Heavy metal capturing agent immobilized multifunctional fenton-like catalyst, and preparation method and application thereof
By preparing a multifunctional Fenton-like catalyst immobilized on a heavy metal scavenger, the problems of harsh pH conditions and complex recycling of Fenton-like systems were solved, and efficient organic pollutant degradation and multiple recycling of catalysts under neutral and acidic conditions were achieved, with good ecological and economic benefits.
Patent Information
- Application Number
- CN202311441572.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-01
- Publication Date
- 2025-10-14
- Estimated Expiration
- 2043-11-01
AI Technical Summary
The existing Fenton-like systems have harsh reaction pH conditions, low catalytic activity, slow degradation rate, and complex recycling processes, making it difficult to efficiently degrade organic pollutants under neutral and acidic conditions.
A multifunctional Fenton-like catalyst immobilized on a heavy metal scavenger is prepared by regulating the H content in the catalyst's -S-Fe-S- main active structure and its neighboring structures to exhibit high organic pollutant degradation activity over a wide pH range from neutral to acidic. This catalyst combines photocatalytic and non-photocatalytic activities to achieve multiple recycling of the catalyst.
It can efficiently degrade organic pollutants under neutral and acidic conditions, has good catalyst stability, produces almost no iron sludge, reduces the complexity and cost of the treatment process, realizes multiple recycling of the catalyst, and has good ecological and economic benefits.
Smart Images
Figure CN117443457B_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of water treatment, and in particular relates to a multifunctional Fenton-like catalyst immobilized with a heavy metal scavenger, and a preparation method and application thereof. Background Art
[0002] With rapid population and economic growth, global water, air, and soil pollution are becoming increasingly severe, and environmental problems are becoming more acute than ever. In particular, the rapid development of modern industry has led to a dramatic increase in the quantity, variety, and toxicity of organic pollutants discharged into water bodies, causing serious environmental pollution. Traditional biological treatment technologies are far from sufficient to meet the required effluent quality for the high concentrations and toxicity of recalcitrant organic pollutants in water. Therefore, it is urgent to treat recalcitrant organic pollutants in water, render them harmless, and recycle them as resources to alleviate water shortages. Advanced oxidation processes (AOPs) have become a research hotspot in the water treatment field due to their rapid oxidation rates, wide applicability, and high mineralization rates.
[0003] Advanced oxidation technology primarily utilizes the highly oxidative hydroxyl radicals (•OH) generated within the system to selectively remove and degrade refractory organic pollutants that are inaccessible to conventional methods. It has been widely used in the treatment of wastewaters containing phenols, pharmaceuticals, pesticides, and landfill leachate. Compared to other advanced oxidation technologies, the Fenton system has a longer research history and accumulated experience. Its advantages include non-toxic reagents, simple operation, and relatively low investment. It is an important and promising advanced oxidation technology for wastewater treatment and has been widely used to treat toxic and hazardous wastewaters. While possessing these advantages, the traditional Fenton process also has limiting drawbacks such as high reagent usage, low H2O2 utilization, a specific low pH range (pH ≈ 3) required for the reaction, and the generation of large amounts of iron sludge.
[0004] Fenton-like system by immobilizing Fe 2+ The development of Fenton-like catalysts with high catalytic activity, a wide pH range, and the ability to recycle the catalysts is crucial for achieving a homogeneous Fenton-like system. The development of Fenton-like catalysts with high catalytic activity, a wide pH range, and the ability to be recycled continuously and / or in situ is therefore of great significance. Summary of the Invention
[0005] In view of the problems existing in the prior art such as the harsh pH conditions of Fenton-like degradation reactions and the complex operation of the recycling and reuse process, the present invention provides a multifunctional Fenton-like catalyst supported on a heavy metal scavenger, a preparation method thereof, and an application thereof.
[0006] The application mainly regulates the H content in the prepared catalyst-S-Fe-S-main active structure and its adjacent structure, so that the catalyst has high organic pollutant degradation activity under neutral and acidic wide pH conditions, and the catalyst has non-photocatalytic activity and photocatalytic activity, can be recycled multiple times under light and no light conditions, and can efficiently degrade and treat various organic wastewater such as coal chemical industry, dyes and medicines after in-situ photocatalytic reduction and chemical reagent reduction regeneration.
[0007] The application adopts the following technical scheme:
[0008] The heavy metal capture agent supported multifunctional Fenton-like catalyst is an amorphous and / or crystalline material containing a-S-Fe-S-main active structure, and has non-photocatalytic activity and photocatalytic activity, and can efficiently catalyze and degrade organic pollutants under light and no light conditions.
[0009] A preparation method of a heavy metal capture agent supported multifunctional Fenton-like catalyst, comprising the following steps:
[0010] In the first step, the heavy metal capture agent is dissolved in deionized water to form solution A; and the iron source is dissolved in deionized water to form solution B;
[0011] In the second step, solution B is slowly added dropwise to solution A, the obtained mixed solution is stirred at room temperature, the stirring speed is 100-1000 rpm, inert gas N2 is protected, the reaction time is 0.5-24 h, after the reaction is completed, the precipitate is obtained, the precipitate is filtered and washed, and then dried, the drying temperature is 40-100 DEG C, the time is 12-24 h, and the powder is ground, so that the heavy metal capture agent supported Fenton-like catalyst is obtained.
[0012] Further, the heavy metal capture agent includes at least one of dithiocarbamic acid salt and xanthate derivative; the iron source includes at least one of ferrous sulfate, ferrous chloride and ferrous acetate; and the molar ratio of the heavy metal capture agent to the iron source is 1:0.1-1:6.
[0013] Further, the heavy metal capture agent includes at least one of trisodium trithiocyanate, ammonium dithiocarbamate and sodium ethyl xanthate.
[0014] Further, in the second step, the filtering and washing are performed by using at least one of deionized water, 0.01 M H2SO4, 0.05 M H2SO4, 0.10 M H2SO4, 0.15 M H2SO4, 0.20 M H2SO4, 0.50 M H2SO4 and 1.00 M H2SO4.
[0015] The application of a heavy metal capture agent immobilized multifunctional Fenton-like catalyst in treating pollutants in water, comprising the following steps:
[0016] First step: the prepared heavy metal capture agent immobilized Fenton-like catalyst is put into wastewater containing organic pollutants, and dark adsorption is carried out at room temperature with continuous stirring, so that the catalyst and the pollutants reach adsorption equilibrium, and then H2O2 is added, so that the pollutants in the wastewater can be catalytically degraded under light and without light;
[0017] Second step: under light, intermittent operation and / or continuous operation, wastewater and H2O2 are added in proportion, and the catalyst can continuously degrade the pollutants; under no light, after the degradation process in the first step is completed, the catalyst is regenerated by photocatalytic reduction and chemical reducing agent reduction, and then the first step and the second step are repeated, so that the catalyst can be recycled multiple times.
[0018] Further, in the first step, the concentration of the organic pollutants is 1-1000 ppm, the mass / volume ratio of the catalyst addition amount to the wastewater is (1:10-1:100) g / L, the mass / volume ratio of the catalyst addition amount to H2O2 is (1:0.01-1:1) g / L, the dark adsorption time is 0.5-3 h, and the catalytic degradation time is 0.5-3 h.
[0019] Further, in the first step and the second step, the light used for degrading the pollutants by the photocatalytic activity of the catalyst is at least one of visible light and sunlight, and the volume ratio of H2O2 to wastewater is 1:100-1:1000.
[0020] Further, in the second step, under no light, after the catalyst degrades the pollutants by non-photocatalytic activity, the light used for photocatalytic reduction includes at least one of visible light and sunlight.
[0021] Further, in the second step, under no light, after the catalyst degrades the pollutants by non-photocatalytic activity, the reducing agent used for chemical reduction includes at least one of sulfite and hydrazine hydrate and its derivatives.
[0022] Further, in the second step, under no light, after the catalyst degrades the pollutants by non-photocatalytic activity, the reducing agent used for chemical reduction includes at least one of sodium sulfite, potassium sulfite, hydrazine, hydrazine sulfate, and hydroxylamine sulfate.
[0023] Further, the organic pollutants include one or more of coal chemical, dye, and pharmaceutical wastewater.
[0024] Further, the organic pollutants include one or more of phenol, p-chlorophenol, pyridine, quinoline, rhodamine B, methylene blue, tetracycline, and diclofenac sodium.
[0025] The beneficial effects of the present application are as follows:
[0026] 1. The heavy metal capture agent immobilized multifunctional Fenton-like catalyst provided by the present application has a wide source of raw materials, a simple preparation method, excellent non-photocatalytic activity and photocatalytic activity, a wide pH range, and does not need to repeatedly adjust the pH value of the reaction system, thereby reducing the complexity and cost of the wastewater treatment process.
[0027] 2. The heavy metal capture agent immobilized multifunctional Fenton-like catalyst provided by the present application has a low metal dissolution rate, almost no iron sludge is produced in the wastewater treatment process, the formation of secondary pollutants is reduced, and good ecological benefits are achieved.
[0028] 3. The heavy metal capture agent immobilized multifunctional Fenton-like catalyst provided by the present application has good stability, utilizes photocatalytic activity to continuously achieve the degradation of pollutants in wastewater under light conditions, utilizes non-photocatalytic activity to achieve in-situ regeneration of the catalyst after degrading pollutants through photocatalytic reduction and / or chemical reagent reduction, realizes multiple recycling of the catalyst, and does not need to be recovered, thereby achieving good economic benefits.
[0029] 4. The heavy metal capture agent immobilized multifunctional Fenton-like catalyst provided by the present application can simultaneously effectively degrade two or more pollutants in simulated actual industrial wastewater treatment, is almost not affected by other impurities such as dissolved organic matter in water, reduces social problems caused by industrial wastewater treatment, and has good social benefits. BRIEF DESCRIPTION OF DRAWINGS
[0030] Figure 1 The figure is the effect diagram of the heavy metal capture agent immobilized Fenton-like catalyst prepared in Example 1 for multiple cycle degradation of phenol under photocatalytic conditions;
[0031] Figure 2 The figure is the effect diagram of the heavy metal capture agent immobilized Fenton-like catalyst prepared in Example 1 for multiple cycle degradation of phenol under non-illumination conditions through photoreduction;
[0032] Figure 3 The figure is a comparison diagram of the degradation effects of the heavy metal capture agent immobilized Fenton-like catalyst prepared in Example 1 on different pollutants;
[0033] Figure 4 The figure is a comparison diagram of the degradation effects of the heavy metal capture agent immobilized Fenton-like catalysts in Examples 1, 2 and 3 on phenol. DETAILED DESCRIPTION
[0034] In order to more clearly illustrate the present invention and have a clearer understanding of the technical features, purposes and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below. Unless otherwise specified, the raw materials, reagents or devices used in the following examples can be obtained from conventional commercial channels or can be obtained by existing known methods.
[0035] Example 1
[0036] A method for preparing a Fenton-like catalyst supported on a heavy metal scavenger comprises the following steps:
[0037] (1) Dissolve 2 g of trisodium thiocyanate (TMT) in 20 mL of deionized water and stir at room temperature to form solution A.
[0038] (2) Dissolve 2.29 g of FeSO4·7H2O in 20 mL of deionized water and stir at room temperature to form solution B;
[0039] (3) Solution B was slowly added to solution A and mixed, and stirred at room temperature at a stirring speed of 600 rpm for 30 min, while introducing inert gas N2 for protection.
[0040] (4) The solution obtained in step (3) was filtered, and the filtered precipitate was washed with 0.1 M H2SO4.
[0041] (5) The precipitate obtained in step (4) was placed in a vacuum drying oven at 60°C for 12 h until dry.
[0042] (6) After the product in step (5) is cooled naturally, it is ground into powder to obtain a Fenton-like catalyst supported by a heavy metal scavenger.
[0043] Example 2
[0044] A method for preparing a Fenton-like catalyst supported on a heavy metal scavenger comprises the following steps:
[0045] (1) Dissolve 0.47 g of sodium ethyl xanthate (SEX) in 20 mL of deionized water and stir at room temperature to form solution A.
[0046] (2) Dissolve 1.80 g of FeSO4·7H2O in 20 mL of deionized water and stir at room temperature to form solution B;
[0047] (3) Solution B was slowly added to solution A and mixed, and stirred at room temperature at a stirring speed of 600 rpm for 30 min, while introducing inert gas N2 for protection.
[0048] (4) The solution obtained in step (3) is filtered, and the filtered precipitate is washed with 0.1 M H2SO4.
[0049] (5) The precipitate obtained in step (4) is placed in a vacuum drying oven and dried at 60°C for 12 h until dry.
[0050] (6) After the product in step (5) is naturally cooled, it is ground into powder to obtain the heavy metal capture agent immobilized Fenton-like catalyst.
[0051] Example 3
[0052] A method for preparing a heavy metal capture agent immobilized Fenton-like catalyst, comprising the following steps:
[0053] (1) 1 g of ammonium dithiocarbamate (DTC) is dissolved in 20 mL of deionized water to form solution A under stirring at room temperature;
[0054] (2) 2.52 g of FeSO4·7H2O is dissolved in 20 mL of deionized water to form solution B under stirring at room temperature;
[0055] (3) Solution B is slowly added to solution A and stirred at a stirring speed of 600 rpm for 30 min at room temperature under protection of inert gas N2.
[0056] (4) The solution obtained in step (3) is filtered, and the filtered precipitate is washed with 0.01 M H2SO4.
[0057] (5) The precipitate obtained in step (4) is placed in a vacuum drying oven and dried at 60°C for 12 h until dry.
[0058] (6) After the product in step (5) is naturally cooled, it is ground into powder to obtain the heavy metal capture agent immobilized Fenton-like catalyst.
[0059] Example 4
[0060] With phenol as a simulated pollutant, the performance of the heavy metal capture agent immobilized Fenton-like catalysts in examples 1-3 in degrading pollutants in simulated real water bodies is investigated, comprising the following steps:
[0061] (1) 3.7 mg of the heavy metal capture agent immobilized Fenton-like catalyst described in example 1 is added to 100 mL of a phenol solution with a concentration of 300 ppm, the solution system temperature is room temperature, and dark adsorption is performed under stirring for 30 min.
[0062] (2) After the catalyst and pollutants reach adsorption equilibrium, 0.3 mL of 30% H2O2 is added to the solution, and the solution is irradiated with a 420 nm LED light for 120 min. At different time intervals, samples are taken, and the change in phenol concentration is detected.
[0063] Experimental Example 5
[0064] To explore the stability of the heavy metal capture agent immobilized Fenton-like catalyst described in Example 1 in long-term water treatment under non-illumination conditions, a cyclic test was performed with phenol as the target pollutant. The steps are as follows:
[0065] (1) 3.7 mg of the heavy metal capture agent immobilized Fenton-like catalyst prepared by acid washing is added to 100 mL of a phenol solution with a concentration of 300 ppm. The solution system is at room temperature, and stirring is performed for 30 min for dark adsorption.
[0066] (2) After the catalyst and pollutants reach adsorption equilibrium, 0.3 mL of 30% H2O2 is added to the solution, and the solution is irradiated with a 420 nm LED light for 120 min. At different time intervals, samples are taken, and the change in phenol concentration is detected.
[0067] (3) The solution after the reaction in step (2) is irradiated with a 420 nm LED light under an O2 atmosphere for 4 h to fully reduce and regenerate the catalyst.
[0068] (4) Phenol is added to the above solution to make the solution concentration 300 ppm, and the dark adsorption in step (1) and steps (2) and (3) are repeated.
[0069] Figure 1 The results show that the FeSO4 / TMT catalyst has excellent photocatalytic degradation activity, and the degradation rate of the catalyst for phenol is still ≥99% after 25 cycles.
[0070] Figure 2 The results show that the FeSO4 / TMT catalyst still has excellent photocatalytic degradation activity under non-illumination conditions, and the catalyst can restore its excellent non-photocatalytic activity after photocatalytic reduction. The degradation rate of the catalyst for phenol is still ≥95% after 22 cycles.
[0071] Figure 3The comparison chart of degradation effects of the heavy metal capturing agent immobilized Fenton-like catalyst prepared in Example 1 on different pollutants shows that FeSO4 / TMT has good catalytic degradation activity on phenol, p-chlorophenol, pyridine, quinoline, rhodamine B, methylene blue, tetracycline, diclofenac sodium and other main organic pollutants in coal chemical, dye and pharmaceutical wastewater.
[0072] Figure 4 The comparison chart of degradation effects of the heavy metal capturing agent immobilized Fenton-like catalysts in Examples 1, 2 and 3 on phenol shows that these catalysts all have excellent catalytic degradation activity on pollutants, indicating that the Fenton-like catalysts can be prepared by using similar heavy metal capturing agents.
[0073] The results show that the heavy metal capturing agent immobilized Fenton-like catalyst has the potential for long-term stable treatment of actual polluted water bodies or actual industrial wastewater.
[0074] The above only describes the preferred embodiments of the present application, and any equivalent changes and modifications made within the scope of the patent application of the present application shall be included in the scope of the present application.
Claims
1. A multifunctional Fenton-like catalyst supported on a heavy metal scavenger, characterized in that: The catalyst comprises an amorphous and / or crystalline material with a main active structure of -S-Fe-S-, has both non-photocatalytic activity and photocatalytic activity, and can efficiently catalytically degrade organic pollutants under both light and no light conditions; The heavy metal scavenger includes at least one of trisodium thiocyanate, ammonium dithiocarbamate, and sodium ethyl xanthate.
2. A method for preparing the multifunctional Fenton-like catalyst supported on a heavy metal scavenger according to claim 1, characterized in that: The steps include: In the first step, a heavy metal scavenger is dissolved in deionized water to form solution A; an iron source is dissolved in deionized water to form solution B; In the second step, solution B is slowly added dropwise to solution A, and the resulting mixed solution is stirred at room temperature at a stirring speed of 100-1000 rpm, with N2 protection, and a reaction time of 0.5-24 hours. After the reaction is completed, a precipitate is obtained, which is filtered and washed, and then dried at a drying temperature of 40-100°C for 12-24 hours. The precipitate is ground into powder to obtain a Fenton-like catalyst supported on a heavy metal scavenger.
3. The method for preparing a multifunctional Fenton-like catalyst supported on a heavy metal scavenger according to claim 2, characterized in that: The iron source includes at least one of ferrous sulfate, ferrous chloride and ferrous acetate; the molar ratio of the heavy metal scavenger to the iron source is 1:0.1-1:
6.
4. The method for preparing a multifunctional Fenton-like catalyst supported on a heavy metal scavenger according to claim 3, characterized in that: The filtration and washing in the second step are washed with at least one of deionized water, 0.01 M H2SO4, 0.05 M H2SO4, 0.10 M H2SO4, 0.15 M H2SO4, 0.20 M H2SO4, 0.50 M H2SO4, and 1.00 M H2SO4.
5. Use of the multifunctional Fenton-like catalyst supported on a heavy metal scavenger as claimed in claim 1 in treating pollutants in water, characterized in that: The steps include: The first step is to add the prepared heavy metal scavenger-supported Fenton-like catalyst to wastewater containing organic pollutants, and continuously stir at room temperature for dark adsorption until the catalyst and the pollutants reach adsorption equilibrium. Subsequently, H2O2 is added to catalyze the degradation of pollutants in the wastewater under both light and no light conditions. Step 2: Under light conditions, intermittent operation and / or continuous operation are carried out, and wastewater and H2O2 are added in proportion, and the catalyst can continuously degrade pollutants; under no light conditions, after the degradation process described in the first step is completed, the catalyst is regenerated by photocatalytic reduction and chemical reducing agent reduction, and then the first and second steps are repeated to achieve multiple recycling of the catalyst.
6. The use of a multifunctional Fenton-like catalyst supported on a heavy metal scavenger according to claim 5, characterized in that: In the first step, the concentration of organic pollutants is 1-1000 ppm, the mass volume ratio of catalyst dosage to wastewater is (1:10-1:100) g / L, the mass volume ratio of catalyst dosage to H2O2 is (1:0.01-1:1) g / L, the dark adsorption time is 0.5-3 hours, and the catalytic degradation time is 0.5-3 hours; In the first and second steps, the light conditions for degrading pollutants by utilizing the photocatalytic activity of the catalyst are at least one of visible light and sunlight, and the volume ratio of added H2O2 to wastewater is 1:100-1:1000.
7. The use of a multifunctional Fenton-like catalyst supported on a heavy metal scavenger according to claim 5, characterized in that: In the second step, after the pollutants are degraded by the non-photocatalytic activity of the catalyst under the absence of light, the light conditions for the photocatalytic reduction include at least one of visible light and sunlight; In the second step, after the pollutants are degraded by the non-photocatalytic activity of the catalyst under the condition of no light, the reducing agent for chemical reduction includes at least one of sulfite and hydrazine hydrate and their derivatives.
8. The use of a multifunctional Fenton-like catalyst supported on a heavy metal scavenger according to claim 7, characterized in that: In the second step, after the pollutants are degraded by the non-photocatalytic activity of the catalyst under the condition of no light, the reducing agent for chemical reduction includes at least one of sodium sulfite, potassium sulfite, hydrazine, hydrazine sulfate, and hydroxylamine sulfate.
9. The use of a multifunctional Fenton-like catalyst supported on a heavy metal scavenger according to claim 5, characterized in that: The organic pollutants include one or more of the main pollutants in coal chemical, dye and pharmaceutical wastewater.
10. The use of a multifunctional Fenton-like catalyst supported on a heavy metal scavenger according to claim 9, characterized in that: The organic pollutants include phenol, p-chlorophenol, pyridine, quinoline, rhodamine B, methylene blue, tetracycline, and diclofenac sodium.