A high-efficiency adsorption Cs + Layered metal sulfide adsorbent and preparation method and application thereof
By preparing a highly efficient layered metal sulfide adsorbent K1.82Cs0.51Ga2.33Sn1.67S8H2O for Cs+ adsorption, the problem of Cs+ adsorption performance being affected by competing ions in neutral solution was solved, realizing efficient Cs+ adsorption and waste liquid treatment under complex environments.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- FUJIAN INST OF RES ON THE STRUCTURE OF MATTER CHINESE ACAD OF SCI
- Filing Date
- 2023-12-15
- Publication Date
- 2026-06-12
AI Technical Summary
In the prior art, the selective adsorption performance of layered metal sulfides for Cs+ in neutral solution is significantly affected by competing ions such as K+, Na+, Ca2+, Mg2+, Sr2+ and lanthanide ions, and there is a lack of effective solutions.
A layered metal sulfide adsorbent K1.82Cs0.51Ga2.33Sn1.67S8H2O with high efficiency for adsorbing Cs+ was prepared by using an inorganic ion-imprinted adsorbent synthesis strategy. The mixture was heated and activated in a closed container to form a material with Cs+ recognition ability.
Even in the presence of excess Na+, K+, Ca2+, Mg2+, Sr2+, and Eu3+ ions, it can still selectively adsorb Cs+ and remain stable within the pH range of 2-11.5. After γ-ray irradiation, it still maintains high adsorption performance, realizing efficient treatment of Cs+ waste liquid and reducing the 137Cs activity in the waste liquid by 89.93%-99.45%.
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Figure CN117695994B_ABST
Abstract
Description
Technical Field
[0001] This application relates to a highly efficient adsorption method for Cs. + The layered metal sulfide adsorbent, its preparation method, and its application belong to the field of new materials technology for wastewater treatment. Background Technology
[0002] With the rapid development of nuclear energy, people are paying increasing attention to the treatment and disposal of radioactive waste. 137 Cs ( t 1 / 2 ~30.17 y) is 235 The fission products of U are the main components of spent fuel. γ One of the sources of X-ray radiation. 137 Cs are highly soluble and mobile in the environment, and can accumulate in the human body through the food chain, causing cell damage, cancer, and even death. Therefore, once released into the environment, they will cause significant pollution and harm to the entire ecosystem. 137 Radioactive waste liquids containing cesium (Cs) are generated during nuclear accidents, spent fuel disposal, and isotope source production. These waste liquids typically also contain large amounts of non-radioactive ions, such as potassium (K). + Na + Ca 2+ and Mg 2+ and fission products, such as Sr 2+ And lanthanide ions, etc. The complex environment and composition make selective separation of Cs from various types of radioactive liquid waste challenging. + This presents enormous challenges. Therefore, developing effective... 137 A Cs-based solution is urgently needed.
[0003] Currently, the main methods for extracting and separating metal ions from water include chemical precipitation, liquid membrane methods, biological treatment, adsorption, and ion exchange. Ion exchange has advantages such as simple operation, high efficiency, and no secondary pollution, and is considered a preferred method for treating Cs-containing water. + Ideally, waste liquids should be disposed of properly. However, many materials (such as ion exchange resins, zeolites, clays, titania silicates, and metal-organic frameworks) face problems such as low selectivity, limited capacity, or poor stability in practical applications. This is especially true in neutral solutions. + Na + Ca 2+ Mg 2+ 、Sr 2+ Competing ions, such as lanthanides, significantly affect the extraction of Cs by most adsorbents. + The performance of metal sulfides. Metal sulfides are a class of excellent ion exchange materials, and their Lewis soft base S 2- Site pair Cs + The strong affinity and flexible sulfide framework of metal sulfides enable Cs to bind to metal sulfides.+ It exhibits excellent removal capabilities. Although a highly stable layered metal sulfide (InSnS-1) achieves the removal of substances containing excessive interfering ions (K... + Ca 2+ Na + Mg 2+ 、Sr 2+ La 3+ Selective capture of Cs in nitric acid solution + However, interfering ions in neutral solutions can significantly affect the ion exchanger's effect on Cs. + There is currently no effective solution or material for addressing the adsorption performance issue. Summary of the Invention
[0004] To address the aforementioned issues, a synthesis strategy of "inorganic ion-imprinted adsorbents" was employed to prepare Cs-containing adsorbents. + Metal sulfides with enhanced recognition capabilities significantly improve the metal sulfide's ability to target Cs. + The selective adsorption performance of Cs + The adsorption performance of adsorbents is significantly affected by competing ions, especially high-valence ions.
[0005] According to one aspect of this application, a highly efficient adsorption Cs method is provided. + Layered metal sulfide adsorbent.
[0006] The technical solution adopted in this application is as follows:
[0007] A highly efficient adsorption method for Cs + Layered metal sulfide adsorbent, the highly efficient adsorbent for Cs + The chemical formula of the layered metal sulfide adsorbent is:
[0008] K 1.82 Cs 0.51 Ga 2.33 Sn 1.67 S8H2O.
[0009] Optionally, the highly efficient adsorption of Cs + The layered metal sulfide adsorbent belongs to the orthorhombic crystal system, space group 1. Pmc 21, unit cell parameters are a = 7.3860~7.3880 Å, b = 10.1490~10.1505 Å, c = 12.2115~12.2145Å, Z = 2.
[0010] Optionally, the highly efficient adsorption of Cs +The maximum adsorption capacity of the layered metal sulfide adsorbent for cesium ions is 239-255 mg / g.
[0011] According to another aspect of this application, a highly efficient adsorption Cs method is provided. + The preparation method of the layered metal sulfide adsorbent includes the following steps:
[0012] S1. A mixture containing Cs2CO3, Ga(NO3)3, Sn, S, and N2H4 is heated in a closed container to react and obtain the precursor.
[0013] S2. The precursor is activated by immersing it in a solution containing KCl to obtain the highly efficient adsorbent Cs. + Layered metal sulfide adsorbent.
[0014] Optionally, the precursor has the chemical formula Cs 2.33 Ga 2.33 Sn 1.67 S8H2O.
[0015] Optionally, the heating reaction is followed by washing the product with water and ethanol to remove the solvent.
[0016] Optionally, in step S1, the weight ratio of Cs2CO3 to Ga(NO3)3, Sn, and S is 1:(0.3~0.8):(0.11-0.18):(0.2~0.35).
[0017] The solid-liquid ratio of Cs2CO3 to N2H4 is 1g:(0.5~2.5)mL.
[0018] Optionally, the mixture further contains water, and the solid-liquid ratio of Cs2CO3 to water is 1 g:(0~1) mL.
[0019] Optionally, the solid-liquid ratio of Cs2CO3 to water is selected from any value among 1g:0.01mL, 1g:0.1mL, 1g:0.2mL, 1g:0.3mL, 1g:0.4mL, 1g:0.5mL, 1g:0.6mL, 1g:0.7mL, 1g:0.8mL, 1g:0.9mL, and 1g:1mL, or a range between any two.
[0020] Optionally, the amounts of Cs2CO3, Ga(NO3)3, Sn, S, N2H4, and water are determined according to Cs. 2.33 Ga 2.33 Sn 1.67 The mixture is prepared by weighing and preparing the molar ratio of each element in the general chemical formula S8H2O.
[0021] Optionally, in step S1, the conditions for the heating reaction include: a reaction temperature of 170~190 ℃ and a reaction time of 3~7 days.
[0022] Optionally, in step S2, the activation treatment conditions include: shaking at room temperature for 6 to 24 hours.
[0023] Optionally, in step S2, the oscillation time at room temperature is selected from any value among 6h, 8h, 10h, 12h, 14h, 16h, 18h, 20h, 22h, and 24h, or any value between the two.
[0024] Optionally, in this application, room temperature refers to 10~35℃.
[0025] Optionally, in step S2, the concentration of KCl in the KCl-containing solution is 1~3 mol / L;
[0026] According to another aspect of this application, a highly efficient adsorption Cs adsorption method is also provided. + Layered metal sulfide adsorbents and highly efficient Cs adsorbents prepared according to the above preparation method + Layered metal sulfide adsorbents adsorb Cs in water + Applications.
[0027] Optionally, the application conditions include: the pH value of the water body is 2 to 11.5;
[0028] This application features efficient adsorption of Cs. + Cs layered metal sulfide adsorbent + The extraction performance remains stable in aqueous solutions with a pH range of approximately 2 to 11.5.
[0029] Optionally, the adsorption method is as follows: the highly efficient adsorbent Cs + Layered metal sulfide adsorbents and those containing Cs + Water contact;
[0030] Optionally, the adsorption method is as follows: filling the adsorption column with the highly efficient adsorbent Cs + Using layered metal sulfide adsorbents as the stationary phase, Cs-containing adsorbents are adsorbed... + Water is passed through an adsorption column and subjected to highly efficient adsorption of Cs. + The layered metal sulfide adsorbent is contacted, and Cs in the solution is enriched and / or extracted in the adsorption column. + ;
[0031] Optionally, the adsorption conditions include: contact at room temperature for 3 to 5 hours.
[0032] Optionally, the interfering ions in the water body include Sr2+ Eu 3+ Ions, alkali metal ions, or alkaline earth metal ions. When containing Cs... + Sr mixed in water 2+ Eu 3+ When Cs ions, alkali metal ions, or alkaline earth metal ions are present, the highly efficient adsorption of Cs is achieved. + Layered metal sulfide adsorbents can effectively adsorb Cs in aqueous solutions. + .
[0033] Optionally, the application includes the highly efficient adsorption of Cs. + Layered metal sulfide adsorbents under high dose γ The layered metal sulfide adsorbent can be reused after irradiation with high doses of radiation; γ Even after X-ray irradiation, it still efficiently adsorbs Cs from aqueous solution. + .
[0034] Optionally, the application includes eluting the highly efficient adsorbed Cs using an ammonium chloride solution. + Cs adsorbed by layered metal sulfide adsorbent + ;
[0035] Optionally, the elution conditions include: an ammonium chloride concentration of 0.5~1.5 mol / L and a contact time of 12 h.
[0036] The adsorption column filled with the layered metal sulfide adsorbent adsorbs Cs + Then, the adsorbed Cs can be passed through an adsorption column using an ammonium chloride solution. + Washing off.
[0037] In this application, the layered metal sulfide adsorbent adsorbs Cs in an ammonium chloride aqueous solution. + After washing, it was again mixed with Cs. + Cs can still be adsorbed from aqueous solutions after a certain period of contact. + This enables the reuse of the layered metal sulfide adsorbent.
[0038] Optionally, the one containing Cs + Water bodies include 137 Cs waste liquid.
[0039] The beneficial effects that this application can produce include:
[0040] This application provides a highly efficient adsorption Cs + A layered metal sulfide adsorbent, prepared by an "inorganic ion-imprinted adsorbent" method, is effective for Cs. + The adsorption of Na+ exhibits advantages such as rapid kinetic response, high adsorption capacity, and high selectivity. +K + Ca 2+ Mg 2+ 、Sr 2+ Eu 3+ Cs can still be selectively adsorbed in aqueous solutions where ions are in excess. + Ions, overcoming Cs + This addresses the drawback of adsorbents whose adsorption performance is significantly affected by competing ions, especially high-valence ions, and effectively handles practical applications. 137 Cs waste liquid, after high dosage γ Even after X-ray irradiation, it still efficiently adsorbs Cs from aqueous solution. + , making the waste liquid 137 The Cs activity concentration decreased by 89.93%~99.45%, indicating that the Cs highly efficient adsorbent prepared in this application... + Layered metal sulfide adsorbents are highly efficient adsorbents for Cs. + The material possesses excellent acid and alkali stability, cycle stability, radiation stability, ease of handling, and easy recyclability, enabling rapid and convenient processing of Cs-containing materials. + Waste liquid, minimizing waste, in the treatment of Cs-containing liquids + The field of radioactive waste liquid has good prospects for industrial application. Attached Figure Description
[0041] Figure 1 For Cs 2.33 Ga 2.33 Sn 1.67 S8·H2O and K 1.82 Cs 0.51 Ga 2.33 Sn 1.67 [Ga] in the S8·H2O sample 2.33 Sn 1.67 S8] n 2.33n- Layer structure diagram and layer stacking diagram.
[0042] Figure 2 K is a layered metal sulfide adsorbent 1.82 Cs 0.51 Ga 2.33 Sn 1.67 S8·H2O removes Cs + The dynamic diagram.
[0043] Figure 3 K is a layered metal sulfide adsorbent 1.82 Cs 0.51 Ga 2.33 Sn 1.67 S8·H2O removes Cs + Adsorption model diagram.
[0044] Figure 4 K is a layered metal sulfide adsorbent 1.82 Cs 0.51 Ga 2.33 Sn 1.67 S8·H2O has a wide pH range of effects on Cs + The removal rate and allocation coefficient diagram.
[0045] Figure 5 K is a layered metal sulfide adsorbent 1.82 Cs 0.51 Ga 2.33 Sn 1.67 S8·H2O affects Cs in the presence of different competing ions + The removal capacity diagrams are as follows: (a) Sodium ions, (b) Potassium ions, (c) Calcium ions, (d) Magnesium ions, (e) Strontium ions, and (f) Europium ions.
[0046] Figure 6 K, a raw and irradiated layered metal sulfide adsorbent 1.82 Cs 0.51 Ga 2.33 Sn 1.67 (a) Removal of Cs by S8·H2O + (a) Rendering; (b) X-ray powder diffraction pattern.
[0047] Figure 7 For (a) adsorption of Cs + Cs were then eluted with (b) + The energy spectrum of the sample after processing.
[0048] Figure 8 As a layered metal sulfide adsorbent (a), Cs was subjected to three adsorption-desorption cycles. + (a) Removal rate diagram and (b) X-ray powder diffraction pattern of sample.
[0049] Figure 9 K is a layered metal sulfide adsorbent 1.82 Cs 0.51 Ga 2.33 Sn 1.67 (a) Adsorption of Cs on an S8·H2O-filled adsorption column + The breakthrough curve and (b) adsorbed Cs + Cs was eluted from the adsorption column afterward. + Capability chart.
[0050] Figure 10 K is a layered metal sulfide adsorbent 1.82 Cs 0.51 Ga 2.33 Sn 1.67 S8·H2O processing actual137 The diagram shows the capacity of Cs waste liquid, where (a) represents neutral waste liquid and (b) represents acidic waste liquid. Detailed Implementation
[0051] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.
[0052] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.
[0053] Unless otherwise specified, all test methods are conventional and all instrument settings are those recommended by the manufacturer.
[0054] Sample Cs 2.33 Ga 2.33 Sn 1.67 S8·H2O and K 1.82 Cs 0.51 Ga 2.33 Sn 1.67 X-ray diffraction data of the structure of S8·H2O were obtained using a SuperNova CCD X-ray diffractometer with a Mo target. Kα Radiation source ( λ = 0.71073 Å).
[0055] X-ray powder diffraction (XRD) phase analysis was performed on a Miniflex II X-ray diffractometer at 30 kV and 15 mA, using a Cu target. Kα Radiation source ( λ = 1.54178 Å).
[0056] Scanning electron microscopy (SEM) was performed on a JEOL JSM-6700F instrument.
[0057] 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.
[0058] Example 1: Preparation and structural characterization of layered metal sulfide adsorbents
[0059] 0.7172 g Cs₂CO₃, 0.2566 g Ga(NO₃)₃·6H₂O, 0.0842 g Sn, 0.1927 g S, 1 mL N₂H₄·H₂O (98%), and 0.5 mL H₂O were mixed thoroughly at room temperature and placed in a stainless steel reactor lined with polytetrafluoroethylene. The mixture was reacted at a constant temperature of 180 °C for 7 days, then allowed to cool naturally to room temperature. The resulting sample was filtered, washed successively with distilled water and ethanol, and then air-dried to obtain the precursor Cs. 2.33Ga 2.33 Sn 1.67 S8·H2O. The precursor was then shaken in a 2 mol / L potassium chloride solution for 24 h. The collagen fiber sample was subsequently filtered, washed multiple times with deionized water, and naturally dried to obtain the layered metal sulfide adsorbent K. 1.82 Cs 0.51 Ga 2.33 Sn 1.67 S8·H2O.
[0060] Among them, Cs 2.33 Ga 2.33 Sn 1.67 S8·H2O and K 1.82 Cs 0.51 Ga 2.33 Sn 1.67 The crystal structure of S8·H2O was obtained by single-crystal XRD. Both have [Ga 2.33 Sn 1.67 S8] n 2.33n- The layered structure of Cs exhibits different charge balances between cations in the interlayers. 2.33 Ga 2.33 Sn 1.67 S8·H2O and K 1.82 Cs 0.51 Ga 2.33 Sn 1.67 [Ga] in the S8·H2O sample 2.33 Sn 1.67 S8] n 2.33n- Layer structure diagram and layer stacking diagram as follows Figure 1 As shown, where, Figure 1 (a) is [Ga 2.33 Sn 1.67 S8] n 2.33n- The structural diagram of the layer, where the black spheres represent Sn atoms and the white spheres connected to them represent S atoms; Figure 1 (b) is Cs 2.33 Ga 2.33 Sn 1.67 Layer packing diagram of S8·H2O, Cs + Filling the interlayer, where black spheres represent Sn atoms, connected white spheres represent S atoms, and gray spheres represent Cs atoms. + ; Figure 1 (c) is K 1.82 Cs 0.51 Ga 2.33 Sn 1.67 Layer packing diagram of S8·H2O, K + and Cs +Filling the interlayer space, black spheres represent Sn atoms, white spheres connected to them represent S atoms, and gray spheres represent Cs atoms. + The light gray sphere represents K. + For clarity, the H and O atoms have been omitted from the diagram.
[0061] Example 2 Extraction and separation of Cs + Dynamics test
[0062] K prepared in Example 1 1.82 Cs 0.51 Ga 2.33 Sn 1.67 S8·H2O reacts with a certain initial concentration of Cs-containing compounds. + The aqueous solution was mixed, and the mixture was stirred at room temperature. V (Solution volume): m (Exchanger mass) = 1000 mL / g. Small amounts of the supernatant were taken from the mixture at regular intervals, and Cs were determined using inductively coupled plasma atomic emission spectrometry. + Concentration. Experimental results are as follows: Figure 2 K 1.82 Cs 0.51 Ga 2.33 Sn 1.67 S8·H2O on Cs + The removal of the particles can reach equilibrium within 5 minutes.
[0063] Example 3: Cs + Isothermal adsorption model test
[0064] K prepared in Example 1 1.82 Cs 0.51 Ga 2.33 Sn 1.67 S8·H2O reacted with different initial Cs + Mixing aqueous solutions of varying concentrations, according to V (Solution volume): m (Exchanger mass) = 1000 mL / g, shaken at room temperature for 4 h. After adsorption is complete, the supernatant and initial solution are collected, and Cs is determined by inductively coupled plasma mass spectrometry. + The concentration. Experimental results are as follows: Figure 3 As shown, layered metal sulfide adsorbent K 1.82 Cs 0.51 Ga 2.33 Sn 1.67 The maximum adsorption capacity of S8·H2O for cesium is 246 mg / g.
[0065] Example 4: Extraction of Cs at different pH values + Ability Test
[0066] The Cs prepared in Example 1 were compared with those at different pH values. + Solution mixing, according to V (Solution volume): m (Exchanger mass) = 1000 mL / g, shaken at room temperature for 4 h. After adsorption is complete, the supernatant and initial solution are collected, and the uranium concentration is determined by inductively coupled plasma mass spectrometry. The results are as follows: Figure 4 As shown, layered metal sulfide adsorbent K 1.82 Cs 0.51 Ga 2.33 Sn 1.67 S8·H2O can maintain its resistance to Cs within a pH range of approximately 2-11.5. + The layered metal sulfide adsorbent provided in this application exhibits high removal activity for Cs over a wide pH activity range. + It has a strong removal ability.
[0067] Example 5: Extraction and Separation of Cs + Selective Ability Test
[0068] K prepared in Example 1 1.82 Cs 0.51 Ga 2.33 Sn 1.67 S8·H2O reacted with different concentrations of Na... + K + Ca 2 + Mg 2+ 、Sr 2+ Eu 3+ Mixing ion-soluble aqueous solutions, according to V (Solution volume): m (Exchanger mass) = 1000 mL / g, shaken at room temperature for 4 h. After the reaction is complete, the supernatant and the initial solution are taken and the ion concentrations are determined by inductively coupled plasma atomic emission spectrometry and atomic absorption spectrometry, respectively. The test results are as follows: Figure 5 As shown in (a)~(f), in the competition ion Na + K + Ca 2+ Mg 2+ 、Sr 2+ Eu 3+ In the presence of large amounts of excess, layered metal sulfide adsorbent K 1.82 Cs 0.51 Ga 2.33 Sn 1.67 S8·H2O can still effectively remove Cs + And its removal of Cs +The ability of the layered metal sulfide adsorbent to resist the increase in competing ion concentration is almost unaffected by the Cs ion concentration. The layered metal sulfide adsorbent provided in this application overcomes the limitations of Cs ions. + The adsorption performance of adsorbents is significantly affected by competing ions, especially high-valence ions.
[0069] Example 6: Removal of Cs after irradiation + Ability Test
[0070] K prepared in Example 1 1.82 Cs 0.51 Ga 2.33 Sn 1.67 S8·H2O at 100 kGy γ and 200 kGy γ Materials irradiated with X-rays and Cs + Solution mixing, according to V (Solution volume): m (Exchanger mass) = 1000 mL / g, shaken at room temperature for 4 h. After adsorption is complete, the supernatant and initial solution are collected, and Cs is determined by inductively coupled plasma mass spectrometry. + The concentration. Test results are as follows: Figure 6 (b) shows the layered metal sulfide adsorbent K 1.82 Cs 0.51 Ga 2.33 Sn 1.67 S8·H2O maintains structural stability after irradiation, and as Figure 6 (a) shows the Cs + The allocation coefficient remains high (>10). 5 The layered metal sulfide adsorbent provided in this application exhibits excellent radiation resistance and has undergone high-strength treatment. The adsorbent has a removal rate (>99.5%) of mL / g and a removal efficiency of >99.5%. γ It maintained its stable structure and excellent Cs properties after X-ray irradiation. + Removal ability.
[0071] Example 7 Adsorption-desorption cycle stability test
[0072] K prepared in Example 1 1.82 Cs 0.51 Ga 2.33 Sn 1.67 S8·H2O and 5000 mg / L Cs + Solution mixing, according to V (Solution volume): m (Exchanger mass) = 1000 mL / g, shake at room temperature for 12 h to fully adsorb Cs. +The resulting product was designated as Sample 1#. 250 mg of Sample 1# was mixed with 250 mL of 1 mol / L ammonium chloride solution and shaken for 24 hours to fully elute the Cs adsorbed by the material. + The resulting product is designated as Sample 2#. Sample 1# and Sample 2# are then tested for EDS, as follows: Figure 7 As shown, after elution with ammonium chloride solution, Cs in sample 1# + It has been largely washed away.
[0073] Sample 2# was used as the starting material for the adsorption-desorption cycle experiment, i.e., the material used in the first cycle of adsorption. The product obtained after adsorption was used as the reactant in the desorption stage. Each cycle included two stages: adsorption and desorption. After the adsorption / desorption reaction was completed, the supernatant was taken and analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES). After washing and drying, a portion of the solid sample was used for PXRD to confirm the framework stability of the compound, and the remainder was used for the next cycle of adsorption / desorption experiments. The solution used in the adsorption process was a 79.45 mg / L cesium chloride solution with a contact time of 4 hours; the solution used in the desorption process was a 1 mol / L ammonium chloride solution with a contact time of 12 hours. The solid sample used in each adsorption / desorption experiment was weighed and added to the corresponding amount of solution to ensure... V (Solution volume): m (Exchanger mass) = 1000 mL / g. The results of the three-cycle test are as follows: Figure 8 As shown, layered metal sulfide adsorbent K 1.82 Cs 0.51 Ga 2.33 Sn 1.67 S8·H2O exhibits excellent framework stability and Cs + Removal capacity stability. This application describes the layered metal sulfide adsorbent K. 1.82 Cs 0.51 Ga 2.33 Sn 1.67 S8·H2O has excellent recycling capabilities.
[0074] Example 8: Enrichment and Extraction of Cs Using Packed Adsorption Columns + Performance testing
[0075] 95 mg of K prepared in Example 1 was used. 1.82 Cs 0.51 Ga 2.33 Sn 1.67 The S8·H2O packing material was placed in a 4.50 mm inner diameter polyethylene column to a height of approximately 7.56 mm. A 10 μm sieve plate was placed at the bottom of the column to prevent loss of solid samples. 31.995 mg / L of Cs +The solution was passed through the adsorption column at a flow rate of 0.6 mL / min (5 BV / min). Samples of the eluent were collected in polyethylene tubes at every 5-minute interval, and the concentration was measured to approximate the midpoint of the time interval. After adsorption was complete, the adsorbed Cs were eluted with 1 mol / L ammonium chloride solution. + Samples of the eluent were collected using polyethylene tubes at 5-minute intervals, and the Cs of the eluent collected in each tube were determined. + Concentration. Solution flow rate and sample collection are controlled by a peristaltic pump and an automated collector.
[0076] Test results are as follows Figure 9 As shown in (a), layered metal sulfide adsorbent K was filled. 1.82 Cs 0.51 Ga 2.33 Sn 1.67 The adsorption column of S8·H2O for Cs + The breakthrough curve of the solution conforms to the Thomas model, for Cs + The dynamic adsorption capacity was 282 mg / g. The breakthrough treatment volume was 4500 bed volumes, or approximately 540 mL of 31.995 mg / L Cs. + After effective treatment, the solution produced only one bed volume (0.12 mL) of solid waste, thus reducing the waste volume by three orders of magnitude. After reaching saturation adsorption, the adsorbed Cs... + It can be eluted with a 1 mol / L ammonium chloride solution, such as... Figure 9 As shown in (b), Cs in the first four eluent samples (total 12 mL) + Concentration exceeding 10 3 mg / L, the first 16 eluent samples (total 12 mL) yielded 32.10 mg of Cs. + The elution rate reached 95.65%. This demonstrates that the layered metal sulfide adsorbent K provided in this application... 1.82 Cs 0.51 Ga 2.33 Sn 1.67 Filling an adsorption column with S8·H2O can rapidly and effectively enrich and concentrate Cs. + The layered metal sulfide adsorbent K provided in this application 1.82 Cs 0.51 Ga 2.33 Sn 1.67 S8·H2O can be used to contain radioactive Cs + Engineering treatment of waste liquid to reduce its volume.
[0077] Example 9: Processing the actual situation 137 Cs waste liquid
[0078] K prepared in Example 1 1.82 Cs 0.51 Ga 2.33 Sn 1.67 S8·H2O is used to treat neutral and acidic substances (pH = 2.6) generated during industrial production by China National Nuclear Corporation's Atomic High Technology Co., Ltd. 137 Cs waste liquid. The initial active concentrations of the two waste liquids were 8.78 × 10⁻⁶ and 8.78 × 10⁻⁶, respectively. 4 Bq / mL and 1.53 × 10 4 The concentrations of Kq / mL were [values missing], and the conductivity was 9.72 mS / cm and 12.06 mS / cm, respectively. 5 mg, 10 mg, and 40 mg of layered metal sulfide adsorbent Kq were [values missing]. 1.82 Cs 0.51 Ga 2.33 Sn 1.67 S8·H2O was reacted with 5 mL of neutral or acidic solution respectively. 137 The Cs waste liquid was mixed and shaken for 6 hours. The supernatant was then filtered and used... γ Spectrometer Measurement 137 The activity of Cs. The test results are as follows: Figure 10 As shown, layered metal sulfide adsorbent K 1.82 Cs 0.51 Ga 2.33 Sn 1.67 S8·H2O to 137 The removal rate of Cs can reach 89.93%-99.45%, which can effectively remove both types of waste liquids. 137 The Cs activity concentration decreased by two orders of magnitude. This indicates that the layered metal sulfide adsorbent K provided in this application... 1.82 Cs 0.51 Ga 2.33 Sn 1.67 S8·H2O exhibits excellent performance under actual working conditions. 137 Cs removal performance is a promising technology for industrial applications. 137 Cs adsorbent materials.
[0079] 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 highly efficient adsorption method for Cs + A layered metal sulfide adsorbent, characterized in that, The highly efficient adsorption of Cs + The chemical formula of the layered metal sulfide adsorbent is: K 1.82 Cs 0.51 Ga 2.33 Sn 1.67 S8H2O。 2. The highly efficient Cs adsorption method according to claim 1 + A layered metal sulfide adsorbent, characterized in that, The highly efficient adsorption of Cs + The layered metal sulfide adsorbent belongs to the orthorhombic crystal system, space group 1. Pmc 21, unit cell parameters are a = 7.3860~7.3880 Å, b = 10.1490~10.1505 Å, c = 12.2115~12.2145 Å, Z = 2.
3. The highly efficient adsorption Cs method according to claim 1 + A layered metal sulfide adsorbent, characterized in that, The highly efficient adsorption of Cs + The maximum adsorption capacity of the layered metal sulfide adsorbent for cesium ions is 239-255 mg / g.
4. The highly efficient Cs adsorption method according to any one of claims 1 to 3 + A method for preparing layered metal sulfide adsorbents, characterized in that, Includes the following steps: S1. A mixture containing Cs2CO3, Ga(NO3)3, Sn, S, and N2H4 is heated in a closed container to react and obtain the precursor. S2. The precursor is activated by immersing it in a solution containing KCl to obtain the highly efficient adsorbent Cs. + Layered metal sulfide adsorbent; The weight ratio of Cs2CO3 to Ga(NO3)3, Sn, and S is 1:(0.3~0.8):(0.11-0.18):(0.2~0.35). The solid-liquid ratio of Cs2CO3 to N2H4 is 1g:(0.5~2.5)mL; The conditions for the heating reaction include: a reaction temperature of 170~190 ℃ and a reaction time of 3~7 days; The concentration of KCl in the KCl-containing solution is 1~3 mol / L; The activation treatment conditions include: shaking at room temperature for 6 to 24 hours.
5. The preparation method according to claim 4, characterized in that, In step S1, The mixture also contains water, and the solid-liquid ratio of Cs2CO3 to water is 1 g:(0~1) mL.
6. The highly efficient Cs adsorption method according to any one of claims 1 to 3 + Layered metal sulfide adsorbents, and highly efficient Cs adsorbents prepared by the preparation method according to any one of claims 4 to 5 + Layered metal sulfide adsorbents adsorb Cs in water + Applications.
7. The application according to claim 6, characterized in that, The conditions for the application include: the pH value of the water body is 2 to 11.
5.
8. The application according to claim 6, characterized in that, The adsorption method is as follows: the highly efficient adsorbent Cs is... + Layered metal sulfide adsorbents and those containing Cs + Water contact.
9. The application according to claim 6, characterized in that, The adsorption method is as follows: the adsorption column is filled with the highly efficient adsorbent Cs. + Using layered metal sulfide adsorbents as the stationary phase, Cs-containing adsorbents are adsorbed... + Water is passed through an adsorption column and subjected to highly efficient adsorption of Cs. + The layered metal sulfide adsorbent is contacted, and Cs in the solution is enriched and / or extracted in the adsorption column. + .
10. The application according to claim 6, characterized in that, The application includes eluting the highly efficient adsorbed Cs using an ammonium chloride solution. + Cs adsorbed by layered metal sulfide adsorbent + .
11. The application according to claim 6, characterized in that, Contains Cs + Water bodies include 137 Cs waste liquid.