Preparation method of green and efficient heterogeneous fenton catalyst

Abstract

The application discloses a kind of green efficient heterogeneous Fenton catalyst preparation method, specifically related to environmental functional materials and wastewater treatment technical field, including step one, red mud pretreatment, step two, waste glass pretreatment, step three, wet blank processing, step four, drying forming, step five, catalyst raw material preparation, step six, catalyst raw material roasting.The catalyst matrix is formed by using two kinds of solid waste, red mud and waste glass, as main raw material, after being adhered in sodium silicate solution, sintered, its structural strength is higher, more holes, resistant to acid and alkali corrosion, at the same time, surface modification is carried out using transition metal ion solution, so that it can efficiently catalyze heterogeneous Fenton reaction, so that organic pollutants in water can be quickly removed, and by changing the parameter conditions of modified solution, the catalytic efficiency and metal dissolution rate can be controlled, the sintering temperature can be controlled to make the catalyst pore uniform, and the metal dissolution rate can be effectively controlled by changing the calcination temperature.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of environmental functional materials and sewage treatment technology, more particularly, the present application relates to a preparation method of a green and efficient heterogeneous Fenton catalyst. BACKGROUND

[0002] Red mud is a kind of bulk industrial solid waste, which is produced in the process of extracting alumina. China is a big country in alumina production. Under the current production technology level and bauxite grade, 1-1.8 tons of red mud are discharged for every ton of alumina produced. At present, there is still no good method for the treatment and disposal of a large amount of red mud. Generally, it is piled up in a large area, which has potential environmental threat to the surrounding environment. According to different methods of extracting alumina, red mud is generally divided into Bayer red mud, sintered red mud and combined red mud. The main components of red mud are SiO2, Al2O3, Fe2O3, etc., and the alkalinity is large.

[0003] Waste glass is also a kind of solid waste, whose main components are silicon dioxide and sodium silicate, etc. Its chemical properties are very stable, and it has little direct harm to human beings, but it also has many potential problems. The waste glass entering the incinerator may adhere to the furnace wall and not provide heat value. If it is landfilled, it will occupy a large amount of landfill area. At present, the average recycling rate of waste glass in the world is close to 50%, while the average recycling rate of waste glass in China is only about 13%, which is far lower than the world average level.

[0004] The utilization rate of red mud in China is less than 3%, which still has great development potential. Red mud contains a large amount of metal compounds. If its characteristics can be utilized to prepare materials or extract metal compounds, it can turn waste into treasure and even produce objective economic effect. However, red mud also has some characteristics that are difficult to utilize. For example, red mud often has strong alkaline property and is difficult to apply in ecological restoration. In most application scenarios, it needs to be acidified before utilization, which increases the processing cost. In addition, red mud contains a large amount of metal salts, some of which are not stable and will be directly released when dissolved in water, which can easily lead to secondary pollution. Moreover, the metal components in red mud are very miscellaneous, which increases the purification cost or leads to inconsistent quality of finished products. In general, there are still many problems in the utilization of red mud at present.

[0005] In addition to solid waste, China also faces the problem of biorefractory organic wastewater, such as circuit board ink wastewater, aged landfill leachate and other industrial organic wastewater, etc. Therefore, biorefractory wastewater often needs to be treated by physical or chemical non-biological methods. Among them, advanced oxidation methods can efficiently and completely remove organic pollutants, such as electrocatalytic oxidation method, ozone catalytic oxidation method and photocatalysis, etc. However, these methods often have high operating costs and high operating conditions, and the management is complex. At present, the widely used advanced oxidation method in wastewater treatment is the traditional Fenton method. The operation and management technology of the traditional Fenton method is relatively mature, but there are still some problems that are difficult to avoid, such as the small pH condition range used in homogeneous Fenton, which often needs to adjust the pH of the water quality to about 3 to make the Fenton reaction proceed normally, and the pH needs to be adjusted repeatedly. In addition, the ferrous ions added are difficult to recover, and a large amount of iron sludge will be produced, and the iron ion content of the effluent is high. Finally, the homogeneous Fenton mainly removes pollutants by metal ion catalytic oxidation in the liquid phase, which is easily affected by other substances. For this reason, many heterogeneous Fenton studies have been carried out. Heterogeneous Fenton mainly relies on the input of solid into wastewater, and the catalytic oxidation reaction of hydrogen peroxide in the liquid phase on the solid phase catalyst produces a large amount of hydroxyl radicals to remove organic or reducing organic matter. Heterogeneous Fenton still has some problems that have not been widely used on a large scale, such as high raw material cost, complex preparation and processing, low reusability, substandard metal dissolution rate, and small structural strength, etc.

[0006] At present, Chinese patent CN 201610101449.6 discloses "a porous ceramic Fenton catalyst and its preparation method". The method mixes municipal sludge, clay, kaolin and fly ash and other materials uniformly and extrudes them into a shape, and finally sintering forms a Fenton catalyst. This method directly sintering the main catalytic active metal with silicon material will cause a large number of catalytic active sites to be inactivated, reducing the catalytic efficiency. The COD removal rate of the catalyst prepared by complex components in the experiment of removing COD by catalytic hydrogen peroxide is only 40.67% at most. In addition, Chinese patent CN 202310005891 discloses "a red mud-based PBAs derived metal oxide Fenton catalyst, its preparation method and application". The method stirs the red mud after pickling with mixed transition metals and potassium ferrocyanide, and finally calcines to prepare the material. The degradation rate of the prepared material for treating 50 ppm of active black 5 is only 94.96% at most. The process condition is complex and the removal effect is limited.

[0007] In order to overcome the shortcomings of the prior art, greatly reduce the production and processing cost of the material, and improve the catalytic oxidation ability of the catalyst, the present application provides a preparation method of a green and efficient heterogeneous Fenton catalyst. SUMMARY

[0008] In order to overcome the above-mentioned defects of the prior art, the present application provides a preparation method of a green and efficient heterogeneous Fenton catalyst to solve the problems raised in the above background art.

[0009] To achieve the above object, the present application provides the following technical scheme: a preparation method of a green and efficient heterogeneous Fenton catalyst, specifically comprising the following steps:

[0010] Step one, take the red mud produced in the process of extracting alumina, dry it, crush it, put it into a ball mill for ball milling, sieve it, and take the undersize for use;

[0011] Step two, select the waste glass produced by crushing glassware in the laboratory, dry it, crush it, put it into a ball mill for ball milling, sieve it, and take the undersize for use;

[0012] Step three, mix the red mud powder pretreated in step one and the waste glass powder pretreated in step two uniformly at a weight ratio of 6-8:2-4 as mixed raw materials, mix and bond the mixed raw materials with a sodium silicate solution with a mass concentration of 25%-45% at a ratio of 100g mixed raw materials:10mL sodium silicate solution to process 5-30mm wet blanks;

[0013] Step four, dry the wet blanks processed in step three, put the dried blanks into a muffle furnace for sintering and fixing at 880-960℃, and obtain the red mud-based carrier after cooling;

[0014] Step five, take the red mud-based carrier in step four, put it into a modified solution at a mass ratio of 1:1, stir for 15min, immerse for 2-10h, take out the solid, drain, and put it into an oven for drying at 105℃ for 1h to obtain catalyst raw material;

[0015] Step six, take the catalyst raw material in step five, put it into a muffle furnace for calcination at 220-280℃ for 2h, naturally cool it after calcination, seal it for later use, and finally obtain a green and efficient heterogeneous Fenton catalyst.

[0016] Preferably, the drying, crushing, ball milling and sieving in steps one and two are respectively performed using an electric thermostatic air drying oven at 105℃ for 2h, an iron hammer for manual crushing, a ball mill for ball milling for 2h, and a non-metallic sieve with a mesh size of 100-200 for sieving.

[0017] Preferably, the red mud in step one is Bayer red mud produced by Bayer process for extracting alumina, and the main components are 30%-40% Fe2O3, 15%-25% Al2O3, 10%-15% CaO, 5%-10% SiO2 and 5%-10% TiO2.

[0018] Preferably, the waste glass in the step two is mainly composed of 60-80% of SiO2, 10-15% of Na2O, 10-15% of CaO and 1.5-3% of Al2O3.

[0019] Preferably, the mixing and bonding process in the step three is to preliminarily bond part of the mixed raw materials with part of the sodium silicate solution, and then to bond all the mixed raw materials with the sodium silicate solution according to the uniformity of the green mixture.

[0020] Preferably, the wet green mixture in the step three is in the shape of a sphere or a cylinder, which is determined according to the actual situation.

[0021] Preferably, the sintering operation in the step four is to use a muffle furnace to sinter and form under a preset temperature rising program, the dry green mixture is placed in the central position of the muffle furnace and is suspended to be heated uniformly.

[0022] Preferably, the modifying solution in the step five is mainly prepared by using single or multiple transition metal ion solutions, specifically, the solutions of ferrous ions, iron ions and copper ions, the total metal ion concentration is 0.2-1 mol / L, and the molar concentration ratio of the metals is 0-3:0-3:0-4, further, for the catalyst raw material that is less dense than the solution and floats upward, a method is needed to ensure that it is immersed under the liquid surface.

[0023] Preferably, the heating and cooling speed of the calcination process in the step six is controlled to be below 5℃ / min.

[0024] Preferably, the heating speed of the sintering operation in the step four is in the range of 1-10℃ / min, the sintering temperature is 880-960℃, and the sintering time is 240-400 min.

[0025] Technical effects and advantages of the present application:

[0026] 1. The catalyst prepared by the present application mainly uses red mud and waste glass as raw materials, which are solid wastes, so that waste is treated by waste;

[0027] 2. The catalyst prepared by the present application mainly uses red mud, waste glass, sodium silicate and iron-copper ion compounds as raw materials, which are simple and easy to obtain, low in cost, easy to operate in preparation method and condition, and further reduce the production cost;

[0028] 3. The catalyst prepared by the present application uses red mud and waste glass, and the matrix formed after mixing and sintering is "ceramic-like", which is high in structural strength and stable in chemical properties;

[0029] 4. The catalyst prepared by this invention uses a high proportion of red mud and has strong durability, which has engineering application value and can alleviate the current shortage of red mud, a type of bulk solid waste.

[0030] 5. The catalyst prepared by this invention has high safety. After the material is melted and stabilized during the preparation process, the chemical properties of both the heavy metals carried by the red mud material and the metal ions brought by the metal surface modification are very stable. Through repeated experiments, it has been verified that the catalyst prepared by this invention has the advantages of acid and alkali corrosion resistance, stable active sites that do not adsorb organic matter, high compressive strength, and extremely low metal precipitation rate.

[0031] 6. The catalyst prepared by this invention has a high removal capacity for organic pollutants. By stably loading iron, copper or other transition metals onto the surface of the catalyst matrix, and then placing the metal-modified catalyst into wastewater and adding an appropriate amount of hydrogen peroxide, a catalytic oxidation reaction can be carried out on the catalyst surface, which can efficiently remove organic pollutants.

[0032] 7. The catalyst prepared by this invention has a wide range of applicable conditions. In the field of wastewater treatment, the modified catalyst is suitable for wastewater with pH = 3-10 and does not require repeated acid-base adjustment.

[0033] 8. The catalyst prepared by this invention requires no activation or cleaning before or after use. When applied to wastewater treatment, it generally does not require adjustment of the wastewater quality, making it suitable for a wide range of applications and simple to use.

[0034] In summary, this invention uses red mud and waste glass as the main raw materials. After being bonded together in a sodium silicate solution, the resulting catalyst matrix is ​​sintered and exhibits high structural strength, numerous pores, and resistance to acid and alkali corrosion. After modification, it utilizes the heterogeneous Fenton principle to effectively remove organic pollutants. Furthermore, by altering the composition of the red mud and waste glass, the structural strength, pore size, and quantity of the catalyst can be controlled. By controlling the modification solution, the catalytic efficiency and metal dissolution rate can be modified. The sintering temperature can be controlled to ensure uniform pore formation, and the calcination temperature can be adjusted to effectively control the metal dissolution rate. This invention demonstrates good removal effects on organic pollutants from PCB circuit board wastewater, dyeing and printing wastewater, and landfill leachate, embodying the concept of "treating waste with waste." Attached Figure Description

[0035] Figure 1 The cross-section of the red mud-based lightweight foamed ceramsite prepared according to the present invention. Figure 1 .

[0036] Figure 2 The cross-section of the red mud-based lightweight foamed ceramsite prepared according to the present invention. Figure 2 .

[0037] Figure 3State diagram when magnified 1000 times without modification.

[0038] Figure 4 State diagram when magnified 5000 times without modification.

[0039] Figure 5 State diagram when magnified 10000 times without modification.

[0040] Figure 6 State diagram when magnified 2000 times after modification.

[0041] Figure 7 State diagram when magnified 5000 times after modification.

[0042] Figure 8 State diagram when magnified 10000 times after modification.

[0043] Figure 9 Eds range data electronic image when not modified.

[0044] Figure 10 Eds range data image when not modified.

[0045] Figure 11 Eds range data electronic image after modification.

[0046] Figure 12 Eds range data image after modification. DETAILED DESCRIPTION

[0047] Example 1,

[0048] The embodiment provides a preparation method of a green and efficient heterogeneous Fenton catalyst, and specifically comprises the following steps:

[0049] Step one, 100g of dried red mud is put into a ball mill for grinding, and is passed through a 100-mesh sieve, and the undersize is taken for use;

[0050] Step two, 50g of waste glass is put into a ball mill for grinding, and is passed through a 100-mesh sieve, and the undersize is taken for use;

[0051] Step three, a 40% sodium silicate solution is prepared, air bubbles are removed, and the solution is stirred uniformly and taken for use;

[0052] Step four, 65g of red mud powder and 35g of waste glass powder are uniformly mixed, 10mL of the sodium silicate solution is slowly added, and the mixture is uniformly mixed and granulated to form a wet blank, the particle size is between 5-10mm, the wet blank is naturally air-dried, and then is put into a 105 DEG C oven for drying for 2h to obtain a dry blank, and the dry blank is taken out for use.

[0053] Step five, take the dry embryo material into the muffle furnace, set the sintering temperature to 900℃, control the heating rate to 5℃, and sinter for 240min. After sintering, wait for cooling to room temperature to obtain a brick red porous spherical solid catalyst matrix.

[0054] Example 2,

[0055] Take the catalyst matrix prepared in Example 1, measure the open porosity and bulk density of the catalyst matrix according to GB / T3810.3—2016, measure the true density according to GB / T24203-2009, and calculate the apparent porosity and total porosity. The measurement data is shown in Table 1 below:

[0056] The apparent result of the catalyst matrix is that it has strong water absorption, and the filler can also absorb ions, which provides conditions for subsequent modification.

[0057] Table 1

[0058]

[0059] It can be seen that the apparent porosity and total porosity of the filler matrix perform well, and the abundant pores can provide more modification sites for subsequent modification operation. At the same time, the matrix also has a large number of closed pores, and the true density of 3.173(g / cm3) provides the stability of the closed pores and the whole matrix material;

[0060] Finally, the bulk density of the matrix material is controlled at 1.020(g / cm3), so that the matrix material has the characteristics of light weight, can be suspended in water, facilitates the loading and removal of the filler, and has stronger mass transfer capacity in the reactor.

[0061] Example 3,

[0062] Take 20g of the catalyst matrix prepared in Example 1, add it to a solution containing iron ions with a concentration of 0.4mol / L and copper ions with a concentration of 0.6mol / L, stir for 15min, and immerse for 6 hours. After immersion, naturally drain, put into a muffle furnace, adjust the calcination temperature to 220℃, calcine for 2 hours, and control the heating rate to 2℃. After calcination, cool and seal for standby, which is a green and efficient heterogeneous Fenton catalyst. The cross-sectional view of the catalyst is shown in FIG. 1 and FIG. 2. Figure 1 and FIG. 2. Figure 2

[0063] Example 4,

[0064] Take 20g of the catalyst prepared in Example 3, detect the heavy metal leaching concentration of the catalyst according to the method of GB / T30810—2014, detect the heavy metal concentration of the leaching solution by ICP / ICP-MS, qualitatively determine the mass spectrum or characteristic ion of the element, and quantitatively determine by internal standard method. The experimental results are shown in Table 2 below:​

[0065] Table 2

[0066]

[0067] According to the data results shown in Table 2, it can be seen that the leaching concentrations of the six metals can meet the comprehensive discharge standard of wastewater, indicating that the surface active factors of the catalyst can be stably attached to the surface.

[0068] Example 5,

[0069] 10 g of the unmodified catalyst substrate prepared in Example 1 and 10 g of the catalyst prepared in Example 3 were respectively taken to measure their properties by SEM and EDS, and the results are shown in the accompanying Figure 3 Figures Figure 12 As shown in the accompanying figures, they are respectively the SEM graph of the unmodified substrate at 1000 times, the SEM graph of the unmodified substrate at 5000 times, the SEM graph of the unmodified substrate at 10000 times, the SEM graph of the modified catalyst at 1000 times, the SEM graph of the modified catalyst at 5000 times, the SEM graph of the modified catalyst at 10000 times, the EDS data graph of the unmodified substrate and the EDS data graph of the modified catalyst.

[0070] According to the data results, it can be seen that the catalyst substrate prepared by firing has obvious rough holes under the electron microscope at 1000 times, and the material substrate surface has vitrification phenomenon, and the particles are wrapped, and the surface particle is less under the electron microscope at 5000 times and 10000 times. After modification, the surface of the prepared catalyst is obviously rough, and under the high-power electron microscope, many metal oxide crystals can be seen. According to the subsequent EDS characterization, it can be known that the main elements before modification are oxygen, silicon and carbon, and the metal elements are less. After modification, the total number of iron elements is increased to the second, which can greatly improve the catalytic effect of the catalyst.

[0071] Example 6,

[0072] (1) 10 g of the catalyst prepared in Example 3 was added to 1000 mL of pharmaceutical wastewater, and the wastewater quality was COD (all CODCr in the specification) = 744 mg / L, pH = 8.09, and colority was 100 times;

[0073] (2) 6 mL of hydrogen peroxide with a mass concentration of 30% was added at the initial stage, 2 mL was added at the first hour of reaction, and 1 mL was added at the second hour of reaction, and the total reaction time was 4 hours. The stirring speed was maintained at 60 r / min during the reaction;

[0074] (3) After 1 hour, 2 hours, 3 hours and 4 hours of reaction, samples were taken, manganese dioxide was added after sampling, and the reaction was terminated after stirring for 10 min. After passing through a 0.45 um membrane, the COD concentration was measured.

[0075] (4) Repeated experiments were performed, and sampling was only taken at the time when the reaction was terminated at 4 hours, and the water samples from the 1st, 3rd, 5th, 7th, 10th, 15th and 20th experiments were selected for COD concentration determination. In all reaction batches, the effluent color was completely removed in less than 1 hour, and the experimental results described above are shown in Tables 3 and 4 below:

[0076] Table 3

[0077]

[0078] Table 4

[0079]

[0080]

[0081] According to the experimental data in Tables 3 and 4, the prepared catalyst not only has a metal leaching concentration that meets the comprehensive wastewater discharge standard, but also has excellent catalytic oxidation capacity. In repeated experiments, the addition of the catalyst and a small amount of hydrogen peroxide can remove about 90% of the COD in the pharmaceutical wastewater, and the color is quickly removed.

[0082] Example 7,

[0083] (1) 10 g of the catalyst prepared in Example 3 was added to 1000 mL of the nanofiltration concentrated solution of landfill leachate, and the wastewater quality was COD = 7260 mg / L and pH = 7.84;

[0084] (2) 10 mL of hydrogen peroxide with a mass concentration of 30% was added initially at 5 mL, 3 mL at 1 hour of reaction, and 2 mL at 2 hours of reaction, and the total reaction time was 4 hours. The stirring speed was maintained at 60 r / min during the reaction;

[0085] (3) Sampling was performed after 1 hour, 2 hours, 3 hours and 4 hours of reaction, and manganese dioxide was added after sampling to terminate the reaction after stirring for 10 min. The COD concentration was measured after passing through a 0.45 um membrane;

[0086] (4) Repeated experiments were performed, and sampling was only taken at the time when the reaction was terminated at 4 hours, and the water samples from the 1st, 2nd, 3rd, 5th, 7th, 10th, 15th and 20th experiments were selected for COD concentration determination.

[0087] The experimental results described above are shown in Tables 5 and 6 below:

[0088] Table 5

[0089]

[0090] Table 6

[0091]

[0092]

[0093] According to the data results of Table 5 and Table 6, it can be found that the catalyst has strong catalytic effect in catalyzing hydrogen peroxide to oxidize landfill leachate nanofiltration concentrate. Compared with Example 5, using the same amount of hydrogen peroxide, more COD can be degraded. It is particularly pointed out that the nanofiltration concentrate of landfill leachate is wastewater with extremely poor biodegradability, which generally belongs to macromolecular humic acid substances, further embodying the high catalytic capacity of the catalyst.

[0094] Example 8,

[0095] (1) 10 g of the catalyst prepared in Example 3 was added to 1000 mL of rhodamine dye wastewater, and the wastewater quality was COD = 230 mg / L and pH = 8.25.

[0096] (2) 6 mL of hydrogen peroxide with a mass concentration of 30% was added at the initial stage, 2 mL was added at the first hour of reaction, and 1 mL was added at the second hour of reaction, and the total reaction time was 4 hours. The stirring speed was maintained at 60 r / min during the reaction.

[0097] (3) After 1 hour, 2 hours, 3 hours and 4 hours of reaction, samples were taken. After sampling, manganese dioxide was added and stirred for 10 min to terminate the reaction. The absorbance at a wavelength of 554 nm was measured, and the COD concentration of the water sample was measured after passing through a 0.45 um membrane.

[0098] (4) Repeated experiments were performed, and water samples were taken only at the fourth hour of termination. The water samples of the first, second, third, fifth, seventh, tenth, fifteenth and twentieth experiments were selected for 554 nm absorbance determination and COD concentration determination. The experimental results showed that the 554 nm wavelength detection was 0 absorbance within 1 hour, indicating a decolorization rate of 100%. The COD data is shown in the following table:

[0099] Table 7

[0100]

[0101] Table 8

[0102]

[0103] According to the data results, it can be known that the catalyst has good catalytic oxidation effect in removing rhodamine dye wastewater, and the decolorization efficiency is high. The COD removal rate can reach 92%, and the catalytic performance is excellent.

[0104] Example 9,

[0105] In order to explore the metal dissolution rate of the catalyst in the repeated reaction process, the dye water without heavy metal ions in Example 7 was taken for experiment, the water sample in the repeated 20 times experiment in Example 7 was taken for metal detection, and the partial metal dissolution rate of the 1st, 2nd, 3rd, 5th, 7th, 10th, 15th and 20th experiments was measured by ICP. The data is shown in Table 9 as follows:

[0106] Table 9

[0107]

[0108]

[0109] According to the above data, it can be found that after the catalyst is used for multiple reactions, the heavy metal concentration of the effluent meets the wastewater comprehensive discharge standard, which indicates that the catalyst has certain corrosion-resistant stability and can avoid secondary pollution caused by the precipitation of the catalyst in repeated use;

[0110] It is worth noting that in the drawings of the specification Figure 1 and Figure 2 are two different cross-sectional views of the red mud-based light foamed ceramsite prepared by the present application;

[0111] In the above Examples 2-8:

[0112] Figure 3 , Figure 4 and Figure 5 are state diagrams of unmodified 1000 times, 5000 times and 10000 times;

[0113] Figure 6 , Figure 7 and Figure 8 are state diagrams of 2000 times, 5000 times and 10000 times after modification;

[0114] Figure 9 and Figure 10 are electronic images and data diagrams collected before modification;

[0115] Figure 11 and Figure 12 are electronic images and data diagrams collected after modification;

[0116] In combination with the above drawings, the state of Figure 3 , Figure 4 and Figure 5 before modification is compared with the state of Figure 6 , Figure 7 and Figure 8 after modification, and Figure 9 and Figure 10The electronic image and the data image without modification are compared with Figure 11 and Figure 12 The electronic image and the data image without modification are compared with

[0117] In addition, in the above embodiment, the tools and conditions used for "drying", "crushing", "ball milling" and "sieving" are only part of the operation in the embodiment, and the results are the necessary pretreatment stage for completing the sample of solid waste. It should be understood that the specific tools used in the pretreatment stage are not limited, and all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the present application.

[0118] The shape of the wet embryo material determines the final shape of the catalyst. The processing process can be manual or simple mechanical processing. It should be understood that the shape is not strictly spherical or cylindrical, and the modeling processing form is various. All other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the present application.

[0119] The muffle furnace used has oxygen supply conditions and has a certain oxidation environment. It should be understood that the specific tools used in the sintering process are not limited, and the use of similar production tools also belongs to the protection scope of the present application. All other embodiments obtained by those skilled in the art without creative labor also belong to the protection scope of the present application.

[0120] The above only describes the preferred embodiments of the present application and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method for preparing green and efficient heterogeneous Fenton catalysts, characterized in that: Specifically comprising the following steps: Step one, take the red mud produced in the extraction of alumina process, and dry it after crushing, put it into the ball mill, sieve, take the undersize for use; Step two, select the broken glassware produced by the waste glass in the laboratory, dry it after crushing, put it into the ball mill, sieve, take the undersize for use; Step three, mix the pretreated red mud powder in step one and the waste glass powder pretreated in step two uniformly at a weight ratio of 6-8:2-4 as mixed raw material, use sodium silicate solution with a mass concentration of 25%-45% to mix and bond at a ratio of 100g mixed raw material:10mL sodium silicate solution to process 5-30mm wet billets; Step four, dry the wet billets processed in step three, put the dried billets into the muffle furnace, sinter and form at 880-960℃, and get the red mud-based carrier after cooling; Step five, take the red mud-based carrier in step four, put it into the modified solution at a mass ratio of 1:1, stir for 15min, soak for 2-10h, take out the solid, drain, and put it into the oven after the surface is free of obvious water film, dry at 105℃ for 1h, and get the catalyst raw material; Step six, take the catalyst raw material in step five, put it into the muffle furnace, calcine at 220-280℃ for 2h, naturally cool after calcination, seal and reserve for use, and finally get a green and efficient heterogeneous Fenton catalyst.

2. The method for preparing a green and efficient heterogeneous Fenton catalyst according to claim 1, characterized in that: The drying, crushing, ball milling and sieving in steps one and two respectively use electric heating constant temperature air drying oven to dry at 105℃ for 2h, iron hammer to manually crush, ball mill to ball mill for 2h, and non-metal sieve of 100-200 mesh to sieve.

3. The method for preparing a green and efficient heterogeneous Fenton catalyst according to claim 1, characterized in that: The red mud in step one is the Bayer process red mud produced in the Bayer process for extracting alumina, and the main components are 30%-40% Fe2O3, 15%-25% Al2O3, 10%-15% CaO, 5%-10% SiO2 and 5%-10% TiO2.

4. The method for preparing a green and efficient heterogeneous Fenton catalyst according to claim 1, characterized in that: The waste glass in step two mainly contains 60%-80% SiO2, 10%-15% Na2O, 10%-15% CaO and 1.5%-3% Al2O3.

5. The method for preparing a green and efficient heterogeneous Fenton catalyst according to claim 1, characterized in that: The mixing and bonding processing in step three is to preliminarily bond part of the mixed raw material with part of the sodium silicate solution, and then gradually bond all the mixed raw material with the sodium silicate solution according to the uniformity of the billet.

6. The method for preparing a green and efficient heterogeneous Fenton catalyst according to claim 1, characterized in that: The shape of the wet billet in step three is spherical and cylindrical, which is determined according to the actual situation.

7. The method for preparing a green and efficient heterogeneous Fenton catalyst according to claim 1, characterized in that: The sintering operation in step four is to use the muffle furnace to sinter and form at the preset temperature program, and the dry billets need to be placed in the center of the muffle furnace and hung in the air to be heated uniformly.

8. The method for preparing a green and efficient heterogeneous Fenton catalyst according to claim 1, characterized in that: The modified solution in step five is mainly prepared by single or multiple transition metal ion solutions, specifically the solutions of ferrous ion, iron ion and copper ion, with a total metal ion concentration of 0.2mol / L-1mol / L, and the molar concentration ratio of the metals is 0-3:0-3:0-4.

9. The method for preparing a green and efficient heterogeneous Fenton catalyst according to claim 1, characterized in that: The temperature rising rate and the temperature falling rate of the step six roasting process are controlled below 5℃ / min.

10. The method for preparing a green and efficient heterogeneous Fenton catalyst according to claim 1, characterized in that: The temperature rising rate of the step four sintering operation is in the range of 1-10℃ / min, the sintering temperature is 880-960℃, and the sintering time is 240-400min.

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