thiosulfate, and thiols; The surfactant is selected from at least one of octadecylamine, sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, polyvinylpyrrolidone, and ethylenediaminetetraacetic acid; The temperature for the alkali treatment is 40~60℃; The mixing ratio of the collagen fiber to the alkali is 1 ~ 5 g : 80 ~ 120 mL; the alkali is an aqueous solution of sodium hydroxide with a concentration of 0.025 ~ 0.1 mol / L.

4. The method for preparing a composite adsorbent material according to claim 1, characterized in that, In step S1, the reaction I process includes: immersing the collagen fibers in the solution of the organic zinc salt, heating to evaporate the solvent, replenishing the solution of the organic zinc salt, repeating this process multiple times to obtain the Zn ion / collagen fiber complex; The mixing ratio of the collagen fiber and the organic zinc salt solution is 0.03 ~ 0.15 g : 2 ~ 10 mL, and the concentration of the organic zinc salt solution is 0.02 ~ 0.08 mol / L; The temperature for heating and evaporating the solvent is 50-65°C, the time for heating and evaporating the solvent is 1.5-3.5 hours, and the process is repeated 3-6 times. In step S2, the mixing ratio of the Zn ion / collagen fiber complex, the sulfide and the surfactant is (0.2 ~ 1.5) g : (0.5 ~ 5) mmol : (0.02 ~ 2) mmol.

5. The method for preparing a composite adsorbent material according to claim 1, characterized in that, In step S2, the mixture also includes a solution of the same organic zinc salt and water, which are added again. The reaction II was carried out at room temperature; the product after the reaction II was washed and freeze-dried to obtain the collagen fiber-based nano-metal sulfide composite adsorbent material. In step S2, the mixing ratio of Zn ion / collagen fiber complex, ethanol solution of sulfide, ethanol solution of surfactant, solution of the same organic zinc salt added again, and water is (0.2 ~ 1.5) g : (2 ~ 15) mL : (2 ~ 15) mL : (40 ~ 150) mL : 1 mL; The concentration of the ethanol solution of the sulfide is 200-300 mmol / L; The concentration of the surfactant in the ethanol solution is 8 ~ 12 mmol / L; The concentration of the solution of the same organic zinc salt added again is 0.03 ~ 0.08 mol / L.

6. The method for preparing a composite adsorbent material according to claim 1, characterized in that, The specific surface area of ​​the composite adsorbent material is 15-30 m². 2 / g.

7. The application of the composite adsorbent material prepared by the method according to any one of claims 1 to 6 in the adsorption treatment of uranium-containing wastewater.

8. A method for treating uranium-containing wastewater, characterized in that, The method includes the following steps: contacting an adsorbent material with a uranium-containing solution, wherein the adsorbent material adsorbs uranium ions from the uranium-containing solution, and separating the adsorbent material and solution adsorbed with uranium ions; The adsorbent material is a composite adsorbent material prepared by the method described in any one of claims 1 to 6.

9. A method for treating uranium-containing wastewater according to claim 8, characterized in that, The adsorption temperature is 25~60 ℃; the contact time is 6~12 h; the pH of the uranium-containing solution is 2~11; and the concentration of uranyl ions in the uranium-containing solution is 4.35~588 ppm. The uranium-containing solution flows through an adsorption column, which is filled with an adsorption material. The adsorption material adsorbs and extracts uranyl ions from the uranium-containing solution.

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