Preparation method of manganese-cerium binary composite and method for removing pollutants in high-salt organic wastewater by activating peroxymonosulfate using the same

Abstract

The application provides a preparation method of a manganese-cerium binary composite material and a method for removing pollutants in high-salt organic wastewater by activating peroxymonosulfate by using the manganese-cerium binary composite material, and belongs to the technical field of water pollution control. The manganese-cerium binary composite material prepared by the application is used as a catalyst to activate PMS through a non-radical route, and is applied to the treatment of tail water of mariculture. In this way, the antibiotics in the tail water of mariculture can be efficiently removed. The catalyst in the application is simple and rapid to prepare and easy to produce industrially. The method has the characteristics of high antibiotic removal efficiency, easy operation, convenient storage and transportation, is suitable for a wide pH range, and has great potential and wide application prospect in the field of polluted seawater treatment.

Description

Technical Field

[0001] This invention relates to the field of water pollution control technology, and in particular to a method for preparing a manganese-cerium binary composite material and a method for using it to activate persulfate to remove pollutants from high-salt organic wastewater. Background Technology

[0002] Marine aquaculture wastewater discharge is large, with high dissolved oxygen and high salinity, while the background concentration of antibiotics and ARGs is relatively low, making it very difficult to control and reduce antibiotics in the marine aquaculture environment.

[0003] In recent decades, it has been able to generate strong oxidative free radicals ( and Advanced oxidation technologies have been rapidly developed and are considered an effective means of treating recalcitrant organic pollutants. However, OH and It lacks selectivity for most organic pollutants and is easily affected by water quality characteristics, especially in the presence of large amounts of inorganic salt anions, leading to the unproductive consumption of free radicals and wasting reagents. In recent years, singlet oxygen (… 1 O2, as a non-radical active oxidant, has been widely used for the selective removal of organic pollutants and the inactivation of pathogens. 1 O2, as a moderately reactive electrophile, can rapidly oxidize electron-rich functional groups, selectively removing pollutants at low concentrations, while being relatively insensitive to background components in wastewater. Therefore, utilizing... 1 O2 is an effective way to remove pollutants from saline organic wastewater.

[0004] Persulfate (PMS), as a strong oxidizing agent, is frequently used as a disinfectant and water quality conditioner in aquaculture. Besides being activated via a free radical pathway, PMS also produces... and In addition, PMS can also be activated via non-radical pathways, thereby generating singlet oxygen. Ultrasound, photolysis, heating, transition metal ions, and oxides can all activate PMS, but most PMS activation occurs via radical pathways. Therefore, finding methods for activating PMS based on non-radical pathways is essential. Summary of the Invention

[0005] In view of this, the present invention provides a method for preparing a manganese-cerium binary composite material and a method for using it to activate persulfate to remove pollutants from high-salt organic wastewater. The present invention utilizes the prepared manganese-cerium binary composite material as a catalyst to activate PMS via a non-radical pathway, and applies this method to the treatment of marine aquaculture wastewater. This approach enables the efficient removal of antibiotics from marine aquaculture wastewater. The catalyst preparation method of the present invention is simple and rapid, and easy to industrialize. The method features high antibiotic removal efficiency, ease of operation, and convenient storage and transportation. It is applicable to a wide pH range and has great potential and broad application prospects in the field of polluted seawater treatment.

[0006] The preparation method of the manganese-cerium binary composite material of the present invention includes the following steps: S1: Preparation of cerium dioxide by hydrothermal reflux method: S1-1: Dissolve cerium nitrate hexahydrate in deionized water and stir to dissolve, thus obtaining a cerium nitrate solution; S1-2: Dissolve urea in deionized water and stir to dissolve, thus obtaining a urea solution; S1-3: Mix the cerium nitrate solution and urea solution, then add glycerol and stir until homogeneous to obtain a mixed solution; S1-4: The mixed solution is heated in a constant temperature oil bath and cooled with circulating water, the mixture is stirred and reacted, and the suspension is collected. S1-5: After the reaction is completed, cool to room temperature and separate the resulting suspension by high-speed centrifugation to obtain a white powder solid. After washing with anhydrous ethanol and deionized water, dry to obtain the cerium dioxide precursor basic cerium carbonate. S2: Preparation of manganese-cerium binary composite materials S2-1: Dissolve KMnO4 and MnSO4 separately in deionized water and stir to dissolve them to obtain KMnO4 solution and MnSO4 solution; S2-2: Mix the KMnO4 solution and MnSO4 solution, add basic cerium carbonate and stir ultrasonically to form a uniformly dispersed suspension; S2-3: The suspension solution is placed in a muffle furnace, heated and calcined, and then cooled to form a composite material solid; S2-4: The solid composite material is washed with anhydrous ethanol and distilled water and dried to obtain the manganese-cerium binary composite material.

[0007] Preferably, the concentration of the cerium nitrate solution in step S1-1 is 0.17-0.18 g / mL; and the concentration of the urea solution in step S1-2 is 0.07-0.08 g / mL.

[0008] Preferably, the volume ratio of cerium nitrate solution, urea solution and glycerol in steps S1-3 is 1-1.2:1-1.2:1-1.2.

[0009] Preferably, the temperature of the stirring reaction in steps S1-4 is 140-150℃, the stirring rate is 150-200 r / min, and the time is 4-5 h.

[0010] Preferably, the high-speed centrifugation in steps S1-5 is performed at a speed of 15000-20000 r / min for 15-20 min; the drying temperature is 100-110℃ for 6-8 h.

[0011] Preferably, the concentration of the KMnO4 solution in step S2-1 is 0.03-0.04 g / mL; and the concentration of the MnSO4 solution is 0.01-0.02 g / mL.

[0012] Preferably, the volume-to-mass ratio of the KMnO4 solution, MnSO4 solution and basic cerium carbonate in step S2-2 is 70-80 mL: 70-80 mL: 1.7-1.8 g.

[0013] Preferably, the heating and calcination method in step S2-3 is as follows: the temperature is raised from 150°C to 360°C for 0.3-0.5 hours, and then calcined for 3.5-4 hours.

[0014] Preferably, the drying temperature in steps S2-4 is 60-80℃, and the drying time is 10-12h.

[0015] Another object of the present invention is to provide an application of the manganese-cerium binary composite material prepared by the above method, which is used to activate persulfate to remove pollutants from high-salt organic wastewater.

[0016] Preferably, the method for removing pollutants from high-salt organic wastewater is as follows: The manganese-cerium binary composite material is mixed with persulfate and added to high-salt organic wastewater containing pollutants. After a full reaction, the pollutants in the high-salt organic wastewater can be oxidized and removed. The pH value of high-salt organic wastewater is 3-9.5; The amount of manganese-cerium binary composite material used is 0.1-0.8 g / L, and the concentration of persulfate is 1-10 mM / 200 mL; The high-salt organic wastewater is wastewater or seawater with a Na2SO4 concentration > 0.2M.

[0017] Compared with the prior art, the present invention has the following beneficial effects: This invention uses nano-potassium permanganate, manganese sulfate, and basic cerium carbonate (Ce(CO3)(OH)) as raw materials. A one-step hydrothermal method is employed to bond nano-cerium dioxide microspheres onto manganese dioxide nanorods, forming a manganese-cerium binary composite catalytic material. This manganese-cerium binary material and persulfate are then added to high-salt organic wastewater containing pollutants. The reaction at room temperature achieves rapid degradation of organic pollutants such as antibiotics. This invention utilizes a method for oxidizing organic pollutants in high-salt water primarily based on singlet oxygen. The synthesized manganese-cerium binary material, combined with persulfate, achieves rapid and efficient removal of pollutants such as antibiotics, demonstrating broad application prospects. Attached Figure Description

[0018] Figure 1 Scanning electron microscope (SEM) image of the manganese-cerium binary composite material prepared in Example 1; Figure 2 The electron paramagnetic resonance spectrum of the manganese-cerium binary composite material prepared in Example 1; Figure 3 The degradation of ciprofloxacin in sodium sulfate saline solution is shown in Example 1 and Comparative Examples 1-3. Figure 4 The degradation of atrazine and Acid Orange 7 in seawater is shown in Examples 2 and 3. Detailed Implementation

[0019] The present invention will be further described below with reference to the embodiments. In the specific embodiments of the present invention, the methods described are conventional methods in the art, unless otherwise specified.

[0020] Example 1 S1: Preparation of cerium dioxide by hydrothermal reflux method: S1-1: Dissolve 17.3648 g of cerium nitrate hexahydrate in 100 mL of deionized water and stir until dissolved to obtain a cerium nitrate solution; S1-2: Dissolve 7.2072 g of urea in 100 mL of deionized water and stir until dissolved to obtain a urea solution; S1-3: Mix the cerium nitrate solution and urea solution, then add 100 mL of glycerol and stir until homogeneous to obtain a mixed solution; S1-4: Transfer the mixed solution into a 500 mL single-necked round-bottom flask, then place it in a constant-temperature oil bath, connect a condenser, turn on the water cooling circulation, heat in a constant-temperature oil bath at 140℃, stir the reaction for 4 hours at a stirring rate of 150 r / min, and collect the suspension. S1-5: After the reaction is completed, cool to room temperature and separate the resulting suspension by high-speed centrifugation (20000 r / min, 20 min) to obtain a white powder solid. Wash the solid repeatedly with anhydrous ethanol and deionized water three times (100 ml of anhydrous ethanol and 100 ml of deionized water each time), and then dry it in an oven at 105 °C to obtain the cerium dioxide precursor basic cerium carbonate (Ce(CO3)(OH)). S2: Preparation of manganese-cerium binary composite materials S2-1: Dissolve 2.8066g KMnO4 and 1.5144g MnSO4 in 80 mL of deionized water and stir until dissolved to obtain KMnO4 solution and MnSO4 solution; S2-2: Mix the KMnO4 solution and MnSO4 solution, add 1.75g ​​Ce(CO3)(OH) and stir (stirring rate 250r / min) and sonicate (sonic power 200w) for 30min to form a uniformly dispersed suspension. S2-3: The suspension solution is transferred into a polytetrafluoroethylene reactor, placed in a muffle furnace, and the temperature is raised from 150°C to 360°C for 0.5 hours. Then, it is calcined at this temperature for 4 hours and then cooled and removed to form a composite material solid. S2-4: The composite material solid is repeatedly washed three times with anhydrous ethanol and distilled water (100 ml of anhydrous ethanol and 100 ml of deionized water each time), and dried at 80°C for 12 hours to obtain the manganese-cerium binary composite material.

[0021] The scanning electron microscope image of the manganese-cerium binary composite material is shown below. Figure 1 The electron paramagnetic resonance spectrum of the manganese-cerium binary composite material is shown below. Figure 2 .from Figure 1 It can be seen that the material consists of cerium dioxide nanospheres loaded on manganese dioxide nanopillars.

[0022] 1 mM persulfate was added to 200 mL of high-salt wastewater containing 0.050 mM ciprofloxacin and 0.2 M Na₂SO₄. The pH was adjusted to neutral, and then 0.1 g / L of manganese-cerium binary catalyst was added. With continuous stirring, the degradation rate of ciprofloxacin reached 96.8% within 60 min. Figure 3 As shown.

[0023] Example 2 1 mM persulfate was added to 200 mL of seawater containing 0.050 mM atrazine, followed by 0.1 g / L of the manganese-cerium binary catalyst prepared in Example 1. With continuous stirring, the degradation rate of atrazine reached 94.3% within 60 min. Figure 4 As shown.

[0024] Example 3 1 mM persulfate was added to 200 mL of seawater containing 0.2 mM Acid Orange 7, followed by 0.1 g / L of the manganese-cerium binary catalyst prepared in Example 1. With continuous stirring, the degradation rate of Acid Orange 7 reached 99.4% within 60 min. Figure 4 As shown.

[0025] Comparative Example 1 S1-1: Dissolve 2.8066g KMnO4 and 1.5144g MnSO4 in 80 mL of deionized water and stir to dissolve, to obtain KMnO4 solution and MnSO4 solution respectively; S1-2: Mix the KMnO4 solution and the MnSO4 solution to obtain a mixed solution; S1-3: The mixed solution is transferred into a polytetrafluoroethylene reactor, placed in a muffle furnace and heated to 360°C for half an hour. After continuous calcination for 4 hours, it is cooled and taken out to form a composite material solid. S1-4: The composite material solid is repeatedly washed three times with anhydrous ethanol and distilled water (100 ml of anhydrous ethanol and 100 ml of deionized water each time), and dried at 80°C for 12 h to obtain manganese dioxide (MnO2) material.

[0026] 1 mM persulfate was added to 200 mL of high-salt wastewater containing 0.050 mM ciprofloxacin and 0.2 M Na₂SO₄. The pH was adjusted to neutral, and then 0.1 g / L MnO₂ was added. With continuous stirring, the degradation rate of ciprofloxacin was 19.98% within 60 min. Figure 3 As shown.

[0027] Comparative Example 2 The basic cerium carbonate (Ce(CO3)(OH)) obtained in Example 1 was placed in a porcelain crucible and then transferred to a muffle furnace and directly calcined at 360 °C for 4 hours to obtain yellow cerium dioxide (CeO2) powder.

[0028] 1 mM persulfate was added to 200 mL of high-salt wastewater containing 0.050 mM ciprofloxacin and 0.2 M Na₂SO₄. The pH was adjusted to neutral, and then 0.1 g / L CeO₂ was added. With continuous stirring, the degradation rate of ciprofloxacin was 18.75% within 60 min. Figure 3 As shown.

[0029] Comparative Example 3 1 mM persulfate was added to 200 mL of high-salt wastewater containing 0.050 mM ciprofloxacin and 0.2 M Na₂SO₄. The pH was adjusted to neutral, and then 0.05 g / L CeO₂ and 0.05 g / L MnO₂ (CeO₂ + MnO₂) were added. With continuous stirring, the degradation rate of ciprofloxacin was 29.10% within 60 min. Figure 3 As shown.

[0030] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a manganese-cerium binary composite material, characterized in that, Includes the following steps: S1: Preparation of cerium dioxide by hydrothermal reflux method: S1-1: Dissolve cerium nitrate hexahydrate in deionized water and stir to dissolve, thus obtaining a cerium nitrate solution; S1-2: Dissolve urea in deionized water and stir to dissolve, thus obtaining a urea solution; S1-3: Mix the cerium nitrate solution and urea solution, then add glycerol and stir until homogeneous to obtain a mixed solution; S1-4: The mixed solution is heated in a constant temperature oil bath and cooled with circulating water, the mixture is stirred and reacted, and the suspension is collected. S1-5: After the reaction is completed, cool to room temperature and separate the resulting suspension by high-speed centrifugation to obtain a white powder solid. After washing with anhydrous ethanol and deionized water, dry to obtain the cerium dioxide precursor basic cerium carbonate. S2: Preparation of manganese-cerium binary composite materials S2-1: Dissolve KMnO4 and MnSO4 separately in deionized water and stir to dissolve them to obtain KMnO4 solution and MnSO4 solution; S2-2: Mix the KMnO4 solution and MnSO4 solution, add basic cerium carbonate and stir ultrasonically to form a uniformly dispersed suspension; S2-3: The suspension solution is placed in a muffle furnace, heated and calcined, and then cooled to form a composite material solid; S2-4: The solid composite material is washed with anhydrous ethanol and distilled water and dried to obtain the manganese-cerium binary composite material.

2. The method for preparing the manganese-cerium binary composite material according to claim 1, characterized in that, The concentration of the cerium nitrate solution in step S1-1 is 0.17-0.18 g / mL; the concentration of the urea solution in step S1-2 is 0.07-0.08 g / mL.

3. The method for preparing the manganese-cerium binary composite material according to claim 1, characterized in that, The volume ratio of cerium nitrate solution, urea solution and glycerol in steps S1-3 is 1-1.2:1-1.2:1-1.

2.

4. The method for preparing the manganese-cerium binary composite material according to claim 1, characterized in that, The stirring reaction in steps S1-4 is carried out at a temperature of 140-150℃, a stirring rate of 150-200 r / min, and a time of 4-5 h.

5. The method for preparing the manganese-cerium binary composite material according to claim 1, characterized in that, The high-speed centrifugation in steps S1-5 is carried out at a speed of 15000-20000 r / min for 15-20 min; the drying temperature is 100-110℃ and the drying time is 6-8 h.

6. The method for preparing the manganese-cerium binary composite material according to claim 1, characterized in that, The concentration of the KMnO4 solution in step S2-1 is 0.03-0.04 g / mL; the concentration of the MnSO4 solution is 0.01-0.02 g / mL.

7. The method for preparing the manganese-cerium binary composite material according to claim 1, characterized in that, The volume-to-mass ratio of the KMnO4 solution, MnSO4 solution, and basic cerium carbonate in step S2-2 is 70-80 mL: 70-80 mL: 1.7-1.8 g.

8. The method for preparing the manganese-cerium binary composite material according to claim 1, characterized in that, The heating and calcination method described in step S2-3 is as follows: the temperature is raised from 150℃ to 360℃ for 0.3-0.5h, and then calcined for 3.5-4h.

9. The method for preparing the manganese-cerium binary composite material according to claim 1, characterized in that, The drying temperature in steps S2-4 is 60-80℃, and the drying time is 10-12h.

10. The application of the material prepared by the method according to claim 1, characterized in that, The manganese-cerium binary composite material is used to activate persulfate to remove pollutants from high-salt organic wastewater; The method for removing pollutants from high-salt organic wastewater is as follows: The manganese-cerium binary composite material is mixed with persulfate and added to high-salt organic wastewater containing pollutants. After a full reaction, the pollutants in the high-salt organic wastewater can be oxidized and removed. The pH value of high-salt organic wastewater is 3-9.5; The amount of manganese-cerium binary composite material used is 0.1-0.8 g / L, and the concentration of persulfate is 1-10 mM / 200 mL; The high-salt organic wastewater is wastewater or seawater with a Na2SO4 concentration > 0.2M.

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