Method for degrading organic pollutants in water body by using microdroplet self-fenton system
By using ultrasonic atomization of microdroplets from the Fenton system, the problems of high reagent cost and poor adaptability of the existing Fenton method are solved, achieving efficient and low-cost degradation of organic pollutants, which is suitable for industrial applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HUNAN UNIV
- Filing Date
- 2023-11-22
- Publication Date
- 2026-06-12
AI Technical Summary
Existing Fenton chemical oxidation methods for treating organic pollutant wastewater suffer from problems such as high reagent costs, difficulty in preserving H2O2, poor adaptability to photo-Fenton systems, difficulty in separating catalytic materials, and complex preparation, resulting in high treatment costs, low efficiency, and limited applicability.
The microdroplet self-Fenton system is adopted. By adjusting the pH of the water to acidity, iron salt is added and ultrasonically atomized to form micron-sized droplets. The high electric field chemical environment of the microdroplet air-water interface and the active species generated by ultrasonic atomization are utilized to achieve efficient reduction of ferric iron to ferrous iron and in-situ generation of H2O2, thus constructing an iron-cycle self-Fenton system to degrade organic pollutants.
It achieves efficient degradation of organic pollutants under conditions of no light, no catalyst, and no sacrificial agent, reduces treatment costs, improves oxidation-reduction capacity, has good adaptability, simple process, and is suitable for industrial application.
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Figure CN117682649B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of Fenton degradation of organic pollutants, and relates to a method for degrading organic pollutants in water using a microdroplet self-Fenton system. Background Technology
[0002] In recent years, with rapid industrial development and the large-scale production and use of various chemicals, the harm of some emerging organic pollutants to public health and the ecological environment is gradually becoming apparent. Emerging organic pollutants commonly found in wastewater, such as antibiotics, endocrine disruptors, pharmaceuticals, and personal care products, have strong concealment and environmental persistence in water bodies, and may be transmitted through the food chain, causing adverse effects on the human body such as teratogenicity, carcinogenicity, and drug resistance. Furthermore, with the continuous growth of the global population, the pressure of global water scarcity is constantly increasing, and the problem of water pollution control is undoubtedly a huge challenge. Therefore, the development of new and efficient water pollution treatment technologies is extremely urgent.
[0003] Currently, methods for degrading organic pollutants mainly rely on traditional water treatment methods. These methods often have limitations. For example, adsorption methods require stringent reaction conditions and cannot fundamentally remove pollutants; microbial methods have poor periodicity; and some chemical oxidation technologies are costly and may generate secondary pollution. Furthermore, in recent years, advanced oxidation technologies for water pollution treatment have developed rapidly, such as ozone oxidation, photocatalytic oxidation, and persulfate oxidation. However, most of these methods require specialized reaction equipment, and the preparation and recovery of catalysts present challenges, resulting in high operating costs and cumbersome operations. Most of these methods remain in the experimental stage. Therefore, it is essential to develop a novel water pollution treatment technology that is environmentally friendly, green, and highly efficient, and capable of effectively removing multiple pollutants.
[0004] Fenton chemical oxidation, as an advanced oxidation treatment technology, can oxidize organic pollutants in wastewater into carbon dioxide and water in the dark. It boasts advantages such as simple operation, strong oxidizing power, high reliability, and environmental friendliness, effectively removing organic pollutants from wastewater. However, existing Fenton chemical oxidation methods require the addition of large amounts of iron salts and H₂O₂ reagents, and even more so in order to achieve Fe... 3+ / Fe 2+ The cyclical transformation requires the addition of other reducing agents, which means that the Fenton chemical oxidation method still has drawbacks such as high reagent costs in the treatment of organic pollutant wastewater. In particular, H2O2 reagent is not easy to store and the transportation process is complicated, which greatly increases the treatment cost and limits the widespread application of the Fenton chemical oxidation method in the treatment of organic pollutant wastewater.
[0005] In existing technologies, coupling Fenton chemical oxidation with photocatalysis can realize a photo-induced Fenton catalytic system. This system utilizes the photoreduction reaction of photocatalytic materials to reduce oxygen in the air to H₂O₂, while simultaneously allowing photogenerated electrons to rapidly transfer to Fe. 3+ It is reduced to Fe 2+ Promote Fe 2+ Activating the in-situ produced H2O2 generates a large amount of ·OH, thus enabling the oxidation and removal of pollutants without adding H2O2. However, the above-mentioned photo-Fenton system and some traditional self-Fenton systems still have the following defects: (1) In most photocatalytic self-Fenton systems or traditional self-Fenton systems, the reduction of oxygen to hydrogen peroxide with two electrons and the reduction of ferric iron to ferrous iron are competitive, which will have a negative impact on the catalytic effect; (2) Self-Fenton catalysis can only be achieved under light conditions, and its adaptability is poor; (3) Photocatalytic materials still have defects such as poor oxygen adsorption capacity and poor photocatalytic capacity, resulting in low efficiency of self-produced H2O2; (4) Photocatalytic materials are difficult to separate from the system, which can easily lead to secondary pollution, or the separation operation process is complicated and the recovery cost is high; (5) The preparation process of photocatalytic materials is complicated and the preparation cost is high, which is not conducive to reducing the cost of use. The existence of the above defects makes it difficult for the existing self-Fenton system to achieve rapid degradation of organic pollutants in water, which is not conducive to promoting the widespread application of Fenton chemical oxidation in the treatment of organic pollutant wastewater. Therefore, obtaining a self-Fenton system constructed under light-free, catalyst-free, and sacrificial agent-free conditions, and improving the redox capacity of this self-Fenton system to achieve efficient reduction of ferric iron to ferrous iron and efficient utilization of in-situ generated H2O2, is of great significance for promoting the widespread application of Fenton chemical oxidation in the field of organic pollutant wastewater treatment and reducing treatment costs. Summary of the Invention
[0006] The technical problem to be solved by the present invention is to address the shortcomings of the existing technology by providing a method for degrading organic pollutants in water using a microdroplet self-Fenton system, which is simple in process, convenient in operation, low in processing cost, high in processing efficiency, and good in removal effect.
[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:
[0008] A method for degrading organic pollutants in water using a microdroplet self-Fenton system includes the following steps:
[0009] S1. Adjust the pH of the water body containing organic pollutants to acidity by adding iron salts to obtain a mixed solution;
[0010] S2. The mixed solution obtained in step S1 is subjected to ultrasonic atomization treatment to atomize the mixed solution into micron-sized droplets, thereby constructing a microdroplet self-Fenton system to complete the degradation of organic pollutants in the water.
[0011] In a further improvement to the above method, in step S2, the mixed solution obtained in step S1 is subjected to ultrasonic atomization treatment using the following apparatus: the apparatus includes an atomizing reactor for storing the mixed solution and an ultrasonic generator for providing ultrasonic waves to the atomizing reactor.
[0012] In a further improvement to the above method, the ultrasonic generator includes a tank and an ultrasonic transducer for providing ultrasonic waves to the tank; the tank contains a liquid medium, and the bottom of the atomizing reactor is disposed in the liquid medium.
[0013] In a further improvement to the above method, the atomizing reactor includes a liquid storage tank, the inlet of which is connected to a feeding assembly, and a vibrating membrane disposed at the bottom of the liquid storage tank; the liquid storage tank is a hollow sphere; the material of the liquid storage tank is glass; the feeding assembly is a conical funnel; the material of the feeding assembly is glass; the thickness of the vibrating membrane is 0.1 mm; and the vibrating membrane is an aluminum foil or a polyethylene film.
[0014] In a further improvement to the above method, the tank is made of aluminum foil; the thickness of the aluminum foil is 0.1 mm; the liquid medium in the tank is water; and the bottom of the ultrasonic generator is provided with a liftable base.
[0015] In a further improvement to the above method, the process parameters used in step S2 during the ultrasonic atomization process are as follows: atomization rate of 3 mL / min, a particle distribution with a particle diameter of less than 4.1 μm of >65%, and a working frequency of 1.7 ± 0.17 MHz.
[0016] In a further improvement to the above method, in step S2, the ultrasonic atomization treatment is performed at a temperature of 23℃ to 27℃; and the ultrasonic atomization treatment time is 5 min to 30 min.
[0017] In a further improvement to the above method, in step S1, the pH value of the water containing organic pollutants is adjusted to 2.5–3.
[0018] In a further improvement to the above method, in step S1, the ratio of the organic pollutant water to the iron salt is 0.5 mg to 2.5 mg: 3 mL.
[0019] In a further improvement to the above method, in step S1, the initial concentration of the organic pollutant in the water body is ≤20 mg / L; the organic pollutant is at least one of sulfamethoxazole, tetracycline hydrochloride, carbamazepine, and bisphenol A.
[0020] In a further improvement to the above method, in step S1, the iron salt is a divalent iron salt and / or a trivalent iron salt; the divalent iron salt is at least one of ferrous chloride and ferrous sulfate; and the trivalent iron salt is at least one of ferric chloride and ferric sulfate.
[0021] Compared with the prior art, the advantages of the present invention are as follows:
[0022] (1) To address the shortcomings of existing photo-based self-Fenton systems, such as the need for light, catalysts, and sacrificial agents, complex construction methods, high costs, low efficiency of self-generated H2O2, and poor redox capabilities, resulting in complex, costly, inefficient, and poorly effective treatment of organic pollutants, this invention creatively provides a method for degrading organic pollutants in water using a microdroplet self-Fenton system. First, the pH of the water containing organic pollutants is adjusted to acidity, and ferric salts are added to obtain a mixed solution. Then, the acidic solution containing iron is subjected to ultrasonic atomization. During ultrasonic atomization, the droplets are atomized into micron-sized droplets using ultrasound. The unique high-electric-field chemical environment formed at the air-water interface of the droplets and the highly oxidizing ·OH, H2O2, and highly reducing e-generators generated during atomization are utilized. - This enables the efficient reduction of ferric iron to ferrous iron in microdroplets and the efficient utilization of in-situ generated H2O2, forming an iron-cycle self-Fenton system. Then, the highly oxidizing reactive species (ROS) generated in large quantities in this iron-cycle self-Fenton system are used to convert organic pollutants in water into water and carbon dioxide, thereby achieving efficient degradation of organic pollutants in water. Compared with traditional degradation methods based on photocatalytic self-Fenton systems, the method of degrading organic pollutants in water using a microdroplet self-Fenton system has the following advantages: (a) Good adaptability: an iron-cycle self-Fenton system can be constructed through ultrasonic atomization, which can efficiently degrade organic pollutants under conditions of no light, no catalyst, and no sacrificial agent, thus effectively reducing the limitations imposed on the degradation system by light, catalysts, and sacrificial agents; (b) Good treatment effect: the reaction system constructed through ultrasonic atomization has high reaction energy, which can promote the large-scale release of high-energy electrons and the large-scale formation of active species such as hydroxyl radicals (·OH), and effectively mitigate the competition between electrons in the self-Fenton system during the reduction of hydrogen peroxide and the reduction of ferric iron to ferrous iron. It can not only directly utilize the strongly oxidizing hydroxyl radicals (·OH) to continuously produce H2O2 in situ, but also utilize the strongly reducing electrons. - Quickly transfer Fe3+ Reduced to Fe 2+ This promotes Fe 2+ (c) The process is simple, easy to operate, low in cost, green and environmentally friendly, suitable for industrial application, and facilitates the effective treatment of organic pollutant wastewater; (d) The self-Fenton system constructed by activating the in-situ produced H2O2 to rapidly generate a large amount of ·OH, thereby improving the generation rate and yield of ·OH in the system. The self-Fenton system constructed by this process has stronger redox ability and can achieve efficient degradation of organic pollutants. It has important guiding significance for promoting the effective treatment of organic pollutant wastewater;
[0023] (2) The device used in this invention is not only simple in structure and convenient for sampling, but also can effectively alleviate the loss caused by the drift of microdroplets during the reaction process, so as to better construct the microdroplet self-Fenton system, which is conducive to the complete degradation of organic pollutants. It has high use value and good application prospects. Attached Figure Description
[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.
[0025] Figure 1 This is a schematic diagram of the device structure used to construct the microdroplet self-Fenton system in Embodiment 1 of the present invention.
[0026] Figure 2 This is a comparison chart of the degradation effects of sulfamethoxazole on simulated wastewater under different reaction conditions in Example 1 of the present invention.
[0027] Figure 3 In Example 2 of this invention, Fe is used in the reaction process of degrading organic pollutants in water using a microdroplet self-Fenton system. 2+ The concentration change graph.
[0028] Figure 4 This is a graph showing the degradation effect of the microdroplet self-Fenton system on different organic pollutants in Example 3 of the present invention.
[0029] Legend:
[0030] 1. Atomizing reactor; 11. Vibrating membrane; 21. Tank; 22. Ultrasonic transducer; 3. Base; a. Iron-containing acidic solution; b. Liquid medium. Detailed Implementation
[0031] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention.
[0032] The materials and instruments used in the following examples are all commercially available.
[0033] Example 1:
[0034] A method for degrading organic pollutants in water using a microdroplet self-Fenton system, specifically utilizing... Figure 1 The device described above constructs a microdroplet self-Fenton system and degrades sulfamethoxazole in wastewater, comprising the following steps:
[0035] Measure 15 mL of 10 mg / L sulfamethoxazole simulated wastewater, adjust the pH of the wastewater to 2.5 with 0.2 mol / L hydrochloric acid, weigh 7.5 mg of anhydrous FeCl3 powder and add it to the simulated wastewater. After dissolving and mixing, transfer the solution to a container as shown in the image. Figure 1 In the atomizing reactor of the device shown, the power supply of the ultrasonic transducer is turned on to start the reaction (ultrasonic atomization treatment), which atomizes the mixed solution into micron-sized droplets, constructing a microdroplet self-Fenton system. During the reaction, the temperature of the reaction solution in the reactor is controlled at 25°C by adding ice packs in the water tank. At reaction times of 0 min, 5 min, 10 min, 15 min, and 20 min, 0.5 mL of the reaction solution is pipetted, filtered through a 0.22 μm organic filter membrane, and the absorbance is measured using a high-performance liquid chromatograph to determine the concentration of each pollutant after degradation at each time point and analyze its degradation status.
[0036] In this embodiment, the process parameters used in the ultrasonic atomization process are: atomization rate of 3 mL / min, a particle distribution of >65% of particles with a diameter of less than 4.1 μm, and a working frequency of 1.7 ± 0.17 MHz.
[0037] In this embodiment, the device used is, for example... Figure 1 As shown, the device includes an atomizing reactor 1 for storing an iron-containing acidic solution a (i.e., a mixed solution of organic pollutants and iron) and an ultrasonic generator for supplying ultrasonic waves to the atomizing reactor 1. The ultrasonic generator includes a tank 21 and an ultrasonic transducer 22 for supplying ultrasonic waves to the tank 21. The tank is filled with a liquid medium b, and the bottom of the atomizing reactor 1 is disposed in the liquid medium b.
[0038] In this embodiment, an oscillating membrane 11 is provided at the bottom of the atomizing reactor 1, and the oscillating membrane 11 is disposed in the liquid medium b. In this embodiment, the ultrasonic transducer is made of piezoelectric ceramic material, which can convert electrical energy into mechanical energy and generate high-frequency ultrasonic waves. Then, through the water in the tank 21 and the oscillating membrane 11 at the bottom of the atomizing reactor 1, the ultrasonic waves are transmitted to the iron-containing acidic solution, and the iron-containing acidic solution is atomized into micron-sized, fine droplets.
[0039] In this embodiment, the atomizing reactor 1 includes a liquid storage tank, with a feeding component connected to the inlet of the storage tank. A vibrating membrane 11 is installed at the bottom of the storage tank. The storage tank is a hollow sphere made of glass. The feeding component is a conical funnel made of glass. The vibrating membrane 11 is made of aluminum foil with a thickness of 0.1 mm. Specifically, in this embodiment, the atomizing reactor 1 is composed of a splash-proof glass sphere and a spherical funnel. During use, this not only facilitates sampling but also effectively mitigates the loss caused by microdroplets drifting away during the reaction, thereby achieving better internal circulation atomization degradation.
[0040] In this embodiment, the tank 21 is made of aluminum foil with a thickness of 0.1 mm, and the liquid medium b in the tank 21 is water.
[0041] In this embodiment, the bottom of the ultrasonic generator is provided with a height-adjustable base 3. By adjusting the up-and-down movement of the base 3, the atomization effect of the ultrasonic waves on the ferric acid solution can be controlled.
[0042] In this embodiment, the device uses an ultrasonic transducer to convert electrical energy into mechanical energy and generate high-frequency ultrasonic waves. These ultrasonic waves are then transmitted through the liquid medium in the tank and the oscillating membrane at the bottom of the atomizing reactor to the iron-containing acidic solution (reaction liquid) in the atomizing reactor. Under the action of the ultrasonic waves, the iron-containing acidic solution is atomized into micron-sized droplets. The unique high-electric-field chemical environment formed at the air-water interface of the droplets and the highly oxidizing ·OH, H2O2, and highly reducing e-generators generated during the atomization process are utilized. - This invention achieves efficient reduction of ferric iron (Fe3+) to ferrous iron (Fe2+) in microdroplets and efficient utilization of the in-situ generated H2O2, forming an iron-cycle self-Fenton system. The highly reactive organic species (ROS) generated in this system are then used to convert organic pollutants in water into water and carbon dioxide, thereby achieving efficient degradation of organic pollutants in water. The device of this invention is not only simple in structure and convenient for sampling, but also effectively mitigates the loss caused by droplet drift during the reaction, thus enabling a better construction of the microdroplet self-Fenton system. This facilitates the complete degradation of organic pollutants, demonstrating high practical value and promising application prospects.
[0043] In this embodiment, an experimental control group was set up under different reaction conditions:
[0044] ① Pure microdroplet system: Except for not adding 7.5 mg of anhydrous FeCl3 powder, the other conditions are the same as those for the microdroplet self-Fenton system described above.
[0045] ② Non-microdroplet / H2O2 system: Measure 15 mL of 10 mg / L sulfamethoxazole simulated wastewater, adjust the pH of the wastewater to 2.5 with 0.2 mol / L hydrochloric acid, add 66.6 μL of 0.12 mol / L H2O2 dilution (derived from twice the amount of H2O2 accumulated in the pure microdroplet system in Example 1 after 20 min of reaction), mix well, transfer to a 50 mL glass beaker, place it on a magnetic stirrer, set the speed to 500 rpm, and at reaction times of 0 min, 5 min, 10 min, 15 min, and 20 min, use a pipette to take 0.5 mL of the reaction solution, filter it through a 0.22 μm organic filter membrane, and use a high performance liquid chromatograph to measure the absorbance to determine the concentration of each pollutant after degradation at each time point and analyze its degradation status.
[0046] ③ Non-microdroplet / H2O2 / Fe(Ⅲ) system: 15 mL of 10 mg / L sulfamethoxazole simulated wastewater was measured, and the pH value of the wastewater was adjusted to 2.5 with 0.2 mol / L hydrochloric acid. 7.5 mg of anhydrous FeCl3 powder and 66.6 μL of 0.12 mol / L H2O2 dilution (derived from twice the amount of H2O2 accumulated in the pure microdroplet system after 20 min of reaction in Example 1) were added to the simulated wastewater in sequence. After mixing, the mixture was transferred to a 50 mL glass beaker and placed on a magnetic stirrer with a speed of 500 rpm. At reaction times of 0 min, 5 min, 10 min, 15 min, and 20 min, 0.5 mL of the reaction solution was pipetted and filtered through a 0.22 μm organic filter membrane. The absorbance was measured using a high-performance liquid chromatograph to determine the concentration of each pollutant after degradation at each time point and to analyze the degradation status.
[0047] Figure 2 This is a comparison chart of the degradation effects of sulfamethoxazole on simulated wastewater under different reaction conditions in Example 1 of the present invention. Figure 2It can be seen that, under different reaction systems, when the total reaction time is 20 min, the degradation rates of sulfonamide in the microdroplet self-Fenton system, pure microdroplet system, non-microdroplet / H2O2 system, and non-microdroplet / H2O2 / Fe(III) system are 100%, 96%, 3%, and 24%, respectively. Among them, the degradation rate of sulfonamide in the microdroplet self-Fenton system reaches 93% at a reaction time of 10 min, which is 2.5 times that of the pure microdroplet system and 5 times that of the non-microdroplet / H2O2 / Fe(III) system. The fact that the microdroplet self-Fenton system constructed in this invention can achieve in-situ, continuous, self-production and efficient utilization of H2O2 without the addition of light, catalysts and sacrificial agents, based on a pure microdroplet system, and generate a greater amount of reactive oxygen species (ROS), accelerates the slow chemical reactions in the non-microdroplet / H2O2 / Fe(Ⅲ) system in the bulk solution. Therefore, the method of using the microdroplet self-Fenton system to degrade organic pollutants in water in this invention can rapidly and thoroughly degrade organic pollutants in water.
[0048] In addition, in this embodiment, the accumulation of H2O2 in the pure microdroplet system was also tested. Specifically, after ultrasonic nebulization for 20 min, the reaction was interrupted, 3 mL of the reaction solution was pipetted into a 5 mL centrifuge tube, and then 1 mL of potassium iodide (0.4 mol / L) solution and 1 mL of potassium hydrogen phthalate (0.1 mol / L) were added to the centrifuge tube and shaken well. After standing for 30 min for color development, the absorbance was measured with a UV spectrophotometer. The results showed that the accumulation of H2O2 in the system after ultrasonic nebulization for 20 min was 4.068 μmol.
[0049] Example 2:
[0050] The study investigated the changes in ferrous ion content in water bodies using a microdroplet self-Fenton system for degrading organic pollutants, including the following steps:
[0051] Measure 15 mL of simulated sulfamethoxazole wastewater at a concentration of 10 mg / L. Adjust the pH of the wastewater to 2.5 with 0.2 mol / L hydrochloric acid. Weigh 7.5 mg of anhydrous FeCl3 powder and add it to the simulated wastewater. After dissolving and mixing, take 1 mL of the reaction stock solution into a 10 mL centrifuge tube, add 0.4 mL of 1,10-o-phenanthroline solution (1.2 g / L) and 2 mL of sodium acetate solution (pH = 4.6), add deionized water to the 10 mL mark, shake well, and let stand for 5 min to develop color. Measure the initial absorbance with a UV spectrophotometer. Then transfer 10 mL of the colorimetric solution to the reactor, turn on the power of the ultrasonic transducer, and start the reaction (ultrasonic atomization treatment) to atomize the mixed solution into micron-sized droplets, constructing a microdroplet self-Fenton system. During the reaction, the temperature of the reaction solution in the reactor is controlled at 25℃ by adding ice packs to the water tank. Using in-situ color development, intermittent reaction, and sampling methods, 3 mL of reaction solution was taken at reaction times of 5 min, 10 min, 15 min, and 20 min. No filtration was required, and the initial absorbance was measured using a UV spectrophotometer. The concentration of ferrous ions at each time point was monitored. After the measurement was completed, the solution was poured back into the reactor to continue the reaction.
[0052] Figure 3 In Example 2 of this invention, Fe is used in the reaction process of degrading organic pollutants in water using a microdroplet self-Fenton system. 2+ The concentration change graph. (From...) Figure 3 It can be seen that during the reaction time of 0–5 min, the ferrous ion concentration increased rapidly, from the initial background value of 0.066 mM to 0.705 mM, indicating that the microdroplet self-Fenton system constructed in this invention does indeed promote the efficient conversion between ferric and ferrous iron in the solution. During the reaction time of 5–10 min, the ferrous ion concentration reached 0.907 mM, and compared to 0–5 min, the increase in ferrous ion concentration was significantly reduced. The changes in ferrous ion concentration were not significant during the reaction times of 10–15 min and 15–20 min, possibly because the cyclic conversion between ferrous and ferric iron tended towards an equilibrium state. In summary, the microdroplet self-Fenton system constructed in this invention can effectively promote the iron cycle process between ferric and ferrous iron in microdroplets without the addition of light, catalysts, or sacrificial agents, based on a pure microdroplet system. This enables in-situ, continuous, self-production, and efficient utilization of H2O2, generating a greater abundance of reactive oxygen species (ROS), and accelerating the slow chemical reactions in the non-microdroplet / H2O2 / Fe(Ⅲ) system in the bulk solution.
[0053] Example 3:
[0054] A method for degrading organic pollutants in water using a microdroplet self-Fenton system, specifically utilizing... Figure 1The device described above constructs a microdroplet-based Fenton system to degrade sulfamethoxazole (SMX), tetracycline hydrochloride (TC), carbamazepine (CBZ), and bisphenol A (BPA) in wastewater, respectively, comprising the following steps:
[0055] Take 15 mL of each of the following simulated wastewater samples: 10 mg / L sulfamethoxazole (SMX), tetracycline hydrochloride (TC), carbamazepine (CBZ), and bisphenol A (BPA). Adjust the pH of each wastewater to 2.5 with 0.2 mol / L hydrochloric acid. Weigh 7.5 mg of anhydrous FeCl3 powder and add it to each of the simulated wastewater samples. After dissolving and mixing, transfer the solutions to the appropriate containers. Figure 1 In the atomizing reactor of the device shown, the power supply of the ultrasonic transducer is turned on to start the reaction (ultrasonic atomization treatment), which atomizes the mixed solution into micron-sized droplets, constructing a microdroplet self-Fenton system. During the reaction, the temperature of the reaction solution in the reactor is controlled at 25°C by adding ice packs in the water tank. At reaction times of 0 min, 5 min, 10 min, 15 min, and 20 min, 0.5 mL of the reaction solution is pipetted, filtered through a 0.22 μm organic filter membrane, and the absorbance is measured using a high-performance liquid chromatograph to determine the concentration of each pollutant after degradation at each time point and analyze its degradation status.
[0056] In this embodiment, the process parameters used in the ultrasonic atomization process are: atomization rate of 3 mL / min, a particle distribution of >65% of particles with a diameter of less than 4.1 μm, and a working frequency of 1.7 ± 0.17 MHz.
[0057] Figure 4 This image shows the degradation effect of the microdroplet self-Fenton system on different organic pollutants in Example 3 of this invention. Figure 4 It can be seen that the degradation rate of the four types of simulated organic pollutant waste liquids after 20 minutes of reaction is 100%, indicating that the microdroplet self-Fenton system constructed in this invention has universality for the degradation of organic pollutants and has a good degradation effect. It does not require the input of catalysts and sacrificial agents, has low cost, and has good application prospects.
[0058] The results above show that, compared with traditional degradation methods based on photocatalytic self-Fenton systems, the method of degrading organic pollutants in water using microdroplet self-Fenton systems has the following advantages: (a) Good adaptability: an iron-cycle self-Fenton system can be constructed through ultrasonic atomization, which can efficiently degrade organic pollutants under conditions of no light, no catalyst, and no sacrificial agent, thus effectively reducing the limitations imposed on the degradation system by light, catalysts, and sacrificial agents; (b) Good treatment effect: the reaction system constructed through ultrasonic atomization has high reaction energy, which can promote the large-scale release of high-energy electrons and the large-scale formation of active species such as hydroxyl radicals (·OH), and effectively mitigate the competition between electrons in the self-Fenton system during the reduction of hydrogen peroxide and the reduction of ferric iron to ferrous iron. It can not only directly utilize the strongly oxidizing hydroxyl radicals (·OH) to continuously produce H2O2 in situ, but also utilize the strongly reducing electrons. - Quickly transfer Fe 3+ Reduced to Fe 2+ This promotes Fe 2+ (c) The process is simple, easy to operate, low in cost, green and environmentally friendly, suitable for industrial application, and facilitates the effective treatment of organic pollutant wastewater; (d) The self-Fenton system constructed by activating the in-situ produced H2O2 to rapidly generate a large amount of ·OH, thereby improving the generation rate and yield of ·OH in the system. The self-Fenton system constructed by this process has stronger redox ability and can achieve efficient degradation of organic pollutants. It has important guiding significance for promoting the effective treatment of organic pollutant wastewater;
[0059] The above embodiments are merely preferred embodiments of the present invention, and the scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.
Claims
1. A method for degrading organic pollutants in water using a microdroplet self-Fenton system, characterized in that, Includes the following steps: S1. Adjust the pH of the water containing organic pollutants to 2.5-3, add iron salts to obtain a mixed solution; the iron salts are ferric salts. S2. The mixed solution obtained in step S1 is subjected to ultrasonic atomization treatment to atomize the mixed solution into micron-sized droplets, constructing a microdroplet self-Fenton system to complete the degradation of organic pollutants in the water. The process parameters used in the ultrasonic atomization treatment are: atomization rate of 3 mL / min, droplet distribution of >65% of droplets with a diameter of less than 4.1 μm, and working frequency of 1.7±0.17 MHz. The ultrasonic atomization treatment time is 5 min to 30 min.
2. The method according to claim 1, characterized in that, In step S2, the mixed solution obtained in step S1 is subjected to ultrasonic atomization treatment using the following apparatus: the apparatus includes an atomizing reactor for storing the mixed solution and an ultrasonic generator for providing ultrasonic waves to the atomizing reactor.
3. The method according to claim 2, characterized in that, The ultrasonic generator includes a tank and an ultrasonic transducer for supplying ultrasonic waves to the tank; the tank contains a liquid medium, and the bottom of the atomizing reactor is disposed in the liquid medium; the atomizing reactor includes a storage tank, the inlet of which is connected to a feeding assembly, and a vibrating membrane is disposed at the bottom of the storage tank; the storage tank is a hollow sphere; the storage tank is made of glass; the feeding assembly is a conical funnel; the feeding assembly is made of glass; the vibrating membrane has a thickness of 0.1 mm; the vibrating membrane is a polyethylene film; the tank is made of aluminum foil; the aluminum foil has a thickness of 0.1 mm; the liquid medium in the tank is water; and the bottom of the ultrasonic generator is provided with a liftable base.
4. The method according to claim 2, characterized in that, In step S2, the ultrasonic atomization treatment is performed at a temperature of 23℃~27℃.
5. The method according to any one of claims 1 to 4, characterized in that, In step S1, the initial concentration of organic pollutants in the water body is ≤20 mg / L; the organic pollutants are at least one of sulfamethoxazole, tetracycline hydrochloride, carbamazepine, and bisphenol A.
6. The method according to any one of claims 1 to 4, characterized in that, In step S1, the ferric salt is at least one of ferric chloride and ferric sulfate.