Perovskite organic metal framework composite material, preparation method and combined cycle system

Abstract

The invention provides a perovskite organic metal framework composite material and a preparation method thereof, and the preparation method comprises the following steps: preparing a perovskite precursor by adopting a sol-gel method, and calcining the perovskite precursor to obtain a perovskite material; preparing an organic metal framework material by adopting a hydrothermal method; the preparation method comprises the following steps: dissolving a perovskite material and an organic metal framework material in a methanol solution, uniformly mixing, stirring at room temperature, and filtering to obtain the perovskite organic metal framework composite material. The invention further provides a combined cycle system of the perovskite organic metal framework composite material, the perovskite organic metal framework composite material is obtained and used for adsorbing ammonia gas and organic pollutants, and the adsorption effect of the perovskite organic metal framework composite material is better than that of an organic metal framework. The perovskite is loaded on the organic metal framework, so that the advantages of the organic metal framework are reserved, and meanwhile, the price of the organic metal framework is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of atmospheric pollutant removal and organic wastewater resource utilization, and specifically to a perovskite organic metal framework composite material, a preparation method and a combined circulation system. Background Art

[0002] Ammonia (NH3) is a nitrogen-hydrogen compound that is colorless and has a pungent odor. Ammonia has a high octane number, a low flame temperature, and its combustion products are only H2O and N2, making it an ideal carbon-free fuel. However, ammonia (NH3) is also one of the five major pollutants. Ammonia is easily oxidized into nitrogen oxides, which react with acidic compounds in the air to form particulate matter, forming PM2.5, which in turn leads to environmental problems such as haze and photochemical smog. In addition, ammonia (NH3) is a highly corrosive gas that can damage the human respiratory tract and mucous membrane tissues. Therefore, the capture of ammonia (NH3) is of great significance in terms of energy, environmental issues, and human health.

[0003] In the printing and dyeing industry, due to the limitations of printing and dyeing technology and other aspects, a large amount of nitrogen-containing dyes or nitrogen-containing additives are used in the printing and dyeing process, resulting in a high ammonia nitrogen content in ammonia nitrogen compounds in printing and dyeing wastewater. After the decomposition of ammonia nitrogen compounds, not only a large amount of ammonia gas will be produced, but also various toxic and harmful dyes will be present in the printing and dyeing wastewater. If the dye wastewater is discharged into the water body without proper treatment, it will have a serious impact on the microorganisms, plants and animals in the water ecosystem. The growth of microorganisms will be inhibited, resulting in a decrease in the purification capacity of the water body; the growth of plants will be hindered, thereby affecting the ecological balance of the water body. Therefore, in order to reduce the harm caused by ammonia nitrogen compounds, it is necessary to adsorb ammonia gas to reduce the ammonia content while also effectively adsorbing harmful dyes in the wastewater.

[0004] At present, the recovery process of ammonia (NH3) mainly includes solvent absorption, catalytic conversion and adsorption. Solvent absorption is divided into chemical absorption and physical absorption. Among them, chemical adsorption was once adopted by virtue of its advantage of using the alkaline properties of ammonia to react with acidic substances to produce nitrogen fertilizer. Although it has rapid absorption and good purification effect, it is accompanied by the disadvantages of strong corrosiveness and difficulty in regeneration, resulting in the chemical absorption method being gradually replaced by new technologies. In contrast, the physical absorption method shows universal applicability. This method absorbs ammonia through soft water, and then obtains concentrated ammonia water through distillation, and further obtains ammonia and liquid ammonia. However, the physical adsorption method still has some limitations, among which high energy consumption is always a problem to be considered. Another method is catalytic conversion, which converts ammonia into hydrogen and nitrogen. Due to its high cost, its recovery difficulty is limited. The adsorption method is to achieve ammonia absorption by accumulating or concentrating ammonia on the surface of a solid adsorbent. Therefore, the development of a high-performance adsorption material is crucial for efficient ammonia adsorption. Many studies have shown that organic metal frameworks or metal oxides have good effects on the adsorption of ammonia, but their application is limited due to their high cost.

[0005] At present, the commonly used treatment methods for printing and dyeing wastewater include biological, chemical and physical methods. Among them, physical adsorption is widely used in wastewater treatment due to its simple operation, high efficiency and low cost. In the early days, activated carbon was generally used for dye adsorption, but with the emergence of organic metal frameworks, its strong adsorption capacity has gradually made it used in related adsorption experiments. However, due to its high cost, the application of organic metal frameworks is limited. Therefore, it is of great significance to design a perovskite organic metal framework composite material with low cost, good adsorption, efficient adsorption of ammonia and purification of organic dye wastewater. Summary of the invention

[0006] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a perovskite organic metal framework composite material, a preparation method and a combined circulation system, which can not only achieve efficient adsorption of ammonia, but also be used for purification of organic wastewater, fully utilize the adsorption performance of the perovskite organic metal framework composite material, and reduce the cost of adsorption materials.

[0007] In order to solve the above technical problems, the first implementation scheme provided by the present invention is to provide a method for preparing a perovskite organic metal framework composite material, comprising the following steps:

[0008] A perovskite precursor is prepared by a sol-gel method, and the perovskite precursor is calcined to obtain a perovskite material;

[0009] The organic metal framework material was prepared by hydrothermal method;

[0010] The perovskite material and the organic metal framework material are dissolved in a methanol solution, stirred at room temperature, and filtered to obtain a perovskite organic metal framework composite material.

[0011] Preferably, the method for preparing the perovskite material comprises the following steps:

[0012] Weigh lanthanum nitrate, nickel nitrate, manganese nitrate and citric acid, mix them in deionized water, adjust the pH to 7-9, and obtain a perovskite precursor, wherein the molar ratio of the total concentration of lanthanum ions, nickel ions and manganese ions to citric acid is (1-1.5):1;

[0013] The perovskite precursor is first dried at 110° C. to 130° C., and then calcined at 750° C. to 850° C. to obtain the perovskite material.

[0014] Preferably, the method for preparing the organic metal framework material comprises the following steps:

[0015] Weigh aluminum chloride and 2,5-dihydroxyterephthalic acid in a molar ratio of 1: (1-1.5) and dissolve them in DMF, stir them thoroughly to make them evenly mixed, and then transfer the solution to a polytetrafluoroethylene reactor, and then place the reactor at 110°C-140°C for hydrothermal reaction for 7h-9h;

[0016] After the reaction is completed, the sample is taken out, and after cooling to room temperature, it is filtered and centrifuged 3 to 4 times using DMF. The filtered solid sample is placed in a centrifuge tube at room temperature for 12 to 24 hours until the DMF solvent is basically evaporated to obtain a metal organic framework;

[0017] Measure a mixed solution of methanol and deionized water in a volume ratio of 1:1, transfer the solid sample to a flask, activate it at 90°C to 110°C for 11h to 13h, take out the mixed liquid after activation, wash it by centrifugation with deionized water 3 to 4 times, dry the solid sample at 50°C to 60°C to obtain a dry solid powder, and obtain an organic metal framework material.

[0018] The mass ratio of perovskite material to organic metal framework material is 1:(1-1.5), and the stirring time at room temperature is 11h-13h

[0019] The second implementation scheme provided by the present invention is to provide a perovskite organic metal framework composite material prepared by a preparation method of a perovskite organic metal framework composite material.

[0020] The third implementation scheme provided by the present invention is to provide a combined circulation system for treating ammonia-organic wastewater, including a perovskite organic metal framework composite material.

[0021] Preferably, a combined circulation system for treating ammonia-organic wastewater comprises:

[0022] A gas generator, connected to an air generator and an ammonia injection pump respectively;

[0023] A pyrolysis furnace, whose air inlet is connected to the gas generator through a mixed gas pipeline, and whose feed port is connected to a feed device and a first conveying pipeline respectively, wherein the perovskite organic metal framework composite material is filled in the pyrolysis furnace to absorb ammonia;

[0024] The adsorption separation device has a feed port connected to the discharge port of the pyrolysis furnace through the second conveying pipeline and the first pneumatic conveying device, and a liquid inlet connected to the organic wastewater storage device; and is used to react the perovskite organic metal framework composite material fed into the adsorption separation device with the organic wastewater;

[0025] A regenerated water storage device, connected to the liquid outlet of the adsorption separation device, for collecting the treated regenerated water;

[0026] The centrifugal dehydration device is connected to the discharge port of the adsorption separation device through the first conveying pipeline and the second pneumatic transport device, and is used to dehydrate the perovskite organic metal framework composite material adsorbed with organic matter in the wastewater.

[0027] Preferably, the organic wastewater storage device and the adsorption separation device are connected via a filter.

[0028] Preferably, a gas outlet is provided on the pyrolysis furnace, and the gas outlet is also connected to the exhaust gas detection device.

[0029] Preferably, the moisture content of the perovskite organic metal framework composite material is less than 10% after being dehydrated by a centrifugal dehydration device.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The perovskite metal organic framework composite material obtained by integrating the perovskite material with the organic metal framework composite material in the present invention can simultaneously realize ammonia adsorption and organic wastewater treatment, complete the combined removal of ammonia and organic wastewater dyes, and realize ammonia capture and resource utilization of organic wastewater. It has the following advantages:

[0032] 1. The present invention does not directly use expensive organic metal framework materials, but loads low-cost perovskite-type metal oxides on organic metal framework materials to obtain perovskite organic metal framework composite materials, so that the adsorption effect of perovskite organic metal framework composite materials on ammonia and organic pollutants is better than that of organic metal frameworks. This is because the metal organic framework has the characteristics of regular pore structure, large specific surface area and low density, and perovskite has the advantages of higher thermal stability, lower cost, higher adsorption and the like. Therefore, perovskite is loaded on the organic metal framework, which retains the advantages of the organic metal framework while reducing the price of the organic metal framework.

[0033] However, in addition to the above advantages, perovskite also has the disadvantage of phase instability. Its crystal structure may become unstable due to factors such as internal stress or defects, resulting in structural distortion or transformation into other structures, which in turn affects the adsorption of ammonia and organic dyes. The organic metal framework can encapsulate the perovskite in it, thereby effectively isolating the perovskite, preventing the decrease in specific surface area caused by the aggregation of perovskite and the degradation of the adsorption of perovskite due to environmental influences, and enhancing the overall stability of the composite material. The perovskite organic metal framework composite material retains the advantages of the organic metal framework while having the advantages of both metal organic framework and perovskite materials, and can effectively capture harmful dyes and ammonia in printing and dyeing wastewater.

[0034] The loaded perovskite organic metal framework composite material has the characteristics of high crystal symmetry, multiple active sites, and large specific surface area. The synergistic effect between perovskite and organic metal framework significantly reduces the reaction activation energy of the perovskite organic metal framework composite material. The electrostatic interaction caused by the effective charge in the direction of the metal site is then enhanced, so that the adsorption strength of the perovskite organic metal framework composite material is enhanced, thereby showing an increase in the adsorption of ammonia and organic dyes. The price of using perovskite organic metal framework composite materials is lower than that of organic metal framework materials for treating the same amount of ammonia and dyes, and can be used in large-scale industrial applications.

[0035] 2. The preparation process of the perovskite organic metal framework composite material given in the present invention, as well as the circulation system for using it to adsorb ammonia and malachite green in malachite green solution, use conventional equipment, thereby reducing the construction and maintenance costs, and have considerable industrial development space and value in terms of practicality and economic benefits.

[0036] 3. The perovskite organic metal framework composite material provided by the present invention is based on an organic metal framework, has characteristics such as more pores and specific surface area, and realizes efficient adsorption and treatment of ammonia. Figure 3The characterization results of NH3 adsorption-desorption curves of a perovskite organic metal framework composite material given show that the isotherm type of perovskite and organic metal framework materials indicates that the composite material has a mesoporous structure. The adsorption amount is 69mL / g in the pressure range of 0bar~0.1bar, which has a fast NH3 static adsorption capacity, indicating that the material has the effective adsorption potential for ammonia under low pressure conditions. In the pressure range of 0bar~1.0bar, the adsorption amount of ammonia by perovskite and organic metal framework increases with the increase of pressure, and the maximum adsorption amount is 142.2876mL / g, showing excellent adsorption performance, which can be used for ammonia capture to maximize economic benefits. After the material completes the adsorption of ammonia, the active sites on the surface of the perovskite can also combine with the harmful molecule malachite green in the malachite green wastewater to achieve water purification regeneration; the system realizes the recycling of composite materials, improves their utilization rate, and has a long cycle life, which can be used in industrial applications to maximize economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a scanning electron microscope (SEM) photograph of a perovskite organic metal framework composite material of the present invention.

[0038] Figure 2 This is an X-ray diffraction spectrum (XRD) of a perovskite organic metal framework composite material of the present invention.

[0039] Figure 3 This is a NH3 adsorption-desorption curve of a perovskite organic metal framework composite material of the present invention;

[0040] Figure 4 This is a curve diagram of the treatment of organic wastewater by the perovskite material organic metal framework composite material of the present invention.

[0041] Figure 5 This is the XRD spectrum of the perovskite material organic metal framework composite material after wastewater treatment in the present invention.

[0042] Figure 6 This is a process flow chart of a combined circulation system for treating ammonia and organic wastewater using a perovskite organic metal framework composite material of the present invention.

[0043] Figure 7 The present invention is a structural schematic diagram of a combined circulation system for treating ammonia and organic wastewater using a perovskite organic metal framework composite material.

[0044] Description of reference numerals:

[0045] 1. Air generator, 2. Air pipeline, 3. Gas generator, 4. Ammonia injection pump, 5. Ammonia pipeline, 6. Mixed gas pipeline, 7. Air inlet, 8. Feeding device, 9. Pyrolysis furnace, 10. Pyrolysis furnace outlet, 11. Tail gas detection device, 12. Discharge port, 13. Second conveying pipeline, 14. Machine pump, 15. Organic wastewater storage device, 16. Adsorption separation device, 17. Recycled water storage device, 18. Centrifugal dehydration device, 19. First conveying pipeline, 20. Feeding port. DETAILED DESCRIPTION

[0046] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention. All other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] The inventors found that organic metal framework materials, as a network structure crystalline porous material, are composed of metal ions or clusters coordinated with organic ligands. They have the characteristics of being porous, having a large specific surface area, and having an adjustable structure, which makes them have great application prospects in ammonia adsorption. The active sites on the surface of perovskite can effectively adsorb harmful molecules in organic wastewater. Therefore, the new material formed by combining perovskite with metal organic framework materials can achieve the joint treatment of ammonia and organic wastewater.

[0048] In view of this, the perovskite organic metal framework composite material prepared by the present invention can not only achieve efficient adsorption of ammonia, but also be used for purification of organic wastewater, making full use of the adsorption performance of the perovskite organic metal framework composite material and reducing the cost of adsorption materials.

[0049] Example 1

[0050] A method for preparing a perovskite organic metal framework composite material comprises the following steps:

[0051] A perovskite precursor is prepared by a sol-gel method, and the perovskite precursor is calcined to obtain a perovskite material;

[0052] The organic metal framework material was prepared by hydrothermal method;

[0053] The perovskite material and the organic metal framework material in a mass ratio of 1:1 were dissolved in a methanol solution, mixed evenly, and stirred at room temperature for 12 hours. After the mixture was dissolved, it was centrifuged and filtered with methanol for washing, dried to a solid powder, and then dried at 120°C for 12 hours.

[0054] The method for preparing the perovskite material comprises the following steps:

[0055] Accurately weigh lanthanum nitrate, nickel nitrate, manganese nitrate, and citric acid, dissolve them in deionized water, and adjust the pH of the solution to 8 with ammonia water to obtain a perovskite precursor, wherein the molar ratio of the total concentration of lanthanum ions, nickel ions, and manganese ions to citric acid is 1:1;

[0056] The obtained perovskite precursor is then dried at 120° C., and then calcined at 700° C. to obtain a perovskite material.

[0057] The method for preparing the organic metal framework material comprises the following steps:

[0058] Aluminum chloride and 2,5-dihydroxyterephthalic acid were weighed according to the stoichiometric ratio and dissolved in 10 mL of DMF. The mixture was stirred thoroughly to make it uniformly mixed and then the solution was transferred to a polytetrafluoroethylene reactor. The reactor was then placed in a forced air drying oven at 125°C for hydrothermal reaction for 8 hours.

[0059] After the reaction is completed, the sample is taken out, cooled to room temperature, filtered and centrifuged three times using DMF, and the filtered solid sample is placed in a centrifuge tube at room temperature for a period of time until the DMF solvent evaporates to obtain a metal organic framework;

[0060] 100 mL of methanol and 100 mL of deionized water were measured and mixed to obtain a mixed solution, and the solid sample was transferred to a flask and activated at 100° C. for 12 hours. After the activation, the mixed liquid was taken out and centrifuged and washed three times with deionized water. The solid sample was dried at 50° C. to obtain a dry solid powder, and the perovskite organic metal framework composite material was obtained.

[0061] Example 2

[0062] A method for preparing a perovskite organic metal framework composite material comprises the following steps:

[0063] A perovskite precursor is prepared by a sol-gel method, and the perovskite precursor is calcined to obtain a perovskite material;

[0064] The organic metal framework material was prepared by hydrothermal method;

[0065] The perovskite material and the organic metal framework material in a mass ratio of 1:1 were dissolved in a methanol solution, mixed evenly, and stirred at room temperature for 11 hours. After the mixture was finished, it was centrifuged and filtered with methanol for washing, dried to a solid powder, and then dried at 110°C for 11 hours;

[0066] The method for preparing the perovskite material comprises the following steps:

[0067] Accurately weigh lanthanum nitrate, nickel nitrate, manganese nitrate, and citric acid, dissolve them in deionized water, and adjust the pH of the solution to 7 with ammonia water to obtain a perovskite precursor, wherein the molar ratio of the total concentration of lanthanum ions, nickel ions, and manganese ions to citric acid is 1:1.2;

[0068] The perovskite precursor is dried at 110°C and then calcined at 750°C to obtain the perovskite material.

[0069] The method for preparing the organic metal framework material comprises the following steps:

[0070] Aluminum chloride and 2,5-dihydroxyterephthalic acid were weighed according to the stoichiometric ratio and dissolved in 10 mL of DMF. The mixture was stirred thoroughly to make it uniformly mixed and then the solution was transferred to a polytetrafluoroethylene reactor. The reactor was then placed in a forced air drying oven at 125°C for hydrothermal reaction for 8 hours.

[0071] After the reaction is completed, the sample is taken out, cooled to room temperature, filtered and centrifuged 4 times using DMF, and the filtered solid sample is placed in a centrifuge tube at room temperature for a period of time until the DMF solvent evaporates to obtain a metal organic framework;

[0072] 100 mL of methanol and 100 mL of deionized water were measured and mixed to obtain a mixed solution, and the solid sample was transferred to a flask and activated at 100° C. for 12 hours. After the activation, the mixed liquid was taken out and centrifuged and washed 4 times with deionized water. The solid sample was dried at 60° C. to obtain a dry solid powder, and the perovskite organic metal framework composite material was obtained.

[0073] Example 3

[0074] A method for preparing a perovskite organic metal framework composite material comprises the following steps:

[0075] A perovskite precursor is prepared by a sol-gel method, and the perovskite precursor is calcined to obtain a perovskite material;

[0076] The organic metal framework material was prepared by hydrothermal method;

[0077] The perovskite material and the organic metal framework material in a mass ratio of 1:1 were dissolved in a methanol solution, mixed evenly, and stirred at room temperature for 13 hours. After the mixture was dissolved, the mixture was centrifuged and washed with methanol, dried to a solid powder, and then dried at 130°C for 13 hours.

[0078] The method for preparing the perovskite material comprises the following steps:

[0079] Accurately weigh lanthanum nitrate, nickel nitrate, manganese nitrate, and citric acid, dissolve them in deionized water, and adjust the pH of the solution to 9 with ammonia water to obtain a perovskite precursor, wherein the molar ratio of the total concentration of lanthanum ions, nickel ions, and manganese ions to citric acid in the perovskite precursor is 1:1.5;

[0080] The perovskite precursor is dried at 130°C and then calcined at 850°C to obtain the perovskite material.

[0081] The method for preparing the organic metal framework material comprises the following steps:

[0082] Aluminum chloride and 2,5-dihydroxyterephthalic acid were weighed according to the stoichiometric ratio and dissolved in 10 mL of DMF. The mixture was stirred thoroughly to make it uniformly mixed and then the solution was transferred to a polytetrafluoroethylene reactor. The reactor was then placed in a forced air drying oven at 125°C for hydrothermal reaction for 8 hours.

[0083] After the reaction is completed, the sample is taken out, cooled to room temperature, filtered and centrifuged three times using DMF, and the filtered solid sample is placed in a centrifuge tube at room temperature for a period of time until the DMF solvent evaporates to obtain a metal organic framework;

[0084] 100 mL of methanol and 100 mL of deionized water were measured and mixed to obtain a mixed solution, and the solid sample was transferred to a flask and activated at 100° C. for 12 hours. After the activation, the mixed liquid was taken out and centrifuged and washed 4 times with deionized water. The solid sample was dried at 60° C. to obtain a dry solid powder, and the perovskite organic metal framework composite material was obtained.

[0085] The following characterization is performed on the perovskite organic metal framework composite material prepared by any one of Examples 1 to 3.

[0086] (1) Scanning electron microscopy (SEM)

[0087] like Figure 1 As shown in the figure, the SEM image shows that the perovskite organic metal framework composite material has an adsorbent granular morphology, and the perovskite organic metal framework composite material accumulates to form a porous structure, which can form a large specific surface area, laying a morphological foundation for good physical adsorption performance. Figure 1 It can also be seen from the SEM image that the perovskite organic metal framework composite material contains a large number of nanoparticles, and the particle size of the nanoparticles is evenly distributed over a large range. The composite material forms a more porous structure and can have a high adsorption capacity at a lower pressure.

[0088] (2) X-ray diffraction (XRD)

[0089] like Figure 2As shown, the XRD diffraction peaks are consistent with the positions of 23.322°, 32.914°, 40.796°, 41.304°, 47.35°, 53.310°, 58.763°, 68.708°, 69.818°, 78.457°, 79.155° and 83.569° of the orthorhombic perovskite structure, indicating that the adsorbent basically maintains the perovskite crystal morphology and has good crystal activity, laying a molecular structure foundation for good chemical adsorption performance. The perovskite organic metal framework composite material forms a crystal framework structure. The active sites of the crystal structure when treating dyes are metal ions and organic ligands. They are adsorbed by van der Waals forces, electrostatic interactions, hydrogen bonds, etc., realizing the simultaneous coordination of physical adsorption and chemical adsorption.

[0090] The prepared and synthesized perovskite organic metal framework composite material is applied to the combined circulation system for treating ammonia and organic wastewater.

[0091] like Figure 6-7 As shown, the specific structure of the combined circulation system for treating ammonia and organic wastewater is given here, including:

[0092] The gas generator 3 is connected to the air generator 1 and the ammonia injection pump 4 respectively, and is used to ensure the concentration and dispersion of the ammonia;

[0093] The pyrolysis furnace 9, the air inlet 7 is connected to the gas generator 3 through the mixed gas pipeline 6, the feed port 20 is connected to the feed device 8 and the adsorbed composite material delivery pipeline 19, the pyrolysis furnace is provided with a gas outlet 10, the gas outlet 10 can be connected to the tail gas detection device 11, the perovskite organic metal framework composite material is filled in the pyrolysis furnace 9, and is used to absorb ammonia;

[0094] The adsorption separation device 16 has a feed port connected to the discharge port 12 of the pyrolysis furnace 9 through a composite material conveying pipeline 13 and a first pneumatic transport device 14. The water inlet of the adsorption separation device 16 is connected to an organic wastewater storage device 15. The liquid outlet of the adsorption separation device 16 is connected to a regenerated water storage device 17. The discharge port of the adsorption separation device 16 is connected to a centrifugal dehydration device 18 through a second pneumatic transport device 14. The centrifugal dehydration device 18 is connected to a composite material conveying pipeline 19 after adsorption. The organic wastewater storage device 15 and the adsorption separation device 16 are connected through a filter. The perovskite organic metal framework composite material is dehydrated by the centrifugal dehydration device 18 to make the moisture content lower than 10% to reduce the energy consumption of the subsequent drying process.

[0095] Working principle:

[0096] The gas generator 3 is connected to the air generator 1 and is also connected to the ammonia injection pump 4 through the ammonia pipeline 5; the ammonia sent by the air generator 3 through the air pipeline 2 and the ammonia injection pump 4 through the ammonia pipeline 5 is passed into the pyrolysis furnace 9 through the mixed gas pipeline 6, and the feeding device 8 sends the perovskite organic metal framework composite material into the reaction chamber of the pyrolysis furnace 9 through the feeding port 20 for ammonia adsorption; the perovskite organic metal framework composite material that has completed the adsorption of ammonia in the pyrolysis furnace 9 body is blown out by the first pneumatic conveying equipment (pump 14) through the second conveying pipeline 13 and sent to the adsorption separation device 16, which is used for the adsorption purification of organic wastewater;

[0097] The organic wastewater in the organic wastewater storage device 15 is passed into the adsorption separation device 16 to fully contact with the perovskite organic metal framework composite material to complete the adsorption and removal process of organic matter, and the regenerated clean water is obtained and stored in the regenerated water storage device 17. The adsorbed perovskite organic metal framework composite material enters the centrifugal dehydration device 18 for dehydration through the second pneumatic transportation device (pump 14), and is then sent to the pyrolysis furnace 9 again through the first transportation pipeline 19 to continue to participate in the ammonia adsorption reaction.

[0098] The organic wastewater refers to typical industrial / domestic organic wastewater, in which the organic matter and metal components have a certain adsorption and decomposition effect on ammonia. The specific process is as follows: the organic wastewater storage device 15 has a medium filter, and the regenerated water storage device 17 has a sterilization device. When the organic wastewater passes through the medium filter to remove visible suspended matter and particulate matter in the water, it enters the adsorption separation device 16 equipped with the perovskite metal organic framework composite material to obtain regenerated water stored in the regenerated water storage device 17.

[0099] pass Figure 3 The characterization results of the NH3 adsorption-desorption curve of a perovskite organic metal framework composite material given show that the isotherm type of the perovskite organic metal framework material indicates that the composite material has a mesoporous structure. The adsorption amount is 69mL / g in the pressure range of 0bar to 0.1bar, and it has a fast NH3 static adsorption capacity, indicating that the material has effective adsorption potential for ammonia under low pressure conditions. In the pressure range of 0bar to 1.0bar, the adsorption amount of ammonia by the perovskite organic metal framework increases with increasing pressure, and the maximum adsorption amount is 142.2876mL / g, showing excellent adsorption performance;

[0100] pass Figure 4 and Figure 5 The given curve of treating organic wastewater with a perovskite material and an organic metal framework composite material and the XRD spectrum of the composite material after treating wastewater show that Figure 4The adsorption performance of perovskite organic metal framework composites on malachite green solutions of different concentrations increases with the increase of malachite green concentration, and the adsorption amount of organic dyes by the perovskite organic metal framework composites also increases, which shows the effective adsorption potential of perovskite organic metal framework composites on organic dyes. In addition, perovskite organic metal framework composites can achieve the adsorption of different molecular sizes from small molecules of ammonia to large molecules in printing and dyeing wastewater such as malachite green. This phenomenon is due to the fact that the incorporation of perovskite gives it better stability.

[0101] like Figure 5 As shown, the XRD spectrum shows that the structure of the composite material is not destroyed after the adsorption of ammonia and organic dyes, and it still has good macromolecular adsorption characteristics. Therefore, the composite material can be considered as a highly efficient, long-life recyclable adsorbent.

[0102] The present invention not only makes the perovskite and metal organic framework composite material have high efficiency adsorption performance for ammonia, but also can still efficiently treat organic wastewater after completing ammonia adsorption treatment, and still has high efficiency adsorption performance after repeated use in the whole combined circulation system, and has a long life and high economic benefits. While achieving high efficiency adsorption of ammonia under mild conditions, effective treatment of organic wastewater is completed. In the system of ammonia removal and domestic sewage combined treatment, material recovery and recycling are adopted, and recycled water is utilized as a resource, and the adsorption performance of the adsorbent is fully utilized, which is of great significance to protecting the environment and improving economic benefits.

[0103] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for preparing a perovskite organic metal framework composite material, characterized in that: The steps include: A perovskite precursor is prepared by a sol-gel method, and the perovskite precursor is calcined to obtain a perovskite material; The organic metal framework material was prepared by hydrothermal method; The perovskite material and the organic metal framework material are dissolved in a methanol solution, stirred at room temperature, and filtered to obtain a perovskite organic metal framework composite material.

2. The method for preparing a perovskite organic metal framework composite material according to claim 1, characterized in that: The perovskite material is prepared according to the following steps: Weigh lanthanum nitrate, nickel nitrate, manganese nitrate and citric acid, mix them in deionized water, adjust the pH to 7-9, and obtain a perovskite precursor, wherein the molar ratio of the total concentration of lanthanum ions, nickel ions and manganese ions to citric acid is (1-1.5):1; The perovskite precursor is first dried and then calcined at 750° C. to 850° C. to obtain the perovskite material.

3. The method for preparing a perovskite organic metal framework composite material according to claim 1, characterized in that: The organic metal framework material is prepared according to the following steps: Aluminum chloride and 2,5-dihydroxyterephthalic acid are weighed in a molar ratio of 1:(1-1.5), mixed in DMF, and then hydrothermally reacted at 110°C-140°C for 7h-9h, and then activated at 90°C-110°C for 11h-13h in a mixed solution of methanol and deionized water in a volume ratio of 1:1 to obtain an organic metal framework material.

4. The method for preparing a perovskite organic metal framework composite material according to claim 1, characterized in that: The mass ratio of the perovskite material to the organic metal framework material is 1:(1-1.5), and the stirring time at room temperature is 11h-13h.

5. A perovskite organic metal framework composite material prepared by the method for preparing a perovskite organic metal framework composite material according to any one of claims 1 to 4.

6. A combined circulation system for treating ammonia-organic wastewater, characterized in that: Includes the perovskite organic metal framework composite material as described in claim 5.

7. The combined circulation system for treating ammonia-organic wastewater according to claim 6, characterized in that: include: A gas generator (3) is connected to the air generator (1) and the ammonia injection pump (4) respectively; A pyrolysis furnace (9), wherein the gas inlet (7) is connected to the gas generator (3) via a mixed gas pipeline (6), and the feed port (20) is connected to the feed device (8) and the first delivery pipeline (19) respectively, and the perovskite organic metal framework composite material is filled in the pyrolysis furnace (9) to absorb ammonia; An adsorption separation device (16), whose feed port (20) is connected to the discharge port (12) of the pyrolysis furnace (9) through a second conveying pipeline (13) and a first pneumatic conveying device, and whose liquid inlet is connected to the organic wastewater storage device (15); and is used to react the perovskite organic metal framework composite material fed into the adsorption separation device (16) with the organic wastewater; A regenerated water storage device (17), connected to the liquid outlet of the adsorption separation device (16), for collecting the treated regenerated water; The centrifugal dehydration device (18) is connected to the discharge port of the adsorption separation device (16) via a first conveying pipeline (19) and a second pneumatic transport device, and is used to dehydrate the perovskite organic metal framework composite material that adsorbs organic matter in the wastewater.

8. The combined circulation system for treating ammonia-organic wastewater according to claim 7, characterized in that: The organic wastewater storage device (15) and the adsorption separation device (16) are connected via a filter.

9. The combined circulation system for treating ammonia-organic wastewater according to claim 7, characterized in that: The pyrolysis furnace is provided with a gas outlet (10), and the gas outlet (10) is also connected to an exhaust gas detection device (11).

10. The combined circulation system for treating ammonia-organic wastewater according to claim 7, characterized in that: The moisture content of the perovskite organic metal framework composite material is less than 10% after being dehydrated by a centrifugal dehydration device (18).

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