CN115970690A - A kind of crystalline boron modified copper oxide catalyst and its preparation method and application - Google Patents

Abstract

A crystal boron modified copper oxide catalyst and a preparation method and application thereof comprise the following steps: 1) Dissolving copper nitrate trihydrate into an aqueous solution, wherein the mass ratio of the copper nitrate trihydrate to the aqueous solution is 1 (10-45); 2) Adding crystal boron (C-boron) into the solution obtained in the step 1), wherein the adding amount of the C-boron is 0.1-10 wt%, and adding alkali during stirring to form an alkaline environment; 3) Stirring for 5-10 min, and standing for 3-4 days; 4) And (4) drying the solution in vacuum and cooling to room temperature to obtain the crystal boron modified copper oxide catalyst. The application method of the C-boron-C-CuO material in degrading organic pollutants in water provided by the invention can effectively remove ibuprofen and benzoic acid, has high removal efficiency, can be used for purifying organic matters, and has application value in treating refractory organic matters, such as emergency treatment of water polluted by non-steroidal anti-inflammatory drugs.

Description

A kind of crystalline boron modified copper oxide catalyst and its preparation method and application

technical field

The invention belongs to the technical field of water treatment, and in particular relates to a crystal boron-modified copper oxide (C-boron-c-CuO) material and a preparation method and application thereof.

Background technique

With the gradual progress of the social economy and the continuous improvement of the level of science and technology, people's requirements for the environment are increasing day by day, which makes the problem of water environment pollution more and more prominent. Among them, with the rapid development of industrialization and urbanization, the types and quantities of organic matter in the water environment have increased dramatically. These organic pollutants can be discharged into natural water bodies in large quantities from municipal, agricultural and industrial sources, causing a series of problems to the water environment and human health. Antibiotics and personal care products (Pharmaceutical and Personal Care Products, d) are a new type of organic pollutants, including various antibiotics, hormones, non-steroidal anti-inflammatory drugs, anti-epileptic antibiotics, blood lipid regulators, β receptor blockers , contrast agents and cytostatic agents, as well as personal care products such as antibacterial agents, synthetic musks, insect repellents, antiseptics, fragrances, sunscreens, etc. As early as the beginning of the 21st century, foreign countries have begun to pay attention to the pollution of such organic pollutants to the environment. Since most refractory organics have strong polarity, high water solubility, and certain bacteriostasis and biological toxicity, it is difficult to pass traditional mixing methods. Water treatment methods such as coagulation, sedimentation, filtration, etc., as well as sewage treatment methods based on activated sludge, can cause PPCPs to persist in surface water, groundwater, drinking water, and sewage. In addition, the accumulation of refractory organic pollutants in the water environment will cause long-term potential harm to human health and ecosystems. Commonly used PPCPs treatment technologies include three categories: biological treatment, physical treatment, and chemical treatment. Biological treatment mainly refers to the removal of organic wastewater by artificially cultivated activated sludge. PPCPs are usually removed by biological transfer or sludge adsorption during treatment. However, due to the large variety of PPCPs and the large differences in their properties, biological treatment methods have significant differences in the treatment effects of different PPCPs. Physical treatment methods include flocculation, precipitation, adsorption, membrane treatment and other methods. At present, the conventional "coagulation-sedimentation-filtration-disinfection" in waterworks is not efficient in removing PPCPs. The physical treatment method mainly transfers pollutants from the water phase to the solid phase, and the resulting sludge/membrane secondary treatment is also a problem. Chemical treatment mainly refers to Advanced Oxidation Processes (AOPs). Advanced Oxidation Processes are characterized by the generation of highly active free radicals, which can degrade most organic substances and have a fast reaction rate. Mainly use the active oxygen components produced in the advanced oxidation process to oxidize and decompose the refractory PPCPs, or directly mineralize them into inorganic substances. Common advanced oxidation technologies include ozone oxidation, electrocatalytic oxidation, photocatalytic oxidation, Fenton/Fenton-like oxidation, etc. Conventional advanced oxidation technology usually refers to the oxidation and degradation of pollutants by OH· as the main active free radical, while activated persulfate is a new advanced oxidation technology that uses SO ₄ ^·- as the main active substance to degrade pollutants. In order to generate SO ₄ ^·− , peroxodisulfate (PDS) or permonomonosulfate (PMS) are generally deactivated using heat, alkali, ultraviolet (UV), ultrasonic waves, transition metals, and the like. Compared with other methods, transition metals are considered to be effective and feasible activators due to their high catalytic efficiency, low energy consumption, and easy handling. Generally, due to the asymmetric structure of PMS, it is always easier to be activated by transition metals than PDS. In addition, PMS is a solid at room temperature, stable in nature and convenient for transportation and storage, which has gradually attracted the attention of scholars. Among PMS catalysts, copper-based catalysts have many advantages over iron-based catalysts, and are widely used in the field of environmental catalysis. The iron-based catalyst has more iron sludge precipitation, and the catalytic activity of copper oxide (CuO) on PMS is significantly stronger than that of iron oxide, and the oxidant utilization rate is high, and the dissolution of metal ions is low. However, since the catalytic rate of copper oxide on PMS is still slow, it is necessary to add a higher concentration of CuO or PMS to achieve efficient removal of organic matter. How to further modify materials and build a more stable and efficient catalytic system is the key to further improving the removal level of refractory pollutants in water by PMS-based advanced oxidation methods. The crystalline boron-modified copper oxide (C-boron-c-CuO) material has high catalytic activity for PMS, and at the same time, it is simple to prepare and has good stability. This will be a new breakthrough in the research field of controlling the pollution of refractory organic pollutants in water and ensuring the safety of drinking water.

Contents of the invention

Technical problem to be solved: Aiming at the problem that the above-mentioned copper oxide material is used to catalyze PMS, the catalytic efficiency is relatively slow, and a higher concentration of CuO or PMS needs to be added to realize the efficient removal of organic matter. The present invention provides a crystal boron modified The copper oxide (C-boron-c-CuO) catalyst and its preparation method and application improve the catalytic efficiency of the CuO catalytic material in the process of catalyzing PMS.

Technical solution: a method for preparing a crystalline boron-modified copper oxide catalyst, comprising the following steps: 1) dissolving copper nitrate trihydrate in an aqueous solution, and the mass ratio of the copper nitrate trihydrate to the aqueous solution is 1:(10～ 45); 2) adding crystalline boron (C-boron) to the solution obtained in step 1), the amount of C-boron added is 0.1wt.% to 10wt.%, adding alkali during stirring to form an alkaline environment; 3 ) stirring for 5-10 minutes, then standing still for 3-4 days; 4) drying the solution in vacuum and cooling to room temperature to obtain a crystalline boron-modified copper oxide catalyst.

The alkaline environment in step 2) means that the concentration of NaOH in the solution after adding NaOH is 1-10 mol/L.

The stirring in step 3) refers to stirring in a magnetic stirrer for 1 to 30 minutes.

The vacuum drying described in step 4) refers to drying in a vacuum drying oven above 60° C. for more than 12 hours.

The crystal boron modified copper oxide catalyst prepared by the above method.

Application of the above-mentioned crystalline boron-modified copper oxide catalyst in degrading organic pollutants in water bodies.

The application steps are as follows: 1) Add borate to the aqueous solution of organic pollutants to adjust the pH of the solution to 6.5-7.5; 2) Pre-prepared peroxymonosulfate solution, add it to the pollutant solution in step 1) , stirring to obtain a mixed solution; 3) adding a crystalline boron-modified copper oxide material to the mixed solution in step 2) to start the reaction.

The above-mentioned organic pollutants include anti-inflammatory and antibacterial drug ibuprofen (IBP), organic pollutants nitrobenzene (NB) and benzoic acid (BA).

The concentration of the above-mentioned peroxosulfate solution is 100mM, and after the peroxosulfate solution is mixed with the pollutant solution, the concentration of the peroxosulfate solution is 0.1-1.2mM.

The concentration of the crystalline boron-modified copper oxide material in step 3) is 0.096g/L in the solution.

Beneficial effects: 1. The preparation process of C-boron-c-CuO provided by the present invention is simple, the raw materials are easy to purchase, the preparation conditions are safe and mild, and it can be produced in batches;

2. In the application method for degrading organic pollutants in water bodies provided by the present invention, C-boron-c-CuO improves the reaction speed of catalyzing PMS to degrade pollutants, reduces the dosage of catalysts, and reduces costs, and C-boron-c-CuO has good stability, simple operation and easy realization;

3. The application method of the C-boron-c-CuO material provided by the present invention in degrading organic pollutants in the water body can effectively remove ibuprofen and benzoic acid, the removal efficiency is high, and it can be used for the purification of organic matter, which is difficult to handle. The application value of degrading organic matter, such as the emergency treatment of water bodies polluted by non-steroidal anti-inflammatory drugs.

Description of drawings

分别表示污染物有机污染物硝基苯、苯甲酸、消炎抗菌药物布洛芬；工况：PMS＝0.6mM；c-CuO＝0.096g/L,[pollutants]＝20μM,pH＝7.5(硼酸缓冲50mM)Fig. 1 is that temperature is 25 ℃ among the embodiment 1, and catalyzer is under c-CuO condition, and c-CuO activates potassium hydrogen persulfate to anti-inflammatory antibacterial drug ibuprofen (IBP), organic pollutant nitrobenzene (NB), Benzoic acid (BA) removal rate versus time graph, in the figure

Respectively represent pollutants organic pollutants nitrobenzene, benzoic acid, anti-inflammatory and antibacterial drug ibuprofen; working conditions: PMS=0.6mM; c-CuO=0.096g/L, [pollutants]=20μM, pH=7.5 (boric acid buffer 50mM)

分别表示污染物有机污染物硝基苯、苯甲酸、消炎抗菌药物布洛芬；工况：PMS＝0.6mM；C-boron-c-CuO＝0.096g/L,[pollutants]＝20μM,pH＝7.5(硼酸缓冲50mM)。Fig. 2 is that temperature is 25 ℃ among the embodiment 2, and catalyst is under the condition of C-boron-c-CuO, and C-boron-c-CuO activates potassium monopersulfate to anti-inflammatory antibacterial drug ibuprofen (IBP), organic pollution nitrobenzene (NB), benzoic acid (BA) removal rate versus time curve, in the figure

Respectively represent pollutants organic pollutants nitrobenzene, benzoic acid, anti-inflammatory and antibacterial drug ibuprofen; working condition: PMS=0.6mM; C-boron-c-CuO=0.096g/L, [pollutants]=20μM, pH= 7.5 (boric acid buffer 50mM).

Fig. 3 is in embodiment 3, and temperature is 40 ℃, under the condition that catalyst is C-boron-c-CuO, C-boron-c-CuO activates potassium hydrogen persulfate to anti-inflammatory antibacterial drug ibuprofen (IBP), organic Pollutant nitrobenzene (NB), benzoic acid (BA) removal rate versus time curve.

Fig. 4 is in embodiment 3, and temperature is 55 ℃, under the condition that catalyst is C-boron-c-CuO, C-boron-c-CuO activates potassium monopersulfate to anti-inflammatory antibacterial drug ibuprofen (IBP), organic Pollutant nitrobenzene (NB), benzoic acid (BA) removal rate versus time curve.

Figure 5 shows that in Example 3, the catalyst is C-boron-c-CuO, and the temperature is 25°C, 40°C, and 55°C respectively, C-boron-c-CuO activates potassium hydrogen persulfate to remove anti-inflammatory and antibacterial drug cloth k _obs numerical diagram of the reaction of iprofen (IBP), organic pollutants nitrobenzene (NB), benzoic acid (BA).

Figure 6 shows that in Example 4, the temperature is 25°C, the catalyst is C-boron-c-CuO, and the NOM concentration is 1mg/L and 20mg/L respectively, C-boron-c-CuO activates hydrogen persulfate Potassium on the anti-inflammatory antibacterial drug ibuprofen (IBP), organic pollutants nitrobenzene (NB), benzoic acid (BA) removal rate versus time curve.

Fig. 7 shows that under the condition that the temperature is 25°C and the catalyst is the recovered C-boron-c-CuO material through primary regeneration, the C-boron-c-CuO material activates potassium hydrogen persulfate to anti-inflammatory and antibacterial drug ibuprofen ( IBP), organic pollutants nitrobenzene (NB), benzoic acid (BA) removal rate versus time curve.

Figure 8 shows that under the condition that the temperature is 25°C and the catalyst is the C-boron-c-CuO material recovered through secondary regeneration, the C-boron-c-CuO material activates potassium hydrogen persulfate for the anti-inflammatory and antibacterial drug ibuprofen (IBP), organic pollutants nitrobenzene (NB), benzoic acid (BA) removal rate versus time curve.

Figure 9 shows that under the condition that the temperature is 25°C and the catalyst is the C-boron-c-CuO material recovered through three regenerations, the C-boron-c-CuO material activates potassium monopersulfate for the anti-inflammatory and antibacterial drug ibuprofen ( IBP), organic pollutants nitrobenzene (NB), benzoic acid (BA) removal rate versus time curve.

FIG. 10 is a scanning electron microscope (SEM) image obtained by scanning the catalyst c-CuO in Example 1. FIG.

FIG. 11 is a scanning electron microscope (SEM) scanning electron microscope (SEM) SEM image obtained by scanning the catalyst C-boron-c-CuO in Example 2.

12 is an energy spectrum obtained by scanning the catalyst C-boron-c-CuO in Example 2 with an energy dispersive spectrometer (EDS).

Detailed ways

The present invention discusses the mechanism and efficiency of copper oxide materials to activate the PMS system, and attempts to use it to degrade typical organic pollutants. It is of great significance to the development of advanced oxidation methods based on potassium hydrogen persulfate and the efficient control of refractory organic pollutants in water. Important academic research and application value. The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example 1: The effect of c-CuO material activating PMS to degrade typical organic pollutants in water

1) Dissolve IBP, NB, and BA in water respectively, and control their concentrations to be 20 μM. adding boric acid to adjust the pH=6.5 to 7.5 to obtain an aqueous solution containing organic pollutants;

2) pre-preparing a potassium monomonosulfate solution with a concentration of about 100 mM, adding it to the pollutant solution in step 1), and stirring to obtain a mixed solution with a concentration of potassium monomonosulfate of 0.55-0.65 mM;

3) Add c-CuO material to the mixed solution in step 2) to make the concentration in the solution about 0.096g/L, start the reaction, and control the reaction temperature to 25°C. A certain amount of sample is taken out at regular intervals for filtration, and the filtrate is subjected to subsequent analysis. The removal effect is shown in Figure 1.

Example 2: C-boron-c-CuO material activates PMS to degrade typical organic pollutants in water

Preparation of crystalline boron-modified copper oxide material (C-boron-c-CuO), the steps are as follows:

1) dissolving copper nitrate trihydrate in an aqueous solution;

2) Add the purchased C-boron to the solution in step 1), and quickly add NaOH to the solution during the stirring process to form an alkaline environment;

3) After stirring for 5-10 minutes, let it stand for 3-4 days;

4) The solution was vacuum-dried and cooled to room temperature to obtain C-boron-c-CuO.

The other follow-up steps are the same as in Example 1, except that the c-CuO added in step 3) of the c-CuO material in the application method of degrading typical organic pollutants in water is changed to C-boron-c-CuO, and the copper oxide The removal rates of IBP, NB, and BA in water by the catalyst are shown in Figure 2. It can be seen from Figure 1 and Figure 2 that, under the condition that other conditions remain unchanged, when using crystalline boron-modified copper oxide as a catalyst, the removal rate of IBP and BA in water is significantly improved compared with using copper oxide as a catalyst. The removal rate of BA increased from 75.6% to 86.3% at 30 minutes, and the removal rate of IBP increased from 92.0% to 96.6% at 30 minutes.

Example 3: Effect of temperature on C-boron-c-CuO material activation of PMS to remove typical organic pollutants in water

The experimental process of embodiment 5 is the same as that of embodiment 2, except that the reaction temperature in step 3) is different, and the preset temperatures are respectively 40°C and 55°C, and the removal effects under different reaction temperatures are shown in Figure 3 and Figure 4, The k _obs at different temperatures are shown in Fig. 5. It can be seen from the figure that as the temperature increases, the removal rate of pollutants in the 3rd, 6th, and 10th minutes increases significantly. But at 30 minutes, the removal rate of each pollutant did not increase significantly. It shows that under this system, with the increase of temperature, the removal rate of pollutants (IBP, NB, BA) is significantly improved.

Example 4: Effect of NOM concentration on the effect of C-boron-c-CuO material activation of PMS to remove typical organic pollutants in water

The experimental process of Example 6 is the same as that of Example 2, except that 1 mg/L and 20 mg/L of NOM are added in step 1), and the removal effects after adding different concentrations of NOM are shown in Figure 6. It can be seen from the figure that when NOM=1mg/L, the removal effect of pollutants (IBP, NB, BA) is significantly better than that of NOM=20mg/L.

Example 5: The influence of C-boron-c-CuO material on the effect of activating PMS to remove typical organic pollutants in water after regeneration and recovery

The mixed solution obtained in Experimental Example 2 was filtered through a glass fiber membrane, washed with distilled water and ethanol, and dried in a vacuum oven at 60° C. for 12 hours to obtain a regenerated C-boron-c-CuO material. The rest of the operation steps are the same as in Example 2, only the C-boron-c-CuO material added in step 3 is replaced with the C-boron-c-CuO material recovered through primary, secondary, and tertiary regeneration. The experimental results are as follows Figure 7 shows. It can be seen from the figure that the C-boron-c-CuO material has good stability. After three times of regeneration and recycling, the C-boron-c-CuO material still has relatively good stability in degrading typical organic pollutants in water by activating PMS. Good activation effect.

Example 6: SEM analysis of c-CuO material and C-boron-c-CuO material

The samples of c-CuO and C-boron-c-CuO were observed by scanning electron microscope (SEM). The SEM acceleration voltage is 10.0keV, the magnification is 5000x, and the working distance is 15.0mm. Fig. 8 is a scanning electron micrograph of a c-CuO sample, and Fig. 9 is a scanning electron micrograph of a C-boron-c-CuO sample. From the comparison of Figure 3 and Figure 4, it can be seen that after adding C-boron, its surface morphology has changed dramatically. It can be seen from Figure 8 that c-CuO is in the shape of a two-dimensional sheet with a smooth surface. It can be seen from Figure 9 that C-boron-c-CuO is in the shape of a long rattan, with a rough surface and increased gaps. C-boron-c-CuO has larger specific surface area and higher surface roughness than c-CuO, which provides more active sites and better catalytic performance.

Example 7: c-CuO material and C-boron-c-CuO material energy spectrometer analysis

The C-boron-c-CuO samples were analyzed by energy dispersive spectroscopy (EDS). It can be seen from Figure 10 that there are Cu elements, O elements, B elements, and C elements in the sample, and the ratio of Cu elements to O element substances is about 1:1, and the ratio of Cu elements, O elements, and B element substances The volume ratio is about 3:2. EDS characterization results indicated that crystalline boron was successfully supported on CuO, and C-boron-c-CuO was the main catalyst.

Claims (10)

1. A preparation method of a crystal boron modified copper oxide catalyst is characterized by comprising the following steps: 1) Dissolving copper nitrate trihydrate into an aqueous solution, wherein the mass ratio of the copper nitrate trihydrate to the aqueous solution is 1 (10-45); 2) Adding crystal boron (C-boron) into the solution obtained in the step 1), wherein the adding amount of the C-boron is 0.1-10 wt%, and adding alkali during stirring to form an alkaline environment; 3) Stirring for 5-10 min, and standing for 3-4 days; 4) And (4) drying the solution in vacuum and cooling to room temperature to obtain the crystal boron modified copper oxide catalyst.

2. The method for preparing the crystalline boron-modified copper oxide catalyst according to claim 1, wherein the alkaline environment in the step 2) is that the concentration of NaOH in a solution after NaOH is added is 1 to 10mol/L.

3. The method for preparing the crystalline boron-modified copper oxide catalyst according to claim 1, wherein the stirring in the step 3) is performed in a magnetic stirrer for 1 to 30 minutes.

4. The method for preparing the crystalline boron-modified copper oxide catalyst according to claim 1, wherein the vacuum drying in step 4) is performed by drying in a vacuum drying oven at a temperature of 60 ℃ or higher for 12h or higher.

5. A crystalline boron-modified copper oxide catalyst obtainable by the process of any one of claims 1 to 4.

6. Use of the crystalline boron-modified copper oxide catalyst of claim 5 for degrading organic contaminants in a body of water.

7. Use according to claim 6, characterized in that the steps are as follows: 1) Adding borate into the aqueous solution of the organic pollutant to be treated to adjust the pH = 6.5-7.5 of the solution; 2) Preparing a peroxymonosulfate solution in advance, adding the peroxymonosulfate solution into the pollutant solution in the step 1), and stirring to obtain a mixed solution; 3) Adding a crystal boron modified copper oxide material into the mixed solution obtained in the step 2) to start reaction.

8. Use according to claim 6, wherein the organic contaminants comprise the anti-inflammatory antibacterial drug Ibuprofen (IBP), the organic contaminants Nitrobenzene (NB) and Benzoic Acid (BA).

9. The use of claim 7, wherein the concentration of the peroxymonosulfate solution is 100mM, and the concentration of the peroxymonosulfate is 0.1 to 1.2mM after the peroxymonosulfate solution is mixed with the contaminant solution.

10. The use of claim 7 wherein the crystalline boron modified copper oxide material of step 3) has a concentration of 0.096g/L in solution.

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