Method for preparing chromium-doped molybdenum disulfide from chrome tanning waste liquid, product and application

Abstract

The invention discloses a method for preparing chromium-doped molybdenum disulfide from chrome tanning waste liquid, a product and application, and the method comprises the following steps: S1, measuring the chrome tanning waste liquid after suction filtration, adding a molybdenum source, and stirring to prepare a mixed metal salt solution; s2, adding a sulfur source into the mixed metal salt solution, and stirring to obtain a mixed solution; and S3, transferring the obtained mixed solution into a polytetrafluoroethylene reaction kettle, carrying out hydrothermal reaction at 150-220 DEG C, and drying to obtain the chromium-doped molybdenum disulfide. The prepared chromium-doped molybdenum disulfide nano material has good adsorption performance, and the removal rates of cesium ions and strontium ions in wastewater can reach 80% and 50% or above respectively.

Description

Technical Field

[0001] This invention relates to the field of radioactive wastewater treatment, specifically to a method, product, and application for preparing chromium-doped molybdenum disulfide using chromium tanning waste liquor. Background Technology

[0002] Chrome tanning agents, due to their excellent comprehensive properties, have become the most widely used tanning agents in the leather industry. However, the utilization rate of traditional chrome tanning agents is low, only 60%-70%, which means that about 30%-40% of the chrome tanning agent remains in the waste liquid, resulting in a Cr2O3 content in the waste liquid as high as 1000-5000 mg / L. Direct discharge of this waste liquid not only wastes chrome resources but also pollutes the environment. Therefore, the resource utilization of chromium in chrome tanning waste liquid is of great significance.

[0003] The environmental pollution caused by the global combustion of fossil fuels and the surge in energy demand have spurred the urgent development of nuclear energy. However, the unavoidable generation of radioactive waste during nuclear energy utilization poses a significant threat, and the resulting nuclear pollution cannot be ignored. Among these, 137Cs and 90Sr, due to their long half-lives, are considered the primary sources of radioactivity and pose the highest safety risks in nuclear waste. Therefore, the efficient and selective removal of Cs from the complex and diverse nuclear wastewater is crucial. + and Sr 2+ It is of vital importance to the global environment and human health.

[0004] Molybdenum disulfide (MoS2) is a typical transition metal sulfide that has attracted widespread attention in the field of adsorption due to its unique graphene-like structure and abundant terminal sulfur sites on its surface. Its structure contains the soft base ion S... 2- For Cs + and Sr 2+ Soft acid ions possess strong affinity and selectivity, making them a promising class of adsorbents for radionuclides. Previous studies have shown that doping with metal atoms in the MoS2 structure can alter the electronic structure of the material surface, and the lattice defects generated by doping can further expose more adsorption active sites, thereby improving its adsorption performance.

[0005] It should be noted that the information disclosed in this background section is intended only to enhance the understanding of the overall background of the present invention, to help understand the context in which the inventors developed their inventive concept, and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] In view of this, and to solve the above-mentioned technical problems, the purpose of this invention is to provide a method, product, and application for preparing chromium-doped molybdenum disulfide using chromium tanning waste liquor. The prepared chromium-doped molybdenum disulfide can be used as an adsorbent and can be used for the efficient and selective removal of Cs in nuclear wastewater (i.e., radioactive wastewater). + and Sr 2+ .

[0007] The technical solution adopted is as follows:

[0008] The present invention discloses a method for preparing chromium-doped molybdenum disulfide using chromium tanning waste liquor, comprising the following steps:

[0009] S1. Measure the filtered chromium tanning waste liquid, add the molybdenum source, and stir to prepare a mixed metal salt solution;

[0010] S2. Add a sulfur source to the mixed metal salt solution and stir to obtain a mixed solution;

[0011] S3. Transfer the resulting mixed solution to a polytetrafluoroethylene reactor and perform a hydrothermal reaction at 150-220 °C. Dry the solution to obtain chromium-doped molybdenum disulfide.

[0012] Further, in step S1, the molybdenum source is ammonium molybdate tetrahydrate or sodium molybdate dihydrate.

[0013] Further, in step S2, the sulfur source is one or a mixture of several of thioacetamide, thiourea, and cysteine.

[0014] Further, in step S1, the chromium content of the chromium tanning waste liquid, calculated as Cr2O3, is 1000-5000 mg / L; 10-800 volume parts of the chromium tanning waste liquid are measured, and 0.1-0.5 weight parts of the molybdenum source are added, wherein volume parts: weight parts = mL:g.

[0015] Further, in step S2, the amount of sulfur source added is 0.4-3 parts by weight. More preferably, the amount of sulfur source added is 0.5-2 parts by weight.

[0016] Further, in step S3, the mixture is hydrothermally reacted at 150-220 °C for 10-48 h, then unreacted impurities are washed away with deionized water, and dried in a vacuum oven at 60 °C for 24 h to obtain chromium-doped molybdenum disulfide.

[0017] The present invention discloses a chromium-doped molybdenum disulfide, characterized in that it is prepared by the method described above.

[0018] An adsorbent of the present invention is composed of or mainly of the aforementioned chromium-doped molybdenum disulfide.

[0019] The application of the adsorbent described in this invention in the treatment of radioactive wastewater containing cesium and strontium ions.

[0020] Furthermore, the initial pH value of the wastewater is 2-12, the mass ratio of adsorbent to wastewater is (0.02-0.1):100, and the adsorption time is 0.5-24 h.

[0021] In the above technical solutions,

[0022] This invention uses chromium tanning waste liquor as a chromium source and, by adjusting the ratio of chromium and molybdenum sources, prepares chromium-doped molybdenum disulfide nanomaterials via a hydrothermal method, thereby improving the control of Cs. + and Sr 2+ Adsorption.

[0023] Using chromium-doped molybdenum disulfide nanomaterials as adsorbents, this method can efficiently and selectively remove Cs ions from radioactive wastewater containing cesium and strontium ions. + and Sr 2+ .

[0024] The beneficial effects of this invention are as follows:

[0025] On the one hand, this invention uses chromium tanning waste liquid as a chromium source to prepare chromium-doped molybdenum disulfide nanomaterials, providing a solution for the resource utilization of chromium-containing waste liquid generated during the leather making process. This can effectively solve the environmental pollution problem of chromium-containing waste liquid and promote the green and sustainable development of the leather industry.

[0026] On the other hand, this invention exposes more active sites for binding with metal ions by doping molybdenum disulfide with chromium, thus promoting its adsorption of radioactive cesium and strontium ions in wastewater. The chromium-doped molybdenum disulfide nanomaterials prepared by this invention have excellent adsorption performance, achieving removal rates of over 80% for cesium ions and over 50% for strontium ions in wastewater. Attached Figure Description

[0027] Figure 1 The image shows the XRD pattern of the chromium-doped molybdenum disulfide nanomaterial prepared in Example 2 of this invention.

[0028] Figure 2 This is a scanning electron microscope image of the chromium-doped molybdenum disulfide nanomaterials prepared in Example 2 of the present invention.

[0029] Figure 3 This is an elemental mapping diagram of the chromium-doped molybdenum disulfide nanomaterials prepared in Example 2 of the present invention.

[0030] Figure 4 This is a graph showing the adsorption efficiency of cesium and strontium ions by the chromium-doped molybdenum disulfide nanomaterials prepared in Example 2 of the present invention. Detailed Implementation

[0031] The present invention will be described in detail below through specific embodiments. However, the uses and purposes of these exemplary embodiments are only for illustrating the present invention and do not constitute any limitation on the actual protection scope of the present invention, nor are they intended to limit the protection scope of the present invention to this.

[0032] Example 1

[0033] This embodiment describes a method for preparing chromium-doped molybdenum disulfide using chromium tanning waste liquor, comprising the following steps:

[0034] Step 1. Measure 100 mL of the filtered chromium tanning waste liquid, add 0.25 g of ammonium molybdate tetrahydrate, stir well, and prepare a mixed metal salt solution;

[0035] Step 2. Add 0.64 g of thiourea to the mixed metal salt solution described in Step 1 and stir until homogeneous;

[0036] Step 3. Transfer the mixed solution obtained in Step 2 to a polytetrafluoroethylene reactor and hydrothermally react at 200°C for 48 h. Then wash away unreacted impurities with deionized water and dry in a vacuum oven at 60°C for 24 h to obtain chromium-doped molybdenum disulfide.

[0037] Example 2

[0038] This embodiment describes a method for preparing chromium-doped molybdenum disulfide using chromium tanning waste liquor, comprising the following steps:

[0039] Step 1. Measure 200 mL of the filtered chromium tanning waste liquid, add 0.25 g of ammonium molybdate tetrahydrate, stir well, and prepare a mixed metal salt solution;

[0040] Step 2. Add 1.28 g of thiourea to the mixed metal salt solution described in Step 1 and stir until homogeneous;

[0041] Step 3. Transfer the mixed solution obtained in Step 2 to a polytetrafluoroethylene reactor and hydrothermally react at 180°C for 24 h. Then wash away unreacted impurities with deionized water and dry in a vacuum oven at 60°C for 24 h to obtain chromium-doped molybdenum disulfide.

[0042] Example 3

[0043] This embodiment describes a method for preparing chromium-doped molybdenum disulfide using chromium tanning waste liquor, comprising the following steps:

[0044] Step 1. Measure 300 mL of the filtered chromium tanning waste liquid, add 0.25 g of ammonium molybdate tetrahydrate, stir well, and prepare a mixed metal salt solution;

[0045] Step 2. Add 0.64 g of thiourea to the mixed metal salt solution described in Step 1 and stir until homogeneous;

[0046] Step 3. Transfer the mixed solution obtained in Step 2 to a polytetrafluoroethylene reactor and hydrothermally react at 150°C for 48 h. Then wash away unreacted impurities with deionized water and dry in a vacuum oven at 60°C for 24 h to obtain chromium-doped molybdenum disulfide.

[0047] Example 4

[0048] This embodiment describes a method for preparing chromium-doped molybdenum disulfide using chromium tanning waste liquor, comprising the following steps:

[0049] Step 1. Measure 500 mL of the filtered chromium tanning waste liquid, add 0.25 g of ammonium molybdate tetrahydrate, stir well, and prepare a mixed metal salt solution;

[0050] Step 2. Add 1.92 g of thiourea to the mixed metal salt solution described in Step 1 and stir until homogeneous;

[0051] Step 3. Transfer the mixed solution obtained in Step 2 to a polytetrafluoroethylene reactor and hydrothermally react at 200°C for 18 h. Then wash away unreacted impurities with deionized water and dry in a vacuum oven at 60°C for 24 h to obtain chromium-doped molybdenum disulfide.

[0052] test:

[0053] The chromium-doped molybdenum disulfide prepared in Example 2 was tested, and the test results are as follows:

[0054] Figure 1 This is the XRD pattern of the chromium-doped molybdenum disulfide nanomaterial prepared in Example 2 of this invention. Figure 1 It can be seen that characteristic diffraction peaks (002), (100), (102) and (110) appeared in both MoS2 and CrMoS2. Compared with MoS2, the characteristic peak (002) of CrMoS2 shifted to a smaller angle, indicating that chromium doping increased the interlayer spacing of CrMoS2, thereby increasing the number of active adsorption sites.

[0055] Figure 2 This is a scanning electron microscope (SEM) image of the chromium-doped molybdenum disulfide nanomaterials prepared in Example 2 of this invention. As can be seen from the image, both MoS2 and CrMoS2 have a plate-like structure, and the chromium doping reduces the lateral size of CrMoS2.

[0056] Figure 3 This is an elemental mapping diagram of the chromium-doped molybdenum disulfide nanomaterial prepared in Example 2 of this invention. Cr, Mo, and S elements were detected in the diagram, and each element was uniformly dispersed, indicating that chromium was successfully introduced into the MoS2 structure.

[0057] Application Example 1

[0058] The chromium-doped molybdenum disulfide prepared in Example 2 was used as an adsorbent for the treatment of radioactive wastewater containing cesium and strontium ions. The initial pH of the wastewater was 4, the mass ratio of adsorbent to wastewater was 0.05:100, and the adsorption time was 10 hours.

[0059] Figure 4 The graph shows the adsorption efficiency of cesium and strontium ions for the chromium-doped molybdenum disulfide nanomaterials prepared in Example 2. As can be seen from the graph, the adsorption capacities of the chromium-doped molybdenum disulfide nanomaterials for cesium and strontium ions are 128.5 mg / g and 70.9 mg / g, respectively, and adsorption equilibrium for cesium and strontium ions is reached after 2 h.

[0060] Application Example 2

[0061] The chromium-doped molybdenum disulfide prepared in Example 2 was used as an adsorbent for the treatment of radioactive wastewater containing cesium and strontium ions. The initial pH of the wastewater was 4, the mass ratio of adsorbent to wastewater was 0.08:100, and the adsorption time was 10 hours.

[0062] Application Example 3

[0063] The chromium-doped molybdenum disulfide prepared in Example 2 was used as an adsorbent for the treatment of radioactive wastewater containing cesium and strontium ions. The initial pH of the wastewater was 4, the mass ratio of the adsorbent to the wastewater was 0.1:100, and the adsorption time was 10 hours.

[0064] The results showed that the removal rates of cesium ions and strontium ions in the wastewater could reach over 80% and 50%, respectively.

[0065] The detailed descriptions listed above are merely specific illustrations of feasible embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing chromium-doped molybdenum disulfide using chromium tanning waste liquor, characterized in that, Includes the following steps: S1. Measure the filtered chromium tanning waste liquid, add the molybdenum source, and stir to prepare a mixed metal salt solution; S2. Add a sulfur source to the mixed metal salt solution and stir to obtain a mixed solution; S3. Transfer the resulting mixed solution to a polytetrafluoroethylene reactor and perform a hydrothermal reaction at 150-220 °C. Dry the solution to obtain chromium-doped molybdenum disulfide.

2. The method for preparing chromium-doped molybdenum disulfide using chromium tanning waste liquor according to claim 1, characterized in that, In step S1, the molybdenum source is ammonium molybdate tetrahydrate or sodium molybdate dihydrate.

3. The method for preparing chromium-doped molybdenum disulfide using chromium tanning waste liquor according to claim 1, characterized in that, In step S2, the sulfur source is one or a mixture of several of thioacetamide, thiourea, and cysteine.

4. The method for preparing chromium-doped molybdenum disulfide using chromium tanning waste liquor according to claim 1, characterized in that, In step S1, the chromium content of the chromium tanning waste liquid, calculated as Cr2O3, is 1000-5000 mg / L; 10-800 volume parts of the chromium tanning waste liquid are measured, and 0.1-0.5 weight parts of the molybdenum source are added, wherein volume parts: weight parts = mL:g.

5. The method for preparing chromium-doped molybdenum disulfide using chromium tanning waste liquor according to claim 4, characterized in that, In step S2, the amount of sulfur source added is 0.4-3 parts by weight.

6. The method for preparing chromium-doped molybdenum disulfide using chromium tanning waste liquor according to claim 4, characterized in that, In step S3, the mixture is hydrothermally reacted at 150-220 °C for 10-48 h, then unreacted impurities are washed away with deionized water, and dried in a vacuum oven at 60 °C for 24 h to obtain chromium-doped molybdenum disulfide.

7. A chromium-doped molybdenum disulfide, characterized in that, It is prepared by the method described in any one of claims 1-6.

8. An adsorbent, characterized in that, It is composed of or primarily of chromium-doped molybdenum disulfide as described in claim 7.

9. The application of the adsorbent according to claim 8 in the treatment of radioactive wastewater containing cesium ions and strontium ions.

10. The application according to claim 9, characterized in that, The initial pH of the wastewater is 2-12, the mass ratio of adsorbent to wastewater is (0.02-0.1):100, and the adsorption time is 0.5-24 h.

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