Preparation and Application of Cu / Ti-Fe3O4@FeOOH Magnetic Heterogeneous Fenton Catalyst for Treating Cyanide-Containing Wastewater

Abstract

This invention relates to the preparation of a Cu / Ti-Fe3O4@FeOOH magnetic heterogeneous Fenton catalyst and its application in treating cyanide-containing wastewater. Ferrous salt, copper salt, and titanium salt are added to a hydrochloric acid solution and stirred until homogeneous to obtain a metal mixture. An alkali source is poured into a container, nitrogen gas is introduced, and the mixture is heated. The resulting mixture is added to the alkali source and stirred until homogeneous to obtain a precipitation reaction solution. A nitrate solution is added to the precipitation reaction solution and stirred until homogeneous to obtain an oxidation reaction solution. The oxidation reaction solution is heated and reacted, then cooled. The resulting solid particles are collected by magnetic separation, centrifugation, washing, drying, and grinding to obtain the copper-titanium doped iron-based magnetic heterogeneous Fenton catalyst Cu / Ti-Fe3O4@FeOOH. This catalyst exhibits excellent cyanide removal efficiency for cyanide-containing wastewater under pH conditions ranging from 6.5 to 12.5. Compared to existing Fenton processes, it eliminates the need to adjust the wastewater pH and can be directly applied to the treatment of cyanide-containing wastewater in various scenarios.

Description

Technical Field

[0001] This invention belongs to the field of cyanide-containing wastewater treatment and environmental catalysis technology, and relates to a copper-titanium doped iron-based magnetic heterogeneous Fenton catalyst for cyanide removal treatment of cyanide-containing wastewater; more specifically, it relates to the preparation of Cu / Ti-Fe3O4@FeOOH magnetic heterogeneous Fenton catalyst and its application in treating cyanide-containing wastewater. Background Technology

[0002] Cyanide-containing wastewater, a type of industrial wastewater characterized by high toxicity, difficulty in treatment, and stringent discharge requirements, is discharged in large quantities in heavy industries such as ferrous and non-ferrous metal smelting, chemical processing, electroplating, and coking. Existing methods for treating cyanide-containing wastewater primarily involve direct oxidation or indirect advanced oxidation. Direct oxidation offers good and rapid cyanide removal, but it is costly and carries the risk of secondary pollution. Advanced oxidation methods often involve long process flows, large equipment footprints, require acid-base adjustments, and result in high salinity effluent. When the wastewater contains a variety of cyanide species with complex structures, multi-stage treatment is necessary to meet discharge standards. As an advanced oxidation technology, the Fenton process, due to the strong oxidizing properties of the generated ·OH radical and its rapid reaction rate, is well-suited for treating cyanide-containing wastewater. However, it has a narrow pH tolerance, requiring pH adjustment, and metal ions easily precipitate under acidic conditions, producing large amounts of iron sludge, leading to high application costs. To overcome these shortcomings of traditional homogeneous Fenton technology, researchers have loaded iron onto solid particles, developing different types of heterogeneous Fenton catalysts and Fenton-like technologies.

[0003] Existing literature reports that iron-based materials such as Fe3O4, Fe2O3, FeOOH, FeOOH@GO, and Fe / SiO2, both unsupported and supported with other elements, exhibit outstanding Fenton oxidation catalytic activity in heterogeneous Fenton catalysts. For example, Cu-doped Fe3O4@FeOOH magnetic nanocomposite materials show good catalytic activity for the oxidative degradation of ofloxacin in wastewater, but their weak magnetism makes them difficult to recover. Other researchers have studied heterogeneous Fenton systems using Fe3O4@b-CD / rGO as a catalyst, finding that the Fe3O4@b-CD / rGO composite material has a stronger degradation effect on bisphenol A than Fe3O4 alone. This is attributed to the synergistic effect between the components enhancing the oxidation of the reaction system. However, this catalyst has an applicable pH range of 3.2-9.0, making it unsuitable for treating highly alkaline wastewater, and the reaction time is relatively long, requiring 120 minutes to completely degrade the pollutants, which implies a longer hydraulic retention time.

[0004] Currently, there are many types of industrial cyanide-containing wastewater, and their pH ranges vary greatly. For example, the pH of cyanide-containing wastewater from blast furnace steelmaking washing gas is around 8, while the pH of cyanide-containing wastewater from gold mines is around 9.5, and some even have higher pH values. This poses a challenge to heterogeneous Fenton technology, and there is an urgent need for a heterogeneous Fenton catalyst with a wide pH range that can be directly applied to cyanide-containing wastewater without adjustment. Summary of the Invention

[0005] The technical objective of this invention is to provide a copper-titanium doped iron-based magnetic heterogeneous Fenton catalyst, Cu / Ti-Fe3O4@FeOOH, which exhibits excellent degradation performance in cyanide-containing wastewater over a wide pH range. This invention prepares the copper-titanium doped iron-based magnetic heterogeneous Fenton catalyst Cu / Ti-Fe3O4@FeOOH by doping Cu and Ti bimetallic elements into the Fe3O4@FeOOH solid component. This catalyst not only possesses the physical properties of both Fe3O4 and FeOOH, but also exhibits excellent Fenton oxidation catalytic effect on cyanide-containing wastewater; it has a wide pH adaptability range, showing good treatment effect for industrial cyanide-containing wastewater in different scenarios with pH ranges of 6.5-12.5, and can completely degrade pollutants within 70 minutes. Especially for weakly acidic wastewater, at pH 6.5, cyanide ions in the solution can be completely degraded in 10 minutes; it also has strong magnetism, facilitating magnetic separation and recovery.

[0006] The method for preparing the Cu / Ti-Fe3O4@FeOOH magnetic heterogeneous Fenton catalyst of the present invention can be carried out by precipitation oxidation method, including the following steps:

[0007] (1) Add ferrous salt, copper salt and titanium salt to hydrochloric acid solution and stir evenly to obtain metal mixture;

[0008] (2) Pour the alkali source into a container, introduce nitrogen gas, and heat;

[0009] (3) Add the mixture obtained in step (1) to the alkali source in step (2), stir evenly, and obtain the precipitated reaction solution;

[0010] (4) Add the nitrate solution to the precipitation reaction solution in step (3) and stir until homogeneous to obtain the oxidation reaction solution;

[0011] (5) The oxidation reaction solution obtained in step (4) is heated and then cooled. The solid particles obtained are collected by magnetic separation. After centrifugation, washing, drying and grinding, copper-titanium doped iron-based magnetic heterogeneous Fenton catalyst Cu / Ti-Fe3O4@FeOOH is obtained.

[0012] In the above technical solution, the concentration of hydrochloric acid solvent in step (1) is 0.5-1.2 mol / L;

[0013] In the above technical solution, the ferrous salt is ferrous sulfate heptahydrate or ferrous chloride; the copper salt is copper sulfate or copper chloride; and the titanium salt is titanium tetrachloride.

[0014] In the above technical solution, the molar ratio of ions in ferrous salt, copper salt and titanium salt in step (1) is (52-55):4:(1-4);

[0015] In the above technical solution, the alkali source in step (2) is KOH or NaOH solution, and the concentration ratio of the alkali source, nitrate solution and metal mixture in step (1) is (6.7-8.7):2:1;

[0016] In the above technical solution, the nitrate in step (4) is NaNO3 or KNO3;

[0017] In the above technical solution, the stirring speed is kept constant, and the stirring is uniform.

[0018] In the above technical solution, the heating temperature in step (2) is 70-90℃;

[0019] In the above technical solution, the reaction temperature in step (5) is 70-90℃ and the reaction time is 3-5h.

[0020] In the above technical solution, the drying temperature in step (5) is 100-120℃ and the grinding fineness is 200 mesh or higher.

[0021] The application of the copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH in the catalytic degradation of cyanide-containing wastewater of the present invention is applicable to cyanide-containing wastewater under different acidity and alkalinity conditions.

[0022] The application of the copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH in the treatment of cyanide-containing wastewater includes the following steps:

[0023] (1) Place the cyanide-containing wastewater in a container, add copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH to the container, and stir thoroughly;

[0024] (2) After stirring, add H2O2 to the solution and continue stirring until the reaction is complete.

[0025] In the above technical solution, the stirring speed should be kept constant throughout the steps to ensure uniform mixing.

[0026] In the above technical solution, the stirring time in step (1) should be more than 10 minutes to ensure that the catalyst reaches the adsorption-desorption equilibrium.

[0027] In the above technical solution, the reaction temperature is room temperature.

[0028] In the above technical solution, the catalyst mass M Fe (Unit: mg), Volume of H2O2 V H2O2 (Unit: mL) and the volume V of cyanide-containing wastewater 水 (Unit: mL) The ratio is controlled at M Fe :V H2O2 :V 水 =(2~3):(2~4.5):10.

[0029] In the above technical solution, the copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH after filtration and separation can be washed and dried and then returned to step (1) for secondary use.

[0030] In the above technical solution, the acidity and alkalinity range of the cyanide-containing wastewater in step (1) is wide, with a pH range of 6.5 to 12.5.

[0031] According to the above scheme, the prepared copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH has excellent treatment effect on cyanide-containing wastewater, with a wide applicable pH range of 6.5 to 12.5. It is particularly effective in wastewater with pH of 6.5 and 12.5, where cyanide ions can be completely removed from the solution in just 10 min and 20 min, respectively, greatly shortening the reaction time. At the same time, the catalyst has good magnetic properties, making it easy to recover by magnetic separation. Moreover, compared with the direct oxidation method, the products of this reaction do not cause secondary pollution, making it environmentally friendly and simplifying the process.

[0032] This invention has the following advantages over existing wastewater decyanation technologies:

[0033] (1) The copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH prepared in this invention is a mixed magnetic nanomaterial of magnetite and goethite. It can be rapidly separated and recovered in an external magnetic field, realizing the reuse of the catalyst.

[0034] (2) The copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH of this invention exhibits excellent cyanide removal effects on cyanide-containing wastewater under pH ranges of 6.5–12.5. Regardless of the pH, all pollutants can be degraded within 70 minutes at room temperature. Furthermore, the effect is best in wastewater with pH values ​​of 6.5 and 12.5, requiring only 10 and 20 minutes respectively to completely remove cyanide ions from the solution, significantly shortening the reaction time. Compared to existing Fenton processes, this method is simpler, requiring no adjustment of wastewater pH or aeration, and can be directly applied to the treatment of cyanide-containing wastewater in various scenarios. Moreover, it requires less catalyst and has a faster reaction rate; a 600 mg / L catalyst achieves a degradation rate of up to 95.9% for actual wastewater, with the reaction completed within 20 minutes. Compared to alkaline chlorination, this significantly reduces input costs.

[0035] (3) This invention uses iron salts, copper salts, and titanium salts to prepare copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH using a wet precipitation method. The catalyst can be obtained in a one-step reaction, eliminating the need for cumbersome secondary processes and greatly simplifying the production process. Furthermore, by adjusting the amount added, the production volume of the catalyst can be easily controlled, improving the flexibility and controllability of production. Therefore, this preparation method is characterized by its simple process, controllable operation, and ease of mass production, providing feasibility and convenience for industrial application in actual production. Attached Figure Description

[0036] Figure 1 The image shows the XRD pattern of the copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH obtained in Example 1 of this invention.

[0037] Figure 2 The image shows the Cu2p XPS plot of the copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH obtained in Example 1 of this invention.

[0038] Figure 3 The image shows the Ti2p XPS plot of the copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH obtained in Example 1 of this invention.

[0039] Figure 4 This is a TEM image of the copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH obtained in Example 1 of the present invention.

[0040] Figure 5 The graphs show the degradation curves of artificial cyanide-containing wastewater under different pH conditions by the copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH obtained in Example 1 of this invention. Detailed Implementation

[0041] The present invention will be described in detail through the following embodiments, but is not limited to the following embodiments. All process technologies implemented based on the above content of the present invention are within the technical scope of the present invention.

[0042] Example 1

[0043] A method for preparing a copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH for cyanide decyanation treatment of cyanide-containing wastewater is as follows:

[0044] (1) Weigh 11.4683 g of FeSO4·7H2O, 0.7490 g of CuSO4·5H2O, and 0.1423 g of TiCl4 into a 200 mL beaker. Add 90 mL of 0.5 mol / L hydrochloric acid aqueous solution and stir until fully dissolved. Add deionized water to make the solution 100 mL. The concentration of Fe in the solution is c(Fe2+) 2+ ):c(Cu 2+ ):c(Ti 4+ The ratio of metal mixture to liquid is 55:4:1, and the concentration of the metal mixture is 0.45 mol / L.

[0045] (2) Measure 100 mL of 3.0 mol / L NaOH solution and pour it into a 1 L three-necked flask. Pour nitrogen gas through the flask for 10 minutes and heat the NaOH in the three-necked flask.

[0046] (3) When the temperature of the solution in the flask rises to 70°C, add the metal ion mixed solution from step (1) dropwise to the three-necked flask at a rate of 10 mL / min and stir at a rate of 300 rpm.

[0047] (4) Five minutes after the solution was added, 100 mL of 0.9 mol / L NaNO3 solution was added to the flask at a rate of 10 mL / min, and the reaction was maintained at 70 °C for 5 hours.

[0048] (5) After the solution cools to room temperature, centrifuge the solid precipitate and wash it three times with deionized water and anhydrous ethanol, respectively. Dry the washed solid sample thoroughly in a drying oven at a set temperature of 100℃. After drying, grind the solid sample to about 200 mesh to obtain the copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH.

[0049] The X-ray diffraction results of the solid sample obtained in this embodiment are shown in the figure. Figure 1The characteristic peaks in the figure are consistent with the standard spectra of Fe3O4 (PDF#99-0073) and FeOOH (PDF#99-0055), indicating that the solid sample is a mixture of magnetite and goethite. The Cu2p XPS spectrum of the solid sample obtained in this example is shown in [Figure number missing]. Figure 2 Cu 2p 3 / 2 The deconvolution of the peak at 932.8 eV yielded two distinct peaks centered at 932.6 eV and 734.1 eV, indicating the simultaneous presence of copper in both Cu(II) and Cu(I) valence states in the solid sample. The Ti 2p XPS spectrum of the solid sample obtained in this example is shown below. Figure 3 The spectrum shows two main peaks located at 458.2 eV (Ti 2p). 3 / 2 ) and 464.2 eV (Ti 2p 1 / 2 At point ), it was confirmed that Ti exists only in the form of Ti(Ⅳ) in the solid sample. TEM observations were performed on the solid sample obtained in this embodiment, and the results are shown in […]. Figure 4 The results indicate that the obtained solid sample has a regular crystal structure, containing both rod-shaped iron hooks and octahedral particles. This also proves that the solid sample contains FeOOH and Fe3O4 particles, and that the content of goethite is relatively high.

[0050] Example 2

[0051] A method for preparing a copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH for cyanide-containing wastewater is described below:

[0052] (1) Weigh 11.2598 g of FeSO4·7H2O, 0.7490 g of CuSO4·5H2O, and 0.2845 g of TiCl4 into a 200 mL beaker. Add 90 mL of 0.8 mol / L hydrochloric acid and stir until fully dissolved. Add deionized water to make the solution 100 mL. The concentration of Fe in the solution is c(Fe2+). 2+ ):c(Cu 2+ ):c(Ti 4+ The ratio of metal mixture to liquid is 54:4:2, and the concentration of the metal mixture is 0.45 mol / L.

[0053] (2) Measure 100 mL of 3.2 mol / L NaOH solution and pour it into a 1 L three-necked flask. Pour nitrogen gas through the flask for 10 minutes and heat the flask.

[0054] (3) When the temperature of the solution in the bottle rises to 70°C, add the metal ion mixed solution from step (1) dropwise to the three-necked flask at a rate of 10 mL / min, while stirring at a rate of 300 rpm.

[0055] (4) Five minutes after the solution was added, 100 mL of 0.9 mol / L NaNO3 solution was added to the three-necked flask at a rate of 10 mL / min. The reaction was maintained at 70 °C for 5 hours.

[0056] (5) After the solution cools to room temperature, centrifuge the solid precipitate and wash it three times with deionized water and anhydrous ethanol, respectively. Dry the washed solid sample thoroughly in a drying oven at a set temperature of 100℃. After drying, grind the solid sample to about 200 mesh to obtain the copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH.

[0057] Example 3

[0058] A method for preparing a copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH for cyanide-containing wastewater is described below:

[0059] (1) Weigh 11.0513 g of FeSO4·7H2O, 0.7490 g of CuSO4·5H2O, and 0.4268 g of TiCl4 into a 200 mL beaker. Add 90 mL of 1.2 mol / L hydrochloric acid and stir until fully dissolved. Add deionized water to make the solution 100 mL. The concentration of Fe in the solution is c(Fe2+). 2+ ):c(Cu 2+ ):c(Ti 4+ The ratio of metal mixture to liquid is 53:4:3, and the concentration of the metal mixture is 0.45 mol / L.

[0060] (2) Measure 100 mL of 3.9 mol / L NaOH solution and pour it into a 1 L three-necked flask. Pour nitrogen gas through the flask for 10 minutes and heat the flask.

[0061] (3) When the temperature of the solution in the bottle rises to 70°C, add the metal ion mixed solution from step (1) dropwise to the three-necked flask at a rate of 10 mL / min, while stirring at a rate of 300 rpm.

[0062] (4) Five minutes after the solution was added, 100 mL of 0.9 mol / L NaNO3 solution was added to the three-necked flask at a rate of 10 mL / min. The reaction was maintained at 70 °C for 5 hours.

[0063] (5) After the solution cools to room temperature, centrifuge the solid precipitate and wash it three times with deionized water and anhydrous ethanol, respectively. Dry the washed solid sample thoroughly in a drying oven at a set temperature of 100℃. After drying, grind the solid sample to about 200 mesh to obtain the copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH.

[0064] Example 4

[0065] A method for preparing a copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH for cyanide-containing wastewater is described below:

[0066] (1) Weigh 10.8428 g of FeSO4·7H2O, 0.7490 g of CuSO4·5H2O, and 0.5690 g of TiCl4 into a 200 mL beaker. Add 90 mL of 0.5 mol / L hydrochloric acid and stir until fully dissolved. Add deionized water to make the solution 100 mL. The concentration of Fe in the solution is c(Fe2+). 2+ ):c(Cu 2+ ):c(Ti 4+ The ratio of metal mixture to liquid is 52:4:4, and the concentration of the metal mixture is 0.45 mol / L.

[0067] (2) Measure 100 mL of 3.2 mol / L NaOH solution and pour it into a 1 L three-necked flask. Pour nitrogen gas through the flask for 10 minutes and heat the flask.

[0068] (3) When the temperature of the solution in the bottle rises to 70℃, add the metal ion mixed solution dropwise to the three-necked flask at a rate of 10mL / min and stir at a rate of 300rpm.

[0069] (4) Five minutes after the solution was added, 100 mL of 0.9 mol / L NaNO3 solution was added to the three-necked flask at a rate of 10 mL / min. The reaction was maintained at 70 °C for 5 hours.

[0070] (5) After the solution cools to room temperature, centrifuge the solid precipitate and wash it three times with deionized water and anhydrous ethanol, respectively. Dry the washed solid sample thoroughly in a drying oven at a set temperature of 100℃. After drying, grind the solid sample to about 200 mesh to obtain the copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH.

[0071] Example 5

[0072] A method for preparing a copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH for cyanide-containing wastewater is described below:

[0073] (1) Weigh 10.8428 g of FeSO4·7H2O, 0.7490 g of CuSO4·5H2O, and 0.5690 g of TiCl4 into a 200 mL beaker. Add 90 mL of 0.5 mol / L hydrochloric acid and stir until fully dissolved. Add deionized water to make the solution 100 mL. The concentration of Fe in the solution is c(Fe2+).2+ ):c(Cu 2+ ):c(Ti 4+ The ratio of metal mixture to liquid is 52:4:4, and the concentration of the metal mixture is 0.45 mol / L.

[0074] (2) Measure 100 mL of 3.2 mol / L NaOH solution and pour it into a 1 L three-necked flask. Pour nitrogen gas through the flask for 10 minutes and heat the flask.

[0075] (3) When the temperature of the solution in the bottle rises to 70℃, add the metal ion mixed solution dropwise to the three-necked flask at a rate of 10mL / min and stir at a rate of 300rpm.

[0076] (4) Five minutes after the solution was added, 100 mL of 0.9 mol / L NaNO3 solution was added to the three-necked flask at a rate of 10 mL / min. The reaction was maintained at 80 °C for 4 hours.

[0077] (5) After the solution cools to room temperature, centrifuge the solid precipitate and wash it three times with deionized water and anhydrous ethanol, respectively. Dry the washed solid sample thoroughly in a drying oven at a set temperature of 110℃. After drying, grind the solid sample to about 200 mesh to obtain the copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH.

[0078] Example 6

[0079] A method for preparing a copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH for cyanide-containing wastewater is described below:

[0080] (1) Weigh 10.8428 g of FeSO4·7H2O, 0.7490 g of CuSO4·5H2O, and 0.5690 g of TiCl4 into a 200 mL beaker. Add 90 mL of 0.5 mol / L hydrochloric acid and stir until fully dissolved. Add deionized water to make the solution 100 mL. The concentration of Fe in the solution is c(Fe2+). 2+ ):c(Cu 2+ ):c(Ti 4+ The ratio of metal mixture to liquid is 52:4:4, and the concentration of the metal mixture is 0.45 mol / L.

[0081] (2) Measure 100 mL of 3.2 mol / L NaOH solution and pour it into a 1 L three-necked flask. Pour nitrogen gas through the flask for 10 minutes and heat the flask.

[0082] (3) When the temperature of the solution in the bottle rises to 70℃, add the metal ion mixed solution dropwise to the three-necked flask at a rate of 10mL / min and stir at a rate of 300rpm.

[0083] (4) Five minutes after the solution was added, 100 mL of 0.9 mol / L NaNO3 solution was added to the three-necked flask at a rate of 10 mL / min. The reaction was maintained at 90 °C for 3 hours.

[0084] (5) After the solution cools to room temperature, centrifuge the solid precipitate and wash it three times with deionized water and anhydrous ethanol, respectively. Dry the washed solid sample thoroughly in a drying oven at a set temperature of 120℃. After drying, grind the solid sample to about 200 mesh to obtain the copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH.

[0085] Application Example 1

[0086] The copper-titanium doped iron-based magnetic heterogeneous Fenton catalyst Cu / Ti-Fe3O4@FeOOH prepared in Example (1) was used to degrade industrial cyanide-containing wastewater, including the following steps:

[0087] (1) Mix 0.06g of catalyst with 200mL of industrial cyanide-containing wastewater with a total cyanide concentration of 50mg / L and stir at 250rpm for pre-adsorption treatment.

[0088] (2) After pre-adsorption for 20 min, add 0.09 mL of 30% H2O2 and carry out Fenton decyanation reaction for 30 min at 30℃ and with the natural pH of wastewater being 8.1, while keeping the mixture stirred.

[0089] After the decyanation reaction was completed, the catalyst obtained in Example (1) showed a degradation rate of 95.94% for total cyanide and 97.49% for free cyanide in the solution. Furthermore, measurements of the dissolved metal ion content in the solution after the reaction revealed that the concentration of dissolved iron was 0.13 mg / L and the concentration of copper was 0.39 mg / L. No titanium precipitation was detected, and no other pollutants were generated, so no secondary pollution was produced.

[0090] Application Example 2

[0091] The copper-titanium doped iron-based magnetic heterogeneous Fenton catalyst Cu / Ti-Fe3O4@FeOOH prepared in Example (4) was used to degrade industrial cyanide-containing wastewater, including the following steps:

[0092] (1) Mix 0.05g of catalyst with 200mL of industrial cyanide-containing wastewater with a total cyanide concentration of 50mg / L and stir at 250rpm for pre-adsorption treatment.

[0093] (2) After pre-adsorption for 20 min, add 0.075 mL of 30% H2O2 and carry out Fenton decyanation reaction for 30 min at 30℃ and with the natural pH of wastewater being 8.1, while keeping the mixture stirred throughout the process.

[0094] After the decyanation reaction was completed, the catalyst obtained in Example (4) showed a degradation rate of 96.53% for total cyanide and 97.29% for free cyanide in the solution. Furthermore, measurements of the dissolved metal ion content in the solution after the reaction revealed that the concentration of dissolved iron was 0.12 mg / L and the concentration of copper was 0.35 mg / L. No titanium precipitation was detected, and no other pollutants were generated, so no secondary pollution was produced.

[0095] Application Example 3

[0096] The copper-titanium doped iron-based magnetic heterogeneous Fenton catalyst Cu / Ti-Fe3O4@FeOOH prepared in Example (1) was used to degrade artificial cyanide-containing wastewater with different pH values. The steps are as follows:

[0097] (1) Mix 0.02g of catalyst with 100mL of CN - Artificial cyanide-containing wastewater with a concentration of 10 mg / L and a pH of 6.5 was mixed and pre-adsorption was carried out by stirring at a speed of 250 rpm.

[0098] (2) After pre-adsorption for 20 min, add 0.02 mL of H2O2 with a concentration of 30% and carry out Fenton decyanation reaction at 22 °C, while keeping the mixture stirred.

[0099] Every 10 minutes, 0.5 mL of solution was drawn using a syringe filter, diluted, and its absorbance was measured using a spectrophotometer to determine the concentration of CN in the solution. - Concentration, then calculate CN - The degradation rate.

[0100] Application Example 4

[0101] The copper-titanium doped iron-based magnetic heterogeneous Fenton catalyst Cu / Ti-Fe3O4@FeOOH prepared in Example (1) was used to degrade artificial cyanide-containing wastewater with different pH values. The steps are as follows:

[0102] (1) Mix 0.02g of catalyst with 100mL of CN - Artificial cyanide-containing wastewater with a concentration of 10 mg / L and a pH of 7.5 was mixed and pre-adsorption was carried out by stirring at a speed of 250 rpm.

[0103] (2) After pre-adsorption for 20 min, add 0.02 mL of H2O2 with a concentration of 30% and carry out Fenton decyanation reaction at 22 °C, while keeping the mixture stirred.

[0104] Every 10 minutes, 0.5 mL of solution was drawn using a syringe filter, diluted, and its absorbance was measured using a spectrophotometer to determine the concentration of CN in the solution. - Concentration, then calculate CN - The degradation rate.

[0105] Application Example 5

[0106] The copper-titanium doped iron-based magnetic heterogeneous Fenton catalyst Cu / Ti-Fe3O4@FeOOH prepared in Example (1) was used to degrade artificial cyanide-containing wastewater with different pH values. The steps are as follows:

[0107] (1) Mix 0.02g of catalyst with 100mL of CN - Artificial cyanide-containing wastewater with a concentration of 10 mg / L and a pH of 8.5 was mixed and pre-adsorption was carried out by stirring at a speed of 250 rpm.

[0108] (2) After pre-adsorption for 20 min, add 0.02 mL of H2O2 with a concentration of 30% and carry out Fenton decyanation reaction at 22 °C, while keeping the mixture stirred.

[0109] Every 10 minutes, 0.5 mL of solution was drawn using a syringe filter, diluted, and its absorbance was measured using a spectrophotometer to determine the concentration of CN in the solution. - Concentration, then calculate CN - The degradation rate.

[0110] Application Example 6

[0111] The copper-titanium doped iron-based magnetic heterogeneous Fenton catalyst Cu / Ti-Fe3O4@FeOOH prepared in Example (1) was used to degrade artificial cyanide-containing wastewater with different pH values. The steps are as follows:

[0112] (1) Mix 0.02g of catalyst with 100mL of CN - Artificial cyanide-containing wastewater with a concentration of 10 mg / L and a pH of 9.5 was mixed and pre-adsorption was carried out by stirring at a speed of 250 rpm.

[0113] (2) After pre-adsorption for 20 min, add 0.02 mL of H2O2 with a concentration of 30% and carry out Fenton decyanation reaction at 22 °C, while keeping the mixture stirred.

[0114] Every 10 minutes, 0.5 mL of solution was drawn using a syringe filter, diluted, and its absorbance was measured using a spectrophotometer to determine the concentration of CN in the solution. - Concentration, then calculate CN - The degradation rate.

[0115] Application Example 7

[0116] The copper-titanium doped iron-based magnetic heterogeneous Fenton catalyst Cu / Ti-Fe3O4@FeOOH prepared in Example (1) was used to degrade artificial cyanide-containing wastewater with different pH values. The steps are as follows:

[0117] (1) Mix 0.02g of catalyst with 100mL of CN - Artificial cyanide-containing wastewater with a concentration of 10 mg / L and a pH of 10.5 was mixed and pre-adsorption was carried out by stirring at a speed of 250 rpm.

[0118] (2) After pre-adsorption for 20 min, add 0.02 mL of H2O2 with a concentration of 30% and carry out Fenton decyanation reaction at 22 °C, while keeping the mixture stirred.

[0119] Every 10 minutes, 0.5 mL of solution was drawn using a syringe filter, diluted, and its absorbance was measured using a spectrophotometer to determine the concentration of CN in the solution. - Concentration, then calculate CN - The degradation rate.

[0120] Application Example 8

[0121] The copper-titanium doped iron-based magnetic heterogeneous Fenton catalyst Cu / Ti-Fe3O4@FeOOH prepared in Example (1) was used to degrade artificial cyanide-containing wastewater with different pH values. The steps are as follows:

[0122] (1) Mix 0.02g of catalyst with 100mL of CN - Artificial cyanide-containing wastewater with a concentration of 10 mg / L and a pH of 11.5 was mixed and pre-adsorption was carried out by stirring at a speed of 250 rpm.

[0123] (2) After pre-adsorption for 20 min, add 0.02 mL of H2O2 with a concentration of 30% and carry out Fenton decyanation reaction at 22 °C, while keeping the mixture stirred.

[0124] Every 10 minutes, 0.5 mL of solution was drawn using a syringe filter, diluted, and its absorbance was measured using a spectrophotometer to determine the concentration of CN in the solution. - Concentration, then calculate CN - The degradation rate.

[0125] Application Example 9

[0126] The copper-titanium doped iron-based magnetic heterogeneous Fenton catalyst Cu / Ti-Fe3O4@FeOOH prepared in Example (1) was used to degrade artificial cyanide-containing wastewater with different pH values. The steps are as follows:

[0127] (1) Mix 0.02g of catalyst with 100mL of CN - Artificial cyanide-containing wastewater with a concentration of 10 mg / L and a pH of 12.5 was mixed and pre-adsorption was carried out by stirring at a speed of 250 rpm.

[0128] (2) After pre-adsorption for 20 min, add 0.02 mL of H2O2 with a concentration of 30% and carry out Fenton decyanation reaction at 22 °C, while keeping the mixture stirred.

[0129] Every 10 minutes, 0.5 mL of solution was drawn using a syringe filter, diluted, and its absorbance was measured using a spectrophotometer to determine the concentration of CN in the solution. - Concentration, then calculate CN - The degradation rate.

[0130] The degradation efficiency curves of artificial cyanide-containing wastewater under different pH conditions are shown below. Figure 5 As shown, the catalyst exhibits the lowest reactivity at pH 10.5, with a cyanide degradation rate of 99.8% after 70 minutes. The catalytic activity increases with both decreasing and increasing wastewater pH. At pH 12.5, the cyanide degradation rate reaches 99.5% after 20 minutes; at pH 6.5, cyanide is almost completely removed after 10 minutes. This demonstrates that the copper-titanium doped iron-based magnetic heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH prepared in this example can be used for wastewater decyanation over a wide pH range, exhibiting excellent cyanide removal performance.

[0131] Adjusting the parameters according to the present invention allows for the preparation of the copper-titanium doped iron-based magnetic heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH, exhibiting performance essentially consistent with the present invention, namely, excellent decyanation performance for cyanide-containing wastewater. The present invention has been described above as exemplary. It should be noted that any simple modifications, alterations, or equivalent substitutions that can be made by those skilled in the art without creative effort, without departing from the core content of the present invention, fall within the protection scope of the present invention.

Claims

1. A method for preparing a Cu / Ti-Fe3O4@FeOOH magnetic heterogeneous Fenton catalyst, characterized in that, Includes the following steps: (1) Add ferrous salt, copper salt and titanium salt to hydrochloric acid solution and stir evenly to obtain metal mixture; (2) Pour the alkali source into a container, introduce nitrogen gas, and heat; (3) Add the mixture obtained in step (1) to the alkali source in step (2), stir evenly, and obtain the precipitated reaction solution; (4) Add the nitrate solution to the precipitation reaction solution in step (3) and stir until homogeneous to obtain the oxidation reaction solution; (5) The oxidation reaction solution obtained in step (4) is heated and then cooled. The solid particles obtained are collected by magnetic separation. After centrifugation, washing, drying and grinding, copper-titanium doped iron-based magnetic heterogeneous Fenton catalyst Cu / Ti-Fe3O4@FeOOH is obtained. In step (1), the concentration of hydrochloric acid solvent is 0.5~1.2 mol / L; the ferrous salt is ferrous sulfate heptahydrate or ferrous chloride; the copper salt is copper sulfate or copper chloride; and the titanium salt is titanium tetrachloride; the molar ratio of ions in the ferrous salt, copper salt and titanium salt is (52~55): 4: (1~4); in step (2), the alkali source is KOH or NaOH solution; the concentration ratio of the alkali source, nitrate solution and metal mixture in step (1) is (6.7~8.7): 2: 1; in step (4), the nitrate is NaNO3 or KNO3, and the concentration ratio of the amount of alkali source and nitrate added is (10~13):

3.

2. The preparation method as described in claim 1; characterized in that, The heating temperature in step (2) is 70~90 ℃; the reaction temperature in step (5) is 70~90 ℃, and the reaction time is 3~5 h.

3. The preparation method as described in claim 1; characterized in that, In step (5), the drying temperature is 100~120 ℃ and the grinding fineness is 200 mesh or more.

4. The application of the copper-titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH prepared by the method of claim 1 in the catalytic degradation of cyanide-containing wastewater.

5. The application as described in claim 4, characterized in that, Includes the following steps: (1) cyanide-containing wastewater is placed in a container, copper titanium doped iron-based heterogeneous Fenton magnetic catalyst Cu / Ti-Fe3O4@FeOOH is added to the container, and stirred thoroughly; the mass M of the catalyst Fe , the volume V of H2O2 H2O2 , and the volume V of cyanide-containing wastewater 水 are in the ratio of M Fe :V H2O2 :V 水 =(2~3) mg: (2~4.5) mL: 10 mL; (2) After stirring, add H2O2 to the solution and continue stirring until the reaction is complete.

6. The application as described in claim 5, characterized in that, In step (1), the stirring time is more than 10 minutes, and the catalyst reaches the adsorption-desorption equilibrium.

Images