Method for removing smelly substances in water through coupling of foam iron-based modified functional interface material and ozone micro-nano catalytic oxidation

Abstract

The invention relates to the technical field of waterworks end treatment, and discloses a method for removing odor substances in water through coupling of a foam iron-based modified functional interface material and ozone micro-nano catalytic oxidation. The foam iron-based modified functional interface material is prepared by the following steps: after foam iron is subjected to acid etching in-situ activation, synthesizing a foam iron-based manganese iron carbonate compound (MnCO3-FeCO3 (at) IF) in situ on the foam iron through a urea gradient hydrothermal method; ozone is introduced into a water phase in the form of micro-nano bubbles by utilizing a gas dissolving and releasing method based on pressurization, shearing force and a Venturi principle, and odor substances are efficiently removed through micro-nano coupling of a foam metal material and ozone. Through the unique interface mass transfer strengthening mechanism of the micro-nano bubbles, MnCO3-FeCO3atIF generated on the surface of the foam iron-based modified functional interface material in situ and the synergistic effect of the MnCO3-FeCO3atIF and ozone, efficient removal of smelly substances is achieved, and the bottleneck of targeted removal of intractable smelly molecules by traditional ozone oxidation is broken through.

Description

Technical Field

[0001] This invention relates to the field of water treatment technology, and in particular to a method for removing odorous substances from water by coupling ozone micro-nano catalytic oxidation with a foamed iron-based modified functionalized interface material. Background Technology

[0002] In recent years, with the expansion of human production activities, the problem of eutrophication in my country's water bodies has become increasingly serious, aquatic ecosystems have been damaged, algal blooms have become frequent, and odorous substances have been generated in the water. The "Standards for Drinking Water Quality" (GB5749-2022) has added specific limits on the concentrations of odorous substances 2-methylisoborneol (2-MIB) and geosmin (GSM), stipulating that they should not exceed 10 ng / L. However, traditional water treatment processes in waterworks are insufficient to meet the concentration limits of the new national standard.

[0003] To address this issue, water treatment plants currently primarily treat high concentrations of odor-causing substances by diluting the water and using activated carbon.

[0004] Diluting involves mixing a small amount of high-concentration raw water with raw water within the limit range (10 ng / L) in a certain proportion to achieve a dilution effect. However, as the concentration of odor-causing substances increases, the amount of raw water within the limit range required also increases, making this method unsuitable for large-scale water treatment needs and preventing long-term use.

[0005] Activated carbon, with its unique pore structure and specific surface area, can effectively adsorb dissolved organic matter in water. When faced with high concentrations of odor-causing substances, water treatment plants typically increase the dosage of powdered activated carbon (PAC) to remove them. However, raw water also contains a large amount of natural organic matter (NOM), which significantly inhibits the adsorption capacity of PAC. Therefore, the adsorption effect of activated carbon on odor-causing substances often fails to meet the limits set by the new national standards.

[0006] Ozone possesses strong oxidizing capabilities and is widely used in water treatment. Ozone, with its high redox potential in water, directly and indirectly oxidizes odor-causing substances in water. However, ozone's low solubility and short residence time in water limit its oxidation efficiency. Combining ozone with micro / nano bubble technology can significantly increase the contact area between ozone and water and prolong its residence time, effectively enhancing its oxidizing ability. Although the residence time is extended, its oxidation and decomposition efficiency remains limited. To further improve oxidation efficiency, ozone micro / nano technology needs to be combined with catalytic materials to form a gas-liquid-solid three-phase synergistic system, thereby improving the utilization rate of ozone in water.

[0007] Metal foams, as three-dimensional porous catalytic supports, have been widely recognized for their excellent compatibility with gas-liquid mass transfer kinetics due to their interconnected pore structure. Among them, iron foam shows unique potential in drinking water treatment due to the low ecotoxicity of iron (LC50 > 100 mg / L) and cost advantages. However, the inert oxide layer (Fe2O3 / Fe3O4) on the surface of pure iron foam makes it difficult to directly serve as an active site for ozone catalysis, requiring surface modification to construct functionalized interfaces. Manganese-based catalysts are often used as ozone catalysts due to their high catalytic activity. Manganese has excellent redox properties, which can promote ozone decomposition and increase the reaction rate, but single manganese compounds have drawbacks such as easy passivation of active sites and the risk of metal leaching. Therefore, the synergistic effect of iron and manganese on iron foam provides an efficient and green catalytic solution for ozone water treatment.

[0008] Compared to existing electrocatalytic ozone coupling processes, such as CN 118221226A which uses modified foamed iron as an electrode for electrocatalytic ozone treatment of organophosphorus compounds in tanning wastewater, this method, using modified foamed iron as the cathode and combining it with ozone treatment, is prone to accelerated corrosion of the foamed iron under the dual effects of electrolysis and ozone oxidation, and also poses a risk of electrode structure collapse. This invention focuses on the removal of trace odor substances (2-MIB / GSM) from drinking water, driving pollutants to accumulate on the catalyst surface through the cavitation effect of micro-nano bubbles, achieving highly efficient removal. Summary of the Invention

[0009] Currently, technologies for removing odor-causing substances in tap water treatment are insufficient to meet national standards, especially during algal blooms, where traditional water treatment technologies cannot efficiently reduce the concentration of these substances. Therefore, this invention provides a method for removing odor-causing substances from water using a foamed iron-based modified functionalized interface material coupled with ozone micro-nano catalytic oxidation. This method effectively removes odor-causing substances from water. It exhibits excellent removal efficiency, and the entire process is environmentally friendly and safe, requiring no external electric field, thus avoiding secondary pollution caused by electrode corrosion. Furthermore, the concentration of metals dissolved by the catalyst meets the limits specified in the "Standards for Drinking Water Quality" (GB5749-2022), providing a simple and feasible green solution for water treatment plants.

[0010] The first aspect of the present invention is to provide a catalytic material for removing odor substances from water, wherein the catalytic material is a foamed iron-based modified functionalized interface material.

[0011] A second aspect of the present invention is to provide a method for preparing a catalytic material for removing odor substances from water, the specific steps of which are as follows:

[0012] (1) Preparation of pure foamed iron: Cut the foamed iron to a suitable size and clean it by ultrasonic cleaning with hydrochloric acid (0.1M), ethanol and deionized water respectively to obtain pure foamed iron.

[0013] (2) Acid etching to activate foamed iron: Immerse pure foamed iron in 0.3M hydrochloric acid and stir magnetically until the solution changes from colorless to yellow-brown. Then remove the foamed iron and quickly rinse it with deionized water. Dry it under vacuum at 60-80℃ for 10-12 hours. Then weigh the foamed iron and record it as IF material.

[0014] (3) Weigh the metal precursor and hydrothermal synthesis alkali source: Weigh the manganese metal salt according to the molar ratio of manganese to iron (3-4):1; Weigh the urea according to the molar ratio of urea: (manganese + iron)≥2;

[0015] (4) Hydrothermal treatment: Dissolve the weighed metal precursor and urea in deionized water and stir with a magnetic stirrer. Then, quickly transfer the solution to a polytetrafluoroethylene (PTFE) liner, and simultaneously place the IF material upright in the PTFE liner and seal it in a hydrothermal reactor. First, heat at 90°C for 2-4 hours, then increase the temperature to 120-140°C and heat for 16-18 hours.

[0016] (5) Drying treatment: After the hydrothermal treatment is completed, the foamed iron-based material is washed several times and then vacuum dried at 60-80℃ for 10-12h to obtain the foamed iron-based modified functionalized interface material MnCO3-FeCO3@IF.

[0017] In one specific embodiment, in step (3), the manganese metal salt is solid manganese chloride.

[0018] A third aspect of the present invention is to provide a method for removing odor substances from water by coupling ozone micro-nano catalytic oxidation with a foamed iron-based modified functionalized interface material. The method uses the foamed iron-based modified functionalized interface material obtained by the above preparation method as a catalyst, and combines it with ozone and micro-nano bubbles to achieve efficient removal of odor substances from water.

[0019] The method for removing odor substances from water includes the following steps:

[0020] (1) Preparation of foamed iron-based modified functionalized interface material MnCO3-FeCO3@IF

[0021] The foamed iron-based modified functionalized interface material MnCO3-FeCO3@IF was prepared according to the above method.

[0022] (2) Generation of ozone micro-nano

[0023] The ozone generator uses air as its gas source and produces ozone gas through dual water-cooled enamel ozone units. The generated ozone gas then enters the micro-nano bubble generator through a negative pressure system. Under the action of negative pressure air intake, the ozone gas is efficiently drawn into the micro-nano bubble generator. The ozone gas dissolves in water in micro-nano bubbles with a particle size of 50μm to 200nm, increasing the contact area between ozone and water, thereby enhancing the reaction efficiency of ozone in the oxidation process.

[0024] (3) Establishment of catalytic oxidation reaction system

[0025] Ozone gas, in micro-nano form, is uniformly injected from the central region at the bottom of the reactor and enters the reactor vertically. A pre-prepared foam-based iron-modified functionalized interface catalytic material is suspended inside the reactor, located above the inlet of the ozone micro-nano oxidation reactor. This foam-based iron-modified functionalized interface material allows for maximum contact with the ozone dissolved in the water, degrading odor-causing substances in the water through its functionalized surface catalytic oxidation reaction.

[0026] In the above method, the main odor substances are 2-methylisoborneol (2-MIB) and geosmin (GSM).

[0027] Compared with the prior art, the advantages of the present invention are:

[0028] 1. In this invention, the foamed iron material used possesses high specific surface area and porous characteristics, enabling self-supporting hydrothermal synthesis of nano-sized MnCO3-FeCO3@IF. Simultaneously, the foamed iron, through acid etching, constructs a rough three-dimensional structure at the micro-nano level on its surface. Its three-dimensional interconnected pores provide directional flow channels for ozone micro-nano bubbles, and this porous structure endows the system with anti-clogging properties, solving the problem of activity degradation caused by micropore clogging in traditional ozone particle catalysts.

[0029] 2. In this invention, the foamed iron material is synthesized as MnCO3-FeCO3@IF material through acid etching induction combined with gradient temperature hydrothermal synthesis. No additional iron source is required, and the entire material preparation process forms a closed-loop iron cycle, achieving self-supply of catalytically active species and avoiding the generation of hazardous waste such as iron sludge. Compared with commercial catalysts, the green manufacturing process of this invention does not rely on precious metal doping, achieving highly efficient catalytic oxidation while reducing material and usage costs.

[0030] 3. This invention employs a gradient temperature hydrothermal process, which promotes heteroepitaxial growth and crystallization, enhancing the interfacial bonding force on the surface of the foamed iron. Specifically, at a low temperature of 90℃, urea begins to hydrolyze, generating a small amount of ammonia (NH3). NH3 adsorbs on the surface of the foamed iron and, through an amination reaction, adjusts the charge density, enhancing the negative charge on the surface of the foamed iron, thereby promoting the formation of positively charged Mn. 2+Ions are electrostatically adsorbed onto the surface of the foamed iron. Simultaneously, at this temperature, urea is not completely hydrolyzed, failing to provide a sufficiently alkaline environment. The interior of the PTFE lining remains acidic, further promoting the continued dissolution of iron in the acid-etched and activated foamed iron, thus eliminating the need for additional iron sources. As the temperature rises to 120–140°C, urea is fully hydrolyzed, and CO32-... 2 The significantly increased concentration drives the epitaxial growth of crystal nuclei along the lattice direction of the foamed iron surface, promoting the formation of strong chemical bonds between iron and manganese. Compared with the constant temperature hydrothermal method of the traditional method, the low-temperature-high-temperature gradient hydrothermal method of this invention can provide stronger interfacial bonding force, effectively promoting the formation of stable interfacial chemical bonds between manganese and iron elements on the foamed iron surface, thereby improving the erosion resistance of the material.

[0031] 4. In this invention, ozone is directly dissolved and enters the aqueous phase through micro-nano bubbles, achieving specific oxidation treatment of reducing solutes in the water. Unlike traditional bubbles, micro-nano ozone bubbles exhibit unique physical, chemical, and biological effects. Compared with traditional ozone oxidation processes, micro-nano ozone oxidation not only improves reactivity and mass transfer performance but also solves the problems of low ozone utilization and high cost in traditional processes.

[0032] 5. In this invention, the ozone system can be directly integrated in situ with the micro-nano bubble generation module and catalytic packing, avoiding the complex equipment modification requirements of traditional processes. Furthermore, the volumetric loading rate of micro-nano ozone aeration is significantly higher than that of traditional aeration methods, providing a more efficient and optimized solution for advanced water treatment in waterworks.

[0033] 6. This invention employs pickling with 0.1M hydrochloric acid and impregnation with 0.3M hydrochloric acid. Foamed iron surfaces are prone to rust formation; pickling with 0.1M hydrochloric acid selectively dissolves the loose rust layer on the foamed iron surface, achieving rust dissolution. Impregnation with 0.3M hydrochloric acid maintains a high level of reactivity on the foamed iron surface. At this time, H... + The process preferentially attacks the grain boundary defect regions of the foamed iron, forming numerous microgrooves, which roughens the surface of the foamed iron and promotes the in-situ growth of manganese-iron composite carbonates on the surface of the foamed iron. However, when impregnated with hydrochloric acid at concentrations >0.3M, H... + Bulk corrosion leads to excessive thinning of the iron skeleton and a decrease in mechanical strength; the subsequent high temperature and high pressure environment of gradient hydrothermal further causes structural softening, making it prone to collapse under the impact of water flow.

[0034] Obviously, based on the above description of the present invention, and according to common technical knowledge and conventional methods in the field, various other modifications, substitutions or alterations can be made without departing from the basic technical concept of the present invention. Attached Figure Description

[0035] Figure 1The image shows the X-ray diffraction (XRD) pattern of the foamed iron-based modified functionalized interface material obtained in Example 1.

[0036] Figure 2 The image shows a scanning electron microscope (SEM) image of the foamed iron-based modified functionalized interface material obtained in Example 1.

[0037] Figure 3 This is a schematic diagram of the reaction apparatus for the method of removing odor substances from water by coupling ozone micro-nano catalytic oxidation with foamed iron-based modified functionalized interface materials obtained in Examples 2 and 3. In the diagram: 1-Micro-nano machine inlet, 2-Balance tank, 3-Booster pump, 4-Dissolved gas tank, 5-Venturi tube, 6-Micro-nano bubble cutter, 7-Micro-nano machine outlet, 8-Air, 9-Ozone generator, 10-Air inlet, 11-Gas flow meter, 12-Ozone micro-nano oxidation reactor, 13-Foamed iron-based modified functionalized interface material, 14-Ozone micro-nano oxidation reactor inlet, 15-Ozone micro-nano oxidation reactor outlet, 16-Tail gas collection.

[0038] Figure 4 The effect of the foamed iron-based modified functionalized interface material obtained in Example 2 combined with ozone micro-nano catalytic oxidation on the removal of 2-methylisoborneol in water is shown.

[0039] Figure 5 The effect of the foamed iron-based modified functionalized interface material obtained in Example 2 and two commercial catalysts (Mn+Cu, Mn+Ti) combined with ozone micro-nano catalytic oxidation on the removal of 2-methylisoborneol in water is shown.

[0040] Figure 6 This is a flowchart illustrating the recycling process of the foamed iron-based modified functionalized interface material obtained in Example 1.

[0041] Figure 7 The effect of the non-gradient hydrothermal method prepared by the foam iron-based modified functionalized interface material obtained in Comparative Example 2 on the removal of 2-methylisoborneol in water by ozone micro-nano catalytic oxidation was investigated.

[0042] Figure 8 The effect of the foamed iron-based modified functionalized interface material obtained in Example 3 on the removal of geosmin in water by ozone micro-nano catalytic oxidation is shown. Detailed Implementation

[0043] The specific embodiments of the present invention will be further described below. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0044] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials used in the following examples were all purchased from commercial sources.

[0045] The tap water containing 2-methylisoborneol and geosmin in the embodiments of the present invention is taken from a waterworks in Zhongshan and flows into the clear water pool after pretreatment processes such as coagulation, flocculation and sand filtration. Then, odor and flavoring substances are added artificially.

[0046] Example 1: Preparation of a foamed iron-based modified functionalized interface material

[0047] Preparation of an iron-based ozone catalyst using foamed iron as a substrate. Using manganese chloride solution as a precursor and urea as an alkali source, without the need for additional iron source, a foamed iron-based modified functionalized interface material is grown in situ on the surface of foamed iron via a self-supporting hydrothermal synthesis method. The preparation method of the foamed iron-supported iron-based ozone catalyst in this embodiment includes the following steps:

[0048] (1) Preparation of pure foamed iron:

[0049] Cut 30×30×10mm foamed iron, and then ultrasonically clean it for 15 minutes with dilute hydrochloric acid (0.1M), ethanol and deionized water respectively to obtain pure foamed iron.

[0050] (2) Acid etching to activate foamed iron:

[0051] The pure foamed iron was immersed in 0.3M hydrochloric acid and magnetically stirred until the solution changed from colorless to yellow-brown. Then the foamed iron was removed and quickly rinsed with deionized water. It was then vacuum dried at 60°C. The mass of the foamed iron was weighed to be 1.62g, and the activated foamed iron was obtained, which was denoted as IF material.

[0052] (3) Weigh the metal precursor and the hydrothermal synthesis alkali source.

[0053] Weigh 10.95g of manganese chloride powder according to the molar ratio of manganese:iron = 3:1; weigh 13.93g of urea according to the molar ratio of urea:(manganese + iron) = 2.

[0054] (4) Hydrothermal treatment

[0055] Dissolve the weighed anhydrous manganese chloride and urea in 60 mL of deionized water and stir with a magnetic stirrer for 15 min. Then, quickly transfer the solution to a polytetrafluoroethylene (PTFE) liner, and simultaneously place the IF material upright in the PTFE liner, seal it and place it in a hydrothermal reactor. Heat at 90 °C for 4 h, then increase the temperature to 130 °C and heat for 16 h.

[0056] (5) Drying treatment

[0057] After hydrothermal treatment, the surface of the foamed iron was washed repeatedly with deionized water to remove redundant precipitates. The mixture was then vacuum dried at 60°C for 12 hours to obtain MnCO3-FeCO3@IF.

[0058] Depend on Figure 1 It can be seen that the main components of the prepared material are MnCO3 and FeCO3. Figure 2 It can be seen that the surface of the foamed iron substrate is in situ grown with uniformly covered cubic particles of different sizes, exhibiting a tightly overlapping three-dimensional stacked morphology.

[0059] Combination Figure 1 and Figure 2 The prepared material is mainly composed of MnCO3 and secondary phase FeCO3. The two phases are bonded together at the interface to form MnCO3-FeCO3@IF. MnCO3-FeCO3 is distributed on the surface pores and edges of the foam iron mesh, with high overall coverage and a grain size of 80-100 nm.

[0060] Comparative Example 1: Preparation of a Foamed Iron-Based Modified Functionalized Interface Material via Isothermal Hydrothermal Process

[0061] Preparation of an iron-based ozone catalyst using foamed iron as a substrate. Using manganese chloride solution as a precursor and urea as an alkali source, without the need for additional iron source, a foamed iron-based modified functionalized interface material is grown in situ on the surface of foamed iron via a self-supporting hydrothermal synthesis method. The preparation method of the foamed iron-supported iron-based ozone catalyst in this embodiment includes the following steps:

[0062] (1) Preparation of pure foamed iron:

[0063] Cut 30×30×10mm foamed iron, and then ultrasonically clean it for 15 minutes with dilute hydrochloric acid (0.1M), ethanol and deionized water respectively to obtain pure foamed iron.

[0064] (2) Acid etching to activate foamed iron:

[0065] The pure foamed iron was immersed in 0.3M hydrochloric acid and magnetically stirred until the solution changed from colorless to yellow-brown. Then the foamed iron was removed and quickly rinsed with deionized water. It was then vacuum dried at 60°C. The mass of the foamed iron was weighed to be 1.62g, and the activated foamed iron was obtained, which was denoted as IF material.

[0066] (3) Weigh the metal precursor and the hydrothermal synthesis alkali source.

[0067] Weigh 10.95g of manganese chloride powder according to the molar ratio of manganese:iron = 3:1; weigh 13.93g of urea according to the molar ratio of urea:(manganese + iron) = 2.

[0068] (4) Hydrothermal treatment

[0069] Anhydrous manganese chloride and urea were weighed and dissolved in 60 mL of deionized water, and stirred with a magnetic stirrer for 15 min. Then, the solution was quickly transferred to a polytetrafluoroethylene (PTFE) liner, and the IF material was placed upright in the PTFE liner. The mixture was then sealed and placed in a hydrothermal reactor and heated at 130 °C for 20 h.

[0070] (5) Drying treatment

[0071] After hydrothermal treatment, the surface of the foamed iron was washed repeatedly with deionized water to remove redundant precipitates. The mixture was then vacuum dried at 60°C for 12 hours to obtain MnCO3-FeCO3@IF.

[0072] Example 2: A method for removing 2-methylisoborneol from water by coupling ozone micro-nano catalytic oxidation using foamed iron-based modified functionalized interface materials as described in Example 1.

[0073] Two pieces of MnCO3-FeCO3@IF prepared in Example 1 were placed in 3L of tap water with an initial concentration of 200±20 ng / L 2-MIB. Adsorption performance was first investigated, followed by catalytic oxidation experiments coupled with ozone micro / nano technology. Under the same conditions, the catalytic performance of the foamed iron-based material was compared with that of two commercially available catalysts. The specific steps included:

[0074] 1. The foamed iron-based material prepared in Example 1 was placed in a 2-MIB solution with an initial concentration of 200±20 ng / L and stirred at room temperature for 10 min. Samples were taken every 2 min to analyze the change in the concentration of 2-MIB in the solution.

[0075] 2. The foamed iron-based modified functionalized interface material was suspended in the reactor, directly above the ozone micro / nano inlet, with appropriate space reserved. The ozone generator (using air as the gas source) was then started, and ozone entered the micro / nano bubble generator through a negative pressure system, where it was pressurized and sheared to form ozone bubbles of 50μm–200nm. The ozone micro / nano bubbles were injected from the bottom center of the reactor, diffused vertically, and contacted the foamed iron-based modified functionalized interface material. The reaction lasted for 10 minutes, with samples taken every 2 minutes. The micro / nano bubble generator had a power of 72W, and the ozone inlet flow rate was 80mL / min. See the device structure diagram below. Figure 3 .

[0076] 3. In step 2, two commercially available manganese-based metal oxide supported catalysts (Mn+Cu, Mn+Ti) were selected to replace the foamed iron-based modified functionalized interface material, and the same experimental operations were performed.

[0077] Figure 4This study investigated the removal efficiency of 2-methylisoborneol (2-MIB) from tap water using a foam-based iron-modified functionalized interface material coupled with ozone micro-nano catalytic oxidation. Results showed that after 8 minutes of ozone micro-nano oxidation, the foam-based iron-modified functionalized interface material coupled with ozone micro-nano oxidation effectively reduced the 2-MIB concentration in tap water from 191.3 ng / L to below 10 ng / L, achieving a removal rate of 98.22%, significantly higher than the 36.51% removal rate achieved by ozone oxidation alone.

[0078] Figure 5 The removal efficiency of 2-MIB by ozone micro-nano catalytic oxidation using foamed iron-based modified functionalized interface materials and commercial catalysts (Mn+Cu, Mn+Ti) was compared. After 8 minutes of ozone micro-nano oxidation, the concentration of 2-MIB in tap water using foamed iron-based modified functionalized interface materials coupled with ozone micro-nano catalytic oxidation decreased from an initial 191.3 ng / L to below 10 ng / L. In contrast, commercial Mn+Cu catalysts (initial concentration 166.0 ng / L) and commercial Mn+Ti catalysts (initial concentration 162.3 ng / L) required 10 minutes and 11 minutes, respectively, to achieve the same removal efficiency. However, due to the different initial concentrations, the removal efficiency of the two commercial catalysts was significantly lower than that of the material presented in this application. Therefore, the method of using foamed iron-based modified functionalized interface materials coupled with ozone micro-nano oxidation offers a shorter oxidation time, higher degradation efficiency, and effectively conserves ozone.

[0079] Therefore, the foam iron-based modified functionalized interface material coupled with ozone micro-nano catalytic oxidation has excellent performance. That is, the present invention can effectively catalyze the oxidation of 2-MIB based on the foam iron-based modified functionalized interface material coupled with ozone micro-nano, and has a high efficiency removal effect on 2-MIB.

[0080] according to Figure 6 The foamed iron recycling process of this invention allows the foamed iron-based modified functionalized interface material prepared by this method to be reused multiple times after cleaning.

[0081] Comparative Example 2: A method for removing 2-methylisoborneol from water by coupling ozone micro-nano catalytic oxidation using foamed iron-based modified functionalized interface materials based on Comparative Example 1.

[0082] Two pieces of MnCO3-FeCO3@IF prepared in Comparative Example 1 were placed in 3L of tap water with an initial concentration of 200±20 ng / L 2-MIB, and ozone micro-nano catalytic oxidation experiments were performed. The specific steps included:

[0083] 1. The foamed iron-based material prepared in Comparative Example 1 was placed in a 2-MIB solution with an initial concentration of 200±20 ng / L and stirred at room temperature for 10 min. Samples were taken every 2 min to analyze the change in the concentration of 2-MIB in the solution.

[0084] 2. The foamed iron-based modified functionalized interface material was suspended in the reactor, directly above the ozone micro / nano inlet, with appropriate space reserved. The ozone generator (using air as the gas source) was then started, and ozone entered the micro / nano bubble generator through a negative pressure system, where it was pressurized and sheared to form ozone bubbles of 50μm–200nm. The ozone micro / nano bubbles were injected from the bottom center of the reactor, diffused vertically, and contacted the foamed iron-based modified functionalized interface material. The reaction lasted for 10 minutes, with samples taken every 2 minutes. The micro / nano bubble generator had a power of 72W, and the ozone inlet flow rate was 80mL / min. See the device structure diagram below. Figure 3 .

[0085] Figure 7 The removal efficiency of two hydrothermal methods (isothermal and gradient hydrothermal) for 2-MIB removal from tap water using ozone micro / nano catalytic oxidation was compared. Results showed that within an 8-minute reaction time, the gradient hydrothermal material exhibited stronger degradation ability for 2-MIB at a higher initial concentration (191.3 vs 135.86 ng / L), with a final residual concentration (3.4 ng / L) lower than the isothermal hydrothermal group (4.2 ng / L). This result confirms that the gradient hydrothermal process, through its unique staged temperature control (heating first at 90℃, then at 130℃), successfully constructs an active material with optimized surface properties, resulting in superior 2-MIB removal performance under the same water quality conditions.

[0086] Example 3: A method for removing geosmin from water using foamed iron-based modified functionalized interface materials coupled with ozone micro-nano catalytic oxidation.

[0087] Two pieces of MnCO3-FeCO3@IF prepared in Example 1 were placed in 3L of tap water with an initial concentration of 170±20 ng / L GSM, and ozone micro-nano catalytic oxidation experiments were performed. The specific steps included the following:

[0088] The foamed iron-based modified functionalized interface material was suspended in the reactor, directly above the ozone micro / nano inlet, with appropriate space reserved. The ozone generator (using air as the gas source) was then activated, and ozone entered the micro / nano bubble generator through a negative pressure system, where it was pressurized and sheared to form ozone bubbles ranging from 50 μm to 200 nm. These ozone micro / nano bubbles were injected from the bottom center of the reactor, diffusing vertically to contact the foamed iron-based modified functionalized interface material, and the reaction lasted for 10 minutes. The micro / nano bubble generator had a power of 72 W, and the ozone inlet flow rate was 80 mL / min. See the device structure diagram below. Figure 3 .

[0089] Figure 8This study demonstrates the removal efficiency of ozone from tap water using a foam-based iron-modified functionalized interface material coupled with ozone micro-nano catalytic oxidation. Experimental results show that after 6 minutes of ozone micro-nano catalytic oxidation, the ozone concentration of GSM from 157.1 ng / L to 2.8 ng / L, achieving a removal rate of 98.21%. This treatment effect not only fully meets the limits of the "Standards for Drinking Water Quality" (GB5749-2022) but also significantly outperforms the 42.26% removal rate of traditional aeration ozone oxidation processes, representing a 2.3-fold increase in treatment efficiency and greatly enhancing the removal effect of ozone micro-nano catalytic oxidation.

[0090] In summary, this invention provides a method for coupling ozone micro-nano catalytic oxidation of odor substances using foamed iron-based modified functionalized interface materials. This method has a good removal effect on 2-MIB and GSM, and the foamed iron-based materials can be reused after cleaning and drying, making it economical and practical.

[0091] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A method for removing odor substances from water by coupling ozone micro-nano catalytic oxidation with a foamed iron-based modified functionalized interface material, characterized in that... The preparation method of the foamed iron-based modified functionalized interface material includes the following steps: (1) Preparation of pure foamed iron: Cut the foamed iron and then wash it with acid, ethanol and deionized water by ultrasonic cleaning to obtain pure foamed iron. (2) Acid etching to activate foamed iron: Pure foamed iron is immersed in acid solution and magnetically stirred until the solution changes from colorless to yellow-brown. Then the foamed iron is taken out, rinsed quickly with deionized water, and vacuum dried to obtain IF material. (3) Weigh the metal precursor and hydrothermal synthesis alkali source: Weigh the manganese metal salt and urea according to the set molar ratio; (4) Hydrothermal treatment: Dissolve the weighed metal precursor and urea in deionized water and stir with a magnetic stirrer. Then transfer the solution to a polytetrafluoroethylene liner and place the IF material vertically into the polytetrafluoroethylene liner. Seal and place it into a hydrothermal reactor for gradient hydrothermal reaction. (5) Drying treatment: After the hydrothermal treatment is completed, the foamed iron-based material is cleaned and then vacuum dried to obtain the foamed iron-based modified functionalized interface material MnCO3-FeCO3@IF.

2. The method for removing odor substances from water using a foamed iron-based modified functionalized interface material coupled with ozone micro-nano catalytic oxidation according to claim 1, characterized in that... In step (1), pickling is performed using a 0.1M hydrochloric acid solution.

3. The method for removing odor substances from water using a foamed iron-based modified functionalized interface material coupled with ozone micro-nano catalytic oxidation, as described in claim 1, is characterized in that... In step (2), the acid solution is a 0.3M hydrochloric acid solution.

4. The method for removing odor substances from water using a foamed iron-based modified functionalized interface material coupled with ozone micro-nano catalytic oxidation, as described in claim 1, is characterized in that... In steps (2) and (5), the vacuum drying is performed at 60-80°C for 10-12 hours.

5. The method for removing odor substances from water using a foamed iron-based modified functionalized interface material coupled with ozone micro-nano catalytic oxidation according to claim 1, characterized in that... In step (3), manganese metal salt is weighed according to the molar ratio of manganese to iron (3-4):1; urea is weighed according to the molar ratio of urea: (manganese + iron)≥2.

6. The method for removing odor substances from water by coupling ozone micro-nano catalytic oxidation with a foamed iron-based modified functionalized interface material according to claim 5, characterized in that, The manganese metal salt is solid manganese chloride.

7. The method for removing odor substances from water by coupling ozone micro-nano catalytic oxidation with a foamed iron-based modified functionalized interface material according to claim 1, characterized in that, In step (4), the gradient hydrothermal reaction process is as follows: first, heating at 90℃ for 2 to 4 hours, and then increasing to 120 to 140℃ for 16 to 18 hours.

8. The method for removing odor substances from water by coupling ozone micro-nano catalytic oxidation with a foamed iron-based modified functionalized interface material according to claim 1, characterized in that, Includes the following steps: (1) Preparation of foamed iron-based modified functionalized interface material MnCO3-FeCO3@IF; (2) The ozone generator uses air as the gas source and generates ozone gas through a double water-cooled enamel ozone unit. The generated ozone gas then enters the micro-nano bubble machine through a negative pressure system. The ozone gas dissolves in water in micro-nano bubbles with a particle size of 50μm to 200nm. (3) The ozone gas generated in step (2) is uniformly injected from the central area at the bottom of the reactor in the form of micro-nano scale and enters the reactor vertically. The foam iron-based modified functionalized interface catalyst material prepared in step (1) is suspended in the reactor and located at the upper end of the water inlet of the ozone micro-nano oxidation reactor. It is in full contact with the ozone dissolved in the water and degrades the odor substances in the water through its functionalized surface catalytic oxidation reaction.

9. The method for removing odor substances from water by coupling ozone micro-nano catalytic oxidation with a foamed iron-based modified functionalized interface material according to claim 8, characterized in that, The odor substances are 2-methylisoborneol and geosmin.

10. The foamed iron-based modified functionalized interface material MnCO3-FeCO3@IF obtained by the preparation method according to any one of claims 1-9, characterized in that, MnCO3-FeCO3 is distributed on the surface pores and edges of the foamed iron mesh structure.

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