A manganese metal organic cluster liquid, its preparation method and application in water purification

Abstract

The application belongs to the technical field of sewage purification, and discloses a manganese metal organic cluster liquid, a preparation method thereof and application of the manganese metal organic cluster liquid in water purification. The preparation method comprises the following steps: uniformly mixing a manganese acetate solution and a 1,3,5-benzene tricarboxylic acid solution; wherein the molar ratio of the manganese acetate to the 1,3,5-benzene tricarboxylic acid is (2-5):1; then performing a hydrothermal reaction, washing and drying the product to obtain a rod-shaped Mn-BTC powder; dispersing the rod-shaped Mn-BTC powder in water to obtain a transparent manganese metal organic cluster liquid; wherein the mass ratio of the rod-shaped Mn-BTC powder to water is (0.005-0.02):10. The unique feature of the Mn-MOC liquid lies in its completely exposed adsorption and active sites, which enables it to uniformly adsorb target ions and avoids the problem that active sites are shielded in traditional solid-phase adsorbents. The application overcomes the shortcomings of heterogeneous adsorption seen in traditional solid-phase adsorbents, not only brings a new solution to the field of water purification, but also provides a new idea for environmental remediation and sustainable development.

Description

Technical Field

[0001] This invention belongs to the field of wastewater purification technology, specifically relating to a manganese metal organic cluster liquid, its preparation method, and its application in water purification. Background Technology

[0002] Water is one of the world's most important natural resources, yet severe water pollution affects the lives and public health of millions worldwide. It also impacts plants and organisms living in lakes, rivers, and oceans. The root causes of this growing problem are multifaceted, stemming from industrial expansion, energy production, and large-scale mining activities. Inadequate regulatory frameworks have led to the release of large quantities of hazardous pollutants, including heavy metal ions (HMIs), oxygen anions, and radioactive ions, into the aquatic environment without proper treatment.

[0003] To address this global concern, various methods for removing target ions from polluted wastewater have been developed, each with its own advantages and disadvantages. For example, chemical precipitation is a commonly used technique favored for its simplicity and efficiency, but it generates large amounts of sludge and toxic gases, potentially leading to secondary pollution. Furthermore, it is expensive and only suitable for treating water contaminated with high concentrations of heavy metals. Electrochemical treatment or wastewater flotation may be very effective for specific HMIs, but they are resource-intensive and economically infeasible for small-scale applications. Membrane purification technologies, including ultrafiltration, reverse osmosis, and nanofiltration, offer high removal efficiencies under ideal conditions, but they are typically costly, susceptible to membrane fouling, and have limited feed flow rates, making them impractical for industrial-scale treatment. Adsorbents or ion exchange resins can also effectively remove HMIs and other contaminants. However, this technology is expensive, suitable for treating small volumes of wastewater, and typically has low efficiency (60%–90%), which decreases over time. Moreover, fully saturated adsorbents or resins must be converted through chemical reactions, which can also lead to uncontrolled secondary pollution.

[0004] It is worth noting that all the existing methods mentioned above share a common drawback: they are designed for the selective removal of specific target ions. In other words, while they may perform well in eliminating a particular type of ion, their effectiveness decreases significantly when treating other ions. Furthermore, in cases involving contaminated water sources, various types of target ions often coexist, resulting in extremely low simultaneous removal efficiency and very limited applicability. Moreover, the efficiency of these technologies drops rapidly when treatment conditions deviate from optimized pH and ion concentrations. Given these limitations, there is an urgent need to develop new materials and methods for general water purification. Summary of the Invention

[0005] To address the problems existing in the prior art, the present invention aims to provide a manganese metal organic cluster liquid, its preparation method, and its application in water purification. The present invention overcomes the shortcomings of heterogeneous adsorption seen in traditional solid-phase adsorbents, and not only brings a new solution to the field of water purification, but also provides new ideas for environmental remediation and sustainable development.

[0006] The technical solution adopted in this invention is as follows:

[0007] A method for preparing a manganese metal organic cluster liquid, comprising:

[0008] Manganese acetate solution and 1,3,5-benzenetricarboxylic acid solution were mixed evenly to obtain mixture A; wherein the molar ratio of manganese acetate to 1,3,5-benzenetricarboxylic acid was (2-5):1.

[0009] The mixture A was subjected to a hydrothermal reaction, and the product obtained from the hydrothermal reaction was washed and dried to obtain rod-shaped Mn-BTC powder.

[0010] The rod-shaped Mn-BTC powder was dispersed in water to obtain a transparent manganese metal organic cluster liquid; wherein the mass ratio of the rod-shaped Mn-BTC powder to water was (0.005-0.02):10.

[0011] Preferably, in the manganese acetate solution, the solvent is deionized water, and the mass ratio of manganese acetate to deionized water is (2.92-7.3):30.

[0012] Preferably, the solvent for the 1,3,5-benzenetricarboxylic acid solution is N,N-dimethylformamide, wherein the mass range of 1,3,5-benzenetricarboxylic acid added for every 30 mL of N,N-dimethylformamide is 1.77-5.31 g.

[0013] Preferably, the manganese acetate solution is mixed with the 1,3,5-benzenetricarboxylic acid solution and stirred at 25°C for 10 minutes to obtain the mixture A.

[0014] Preferably, when the mixture A is subjected to a hydrothermal reaction, the reaction temperature is 120-150℃ and the reaction time is 24-72h.

[0015] Preferably, when washing and drying the product obtained from the hydrothermal reaction, the product is centrifuged and washed with ethanol multiple times, and then dried at 60-100℃ for 12-24h.

[0016] Preferably, when dispersing the rod-shaped Mn-BTC powder in water to obtain a transparent manganese metal organic cluster liquid, the rod-shaped Mn-BTC powder is dispersed in water and then treated under ultrasonic conditions with a power of 100-300W for 1-10 minutes to obtain a transparent manganese metal organic cluster liquid.

[0017] The present invention also provides a manganese metal organic cluster liquid, which is prepared by the preparation method of the present invention as described above.

[0018] This invention relates to the application of the manganese metal organic cluster liquid described above in water purification. The manganese metal organic cluster liquid is used to purify pollutant particles in contaminated wastewater. The pollutant ions include metal cations, oxygen anions, radioactive ions, and noble metal ions, wherein the metal cations include Pb. 2+ Cu 2+ and Hg 2+ Oxygen anions include SeO3 2- TeO3 2- ,HAsO4 - and PO4 3- Radioactive ions include UO2 2+ and Th 4+ Noble metal ions include AuCl4 - and Pd 2+ .

[0019] Preferably, when purifying pollutant particles in polluted wastewater, the manganese metal organic cluster liquid and the polluted wastewater are mixed at a volume ratio of 0.1-1, and then stirred continuously at 200-500 rpm for 0-24 hours, followed by solid-liquid separation, and the pollutant particles are removed in the form of precipitate.

[0020] The concentration of pollutant particles in the polluted wastewater does not exceed 800 ppm.

[0021] The present invention has the following beneficial effects:

[0022] This invention utilizes a hydrothermal reaction between manganese acetate solution and 1,3,5-benzenetricarboxylic acid solution to prepare rod-shaped Mn-BTC powder. The rod-shaped Mn-BTC powder is then dispersed in water to obtain the manganese metal organic cluster liquid of this invention. Firstly, the preparation method of this invention is simple. Secondly, the unique feature of the prepared manganese metal organic cluster liquid (i.e., Mn-MOC liquid) lies in its fully exposed adsorption and active sites, which allows for uniform adsorption of target ions, avoiding the problem of active sites being shielded in traditional solid-phase adsorbents. Furthermore, Mn-MOC liquid can directly reduce toxic metal pollutant ions to valuable metals, which not only reduces environmental pollution but also achieves resource recycling. Compared with traditional water treatment methods, Mn-MOC liquid exhibits superior performance in treating various pollutants, effectively forming large-sized precipitates or flocs, facilitating subsequent separation and recovery. The successful development of this technology not only provides a new solution for the field of water purification but also offers new ideas for environmental remediation and sustainable development. Attached Figure Description

[0023] Figure 1 This is a SEM image of Mn-BTC obtained in Example 1 of the present invention.

[0024] Figure 2 This is a TEM image of Mn-BTC obtained in Example 1 of the present invention.

[0025] Figure 3 This is a TEM image of Mn-MOC obtained by ultrasonic dissolution of Mn-BTC in Example 1 of the present invention.

[0026] Figure 4 The X-ray powder diffraction patterns are those of Mn-BTC and Mn-MOC prepared in Example 1 of this invention.

[0027] Figure 5 The graph shows the removal efficiency of each single pollutant ion by the Mn-MOC liquids prepared in Examples 2-4 of this invention.

[0028] Figure 6 This is a graph showing the removal efficiency of the Mn-MOC liquid prepared in Example 5 of the present invention for multiple coexisting metal cations.

[0029] Figure 7 This is a graph showing the removal efficiency of the Mn-MOC liquid prepared in Example 6 of this invention for multiple coexisting oxygen anions. Detailed Implementation

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0031] This invention synthesizes a low-cost manganese metal-organic cluster (Mn-MOCs) liquid obtained by ultrasonic hydrolysis of Mn-BTC crystals in aqueous solution. The newly prepared Mn-MOC liquid serves as an effective tool for the rapid and efficient removal of various positively and negatively charged HMIs, oxygen anions, and radioactive ions from water, highlighting the versatility of Mn-MOC liquids in contaminant removal. Furthermore, this invention demonstrates that Mn-MOC liquids can even convert expensive metal contaminant ions into valuable metals through direct reduction, thus turning a global risk challenge into a unique opportunity. The superior removal performance of Mn-MOCs is attributed to the fully exposed adsorption and active sites of the clusters, which allows for the uniform adsorption of target ions, overcoming the disadvantages of heterogeneous adsorption seen in traditional solid-phase adsorbents, which have numerous shielded embedded active sites. The interaction between contaminant ions and the Mn-MOC liquid leads to the formation of large-sized particulate precipitates or flocs, promoting efficient heterogeneous separation. This invention is the first report of using metal-organic cluster liquids with adsorption and chemical precipitation functions for general water purification.

[0032] This invention provides a method for preparing manganese metal organic clusters (Mn-MOC) and their application in water purification, comprising the following steps:

[0033] 1) First, dissolve 2.92-7.3 g of manganese acetate in 30 mL of deionized water to obtain a manganese acetate solution. Simultaneously, dissolve 1.77-5.31 g of 1,3,5-benzenetricarboxylic acid (H3BTC) in 30 mL of DMF (N,N-dimethylformamide) to obtain a 1,3,5-benzenetricarboxylic acid solution. Then, mix the above manganese acetate solution and 1,3,5-benzenetricarboxylic acid solution together and stir at 25°C for 10 minutes to obtain a mixed solution. Next, transfer the mixed solution to a 100 mL PTFE-lined stainless steel autoclave and maintain the reaction at 120-150°C for 24-72 h. After the reaction is complete, the resulting product is centrifuged, washed multiple times with ethanol, and finally dried at 60-100°C for 12-24 h to obtain a white rod-shaped Mn-BTC powder.

[0034] 2) Subsequently, 5-20 mg of the white rod-shaped Mn-BTC powder prepared in step 1) was dispersed in 10 mL of deionized water. Then, the mixture was treated under ultrasonic conditions (ultrasonic power of 100-300 W) for 1-10 min to obtain a transparent manganese metal-organic cluster (Mn-MOC) liquid, wherein the average size of Mn-MOC was 1.24 nm.

[0035] 3) Subsequently, the Mn-MOC liquid obtained in step 2) was used for the adsorption experiment of water pollutant ions. The volume ratio of Mn-MOC liquid to ion solution was 0.1-1. The pollutant ions in the ion solution included metal cations (including Pb). 2+ Cu 2+ and Hg 2+ ), oxygen anions (including SeO3), 2- TeO3 2- ,HAsO4 - and PO4 3- ), radioactive ions (including UO2) 2+ and Th 4+ ) and noble metal ions (including AuCl4) - and Pd 2+ The concentration range of the above ions is 0-800 ppm.

[0036] 4) After mixing the Mn-MOC liquid with the solution containing pollutant ions, the mixture is continuously stirred at 20-500 rpm and room temperature for 0-24 hours. Finally, the precipitate is removed by filtration using a 0.22-micron filter membrane. The pollutant ion solution may contain a single type of ion or a mixture of multiple ions. The concentration of pollutant ions in the solution before and after adsorption is measured by inductively coupled plasma atomic emission spectrometry (ICP-OES, ThermoFisher, ICAP 7400) to obtain the removal rate of pollutant ions by the Mn-MOC liquid.

[0037] Example 1

[0038] The preparation process of the manganese metal organic cluster liquid in this embodiment includes:

[0039] 2.92 g of manganese acetate was dissolved in 30 mL of deionized water to obtain a manganese acetate solution. 1.77 g of 1,3,5-benzenetricarboxylic acid (H3BTC) was dissolved in 30 mL of DMF to obtain a 1,3,5-benzenetricarboxylic acid solution. The two solutions were then mixed together and stirred at 25 °C for 10 minutes to obtain a mixed solution. The mixed solution was then transferred to a 100 mL PTFE-lined stainless steel autoclave and reacted at 150 °C for 48 h. After the reaction, the resulting product was centrifuged and washed with ethanol. Finally, it was dried at 60 °C for 12 h to obtain a white rod-shaped Mn-BTC powder. See also Figure 1 and Figure 2 The white rod-shaped Mn-BTC powder prepared in this embodiment has an average length of 500 nm and an average width of 50 nm.

[0040] Subsequently, 20 mg of the Mn-BTC powder prepared in this embodiment was dispersed in 10 mL of deionized water. Then, it was treated under ultrasonic conditions (250 W) for 1 min to obtain a transparent manganese metal-organic cluster (Mn-MOC) liquid. (See [link to previous section]) Figure 3 The transmission electron microscopy (TEM) image of the manganese metal-organic cluster liquid prepared in this embodiment shows that the average size of Mn-MOC is 1.24 nm. Furthermore, as... Figure 4 As shown, the crystal form of Mn-MOC prepared in this embodiment is consistent with that of Mn-BTC.

[0041] The Mn-MOC liquid prepared in this embodiment was then used to treat water pollution ions Pb. 2+ In the adsorption experiment, the volume ratio of Mn-MOC liquid to ionic solution was 1. Pb 2+The ion concentration was 500 ppm. After mixing the Mn-MOC liquid with the solution containing the contaminating ions, the mixture was stirred continuously at 200 rpm and room temperature for 24 hours. Finally, the precipitate was removed by filtration using a 0.22 μm filter membrane. The concentrations of contaminant ions in the solution before and after adsorption were measured by inductively coupled plasma atomic emission spectrometry (ICP-OES, ThermoFisher, ICAP 7400), thus obtaining the Mn-MOC liquid's effect on the contaminant ion Pb. 2+ The removal rate was 99.29%, such as Figure 5 As shown.

[0042] Example 2

[0043] The preparation process of the manganese metal organic cluster liquid in this embodiment includes:

[0044] 2.92 g of manganese acetate was dissolved in 30 mL of deionized water to obtain a manganese acetate solution. Simultaneously, 1.77 g of 1,3,5-benzenetricarboxylic acid (H3BTC) was dissolved in 30 mL of DMF to obtain a 1,3,5-benzenetricarboxylic acid solution. The two solutions were then mixed together and stirred at 25 °C for 10 minutes to obtain a mixed solution. The mixed solution was then transferred to a 100 mL PTFE-lined stainless steel autoclave and reacted at 150 °C for 48 h. After the reaction, the resulting product was centrifuged and washed with ethanol. Finally, it was dried at 60 °C for 12 h to obtain a white rod-shaped Mn-BTC powder. 20 mg of the Mn-BTC powder prepared in this example was then dispersed in 10 mL of deionized water. The solution was then treated under ultrasonic conditions (250 W) for 1 min to obtain a transparent manganese metal-organic cluster (Mn-MOC) liquid.

[0045] The Mn-MOC liquid prepared in this embodiment was then used for water pollution ion UO2. 2+ In the adsorption experiment, the volume ratio of Mn-MOC liquid to ionic solution was 1. UO2 2+ The ion concentration was 250 ppm. After mixing the Mn-MOC liquid with the solution containing the contaminating ions, the mixture was stirred continuously at 200 rpm and room temperature for 24 hours. Finally, the precipitate was removed by filtration using a 0.22-micron filter membrane. The concentrations of contaminant ions in the solution before and after adsorption were measured by inductively coupled plasma atomic emission spectrometry (ICP-OES, ThermoFisher, ICAP 7400), thus obtaining the effect of Mn-MOC liquid on the contaminant ions UO2. 2+ The removal rate was 99.07%, such as Figure 5 As shown.

[0046] Example 3

[0047] The preparation process of the manganese metal organic cluster liquid in this embodiment includes:

[0048] 2.92 g of manganese acetate was dissolved in 30 mL of deionized water to obtain a manganese acetate solution. Simultaneously, 1.77 g of 1,3,5-benzenetricarboxylic acid (H3BTC) was dissolved in 30 mL of DMF to obtain a 1,3,5-benzenetricarboxylic acid solution. The two solutions were then mixed together and stirred at 25 °C for 10 minutes to obtain a mixed solution. The mixed solution was then transferred to a 100 mL PTFE-lined stainless steel autoclave and reacted at 150 °C for 48 h. After the reaction, the resulting product was centrifuged and washed with ethanol. Finally, it was dried at 60 °C for 12 h to obtain a white rod-shaped Mn-BTC powder. 20 mg of the Mn-BTC powder prepared in this example was then dispersed in 10 mL of deionized water. The solution was then treated under ultrasonic conditions (250 W) for 1 min to obtain a transparent manganese metal-organic cluster (Mn-MOC) liquid.

[0049] The Mn-MOC liquid prepared in this embodiment was then used for water pollution ion TeO3. 2- In the adsorption experiment, the volume ratio of Mn-MOC liquid to ionic solution was 1. TeO3 2- The ion concentration was 500 ppm. After mixing the Mn-MOC liquid with the solution containing the contaminating ions, the mixture was stirred continuously at 200 rpm and room temperature for 24 hours. Finally, the precipitate was removed by filtration using a 0.22-micron filter membrane. The concentrations of contaminant ions in the solution before and after adsorption were measured by inductively coupled plasma atomic emission spectrometry (ICP-OES, ThermoFisher, ICAP 7400), thus obtaining the effect of the Mn-MOC liquid on the contaminant ions TeO3. 2- The removal rate was 99.31%, such as Figure 5 As shown

[0050] Example 4

[0051] The preparation process of the manganese metal organic cluster liquid in this embodiment includes:

[0052] 2.92 g of manganese acetate was dissolved in 30 mL of deionized water to obtain a manganese acetate solution. Simultaneously, 1.77 g of 1,3,5-benzenetricarboxylic acid (H3BTC) was dissolved in 30 mL of DMF to obtain a 1,3,5-benzenetricarboxylic acid solution. The two solutions were then mixed together and stirred at 25 °C for 10 minutes to obtain a mixed solution. The mixed solution was then transferred to a 100 mL PTFE-lined stainless steel autoclave and reacted at 150 °C for 48 h. After the reaction, the resulting product was centrifuged and washed with ethanol. Finally, it was dried at 60 °C for 12 h to obtain a white rod-shaped Mn-BTC powder. 20 mg of the Mn-BTC powder prepared in this example was then dispersed in 10 mL of deionized water. The solution was then treated under ultrasonic conditions (250 W) for 1 min to obtain a transparent manganese metal-organic cluster (Mn-MOC) liquid.

[0053] The Mn-MOC liquid prepared in this embodiment was then used to treat water pollution ions Pb. 2+ In the adsorption experiment, the volume ratio of Mn-MOC liquid to ionic solution was 1. AuCl4 - The ion concentration was 500 ppm. After mixing the Mn-MOC liquid with the solution containing the contaminating ions, the mixture was stirred continuously at 200 rpm and room temperature for 24 hours. Finally, the precipitate was removed by filtration using a 0.22-micron filter membrane. The contaminating ion solution could contain a single ion or a mixture of multiple ions. The concentrations of contaminant ions in the solution before and after adsorption were measured by inductively coupled plasma atomic emission spectrometry (ICP-OES, ThermoFisher, ICAP 7400), thus obtaining the effect of the Mn-MOC liquid on the contaminating ion AuCl4. - The removal rate was 99.51%, such as Figure 5 As shown

[0054] Example 5

[0055] The preparation process of the manganese metal organic cluster liquid in this embodiment includes:

[0056] 2.92 g of manganese acetate was dissolved in 30 mL of deionized water to obtain a manganese acetate solution. Simultaneously, 1.77 g of 1,3,5-benzenetricarboxylic acid (H3BTC) was dissolved in 30 mL of DMF to obtain a 1,3,5-benzenetricarboxylic acid solution. The two solutions were then mixed together and stirred at 25 °C for 10 minutes to obtain a mixed solution. The mixed solution was then transferred to a 100 mL PTFE-lined stainless steel autoclave and reacted at 150 °C for 48 h. After the reaction, the resulting product was centrifuged and washed with ethanol. Finally, it was dried at 60 °C for 12 h to obtain a white rod-shaped Mn-BTC powder. 20 mg of the Mn-BTC powder prepared in this example was then dispersed in 10 mL of deionized water. The solution was then treated under ultrasonic conditions (250 W) for 1 min to obtain a transparent manganese metal-organic cluster (Mn-MOC) liquid.

[0057] The Mn-MOC liquid prepared in this embodiment was then used for adsorption experiments of polymetallic cations, with a volume ratio of Mn-MOC liquid to ion solution of 1. 2+ Hg 2+ Pb 2+ Pd 2+ UO2 2+ and Th 4+ The ion concentration was 50 ppm. Mn-MOC liquid was mixed with the solution containing the contaminating ions and stirred continuously at 200 rpm and room temperature for 24 hours. Finally, the precipitate was removed by filtration using a 0.22 μm filter membrane. The concentrations of contaminant ions in the solution before and after adsorption were measured by inductively coupled plasma atomic emission spectrometry (ICP-OES, ThermoFisher, ICAP 7400), thus obtaining the effect of Mn-MOC liquid on the aforementioned contaminant ions Cu. 2+ Hg 2 + Pb 2+ Pd 2+ UO2 2+ and Th 4+ The ion removal rates were 97.8%, 99.32%, 99.41%, 99.74%, 99.58%, and 99.51%, respectively. Figure 6 As shown.

[0058] Example 6

[0059] The preparation process of the manganese metal organic cluster liquid in this embodiment includes:

[0060] 2.92 g of manganese acetate was dissolved in 30 mL of deionized water to obtain a manganese acetate solution. Simultaneously, 1.77 g of 1,3,5-benzenetricarboxylic acid (H3BTC) was dissolved in 30 mL of DMF to obtain a 1,3,5-benzenetricarboxylic acid solution. The two solutions were then mixed together and stirred at 25 °C for 10 minutes to obtain a mixed solution. The mixed solution was then transferred to a 100 mL PTFE-lined stainless steel autoclave and reacted at 150 °C for 48 h. After the reaction, the resulting product was centrifuged and washed with ethanol. Finally, it was dried at 60 °C for 12 h to obtain a white rod-shaped Mn-BTC powder. 20 mg of the Mn-BTC powder prepared in this example was then dispersed in 10 mL of deionized water. The solution was then treated under ultrasonic conditions (250 W) for 1 min to obtain a transparent manganese metal-organic cluster (Mn-MOC) liquid.

[0061] The Mn-MOC liquid prepared in this embodiment was then used for the adsorption experiment of polyoxoanions, with a volume ratio of Mn-MOC liquid to ion solution of 1. SeO3 2- TeO3 2- ,HAsO4 - and PO4 3- The ion concentration was 50 ppm. After mixing the Mn-MOC liquid with the solution containing the contaminating ions, the mixture was stirred continuously at 200 rpm and room temperature for 24 hours. Finally, the precipitate was removed by filtration using a 0.22-micron filter membrane. The concentrations of contaminant ions in the solution before and after adsorption were measured by inductively coupled plasma atomic emission spectrometry (ICP-OES, ThermoFisher, ICAP 7400), thus obtaining removal rates of 99.21%, 99.84%, 99.76%, and 99.99% for the aforementioned contaminant ions by the Mn-MOC liquid. Figure 7 As shown.

[0062] As can be seen from the above scheme, the technical solution of this invention can rapidly and efficiently remove positively and negatively charged heavy metal ions, oxygen anions, and radioactive ions from water, highlighting the versatility of Mn-MOC liquid in pollutant removal. Ultrasonic treatment accelerates the hydrolysis of Mn-BTC crystals, rapidly forming a transparent Mn-MOC liquid. This process not only improves dissolution efficiency but also simplifies the preparation steps. The unique feature of Mn-MOC liquid lies in its fully exposed adsorption and active sites, which allows it to uniformly adsorb target ions, avoiding the problem of active sites being shielded in traditional solid-phase adsorbents. Furthermore, Mn-MOC liquid can directly reduce toxic metal pollutant ions to valuable metals, which not only reduces environmental pollution but also achieves resource recycling. Compared with traditional water treatment methods, Mn-MOC liquid exhibits superior performance in treating various pollutants, effectively forming large-sized precipitates or flocs, facilitating subsequent separation and recovery. The successful development of this technology not only brings a new solution to the field of water purification but also provides new ideas for environmental remediation and sustainable development.

Claims

1. A method for preparing a manganese metal organic cluster liquid, characterized in that, include: Manganese acetate solution and 1,3,5-benzenetricarboxylic acid solution were mixed evenly to obtain mixture A; wherein the molar ratio of manganese acetate to 1,3,5-benzenetricarboxylic acid was (2-5):1; The mixture A was subjected to a hydrothermal reaction, and the product obtained from the hydrothermal reaction was washed and dried to obtain rod-shaped Mn-BTC powder. When the mixture A was subjected to a hydrothermal reaction, the reaction temperature was 120-150℃ and the reaction time was 24-72h. The rod-shaped Mn-BTC powder was dispersed in water to obtain a transparent manganese metal organic cluster liquid; wherein the mass ratio of the rod-shaped Mn-BTC powder to water was (0.005-0.02):

10.

2. The method for preparing a manganese metal organic cluster liquid according to claim 1, characterized in that, In the manganese acetate solution, deionized water is used as the solvent, and the mass ratio of manganese acetate to deionized water is (2.92-7.3):

30.

3. The method for preparing a manganese metal organic cluster liquid according to claim 1, characterized in that, The solvent for the 1,3,5-benzenetricarboxylic acid solution is N,N-dimethylformamide, wherein the mass range of 1.77-5.31g of 1,3,5-benzenetricarboxylic acid is added for every 30mL of N,N-dimethylformamide.

4. The method for preparing a manganese metal organic cluster liquid according to claim 1, characterized in that, Manganese acetate solution and 1,3,5-benzenetricarboxylic acid solution were mixed and stirred at 25°C for 10 minutes to obtain the mixture A.

5. The method for preparing a manganese metal organic cluster liquid according to claim 1, characterized in that, When washing and drying the product obtained from the hydrothermal reaction, it is centrifuged and washed with ethanol multiple times, and then dried at 60-100 °C for 12-24 h.

6. The method for preparing a manganese metal organic cluster liquid according to claim 1, characterized in that, To obtain a transparent manganese metal organic cluster liquid, the rod-shaped Mn-BTC powder is dispersed in water and then treated under ultrasonic conditions with a power of 100-300 W for 1-10 min.

7. A manganese metal organic cluster liquid, characterized in that, The manganese metal organic cluster liquid is prepared by any one of the preparation methods of claims 1-6.

8. The application of the manganese metal organic cluster liquid according to claim 7 in water purification, characterized in that, The manganese metal organic cluster liquid is used to purify pollutant ions in contaminated wastewater. These pollutant ions include metal cations, oxygen anions, radioactive ions, and noble metal ions, wherein the metal cations include Pb. 2+ Cu 2+ and Hg 2+ Oxygen anions include SeO3 2- TeO3 2- ,HAsO4 - and PO4 3- Radioactive ions include UO2 2+ and Th 4+ Noble metal ions include AuCl4 - and Pd 2+ .

9. The application of the manganese metal organic cluster liquid in water purification according to claim 8, characterized in that, When purifying pollutant ions in polluted wastewater, the manganese metal organic cluster liquid and the polluted wastewater are mixed at a volume ratio of 0.1-1, and then stirred continuously at 200-500 rpm for 0-24 hours. After that, solid-liquid separation is performed, and the pollutant ions are removed in the form of precipitates. The concentration of pollutant ions in the polluted wastewater does not exceed 800 ppm.

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