Method for efficiently treating organic wastewater by activating peracetic acid through piezoelectric catalysis

Abstract

The invention relates to the technical field of piezoelectric catalysis and pollution treatment, and discloses a method for efficiently treating organic wastewater by activating peracetic acid through piezoelectric catalysis, which comprises the following steps: polarizing BaTiO3 powder, and then drying and sieving to obtain polarized BaTiO3 powder; pAA and deionized water are mixed, pH is adjusted, then silver nitrate and organic wastewater are added, and a first mixed solution is obtained after uniform mixing; and adding the polarized BaTiO3 powder into the first mixed solution to obtain a second mixed solution, and degrading the second mixed solution in an ultrasonic environment. The method is easy to operate, the BaTiO3 material preparation cost is low, the process is mature, silver nanoparticles can be generated in situ, compared with composite material preparation, the operation is easy and convenient, and meanwhile the degradation rate is greatly increased by adding PAA.

Description

Technical Field

[0001] This invention relates to the field of piezoelectric catalysis and pollution control technology, and in particular to a method for efficiently treating organic wastewater by piezoelectric catalytic activation of peracetic acid. Background Technology

[0002] The discovery and use of antibiotics have made significant contributions to the prevention and treatment of human diseases. However, antibiotics are not completely metabolized in animals and are excreted in feces and urine as parent products or metabolites, thus entering the environment. my country has one of the highest antibiotic usage levels globally, with sulfonamides being the most widely used. High concentrations of various antibiotic residues can be detected in urban wastewater, reaching levels of ng / L or μg / L. Studies have shown that sulfamethoxazole (SMX) has been detected in surface water, drinking water, and even groundwater in many regions worldwide. In Asia, Europe, and North America, SMX has become one of the most common pharmaceutical pollutants. However, traditional wastewater treatment methods are ineffective in removing SMX from water, leading to its persistent presence in the environment. To address water pollution, researchers have actively explored various catalytic technologies, such as photocatalysis, electrocatalysis, and biocatalysis, and have made some progress in environmental remediation. Therefore, developing efficient and green water treatment technologies is crucial.

[0003] Piezoelectric catalysis has been extensively studied and used to degrade organic pollutants in water. In this technology, piezoelectric materials exhibit a piezoelectric effect when subjected to external mechanical forces or strain. The piezoelectric effect manifests as an anomalous electrical response in non-centrosymmetric crystalline materials when subjected to mechanical forces. This unique interaction between mechanical and electrical energy endows piezoelectric materials with the ability to efficiently convert environmental mechanical energy (such as wind, tides, water flow, and sound) into electrical energy. This property stems from the anisotropy of the crystal structure. When a piezoelectric material is subjected to external mechanical forces or strain, it causes displacement of atoms within the crystal lattice, resulting in a mismatch between the positions of cation and anion centers. This difference in atomic positions generates inherent dipole moments, called polarization. Therefore, the ordered summation of these dipole moments within the crystal unit cell produces a macroscopic built-in potential field, commonly referred to as the piezoelectric potential. A significant advantage of this piezoelectric potential is its elasticity to applied strain or stress, as it is generated by fixed and non-annihilated ionic charges. These abundant local charges serve as an effective resource, inducing the generation of reactive oxygen species, which can be used in various catalytic reactions, including energy conversion and wastewater purification. However, existing piezoelectric catalytic materials are expensive, have complex preparation processes, and have low degradation efficiency for pollutants. Therefore, it is very necessary to develop a piezoelectric catalytic material that can efficiently catalyze the degradation of antibiotics.

[0004] To obtain more efficient piezoelectric catalysts, various modification methods have been employed, such as morphology modification, doping, defect manipulation, and noble metal deposition. Noble metal deposition is a surface modification method. Noble metals (silver, gold, and platinum) deposited on semiconductors are often used as effective electron collectors or hole traps, facilitating charge carrier separation. Several methods exist for noble metal deposition, including photochemical methods, impregnation methods, and deposition-precipitation methods. Among these, photochemical methods are widely used due to their simplicity and efficiency. However, photochemical methods also have many drawbacks, such as difficulty in achieving large-area uniform deposition, the need for long illumination times to reach a certain deposition amount, low efficiency, and high equipment costs. Specifically, they require specific light sources (such as ultraviolet lamps or lasers), photoreactors, and illumination control systems. Precise control of deposition rate and particle size is more challenging than with other methods, easily resulting in excessively large particles or uneven distribution. In the impregnation method, during the drying process, the solvent evaporates from the support surface, and the precursor and noble metal ions migrate to the support edge along with the solvent. This results in the noble metal mainly depositing on the surface layer or at the edges of pores, with a lower concentration in the central part, making it difficult to achieve high dispersion. The deposition-precipitation method typically requires pretreatment of the support (such as surface activation or introduction of precipitation nuclei) to promote uniform adsorption or catalytic precipitation of the noble metal precursor, increasing the number of process steps and costs. Even subtle changes in reaction rate, pH, and temperature during precipitation can affect the size, morphology, and dispersion of the noble metal particles. Multiphase materials may be generated: in addition to the noble metal, other precipitate byproducts may also be formed, requiring subsequent removal. The process is complex and costly.

[0005] Traditional oxidants include ozone, hydrogen peroxide, and persulfate. Compared to traditional oxidants, peracetic acid (PAA), as an organic acid and a green disinfectant, holds promise for its residual components and byproducts as potential carbon sources for microorganisms in subsequent biological treatments. There are three main ways to activate PAA: external energy input, homogeneous catalysis, and heterogeneous catalysis. Among these, transition metal catalysts have attracted considerable attention due to their excellent catalytic performance, stability, and economic benefits. However, heterogeneous metal catalysts can lead to the dissolution of metal ions during the reaction, potentially causing environmental impacts and even biotoxicity; they also suffer from low thermal activation efficiency and are prone to ineffective decomposition of PAA; ultraviolet irradiation consumes a large amount of energy; and carbon materials exhibit low activity and short lifespans.

[0006] Therefore, there is an urgent need for a piezoelectric catalytic activation method for the efficient treatment of organic wastewater using peracetic acid to solve the above-mentioned technical problems. Summary of the Invention

[0007] The purpose of this invention is to provide a method for efficiently treating organic wastewater by piezoelectric catalytic activation of peracetic acid. This method is of great significance for improving the piezoelectric properties of BaTiO3 powder, generating silver nanoparticles in situ via piezoelectric activation, and enhancing the degradation efficiency of organic pollutants in water by activating oxidants.

[0008] To achieve the above objectives, the present invention is implemented according to the following technical solution: A method for efficiently treating organic wastewater by piezoelectric catalytic activation of peracetic acid includes the following steps: The BaTiO3 powder was polarized, then dried and sieved to obtain polarized BaTiO3 powder. After mixing PAA and deionized water and adjusting the pH, silver nitrate and organic wastewater were added and mixed evenly to obtain a first mixed solution. Polarized BaTiO3 powder was added to the first mixed solution and mixed evenly to obtain a second mixed solution. The second mixed solution was then degraded under ultrasonic conditions.

[0009] Specifically, it includes the following steps: The tetragonal BaTiO3 powder was polarized. After polarization, the powder was dried in a constant temperature oven and sieved to obtain the polarized powder. After mixing PAA and deionized water and adjusting the pH, silver nitrate and organic wastewater were added and mixed evenly to obtain a first mixed solution. Polarized BaTiO3 powder was added to the first mixed solution and stirred evenly to obtain a second mixed solution. The second mixed solution was then placed in an ultrasonic device for degradation.

[0010] Preferably, the BaTiO3 powder is tetragonal BaTiO3.

[0011] Preferably, during the polarization process, the polarization time is 15 min to 80 min and the polarization field strength is 5 kV to 10 kV.

[0012] Preferably, the drying process is as follows: drying in a constant temperature oven at 60 ℃ for 2 h; the sieving process uses a 140 mesh sieve.

[0013] Preferably, the amount of polarized BaTiO3 powder added to the second mixed solution is 1~6 g / L.

[0014] Preferably, the concentration of silver nitrate solution in the first mixed solution is 0.05~2 mmol / L.

[0015] Preferably, the concentration of PAA in the first mixed solution is 1~5 mmol / L.

[0016] Preferably, anions are also added to the first mixed solution; the concentration of anions in the first mixed solution is 0.2~1 mmol / L.

[0017] More preferably, the concentration of anions in the first mixed solution is 0.5 mmol / L.

[0018] Specifically, the anion is at least one of sulfate ions, bicarbonate ions, etc.

[0019] The degradation system of the present invention also contains anions. The addition of anions not only does not affect the degradation of the present invention, but also unexpectedly shows a stronger degradation effect.

[0020] Preferably, the concentration of antibiotic in the first mixed solution is 2~10 μmol / L.

[0021] More preferably, the concentration of the antibiotic in the first mixed solution is 5 μmol / L.

[0022] More preferably, the antibiotic is SMX.

[0023] Preferably, during the pH adjustment process, the pH is adjusted to 5-8.

[0024] Specifically, the pH adjustment process is as follows: use 0.1~0.5 mol / L NaOH solution and / or 0.1~0.5 mol / L dilute H2SO4 to adjust the pH to 5~8, and the temperature during the pH adjustment process is 25 ℃.

[0025] Preferably, mixing is carried out by stirring for 1 to 3 minutes at a stirring speed of 150 to 300 rpm.

[0026] Preferably, in the ultrasonic environment, the ultrasonic power is 300~600 W, the frequency is 30~50 kHz, the temperature of the second mixed solution is 20~30 ℃ during the ultrasonic process, and the degradation time does not exceed 12 min.

[0027] This invention specifically describes a piezoelectric catalytic system for in-situ generation of silver nanoparticles, capable of piezoelectrically catalytically activating PAA for efficient treatment of organic wastewater. The invention involves polarizing tetragonal BaTiO3 powder, drying it at a specific temperature, and then sieving it to obtain the polarized powder. PAA and deionized water are then mixed, the pH is adjusted, and silver nitrate, organic wastewater, and the polarized BaTiO3 powder are added for ultrasonic catalytic experiments. Piezoelectric catalytic degradation experiments demonstrate that without PAA, the degradation rate of SMX is only 8% after 2 minutes, while the degradation rate reaches 100% after adding PAA. Without silver nitrate solution, the degradation rate of SMX is only 22% after 12 minutes, while the degradation rate reaches 100% after adding silver nitrate solution.

[0028] The method of this invention is simple to operate, has low cost for preparing BaTiO3 materials, and is a mature process. It can also generate silver nanoparticles in situ, making it simpler to operate compared to the preparation of composite materials. Furthermore, the addition of PAA significantly improves the degradation rate. Under the external mechanical stress provided by ultrasonic cavitation, BaTiO3 can generate piezoelectric electrons, which can reduce Ag in the solution. + This process allows for the in-situ generation of silver nanoparticles on the surface of BaTiO3. During piezoelectric catalysis, due to the excellent conductivity of the silver nanoparticles, piezoelectrically induced electrons can be rapidly transferred and temporarily stored in the deposited silver nanoparticles before the BaTiO3 recovers its deformation, reducing the recombination rate of electrons and holes. Simultaneously, the stored electrons react with PAA (polyacrylamide) to generate various free radicals that degrade pollutants, providing a new approach for the efficient degradation of organic wastewater. This method can also be used for the effective treatment of pollutants in environmental water bodies, showing broad application prospects in both piezoelectric catalysis and pollution control.

[0029] The method of this invention utilizes piezoelectric catalysis to generate silver nanoparticles in situ, perfectly avoiding the shortcomings of existing photochemical, impregnation, and deposition-precipitation methods. In this piezoelectric catalytic system, the silver nanoparticles are directly generated on the surface of barium titanate, rather than being loaded later. This means that the silver particles can be more uniformly distributed on the surface of barium titanate, and can even be anchored to specific active sites on the barium titanate. Simultaneously, the generated silver nanoparticles have a large specific surface area, providing more active sites, which is crucial for improving the catalytic reaction rate. Due to the highly dispersed and firmly anchored silver particles, only a very small amount of silver is typically needed to achieve high catalytic activity, significantly reducing the cost of using precious metals.

[0030] Beneficial effects: 1. This invention polarizes tetragonal barium titanate (BaTiO3) powder, causing the dipole moments of the originally randomly arranged barium titanate grains to align along the direction of the applied electric field, generating a macroscopic polarization direction. When mechanical stress is applied, this polarization direction changes, thereby generating electric charge; this is the piezoelectric effect. The piezoelectric constant of the polarized barium titanate (…) d 33 This greatly improves its properties, making it an excellent piezoelectric material; 2. The method of this invention can generate silver nanoparticles in situ, which is simpler than the preparation of composite materials; BaTiO3 can generate piezoelectric induced electrons under the external mechanical stress provided by ultrasonic cavitation effect, which can reduce Ag in solution. +This allows in-situ generated silver nanoparticles to be loaded onto the surface of BaTiO3, eliminating the need for separate synthesis of composite materials and enabling one-step synthesis during the reaction, thus saving reaction preparation time. During piezoelectric catalysis, due to the good conductivity of silver nanoparticles, before the deformation of BaTiO3 recovers, piezoelectrically induced electrons can be rapidly transferred and temporarily stored in the deposited silver nanoparticles, reducing the recombination rate of electrons and holes. Silver also plays a role in enriching and transferring electrons during the reaction. 3. The method of this invention specifically incorporates a novel oxidant, PAA. Compared to traditional oxidants, PAA, as an organic acid and a green disinfectant, has residual components and byproducts that are expected to serve as potential carbon sources for microorganisms in subsequent biological treatments. In the system, the electrons stored in silver nanoparticles can react with PAA, generating organic free radicals (RORs) through PAA activation. • ), hydroxyl radicals ( • OH), superoxide radical ( • O2 - Singlet oxygen () 1 Active substances such as O2 accelerate the removal of pollutants, providing a new solution for the efficient degradation of organic wastewater; 4. Based on practical considerations, this invention constructs a novel piezoelectric catalytic method. The stability of the polarized barium titanate powder is greatly improved. During the reaction process, the silver nanoparticles loaded in one step are stably combined with the barium titanate, which solves the problem of low recycling rate of traditional catalysts. It can achieve efficient and long-lasting pollutant removal and reduce economic expenditure in practical applications. 5. This invention controls the water temperature during the ultrasonic process to keep the barium titanate powder at the phase boundary temperature during piezoelectric catalysis, thus exhibiting excellent piezoelectricity. 6. The method of the present invention still has a very high degradation effect in the presence of various anions, which has great advantages in practical production applications and solves the problem that the degradation effect of other catalysts is greatly reduced in the presence of anions; 7. The method of the present invention requires a very short time to treat wastewater, and only 12 minutes is needed to achieve 100% degradation effect. Attached Figure Description

[0031] Figure 1 The XRD pattern of the tetragonal BaTiO3 powder used in this invention; Figure 2 This is a comparison chart of the performance of Example 1 and Comparative Example 1 in degrading SMX. Figure 3 This is a comparison chart of the performance of Example 1 and Comparative Example 2 in degrading SMX. Figure 4 This is a SEM image of the powder obtained after washing and drying following the completion of the degradation reaction in Example 1 of the present invention. Figure 5 The EDS diagram of Ag element in the powder obtained after washing and drying following the completion of the degradation reaction in Example 1 of this invention; Figure 6 Examples 1 and 4 of the present invention 1 EPR spectrum of O2; Figure 7 Examples 1 and 4 of the present invention • EPR spectrum of OH; Figure 8 Examples 1 and 4 of the present invention • O2 - EPR map; Figure 9 Comparative Examples 4, 5, and 6 of this invention 1 EPR spectrum of O2; Figure 10 This is a diagram of a free radical quenching experiment in Example 1 of the present invention; Figure 11 Examples 6 and 7 of this invention show the effect of SMX degradation performance in Example 1. Detailed Implementation

[0032] The present invention will be further described below with reference to specific embodiments. The illustrative embodiments and descriptions herein are used to explain the present invention, but are not intended to limit the present invention.

[0033] There are no particular restrictions on the source of any raw materials used in this invention; they can be purchased from the market or prepared using conventional methods known to those skilled in the art.

[0034] There are no particular restrictions on the purity of any of the raw materials used in this invention; however, it is preferred to use materials with conventional purity levels used in the field.

[0035] All processes in this invention are referred to by abbreviations that are common abbreviations in the field. Each abbreviation is clear and specific in its relevant application area, and those skilled in the art can understand its conventional process steps based on the abbreviation.

[0036] In the following embodiments, the polarized BaTiO3 powder is prepared as follows: the tetragonal BaTiO3 powder is polarized for 60 min at a polarization field strength of 10 kV. After polarization, it is dried in a constant temperature oven at 60 ℃ for 2 h and then passed through a 140-mesh sieve to obtain the polarized BaTiO3 powder.

[0037] Example 1 A method for efficiently treating organic wastewater by piezoelectric catalytic activation of peracetic acid includes the following steps: At room temperature, 27 μL of 2.85 mol / L PAA solution and 21.85 mL of deionized water were added to a beaker. Then, 1.75 mL of 0.1 mol / L NaOH solution was added to adjust the pH of the solution to 7. 1.25 mL of 10 mmol / L silver nitrate solution was added, followed by 125 μL of 1 mmol / L SMX solution. The final mixed solution had a PAA concentration of 3 mmol / L, a silver nitrate concentration of 0.5 mmol / L, and an SMX concentration of 5 μmol / L. Add 0.1 g of polarized BaTiO3 powder and stir for 1 min to mix evenly. Then place the beaker in an ultrasonic instrument with an ultrasonic power of 432 W and a frequency of 40 kHz. The ultrasonic reaction is carried out for 12 min, and the temperature of the solution during the ultrasonication is 20~30 ℃. During the reaction, 0.2 mL of sample is taken out at certain time intervals (0, 2, 4, 6, 8, 10, 12 min) and filtered through a 0.22 μm filter membrane. The concentration of SMX is determined by high performance liquid chromatography to verify its degradation effect.

[0038] Example 2 A method for efficiently treating organic wastewater by piezoelectric catalytic activation of peracetic acid includes the following steps: At room temperature, 27 μL of 2.85 mol / L PAA solution and 18.1 mL of deionized water were added to a beaker. Then, 1.75 mL of 0.1 mol / L NaOH solution was added to adjust the pH of the solution to 7. 5 mL of 10 mmol / L silver nitrate solution was added, followed by 125 μL of 1 mmol / L SMX solution. The final mixed solution had a PAA concentration of 3 mmol / L, a silver nitrate concentration of 2 mmol / L, and an SMX concentration of 5 μmol / L. Add 0.1 g of polarized BaTiO3 powder and stir for 1 min to mix evenly. Then place the beaker in an ultrasonic instrument with an ultrasonic power of 432 W and a frequency of 40 kHz. The ultrasonic reaction is carried out for 12 min, and the temperature of the solution during the ultrasonication is 20~30 ℃. During the reaction, 0.2 mL of sample is taken out at certain time intervals (0, 2, 4, 6, 8, 10, 12 min) and filtered through a 0.22 μm filter membrane. The concentration of SMX is determined by high performance liquid chromatography to verify its degradation effect.

[0039] Example 3 A method for efficiently treating organic wastewater by piezoelectric catalytic activation of peracetic acid includes the following steps: At room temperature, 27 μL of 2.85 mol / L PAA solution and 22.975 mL of deionized water were added to a beaker. Then, 1.75 mL of 0.1 mol / L NaOH solution was added to adjust the pH of the solution to 7. 0.125 mL of 10 mmol / L silver nitrate solution was added, followed by 125 μL of 1 mmol / L SMX solution. The final mixed solution had a PAA concentration of 3 mmol / L, a silver nitrate concentration of 0.05 mmol / L, and an SMX concentration of 5 μmol / L. Add 0.1 g of polarized BaTiO3 powder and stir for 1 min to mix evenly. Then place the beaker in an ultrasonic instrument with an ultrasonic power of 432 W and a frequency of 40 kHz. The ultrasonic reaction is carried out for 12 min, and the temperature of the solution during the ultrasonication is 20~30 ℃. During the reaction, 0.2 mL of sample is taken out at certain time intervals (0, 2, 4, 6, 8, 10, 12 min) and filtered through a 0.22 μm filter membrane. The concentration of SMX is determined by high performance liquid chromatography to verify its degradation effect.

[0040] Example 4 A method for efficiently treating organic wastewater by piezoelectric catalytic activation of peracetic acid includes the following steps: At room temperature, 9 μL of 2.85 mol / L PAA solution and 23.036 mL of deionized water were added to a beaker. Then, 580 μL of 0.1 mol / L NaOH solution was added to adjust the pH of the solution to 7. 1.25 mL of 10 mmol / L silver nitrate solution was added, followed by 125 μL of 1 mmol / L SMX solution. The final mixed solution had a PAA concentration of 1 mmol / L, a silver nitrate concentration of 0.5 mmol / L, and an SMX concentration of 5 μmol / L. Add 0.1 g of polarized BaTiO3 powder and stir for 1 min to mix evenly. Then place the beaker in an ultrasonic instrument with an ultrasonic power of 432 W and a frequency of 40 kHz. The ultrasonic reaction is carried out for 12 min, and the temperature of the solution during the ultrasonication is 20~30 ℃. During the reaction, 0.2 mL of sample is taken out at certain time intervals (0, 2, 4, 6, 8, 10, 12 min) and filtered through a 0.22 μm filter membrane. The concentration of SMX is determined by high performance liquid chromatography to verify its degradation effect.

[0041] Example 5 A method for efficiently treating organic wastewater by piezoelectric catalytic activation of peracetic acid includes the following steps: At room temperature, 45 μL of 2.85 mol / L PAA solution and 20.58 mL of deionized water were added to a beaker. Then, 3 mL of 0.1 mol / L NaOH solution was added to adjust the pH of the solution to 7. 1.25 mL of 10 mmol / L silver nitrate solution was added, followed by 125 μL of 1 mmol / L SMX solution. The final mixed solution had a PAA concentration of 5 mmol / L, a silver nitrate concentration of 0.5 mmol / L, and an SMX concentration of 5 μmol / L. Add 0.1 g of polarized BaTiO3 powder and stir for 1 min to mix evenly. Then place the beaker in an ultrasonic instrument with an ultrasonic power of 432 W and a frequency of 40 kHz. The ultrasonic reaction is carried out for 12 min, and the temperature of the solution during the ultrasonication is 20~30 ℃. During the reaction, 0.2 mL of sample is taken out at certain time intervals (0, 2, 4, 6, 8, 10, 12 min) and filtered through a 0.22 μm filter membrane. The concentration of SMX is determined by high performance liquid chromatography to verify its degradation effect.

[0042] Example 6 A method for efficiently treating organic wastewater by piezoelectric catalytic activation of peracetic acid includes the following steps: At room temperature, 27 μL of 2.85 mol / L PAA solution and 21.725 mL of deionized water were added to a beaker. Then, 1.75 mL of 0.1 mol / L NaOH solution was added to adjust the pH of the solution to 7. 1.25 mL of 10 mmol / L silver nitrate solution was added, followed by 125 μL of 0.1 mol / L sodium sulfate solution. Finally, 125 μL of 1 mmol / L SMX solution was added. The resulting mixed solution had a PAA concentration of 3 mmol / L, a silver nitrate concentration of 0.5 mmol / L, a sulfate anion concentration of 0.5 mmol / L, and an SMX concentration of 5 μmol / L. Add 0.1 g of polarized BaTiO3 powder and stir for 1 min to mix evenly. Then place the beaker in an ultrasonic instrument with an ultrasonic power of 432 W and a frequency of 40 kHz. The ultrasonic reaction is carried out for 12 min, and the temperature of the solution during the ultrasonication is 20~30 ℃. During the reaction, 0.2 mL of sample is taken out at certain time intervals (0, 2, 4, 6, 8, 10, 12 min) and filtered through a 0.22 μm filter membrane. The concentration of SMX is determined by high performance liquid chromatography to verify its degradation effect.

[0043] Example 7 A method for efficiently treating organic wastewater by piezoelectric catalytic activation of peracetic acid includes the following steps: At room temperature, 27 μL of 2.85 mol / L PAA solution and 21.725 mL of deionized water were added to a beaker. Then, 1.75 mL of 0.1 mol / L NaOH solution was added to adjust the pH of the solution to 7. 1.25 mL of 10 mmol / L silver nitrate solution was added, followed by 125 μL of 0.1 mol / L sodium bicarbonate solution. Finally, 125 μL of 1 mmol / L SMX solution was added. The resulting mixed solution had a PAA concentration of 3 mmol / L, a silver nitrate concentration of 0.5 mmol / L, a bicarbonate anion concentration of 0.5 mmol / L, and an SMX concentration of 5 μmol / L. Add 0.1 g of polarized BaTiO3 powder and stir for 1 min to mix evenly. Then place the beaker in an ultrasonic instrument with an ultrasonic power of 432 W and a frequency of 40 kHz. The ultrasonic reaction is carried out for 12 min, and the temperature of the solution during the ultrasonication is 20~30 ℃. During the reaction, 0.2 mL of sample is taken out at certain time intervals (0, 2, 4, 6, 8, 10, 12 min) and filtered through a 0.22 μm filter membrane. The concentration of SMX is determined by high performance liquid chromatography to verify its degradation effect.

[0044] Comparative Example 1 At room temperature, 27 μL of 2.85 mol / L PAA solution and 21.85 mL of deionized water were added to a beaker. Then, 1.75 mL of 0.1 mol / L NaOH solution was added to adjust the pH to 7, followed by 1.25 mL of 10 mmol / L sodium nitrate solution and 125 μL of 1 mmol / L SMX solution. 0.1 g of the polarized BaTiO3 powder was added, and the mixture was stirred for 1 min to ensure homogeneity. The beaker was then placed in an ultrasonic instrument at a power of 432 W and a frequency of 40 kHz for 12 min. The solution temperature during ultrasonication was maintained at 20–30 °C. At regular intervals (0, 2, 4, 6, 8, 10, 12 min), 0.2 mL of the sample was filtered through a 0.22 μm filter membrane, and the SMX concentration was determined by high-performance liquid chromatography (HPLC) to verify the degradation effect.

[0045] Comparative Example 2 At room temperature, 23.625 mL of deionized water was added to a beaker, followed by 1.25 mL of 10 mmol / L silver nitrate solution, and then 125 μL of 1 mmol / L SMX solution. 0.1 g of the polarized BaTiO3 powder was added, and the mixture was stirred for 1 min to ensure homogeneity. The beaker was then placed in an ultrasonic instrument at a power of 432 W and a frequency of 40 kHz for 12 min. The solution temperature during the ultrasonication process was maintained at 20–30 °C. At regular intervals (0, 2, 4, 6, 8, 10, 12 min), 0.2 mL of the sample was filtered through a 0.22 μm filter membrane, and the SMX concentration was determined by high-performance liquid chromatography (HPLC) to verify the degradation effect.

[0046] Comparative Example 3 At room temperature, 27 μL of 2.85 mol / L PAA solution and 21.85 mL of deionized water were added to a beaker. Then, 1.75 mL of 0.1 mol / L NaOH solution was added to adjust the pH to 7, followed by 1.25 mL of 10 mmol / L silver nitrate solution and 125 μL of 1 mmol / L SMX solution. The mixture was stirred for 1 min to ensure homogeneity. The beaker was then placed in an ultrasonic apparatus at a power of 432 W and a frequency of 40 kHz for 12 min. The solution temperature was maintained at 20–30 °C during the ultrasonication process. At regular intervals (0, 2, 4, 6, 8, 10, 12 min), 0.2 mL of the sample was filtered through a 0.22 μm filter membrane, and the SMX concentration was determined by high-performance liquid chromatography (HPLC) to verify the degradation effect.

[0047] In Comparative Example 3, no BaTiO3 was added. Testing revealed that without BaTiO3 powder, the SMX degradation rate was only 7% after 12 minutes. However, with the addition of BaTiO3 powder, the degradation rate reached 100% (data from degradation under the conditions of Example 1). This is because without BaTiO3 powder, silver nanoparticles cannot be generated through piezoelectric catalysis, and PAA cannot be activated to produce a large amount of RO. • , • OH, • O2 - , 1 Because it contains active substances such as O2, its degradation effect is very poor.

[0048] Comparative Example 4 At room temperature, 27 μL of 2.85 mol / L PAA solution and 23.1 mL of deionized water were added to a beaker. Then, 1.75 mL of 0.1 mol / L NaOH solution was added to adjust the pH to 7, followed by 125 μL of 1 mmol / L SMX solution. 0.1 g of the polarized BaTiO3 powder was added, and the mixture was stirred for 1 min to ensure homogeneity. The beaker was then placed in an ultrasonic apparatus at a power of 432 W and a frequency of 40 kHz for 120 min. The solution temperature during the ultrasonication process was maintained at 20–30 °C. At regular intervals (0, 2, 4, 6, 8, 10, 12 min), 0.2 mL of the sample was filtered through a 0.22 μm filter membrane, and the SMX concentration was determined by high-performance liquid chromatography (HPLC) to verify the degradation effect.

[0049] Comparative Example 5 At room temperature, 24.875 mL of deionized water was added to a beaker, followed by 125 μL of 1 mmol / L SMX solution. 0.1 g of the polarized BaTiO3 powder was added, and the mixture was stirred for 1 min to ensure homogeneity. The beaker was then placed in an ultrasonic apparatus at a power of 432 W and a frequency of 40 kHz for 120 min. The solution temperature during the ultrasonication process was maintained at 20–30 °C. At regular intervals (0, 2, 4, 6, 8, 10, 12 min), 0.2 mL of the sample was filtered through a 0.22 μm filter membrane, and the SMX concentration was determined by high-performance liquid chromatography (HPLC) to verify the degradation effect.

[0050] Comparative Example 6 At room temperature, 27 μL of 2.85 mol / L PAA solution and 23.1 mL of deionized water were added to a beaker. Then, 1.75 mL of 0.1 mol / L NaOH solution was added to adjust the pH to 7, followed by 125 μL of 1 mmol / L SMX solution. The mixture was stirred for 1 min to ensure homogeneity. The beaker was then placed in an ultrasonic apparatus at a power of 432 W and a frequency of 40 kHz for 120 min. The solution temperature was maintained at 20–30 °C during the ultrasonication process. At regular intervals (0, 2, 4, 6, 8, 10, 12 min), 0.2 mL of the sample was filtered through a 0.22 μm filter membrane, and the SMX concentration was determined by high-performance liquid chromatography (HPLC) to verify the degradation effect.

[0051] Results Analysis like Figure 1The figure shows the XRD pattern of the tetragonal BaTiO3 powder used in this invention. As can be seen from the figure, seven diffraction peaks (2θ) are observed at 22°, 32°, 39°, 45°, 51°, 56°, and 66°, attributed to the (100), (110), (111), (002), (200), (210), (211), and (220) crystal planes, respectively. Notably, the peak around 45° is assigned to (002) and (200), at 44.9° and 45.4°, respectively. Splitting is a significant characteristic of the tetragonal BaTiO3 powder.

[0052] like Figure 2 The figure shows a performance comparison of SMX degradation between Example 1 and Comparative Example 1 of the present invention; the line “US / BTO / PAA / AgNO3” in the figure represents Example 1, and the line “US / BTO / PAA / NaNO3” in the figure represents Comparative Example 1. US represents ultrasonication, and BTO represents tetragonal BaTiO3 powder.

[0053] pass Figure 2 It can be seen that without the addition of silver nitrate solution, the degradation rate of SMX was only 22% after 12 minutes, while the degradation rate of SMX reached 100% after the addition of silver nitrate solution. This is because BaTiO3 powder, under the external mechanical stress provided by ultrasonic cavitation, can generate piezoelectrically induced electrons, which can reduce Ag in the solution. + This process allows in-situ generated silver nanoparticles to be loaded onto the BaTiO3 surface. During piezoelectric catalysis, due to the excellent conductivity of the silver nanoparticles, piezoelectrically induced electrons can be rapidly transferred and temporarily stored in the deposited silver nanoparticles before the BaTiO3 recovers its deformation, reducing the recombination rate of electrons and holes. Silver also plays a role in enrichment and electron transfer in the reaction. The presence of silver nanoparticles facilitates the transfer of electrons to PAA (phosphorus adductor arteries) while inhibiting piezoelectrically induced electron-hole recombination, thus activating more PAA and achieving a higher degradation effect.

[0054] like Figure 3 The figure shows a performance comparison of Example 1 and Comparative Example 2 in degrading SMX. The line “US / BTO / PAA / AgNO3” in the figure represents Example 1, and the line “US / BTO / AgNO3” in the figure represents Comparative Example 2.

[0055] pass Figure 3 It can be seen that without the addition of PAA, the degradation rate of SMX was only 8% after 12 minutes, while the degradation rate of SMX reached 100% after the addition of PAA. This is because, without PAA, the system only contains cells generated by the interaction of vacancies and water molecules. • OH and electrons produced by dissolved oxygen• O2 - Its yield is very low, so the degradation effect is poor. The addition of PAA can generate a large amount of RO in the system. • , • OH, • O2 - , 1 Active substances such as O2 can quickly and efficiently remove pollutants.

[0056] like Figure 4 The image shown is an SEM image of the powder obtained after washing and drying following the degradation reaction in Example 1 of this invention; it can be seen that silver nanoparticles are attached to the surface of barium titanate.

[0057] like Figure 5 The image shown is an EDS diagram of Ag in the powder obtained after washing and drying following the degradation reaction in Example 1 of this invention. It can be seen that the powder obtained after the reaction contains a large amount of silver, i.e., silver nanoparticles generated during the degradation process. like Figures 6 to 9 The figures shown are EPR spectra of Embodiment 1 and Comparative Examples 4 to 6 of the present invention; the “US / BTO / PAA / AgNO3” line in the figure represents Embodiment 1, the “US / BTO / PAA” line represents Comparative Example 4, the “US / BTO” line represents Comparative Example 5, and the “US / PAA” line represents Comparative Example 6.

[0058] pass Figures 6-8 It can be seen that BaTiO3 powder, under the external mechanical stress provided by ultrasonic cavitation, can generate piezoelectrically induced electrons, which can reduce Ag in solution. + This process allows in-situ generated silver nanoparticles to be loaded onto the BaTiO3 surface. During piezoelectric catalysis, due to the excellent conductivity of the silver nanoparticles, piezoelectrically induced electrons can be rapidly transferred and temporarily stored in the deposited silver nanoparticles before the BaTiO3 recovers its deformation, reducing the recombination rate of electrons and holes. Silver also plays a role in enriching and transferring electrons in the reaction. Figure 9 It can be seen that ultrasonic barium titanate (i.e., US / BTO) alone does not produce 1 O2 can be generated by sonication of peracetic acid (US / PAA) alone. 1 O2 is generated because ultrasound can activate some PAA, but most PAA remains ineffectively decomposed. It is evident that when BaTiO3 is coupled with PAA (US / BTO / PAA), more O2 is produced. 1O2. It can also be seen that in the (US / BTO / PAA / AgNO3) system, more types of free radicals are generated, and their strength is higher. This is because the presence of silver nanoparticles facilitates the transfer of electrons to PAA, while simultaneously suppressing piezoelectrically induced electron-hole recombination, thus activating more PAA. The presence of in-situ generated Ag nanoparticles provides a channel for electrons to bind with PAA, resulting in the generation of more free radicals in the system. 1 O2, • OH, • O2 - Because BaTiO3 can activate PAA during ultrasound, causing it to decompose more effectively and promoting the production of PAA in the system. 1 Active substances such as O2 attack SMX, thereby achieving efficient degradation.

[0059] like Figure 10 The diagram shown is a free radical quenching experiment diagram of Example 1 of the present invention. Disodium ethylenediaminetetraacetate (EDTA-2Na) is mainly used to quench holes generated on the surface of barium titanate during piezoelectricity, while p-benzoquinone (p-BQ) is mainly used to quench... • O2 - Histidine (L-His) primarily quenches 1 O2 and methanol are the main quenchers. • OH and RO • tert-butanol (TBA) is the primary quencher. • OH. This shows that RO • , 1 O2, • OH, • O2 - Holes exist in the system, including RO • Approximately 20%, • OH contributes approximately 15%, of which 1 O2 has a significant impact on the degradation of the system, acting as the main free radical.

[0060] like Figure 11 The figure shows the effect of Examples 6 and 7 of the present invention on the degradation performance of SMX in Example 1. The "Blank" curve in the figure corresponds to Example 1, the "0.5 mM Na2SO4" curve corresponds to Example 6, and the "0.5 mM NaHCO3" curve corresponds to Example 7. It can be seen that this degradation method still has extremely high degradation efficiency in the presence of various anions, and even shows a stronger degradation effect. This is because the presence of anions enhances the conductivity of the solution, thereby improving the degradation effect of the system. In other existing piezoelectric catalytic degradation technologies, when anions are present, such as bicarbonate ions and sulfate ions, these anions will react with... •The OH reaction generates low-oxidation-activity species, thereby inhibiting the degradation of organic pollutants. However, in this invention, the addition of anions can improve the activation efficiency of PAA, enhance the conductivity of the solution, and may even act as an intermediate for electron transfer between BaTiO3 and PAA, thus exhibiting a stronger degradation effect. This degradation method demonstrates excellent resistance to environmental background degradation, offering significant advantages in practical production applications and solving the problem of other catalysts experiencing a substantial decrease in degradation efficiency in the presence of anions.

[0061] The embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The technical solutions of the present invention are not limited to the specific embodiments described above; all technical modifications made according to the technical solutions of the present invention fall within the protection scope of the present invention.

Claims

1. A method for efficiently treating organic wastewater by piezoelectric catalytic activation of peracetic acid, characterized in that, Includes the following steps: The BaTiO3 powder was polarized, then dried and sieved to obtain polarized BaTiO3 powder. After mixing PAA and deionized water and adjusting the pH, silver nitrate and organic wastewater were added and mixed evenly to obtain a first mixed solution. Polarized BaTiO3 powder was added to the first mixed solution and mixed evenly to obtain a second mixed solution. The second mixed solution was then degraded under ultrasonic conditions.

2. The method for efficiently treating organic wastewater by piezoelectric catalytic activation of peracetic acid according to claim 1, characterized in that: The BaTiO3 powder is a tetragonal BaTiO3.

3. The method for efficiently treating organic wastewater by piezoelectric catalytic activation of peracetic acid according to claim 1, characterized in that: During the polarization process, the polarization time is 15 min to 80 min, and the polarization field strength is 5 kV to 10 kV.

4. The method for efficiently treating organic wastewater by piezoelectric catalytic activation of peracetic acid according to claim 1, characterized in that: The drying process is as follows: drying in a constant temperature oven at 60 ℃ for 2 h; the sieving process uses a 140 mesh sieve.

5. The method for efficiently treating organic wastewater by piezoelectric catalytic activation of peracetic acid according to claim 1, characterized in that: In the second mixed solution, the amount of polarized BaTiO3 powder added is 1~6 g / L.

6. The method for efficiently treating organic wastewater by piezoelectric catalytic activation of peracetic acid according to claim 1, characterized in that: The concentration of silver nitrate solution in the first mixed solution is 0.05~2 mmol / L; the concentration of PAA in the first mixed solution is 1~5 mmol / L.

7. The method for efficiently treating organic wastewater by piezoelectric catalytic activation of peracetic acid according to claim 1, characterized in that: The first mixed solution also contains anions; the concentration of anions in the first mixed solution is 0.2~1 mmol / L.

8. The method for efficiently treating organic wastewater by piezoelectric catalytic activation of peracetic acid according to claim 1, characterized in that: The concentration of antibiotics in the first mixed solution is 2~10 μmol / L.

9. The method for efficiently treating organic wastewater by piezoelectric catalytic activation of peracetic acid according to claim 1, characterized in that: During pH adjustment, the pH should be adjusted to 5-8.

10. A method for efficiently treating organic wastewater by piezoelectric catalytic activation of peracetic acid according to claim 1, characterized in that: In the ultrasonic environment, the ultrasonic power is 300~600 W, the frequency is 30~50 kHz, the temperature of the second mixed solution is 20~30 ℃ during the ultrasonic process, and the degradation time does not exceed 12 min.

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