Preparation method and application of Co-Fe catalyst for catalyzing ozone to remove endocrine disrupters in water

Abstract

The invention belongs to the technical field of environmental protection and water treatment, and particularly relates to a preparation method and application of a Co-Fe catalyst for catalyzing ozone to remove endocrine disrupters in water. The Co-Fe catalyst prepared by the method is prepared by taking alpha-AI2O3 as a carrier and a Co-Fe composite solution as an impregnation liquid. The catalyst prepared by the invention can efficiently remove the endocrine disrupter in the water, and provides a new technical support for removing the endocrine disrupter in the water; according to the preparation method provided by the invention, the materials are simple and wide in source, and the preparation cost is reduced; the prepared catalyst is small in usage amount, capable of effectively degrading endocrine disruptors, high in targeting property and small in usage amount, and the removal rate of bisphenol A in 15 min can be close to 100%.

Description

Technical Field

[0001] The invention belongs to the technical field of environmental protection and water treatment, and specifically relates to a preparation method and application of a Co-Fe catalyst for catalyzing ozone to remove endocrine disruptors in water. Background Art

[0002] With the rapid development of social economy, water environment safety has become increasingly important. Water safety requires that there are no pathogenic microorganisms, toxic chemicals and radioactive substances that pose a health threat in the water. The use of a large number of chemicals increases the risk of water quality. Therefore, removing toxic chemicals in water, especially new pollutants in water, is the key to improving water safety. At present, one of the key tasks of ecological and environmental protection is to prevent and control new pollutants including endocrine disruptors. The implementation of the new drinking water hygiene standard GB5749 has put forward new requirements for the prevention and control of new pollutants in the water supply industry. Endocrine disruptors are an important environmental pollutant. Their monitoring and removal in water bodies are the focus of attention of domestic academic circles and environmental management departments.

[0003] The hazards of endocrine disruptors are extensive and complex, and their hazards mainly include the following aspects: (1) Impact on the endocrine system: ① Precocious puberty: It can cause endocrine system disorders in the human body, interfere with the regulation of sex hormones in the body, and thus cause precocious puberty in children. ② Decreased sperm quality: Damage to the male reproductive system, resulting in a decrease in sperm count, low sperm survival rate, and high sperm deformity rate, thereby affecting male fertility. ③ Infertility: It can interfere with the endocrine function of the hypothalamus and pituitary gland, affect ovulation, and increase the risk of female infertility. (2) Risk of reproductive system tumors: It can induce low differentiation of human cells, thereby increasing the risk of cancer, especially ovarian cancer and prostate cancer. In addition, it may also increase the size and grade of tumors in high-risk breast tissue, thereby increasing the risk of breast cancer. (3) Impact on nervous system behavior: Endocrine disruptors are low-toxic chemicals that can easily affect the development and function of the nervous system, leading to inattention, abnormal behavior, and decreased cognitive ability.

[0004] Advanced oxidation processes (AOPs) are effective methods for degrading endocrine disruptors. The target pollutants are mainly affected by strong oxidizing agents such as ·OH and ·SO4 − The pollutants are converted into low-toxic biodegradable products by attacking them. Currently, the commonly used advanced oxidation technologies are ultraviolet oxidation and ozone oxidation, among which hydroxyl radicals (∙OH) are the main determinant. Advanced oxidation technology uses free radicals to induce chain reactions, which are rapid and easy to control, and have obvious advantages over traditional oxidation methods. However, the efficiency of producing ∙OH in the ozone oxidation process alone is low, which is not enough to completely degrade endocrine disruptors in water. Finding a catalyst that can catalyze ozone oxidation to remove endocrine disruptors in water has become an urgent problem to be solved. Summary of the invention

[0005] In view of the research and development gaps in the prior art, the present invention provides a method for preparing a Co-Fe catalyst for catalyzing ozone to remove endocrine disruptors in water. The Co-Fe catalyst prepared by the method is prepared using α-AI2O3 as a carrier and a Co-Fe composite solution as an impregnation liquid. The use of the catalyst to catalyze ozone can efficiently remove endocrine disruptors in water.

[0006] The present invention also provides the use of the Co-Fe catalyst in catalyzing ozone to remove endocrine disruptors in water.

[0007] The technical solution adopted by the present invention to achieve the above-mentioned purpose is: The present invention provides a method for preparing a Co-Fe catalyst for catalyzing ozone to remove endocrine disruptors in water, comprising the following steps: (1) treating the carrier, washing and drying the α-Al2O3 pellets, and then crushing them to obtain α-Al2O3 powder; (2) Ultrasonic impregnation: weighed α-AI2O3 powder, ferric nitrate and cobalt nitrate are added to deionized water to dissolve, mixed evenly, and then ultrasonically shaken; then magnetic stirring is performed. After the stirring is completed, the impregnation liquid is rotary evaporated and dried to obtain the impregnation mixture; (3) The mixture is fully ground and then calcined to obtain a Co-Fe composite catalyst. 2. The preparation method according to claim 1, characterized in that in step (2), the amount of iron nitrate and cobalt nitrate added is 20% of the mass of the α-Al2O3 powder.

[0008] Preferably, the mass ratio of ferric nitrate to cobalt nitrate is 1:2-2:1; preferably, the mass ratio of ferric nitrate to cobalt nitrate is 1:2.

[0009] Preferably, in step (2), the ultrasonic oscillation time is 90 minutes; and the magnetic stirring is stirring at room temperature for 12 hours.

[0010] Preferably, in step (3), the calcination is performed by heating the temperature to 600° C. at a heating rate of 4° C. / min and keeping the temperature for 3 h.

[0011] The present invention also provides a Co-Fe catalyst prepared by the above preparation method.

[0012] The present invention further provides the use of the Co-Fe catalyst in catalyzing ozone to remove endocrine disruptors in water.

[0013] The catalyst provided by the present invention can adsorb ozone molecules to the active sites on the catalyst surface to form adsorbed ozone molecules. The adsorbed ozone molecules can be enriched on the catalyst surface, which is conducive to the chain reaction of ozone to produce more oxidizing OH. The catalyst can also reduce the activation energy required for the decomposition of ozone molecules by providing electrons or forming a specific chemical environment, thereby efficiently degrading endocrine disruptors in water. The mechanism of O3 generating free radicals is shown in the following formula: O3+H2O+ hv →O2+H2O2 O3+H2O2→∙OH H2O2+ hv →2∙OH O3+OH — →∙OH The beneficial effects of the present invention are: (1) The catalyst prepared by the present invention can efficiently remove endocrine disruptors in water, providing new technical support for removing endocrine disruptors in water; (2) The preparation method provided by the present invention uses simple materials and a wide range of sources, which reduces the preparation cost. The prepared catalyst has a small usage amount and can effectively degrade endocrine disruptors. It has strong targeting and a small usage amount. The removal rate of bisphenol A in 15 minutes can be close to 100%. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Technology roadmap for Co-Fe catalyst preparation; Figure 2 This is a scanning electron microscope image of the Co-Fe catalyst prepared in Example 1; Figure 3 This is a comparison chart of the effect of Co-Fe catalysts on catalytic ozone degradation of endocrine disruptors; Figure 4 This is a comparison chart of the effects of the catalysts prepared in Example 1 and Comparative Example 1 on catalyzing ozone degradation of endocrine disruptors; Figure 5 This is a comparison of the effects of Co-Fe catalysts prepared with different Co-Fe ratios on catalytic ozone degradation of endocrine disruptors. DETAILED DESCRIPTION

[0015] The technical solution of the present invention is further explained and illustrated by means of specific embodiments below.

[0016] Unless otherwise specified, the raw materials used in the present invention are commercially available.

[0017] The specific technical roadmap of the catalyst provided by the present invention is as follows Figure 1 shown.

[0018] In some embodiments, the endocrine disruptors that can be degraded by the catalyst prepared by the present invention include but are not limited to bisphenol endocrine disruptors.

[0019] Example 1 (1) Processing the carrier: When the stable α-Al2O3 pellets are directly used as carriers for impregnation, the contact area is too small, so they need to be ground into powder using a wall-breaking machine to increase the contact area before use. Before grinding into powder, the α-Al2O3 pellets are repeatedly washed three times with deionized water to remove impurities in the drug, then dried in a drying oven, and finally ground into powder for use as a carrier; (2) Calculate the required chemicals, use a 250 ml volumetric flask as the impregnation container, and calculate the required mass of iron nitrate and cobalt nitrate based on the mass of the impregnated carrier, the total mass of cobalt and iron accounting for 20% of the carrier mass and the active component loading ratio of Fe:Co=10%:20%; (3) Weigh the required drugs and solutions, use an electronic balance to weigh the required mass of carrier, ferric nitrate and cobalt nitrate, and use a measuring cylinder to weigh the required volume of deionized water; (4) Ultrasonic impregnation: Pour the weighed carrier, ferric nitrate and cobalt nitrate into a beaker, add 250 mL of deionized water to dissolve, mix evenly and pour into a 250 mL volumetric flask, then place the volumetric flask in a CNC ultrasonic cleaner and ultrasonically vibrate for 90 min to completely dissolve the ferric nitrate and cobalt nitrate, intensify the molecular activity of the solution, and accelerate the impregnation rate; (5) Mechanical stirring: After the ultrasonic immersion is completed, a stirring bar is placed in the volumetric flask, and then placed on a constant temperature magnetic stirrer and stirred at room temperature for 12 hours; (6) Rotary evaporation and drying: after the stirring and impregnation is completed, the mixed solution is poured into an eggplant-shaped bottle, the remaining impregnation solution is evaporated using a rotary evaporator, and then placed in a drying oven for drying; (7) Calcination: Place the dried solid into a grinding mortar, grind it finely, and then calcine it in a crucible to obtain catalyst powder. Set the heating rate of the muffle furnace to 4°C per minute, keep warm for 3 hours, and finally obtain a composite Co-Fe catalyst.

[0020] The scanning electron microscope image of the Co-Fe catalyst prepared in Example 1 is as follows: Figure 2 shown.

[0021] Comparative Example 1 (1) Processing the carrier: When the stable α-Al2O3 pellets are directly used as carriers for impregnation, the contact area is too small, so they need to be ground into powder using a wall-breaking machine to increase the contact area before use. Before grinding into powder, the α-Al2O3 pellets are repeatedly washed three times with deionized water to remove impurities in the drug, then dried in a drying oven, and finally ground into powder for use as a carrier; (2) Calculate the required chemicals, use a 250 ml volumetric flask as the impregnation container, and calculate the required mass of ferric nitrate based on the mass of the impregnated carrier and the ratio of the active component loading of Fe to the total mass of cobalt and iron to 20% of the mass of the carrier; (3) Weigh the required drugs and solutions, use an electronic balance to weigh the required mass of carrier and ferric nitrate, and use a measuring cylinder to weigh the required volume of deionized water; (4) Ultrasonic impregnation: Pour the weighed carrier and ferric nitrate into a beaker, add 250 mL of deionized water to dissolve, mix evenly, pour into a 250 mL volumetric flask, and then place the volumetric flask in a CNC ultrasonic cleaner for 90 min of ultrasonic vibration to completely dissolve the ferric nitrate, intensify the molecular activity of the solution, and accelerate the impregnation rate; (5) Mechanical stirring: After the ultrasonic immersion is completed, a stirring bar is placed in the volumetric flask, and then placed on a constant temperature magnetic stirrer and stirred at room temperature for 12 hours; (6) Rotary evaporation and drying: after the stirring and impregnation is completed, the mixed solution is poured into an eggplant-shaped bottle, the remaining impregnation solution is evaporated using a rotary evaporator, and then placed in a drying oven for drying; (7) Calcination: The dried solid is placed in a grinding mortar, finely ground, and then calcined in a crucible to obtain a catalyst powder. The heating rate of the muffle furnace is set to 4°C per minute, and the insulation time is 3 hours, and finally a composite Fe catalyst is obtained.

[0022] Effect Example 1 Using Taihu Lake water from Suzhou, 2L of water sample with a bisphenol A concentration of 1 mg / L was prepared. 50 mg of the Co-Fe catalyst prepared in Example 1 was added to the water sample, and 2 mg / L of ozone (through an ozone generator) was continuously introduced to treat the water sample. Within 15 minutes, the removal effects of ozone alone and after adding the Co-Fe catalyst on endocrine disruptors in the two water samples were compared. Figure 3 As shown, the effect of adding Co-Fe catalyst to catalyze ozone is significantly improved compared with ozone alone. In the same period of time, the removal rate of endocrine disruptors increased by 10%~20% after adding Co-Fe catalyst.

[0023] According to the same method as above, the same amount of the catalyst prepared in Comparative Example 1 was added to the water sample, and compared with the catalyst prepared in Example 1, Figure 4 As shown, the catalyst loaded with a single active ingredient Fe has a poorer effect on endocrine disruptors than the catalyst prepared in Example 1.

[0024] Effect Example 2 Using pure water as the background water source, 2L of water sample to be treated with a bisphenol A concentration of 1 mg / L was prepared, 50 mg of Co-Fe catalyst was added to the water sample (according to the method provided in Example 1, the Fe:Co ratio was 1:1, 1:2, and 2:1, respectively), and 2 mg / L of ozone was continuously introduced to treat the water sample. Figure 5 As shown in the figure, within 15 minutes, the removal effect of endocrine disruptors in two kinds of water by ozone alone and after adding Co-Fe catalyst was compared, and the best effect was achieved under the condition of Fe:Co=1:2.

Claims

1. A method for preparing a Co-Fe catalyst for catalyzing ozone to remove endocrine disruptors in water, characterized in that: The following steps are involved: (1) treating the carrier, washing and drying the α-Al2O3 pellets, and then crushing them to obtain α-Al2O3 powder; (2) Ultrasonic impregnation: weighed α-AI2O3 powder, ferric nitrate and cobalt nitrate are added to deionized water to dissolve, mixed evenly, and then ultrasonically shaken; then magnetic stirring is performed. After the stirring is completed, the impregnation liquid is rotary evaporated and dried to obtain the impregnation mixture; (3) The mixture is fully ground and then calcined to obtain a Co-Fe composite catalyst.

2. The preparation method according to claim 1, characterized in that: In step (2), the added amount of ferric nitrate and cobalt nitrate accounts for 20% of the mass of α-Al2O3 powder.

3. The preparation method according to claim 1 or 2, characterized in that: The mass ratio of the ferric nitrate to the cobalt nitrate is 1:2-2:1; preferably, the mass ratio of the ferric nitrate to the cobalt nitrate is 1:

2.

4. The preparation method according to any one of claims 1 to 3, characterized in that: In step (2), the ultrasonic oscillation time is 90 minutes; and the magnetic stirring is stirring at room temperature for 12 hours.

5. The preparation method according to claim 1, characterized in that: In step (3), the calcination is carried out by heating the temperature to 600°C at a heating rate of 4°C / min and keeping the temperature for 3 hours.

6. A Co-Fe catalyst prepared by the preparation method according to any one of claims 1 to 5.

7. Use of the Co-Fe catalyst as claimed in claim 6 in catalyzing ozone to remove endocrine disruptors in water.

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