Composite adsorbents, methods of making and using the same

Abstract

The application relates to the field of high polymer chemical industry, and discloses a composite adsorbent as well as a preparation method and application thereof. The adsorbent contains active alumina and carbon nitride, the content of aluminum in the adsorbent is 9-26 wt%, the content of nitrogen is 15-30 wt%, and the content of carbon is 24-40 wt%; under the adsorption condition that the mass ratio of the adsorbent to a solution containing N-methyl pyrrolidone is 0.1:1, the adsorption rate of the adsorbent to N-methyl pyrrolidone is greater than 85%. The preparation method comprises the following steps: mixing an active alumina precursor, a carbon nitride precursor and an additive, and then carrying out a heating reaction. The adsorbent has a good adsorption effect on organic pollutants in wastewater, and cannot cause secondary pollution to the environment; in addition, the adsorbent is low in raw material price, simple in preparation method and low in cost.

Description

Technical Field

[0001] This invention relates to the field of polymer chemistry, specifically to a composite material adsorbent, its preparation method, and its application. Background Technology

[0002] N-Methylpyrrolidone (NMP) is primarily used in the synthesis of power batteries for electric vehicles, conductive agents, solar and wind power storage batteries, and polymer materials such as aramid, polyphenylene sulfide (PPS), and polyphenylene sulfide nitrile (PPS-N). Currently, due to the rapid development of lithium batteries, NMP is widely used as an auxiliary material for the positive electrode, resulting in the generation of large amounts of wastewater containing NMP, which seriously harms the environment and human health. NMP is considered a toxic chemical, irritating to the skin, eyes, and respiratory tract, and can also promote the entry of other toxins into the body. Ingestion or inhalation of NMP can cause headaches, dizziness, nervous confusion, and nausea. Long-term exposure can lead to central nervous system dysfunction and cause lesions in the respiratory organs, kidneys, and vascular system. If NMP wastewater is not effectively treated, it will not only cause environmental pollution but also seriously threaten human health. Therefore, finding efficient and energy-saving methods to treat NMP wastewater is of great significance.

[0003] Currently, research on the treatment of N-methylpyrrolidone wastewater is limited, mainly focusing on physical, chemical, and biological methods, each with its own advantages and disadvantages. Among these methods, the theoretical research and practical engineering applications of biological methods still need further exploration; chemical methods are complex to operate and costly, but their practical applications require further improvement; adsorption methods are attracting more attention due to their low cost, ease of operation, good efficiency, and low risk of secondary pollution. Developing highly efficient adsorbents is crucial for the adsorption treatment of N-methylpyrrolidone wastewater. In adsorption methods, the development of adsorbents with high adsorption performance and mechanical strength, chemical stability, recyclability, and ease of separation from solution is key.

[0004] Currently, adsorbents are classified into inorganic adsorbents, organic adsorbents, and carbonaceous adsorbents based on their chemical structure. Inorganic adsorbents are made from inexpensive and readily available raw materials, mostly natural materials. They generally have a large specific surface area and a loose, porous structure, which is beneficial for the adsorption of N-methylpyrrolidone, but their adsorption efficiency is relatively poor. Organic adsorbents are mostly high-molecular-weight organic compounds, and the materials themselves are artificially synthesized. Excessive use can easily cause secondary pollution to the environment, and they are prone to loss and degradation, with poor mechanical properties. Carbonaceous adsorbents are mainly composed of carbon elements. Currently, activated carbon, graphene, and carbon nanotubes are commonly used, but their high cost hinders their further application.

[0005] Therefore, there is an urgent need to provide an adsorbent for removing N-methylpyrrolidone from wastewater. Summary of the Invention

[0006] The purpose of this invention is to overcome the problems of poor adsorption effect and high pollution of existing adsorbents for N-methylpyrrolidone, and to provide a composite material adsorbent, its preparation method and application. This adsorbent has a good adsorption effect on organic pollutants in wastewater and will not cause secondary pollution to the environment. At the same time, the raw materials of this adsorbent are inexpensive, the preparation method is simple and the cost is low.

[0007] To achieve the above objectives, a first aspect of the present invention provides a composite material adsorbent containing activated alumina and carbon nitride, wherein the adsorbent contains 9-26 wt% aluminum, 15-30 wt% nitrogen, and 24-40 wt% carbon; and under the adsorption conditions where the adsorbent is mixed with a solution containing 5000 mg / L N-methylpyrrolidone at a mass ratio of 0.1:1, the adsorbent exhibits an adsorption rate of greater than 85% for N-methylpyrrolidone.

[0008] Preferably, after five adsorption-desorption cycles, the adsorbent is adsorbed with a solution containing 5000 mg / L N-methylpyrrolidone at a mass ratio of 0.1:1, and the adsorption rate of N-methylpyrrolidone is greater than 80%.

[0009] Preferably, the specific surface area of ​​the adsorbent is 300-600 m². 2 / g, with a pore size of 0.8-1.5nm.

[0010] The second aspect of the present invention provides a method for preparing a composite material adsorbent, comprising the following steps: mixing an activated alumina precursor, a carbon nitride precursor and an additive and heating them for reaction.

[0011] Preferably, the active alumina precursor is an aluminum salt and / or an aluminum oxide.

[0012] Preferably, the aluminum salt is selected from at least one of aluminum nitrate, aluminum sulfate, and aluminum stearate; and the aluminum oxide is aluminum oxide.

[0013] Preferably, the carbon nitride precursor is a compound represented by formula (I) and / or a compound represented by formula (II);

[0014] (CH2N2) n Formula (I); CH4N2X Formula (II);

[0015] Where n is an integer between 2 and 4, and X is 0 or S.

[0016] Preferably, the adjuvant is selected from at least one of starch, glucose, cotton, rice husk, and cellulose.

[0017] Preferably, the activated alumina precursor is aluminum stearate, the carbon nitride precursor is melamine, and the auxiliary agent is cellulose.

[0018] Preferably, the mass ratio of the activated alumina precursor, the carbon nitride precursor, and the additive is 1:0.1-0.5:0.1-0.5.

[0019] Preferably, the conditions for the heating reaction include at least: a temperature of 500-650°C and a time of 2-6 hours.

[0020] The third aspect of the present invention provides the application of the adsorbent described in the first aspect and / or the adsorbent obtained by the preparation method described in the second aspect in the removal of organic pollutants from wastewater.

[0021] Preferably, the organic pollutant is selected from at least one of N-methylpyrrolidone, phenol, cresol, dibromochloromethane, dibromochloromethane, dichloromethane, tribromomethane, chloroform, and carbon tetrachloride, and more preferably N-methylpyrrolidone.

[0022] The fourth aspect of the present invention provides a method for removing N-methylpyrrolidone from wastewater, comprising the following steps: using the adsorbent described in the first aspect and / or the adsorbent obtained by the preparation method described in the second aspect to mix with wastewater containing N-methylpyrrolidone for adsorption.

[0023] Preferably, the mass ratio of the adsorbent to the wastewater containing N-methylpyrrolidone is 0.03-0.15:1.

[0024] Preferably, the concentration of N-methylpyrrolidone in the wastewater is 100-10000 mg / L.

[0025] Preferably, the adsorption conditions include at least the following: a temperature of 40-90°C and a time of 30-120 min.

[0026] Preferably, the method further includes: separating the adsorbed product to obtain a solid adsorbed product, using a desorbent to desorb the solid adsorbed product to obtain a regenerated adsorbent, and continuing to mix the regenerated adsorbent with the wastewater for cyclic adsorption.

[0027] Preferably, the desorbent is ethanol and / or methanol, and more preferably ethanol.

[0028] Preferably, the mass ratio of the solid adsorption product to the desorbent is 1:1-5.

[0029] Preferably, the number of times the cycle is used is 1-5 times.

[0030] The beneficial effects of the present invention through the above technical solution are as follows:

[0031] The composite material adsorbent provided by this invention, through the synergistic effect of specific amounts of aluminum, nitrogen, and carbon elements, exhibits an adsorption rate of over 85% for N-methylpyrrolidone when the mass ratio of the adsorbent to a solution containing 5000 mg / L N-methylpyrrolidone is 0.1:1, demonstrating excellent adsorption performance. Furthermore, when used to remove organic pollutants from wastewater, this adsorbent effectively removes organic pollutants without causing secondary pollution to the environment.

[0032] The method for preparing composite material adsorbents provided by this invention obtains the adsorbent through the synergistic effect between activated alumina precursor, carbon nitride precursor and additives. The raw materials of this adsorbent are inexpensive and the preparation method is simple. It can effectively remove organic pollutants in wastewater and will not cause secondary pollution to the environment.

[0033] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0034] Figure 1 These are scanning electron microscope images of adsorbent D obtained in Examples 1-4. Detailed Implementation

[0035] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0036] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0037] The first aspect of this invention provides a composite material adsorbent containing activated alumina and carbon nitride. The adsorbent contains 9-26 wt% aluminum, 15-30 wt% nitrogen, and 24-40 wt% carbon. Under adsorption conditions where the mass ratio of the adsorbent to a solution containing N-methylpyrrolidone is 0.1:1, the adsorbent exhibits an adsorption rate of greater than 85% for N-methylpyrrolidone. The composite material adsorbent provided by this invention demonstrates a high adsorption rate for N-methylpyrrolidone in solution without causing environmental pollution.

[0038] In this invention, the adsorption rate (η) is calculated using the following formula:

[0039]

[0040] Where c0 is the concentration of N-methylpyrrolidone in the solution before adsorption begins, in mg / L; and c1 is the concentration of N-methylpyrrolidone in the solution when adsorption reaches equilibrium, in mg / L.

[0041] In this invention, the contents of aluminum, nitrogen and carbon in the adsorbent can be directly measured by scanning electron microscopy-elemental analysis (SEM-EDS).

[0042] In this invention, under adsorption conditions where the mass ratio of adsorbent to solution containing N-methylpyrrolidone is 0.1:1, there is no particular limitation on the concentration of N-methylpyrrolidone in the solution. Preferably, the concentration of N-methylpyrrolidone in the solution is 100-10000 mg / L. There is also no particular limitation on the adsorption temperature and time. Preferably, the adsorption temperature is 40-90℃ and the adsorption time is 30-120 min.

[0043] According to the present invention, when the concentration of N-methylpyrrolidone in the solution is 100-10000 mg / L and the mass ratio of the adsorbent to the solution containing 100-10000 mg / L N-methylpyrrolidone is 0.03-0.15:1, the adsorbent has a high adsorption rate for N-methylpyrrolidone, a wide range of applications, and significant market prospects.

[0044] For example, under adsorption conditions where the mass ratio of adsorbent to solution containing 100 mg / L N-methylpyrrolidone is 0.15:1, the adsorption rate of adsorbent for N-methylpyrrolidone is greater than 95%.

[0045] For example, under adsorption conditions where the mass ratio of adsorbent to solution containing 3000 mg / L N-methylpyrrolidone is 0.03:1, the adsorption rate of adsorbent for N-methylpyrrolidone is greater than 94%.

[0046] For example, under the adsorption conditions where the mass ratio of the adsorbent to the solution containing 8000 mg / L N-methylpyrrolidone is 0.08:1, the adsorption rate of the adsorbent for N-methylpyrrolidone is greater than 96%.

[0047] For example, under adsorption conditions where the mass ratio of adsorbent to solution containing 10000 mg / L N-methylpyrrolidone is 0.1:1, the adsorption rate of adsorbent for N-methylpyrrolidone is greater than 89%.

[0048] According to the present invention, after the composite material adsorbent adsorbs a solution containing N-methylpyrrolidone, it can be desorbed by a desorbent and reused for the adsorption of N-methylpyrrolidone in the solution, without generating solid waste and polluting the environment, thus realizing the recycling of the adsorbent and having significant economic benefits. To further improve the adsorption rate of the adsorbent for N-methylpyrrolidone in the solution, preferably, after 5 adsorption-desorption cycles, the adsorbent is adsorbed with a solution containing 5000 mg / L N-methylpyrrolidone at a mass ratio of 0.1:1, achieving an adsorption rate of more than 80% for N-methylpyrrolidone.

[0049] In this invention, after the adsorbent desorbs, N-methylpyrrolidone in the solution is adsorbed again under the above adsorption conditions. The solution refers to a solution containing N-methylpyrrolidone that has not been adsorbed by the adsorbent. The five adsorption-desorption cycles refer to the five adsorption-desorption processes carried out after the first adsorption-desorption of N-methylpyrrolidone in the solution.

[0050] According to the present invention, preferably, the specific surface area of ​​the adsorbent is 300-600 m². 2 The adsorbent provided by this invention has a high specific surface area and a high pore size, which further improves its adsorption rate for N-methylpyrrolidone in solution. The adsorbent has a pore size of 0.8-1.5 nm.

[0051] In this invention, the specific surface area and pore size of the adsorbent can be measured by the BET method.

[0052] The second aspect of the present invention provides a method for preparing a composite material adsorbent, comprising the following steps: mixing an activated alumina precursor, a carbon nitride precursor and an additive and heating them for reaction.

[0053] The preparation method provided by this invention is simple and easy to operate. The prepared adsorbent can effectively remove organic pollutants from wastewater without causing secondary pollution to the environment, and has significant economic benefits.

[0054] According to the present invention, in order to further improve the adsorption rate of the adsorbent for organic pollutants, preferably, the activated alumina precursor is an aluminum salt and / or an aluminum oxide. For example, the activated alumina precursor can be an aluminum salt, an aluminum oxide, or a mixture of an aluminum salt and an aluminum oxide.

[0055] According to the present invention, in order to further improve the adsorption rate of the adsorbent for organic pollutants, preferably, the aluminum salt is selected from at least one of aluminum nitrate, aluminum sulfate and aluminum stearate; and the aluminum oxide is aluminum oxide.

[0056] According to the present invention, in order to further improve the adsorption rate of the adsorbent for organic pollutants, preferably, the carbon nitride precursor is a compound represented by formula (I) and / or a compound represented by formula (II); (CH2N2) n Formula (I); CH4N2X Formula (II); where n is an integer from 2 to 4, specifically 2, 3 or 4, that is, the compound shown in Formula (I) is melamine, melamine or tetramelamine; X is O or S, that is, the compound shown in Formula (II) is urea or thiourea.

[0057] According to the present invention, preferably, the adjuvant is selected from at least one of starch, glucose, cotton, rice husk, and cellulose. The inventors have found that, under this preferred embodiment, the pore size of the adsorbent can be increased, thereby further improving the adsorption rate of the adsorbent for organic pollutants.

[0058] According to the present invention, in a preferred embodiment, the activated alumina precursor is aluminum stearate, the carbon nitride precursor is melamine, and the auxiliary agent is cellulose. The inventors have found that, under this preferred embodiment, the adsorption rate of the prepared adsorbent for organic pollutants is further improved through the synergistic effect between aluminum stearate, melamine, and the auxiliary agent.

[0059] All of the above substances can be obtained commercially.

[0060] According to the present invention, preferably, the mass ratio of the activated alumina precursor, the carbon nitride precursor, and the additive is 1:0.1-0.5:0.1-0.5. The inventors have found that, under this preferred embodiment, the synergistic effect between aluminum stearate, melamine, and the additive in a specific ratio further improves the adsorption rate of the prepared adsorbent for organic pollutants.

[0061] According to the present invention, in order to further improve the reaction rate and product yield of the heating reaction, preferably, the conditions of the heating reaction include at least: a temperature of 500-650°C, specifically 500°C, 550°C, 600°C, 650°C, or any value between the two aforementioned values; and a time of 2-6 hours, specifically 2 hours, 4 hours, 6 hours, or any value between the two aforementioned values.

[0062] As a particularly preferred embodiment of the present invention, the method for preparing the composite material adsorbent includes the following steps: mixing an activated alumina precursor, a carbon nitride precursor and an additive, and heating the mixture at a temperature of 500-650°C for 2-6 hours.

[0063] The activated alumina precursor is an aluminum salt and / or an aluminum oxide; the aluminum salt is selected from at least one of aluminum nitrate, aluminum sulfate, and aluminum stearate; the aluminum oxide is aluminum oxide; the carbon nitride precursor is a compound represented by formula (I) and / or a compound represented by formula (II); (CH2N2) n Formula (I); CH4N2X Formula (II); where n is an integer from 2 to 4, and X is 0 or S; the auxiliary agent is selected from at least one of starch, glucose, cotton, rice husk and cellulose; the mass ratio of the activated alumina precursor, the carbon nitride precursor and the auxiliary agent is 1:0.1-0.5:0.1-0.5.

[0064] Based on the preparation method provided by this invention, an adsorbent is prepared through the synergistic effect between activated alumina precursor, carbon nitride precursor and additives. The raw materials of this adsorbent are inexpensive and the preparation method is simple. It can effectively remove organic pollutants in wastewater and will not cause secondary pollution to the environment.

[0065] The third aspect of the present invention provides the application of the adsorbent described in the first aspect and / or the adsorbent obtained by the preparation method described in the second aspect in the removal of organic pollutants from wastewater.

[0066] In this invention, when the adsorbent described in the first aspect and / or the preparation method described in the second aspect are used to remove organic pollutants from wastewater, they can effectively remove organic pollutants from wastewater without causing secondary pollution to the environment, and have significant economic benefits.

[0067] According to the present invention, organic pollutants refer to organic substances that cause environmental pollution, such as phenolic compounds, chlorinated hydrocarbons, pesticides, dyes, etc. Preferably, the organic pollutant is selected from at least one of N-methylpyrrolidone, phenol, cresol, bromodichloromethane, dibromochloromethane, dichloromethane, tribromomethane, chloroform, and carbon tetrachloride, and more preferably N-methylpyrrolidone. The inventors have found that, under this preferred embodiment, the adsorbent can efficiently and energy-savingly treat N-methylpyrrolidone in wastewater.

[0068] The fourth aspect of the present invention provides a method for removing N-methylpyrrolidone from wastewater, comprising the following steps: using the adsorbent described in the first aspect and / or the adsorbent obtained by the preparation method described in the second aspect to mix with wastewater containing N-methylpyrrolidone for adsorption.

[0069] According to the present invention, in order to further improve the adsorption rate of the adsorbent for N-methylpyrrolidone in wastewater, preferably, the mass ratio of the adsorbent to the wastewater containing N-methylpyrrolidone is 0.03-0.15:1, specifically 0.03:1, 0.06:1, 0.09:1, 0.12:1, 0.15:1, or any value between the two aforementioned values.

[0070] According to the present invention, in order to further improve the adsorption rate of N-methylpyrrolidone in wastewater, preferably, the concentration of N-methylpyrrolidone in the wastewater is 100-10000 mg / L, specifically 100 mg / L, 1000 mg / L, 2000 mg / L, 3000 mg / L, 4000 mg / L, 5000 mg / L, 6000 mg / L, 7000 mg / L, 8000 mg / L, 9000 mg / L, 10000 mg / L, or any value between the two aforementioned values.

[0071] According to the present invention, in order to further improve the adsorption rate of N-methylpyrrolidone in wastewater, the adsorption conditions preferably include at least the following: a temperature of 40-90°C, specifically 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, or any value between the two aforementioned values; and a time of 30-120 min, specifically 30 min, 60 min, 90 min, 120 min, or any value between the two aforementioned values.

[0072] According to the present invention, preferably, the method further includes: separating the adsorbed product to obtain a solid adsorbed product, desorbing the solid adsorbed product with a desorbent to obtain a regenerated adsorbent, and continuing to mix the regenerated adsorbent with the wastewater for cyclic adsorption. The inventors have found that, under this preferred embodiment, the adsorbent can cyclically adsorb N-methylpyrrolidone from the wastewater without generating solid waste that pollutes the environment, thus reducing production costs.

[0073] According to the present invention, the desorbent is an organic solvent conventionally selected in the art for desorbing adsorbents. In order to further improve the desorption rate of the desorbent on the adsorbent, the desorbent is preferably ethanol and / or methanol, more preferably ethanol, and by way of example, anhydrous ethanol.

[0074] According to the present invention, in order to further improve the adsorption rate of N-methylpyrrolidone in wastewater, preferably, the mass ratio of the solid adsorption product to the desorbent is 1:1-5, specifically 1:1, 1:2, 1:3, 1:4, 1:5, or any value between the two aforementioned values.

[0075] According to the present invention, in order to further improve the adsorption rate of the adsorbent for N-methylpyrrolidone in wastewater, preferably, the number of times the adsorbent is recycled is 1-5 times, specifically 1 time, 2 times, 3 times, 4 times, or 5 times. It should be noted that the number of times the adsorbent is recycled (1-5 times) refers to 1-5 adsorption cycles performed after the initial adsorption-desorption of N-methylpyrrolidone in the wastewater.

[0076] The present invention will be described in detail below through embodiments.

[0077] In the following examples, alumina was purchased from Shanghai Lingfeng Chemical Reagent Co., Ltd., model number 1344-28-1; aluminum nitrate was purchased from Shanghai Maclean Biochemical Co., Ltd., model number 7784-27-2; aluminum sulfate was purchased from Shanghai Lingfeng Chemical Reagent Co., Ltd., model number 7784-31-8; aluminum stearate was purchased from Shanghai Aladdin Biotechnology Co., Ltd., model number 637-12-7; boehmite was purchased from the factory; melamine was purchased from Shanghai Lingfeng Chemical Reagent Co., Ltd., model number 461-58-5; melamine was purchased from Shanghai Lingfeng Chemical Reagent Co., Ltd. The following raw materials and reagents were purchased: 108-78-1 (model number); thiourea (model number 62-56-6); urea (model number 57-13-6); starch (model number 9005-84-9); glucose (model number 14431-43-7); cellulose (model number 9004-34-6); and glucose (model number 14431-43-7). Unless otherwise specified, all other raw materials and reagents were commercially available.

[0078] In the following examples, the adsorption rate (η) is calculated using the following formula:

[0079]

[0080] Where c0 is the concentration of N-methylpyrrolidone in the solution before adsorption begins, in mg / L; and c1 is the concentration of N-methylpyrrolidone in the solution when adsorption reaches equilibrium, in mg / L.

[0081] The contents of aluminum, nitrogen, and carbon in the adsorbent can be obtained by elemental analysis.

[0082] The specific surface area and pore size of the adsorbent were determined by the BET method.

[0083] Example 1-1

[0084] Alumina, melamine, and glucose were uniformly mixed in a mass ratio of 1:0.1:0.1 and then calcined at 500℃ for 2 hours to obtain a composite adsorbent, denoted as Adsorbent A.

[0085] Examples 1-2

[0086] Aluminum nitrate, dicyandiamide, and cotton were uniformly mixed in a mass ratio of 1:0.3:0.3 and then calcined at 600℃ for 4.5 h to obtain a composite adsorbent, denoted as Adsorbent B.

[0087] Examples 1-3

[0088] Aluminum sulfate, thiourea, and rice husks were uniformly mixed at a mass ratio of 1:0.3:0.5 and then calcined at 650℃ for 6 hours to obtain a composite adsorbent, denoted as adsorbent C.

[0089] Examples 1-4

[0090] Aluminum stearate, melamine, and cellulose were uniformly mixed in a mass ratio of 1:0.5:0.5 and then calcined at 650°C for 3 hours to obtain a composite adsorbent, denoted as adsorbent D.

[0091] The adsorbent D obtained in Examples 1-4 was imaged using a Zeiss Sigma 500 scanning electron microscope, and the resulting scanning electron microscope images of adsorbent D are shown below. Figure 1 As shown, this image is magnified 9000 times.

[0092] Examples 1-5

[0093] Aluminum stearate, alumina, melamine and cellulose were uniformly mixed in a mass ratio of 1:1:1:1 and then calcined at 650℃ for 3 hours to obtain a composite adsorbent, denoted as adsorbent E.

[0094] Examples 1-6

[0095] Aluminum stearate, melamine, urea and cellulose were uniformly mixed in a mass ratio of 1:0.25:0.25:0.5 and then calcined at 650℃ for 3 hours to obtain a composite adsorbent, denoted as adsorbent F.

[0096] Examples 1-7

[0097] Aluminum stearate, melamine, starch and cellulose were uniformly mixed in a mass ratio of 1:0.5:0.25:0.25 and then calcined at 650℃ for 3 hours to obtain a composite adsorbent, denoted as adsorbent G.

[0098] Examples 1-8

[0099] After uniformly mixing boehmite, urea and starch in a mass ratio of 1:0.5:0.5, the mixture was calcined at 650℃ for 3 hours to obtain a composite adsorbent, denoted as adsorbent H.

[0100] Examples 1-9

[0101] Aluminum stearate, melamine, and calcium carbonate were uniformly mixed in a mass ratio of 1:0.5:0.5 and then calcined at 650°C for 3 hours to obtain a composite adsorbent, denoted as Adsorbent I.

[0102] Examples 1-10

[0103] Aluminum stearate, melamine, and cellulose were uniformly mixed in a mass ratio of 1:0.5:0.5 and then calcined at 400℃ for 1 hour to obtain a composite adsorbent, denoted as adsorbent J.

[0104] Comparative Example 1-1

[0105] Aluminum stearate, melamine, and cellulose were uniformly mixed at a mass ratio of 1:0.05:1 and then calcined at 650℃ for 3 hours to obtain a composite adsorbent, denoted as adsorbent K.

[0106] Comparative Examples 1-2

[0107] Aluminum stearate, melamine, and cellulose were uniformly mixed at a mass ratio of 1:0.05:0.05 and then calcined at 650℃ for 3 hours to obtain a composite adsorbent, denoted as adsorbent L.

[0108] Comparative Examples 1-3

[0109] Aluminum stearate, melamine, and cellulose were uniformly mixed in a mass ratio of 1:2:2 and then calcined at 650°C for 3 hours to obtain a composite adsorbent, denoted as adsorbent M.

[0110] Comparative Examples 1-4

[0111] Aluminum stearate and melamine were uniformly mixed at a mass ratio of 1:0.5 and then calcined at 650℃ for 3 hours to obtain a composite adsorbent, denoted as adsorbent N.

[0112] Comparative Examples 1-5

[0113] Activated alumina (purchased from Shanghai Aladdin Biotechnology Co., Ltd., model number 1344-28-1) and carbon nitride (purchased from Shanghai Aladdin Biotechnology Co., Ltd., model number 143334-20-7) were mixed uniformly at a mass ratio of 1:0.8 and then compacted to obtain a composite material adsorbent, denoted as adsorbent O.

[0114] Test Example 1

[0115] The aluminum, nitrogen, and carbon contents of the adsorbents obtained in Examples 1-1 to 1-10 and Comparative Examples 1-1 to 1-5 were tested by elemental analysis, and the results are shown in Table 1.

[0116] Under the adsorption conditions of 0.1:1 mass ratio of the adsorbent to a solution containing N-methylpyrrolidone (N-methylpyrrolidone concentration of 5000 mg / L) in Examples 1-1 to 1-10 and Comparative Examples 1-1 to 1-5, at a temperature of 90°C and a time of 120 min, the adsorption rate of the adsorbent to N-methylpyrrolidone is shown in Table 1.

[0117] The specific surface area and pore size of the adsorbents prepared in Examples 1-1 to 1-10 and Comparative Examples 1-1 to 1-5 were tested using the BET method. The instrument used was a fully automatic specific surface area and porosity analyzer. The results are shown in Table 1.

[0118] Table 1

[0119]

[0120] Example 2-1

[0121] (1) Treatment of wastewater with N-methylpyrrolidone concentration of 3000 mg / L:

[0122] For wastewater with N-methylpyrrolidone content of 3000 mg / L, adsorbent A was added at a solid-liquid ratio of 0.03:1 to wastewater, and the reaction was carried out by stirring at 40℃ for 30 min. After the reaction, solid-liquid separation was performed to obtain solid adsorption products and liquid fractions. The N-methylpyrrolidone content of the liquid fraction was determined, and the adsorption rate of adsorbent A for N-methylpyrrolidone in the wastewater was calculated. The results are shown in Table 2.

[0123] (2) Treatment method of the obtained solid adsorption products and performance of cyclic removal of N-methylpyrrolidone:

[0124] The solid adsorbent product obtained from the removal of N-methylpyrrolidone was desorbed with anhydrous ethanol at a solid-liquid mass ratio of 1:2. After three shaking and washing cycles at room temperature (25℃), the solid and liquid components were separated (frequency of shaking: 6000 rad / min, time: 5 min each time), yielding the adsorbent recovery product and the liquid fraction. The N-methylpyrrolidone content of the liquid fraction was determined. The obtained adsorbent recovery product was dried to obtain regenerated adsorbent for continued recycling. This cycle was repeated five times. The adsorption rate of the regenerated adsorbent for N-methylpyrrolidone in the wastewater is shown in Table 2.

[0125] Example 2-2

[0126] (1) Treatment of wastewater with N-methylpyrrolidone concentration of 5000 mg / L:

[0127] For wastewater with N-methylpyrrolidone content of 5000 mg / L, adsorbent B was added at a solid-liquid ratio of 0.05:1 to wastewater, and the reaction was carried out by stirring at 60℃ for 60 min. After the reaction, solid-liquid separation was performed to obtain solid adsorption products and liquid fractions. The N-methylpyrrolidone content of the liquid fraction was determined, and the adsorption rate of adsorbent B for N-methylpyrrolidone in the wastewater was calculated. The results are shown in Table 2.

[0128] (2) Treatment method of the obtained solid adsorption products and performance of cyclic removal of N-methylpyrrolidone:

[0129] The solid adsorbent product obtained from the removal of N-methylpyrrolidone was desorbed with anhydrous ethanol at a solid-liquid mass ratio of 1:3. After three shaking and washing cycles at room temperature (25℃), the solid and liquid components were separated (frequency of shaking: 6000 rad / min, time: 5 min each time), yielding the adsorbent recovery product and the liquid fraction. The N-methylpyrrolidone content of the liquid fraction was determined. The obtained adsorbent recovery product was dried to obtain regenerated adsorbent for continued recycling. This cycle was repeated five times. The adsorption rate of N-methylpyrrolidone in the wastewater by the regenerated adsorbent is shown in Table 2.

[0130] Example 2-3

[0131] (1) Treatment of wastewater with N-methylpyrrolidone concentration of 8000 mg / L:

[0132] For wastewater with N-methylpyrrolidone content of 8000 mg / L, adsorbent C was added at a solid-liquid ratio of 0.08:1 to wastewater, and the reaction was carried out by stirring at 80℃ for 90 min. After the reaction, solid-liquid separation was performed to obtain solid adsorption products and liquid fractions. The N-methylpyrrolidone content of the liquid fraction was determined, and the adsorption rate of adsorbent A for N-methylpyrrolidone in the wastewater was calculated. The results are shown in Table 2.

[0133] (2) Treatment method of the obtained solid adsorption products and performance of cyclic removal of N-methylpyrrolidone:

[0134] The solid adsorbent product obtained after removing N-methylpyrrolidone was desorbed with anhydrous ethanol at a solid-liquid mass ratio of 1:4. After three shaking and washing cycles at room temperature (25℃), the solid and liquid components were separated (frequency of shaking: 6000 rad / min, time: 5 min each time), yielding the adsorbent recovery product and the liquid fraction. The N-methylpyrrolidone content of the liquid fraction was determined. The obtained adsorbent recovery product was dried to obtain regenerated adsorbent for continued recycling. This cycle was repeated 5 times. The adsorption rate of N-methylpyrrolidone in the wastewater by the regenerated adsorbent is shown in Table 2.

[0135] Examples 2-4

[0136] (1) Treatment of wastewater with N-methylpyrrolidone concentration of 10000 mg / L:

[0137] For wastewater with N-methylpyrrolidone content of 10000 mg / L, adsorbent D was added at a solid-liquid ratio of 0.1:1 to wastewater, and the reaction was carried out by stirring at 90℃ for 120 min. After the reaction, solid-liquid separation was performed to obtain solid adsorption products and liquid fractions. The N-methylpyrrolidone content of the liquid fraction was determined, and the adsorption rate of adsorbent A for N-methylpyrrolidone in the wastewater was calculated. The results are shown in Table 2.

[0138] (2) Treatment method of the obtained solid adsorption products and performance of cyclic removal of N-methylpyrrolidone:

[0139] The solid adsorbent product obtained after removing N-methylpyrrolidone was desorbed with anhydrous ethanol at a solid-liquid mass ratio of 1:5. After three shaking and washing cycles at room temperature (25℃), the solid and liquid components were separated (frequency of shaking: 6000 rad / min, time: 5 min each time), yielding the adsorbent recovery product and the liquid fraction. The N-methylpyrrolidone content of the liquid fraction was determined. The regenerated adsorbent obtained after drying the recovered adsorbent product was recycled and reused. This cycle was repeated five times. The adsorption rate of N-methylpyrrolidone in the wastewater by the regenerated adsorbent is shown in Table 2.

[0140] Examples 2-5

[0141] The method for removing N-methylpyrrolidone from wastewater was followed according to Examples 2-4, except that adsorbent D was replaced with adsorbent E.

[0142] Examples 2-6

[0143] The method for removing N-methylpyrrolidone from wastewater is the same as in Examples 2-4, except that adsorbent D is replaced with adsorbent F.

[0144] Examples 2-7

[0145] The method for removing N-methylpyrrolidone from wastewater was followed as described in Examples 2-4, except that adsorbent D was replaced with adsorbent G.

[0146] Examples 2-8

[0147] The method described in Examples 2-4 was used to remove N-methylpyrrolidone from wastewater, except that the N-methylpyrrolidone content in the wastewater was 100 mg / L and the solid-liquid ratio of the adsorbent to the wastewater was 0.15:1.

[0148] Examples 2-9

[0149] The method for removing N-methylpyrrolidone from wastewater was followed as described in Examples 2-4, except that adsorbent D was replaced with adsorbent H.

[0150] Example 2-10

[0151] The method for removing N-methylpyrrolidone from wastewater was followed according to Examples 2-4, except that adsorbent D was replaced with adsorbent I.

[0152] Example 2-11

[0153] The method for removing N-methylpyrrolidone from wastewater was followed according to Examples 2-4, except that adsorbent D was replaced with adsorbent J.

[0154] Example 2-12

[0155] Remove phenol from wastewater according to the methods in Examples 2-4.

[0156] Comparative Example 2-1

[0157] The method for removing N-methylpyrrolidone from wastewater was followed as described in Examples 2-4, except that adsorbent D was replaced with adsorbent K.

[0158] Comparative Example 2-2

[0159] The method for removing N-methylpyrrolidone from wastewater was followed according to Examples 2-4, except that adsorbent D was replaced with adsorbent L.

[0160] Comparative Examples 2-3

[0161] The method for removing N-methylpyrrolidone from wastewater was followed as described in Examples 2-4, except that adsorbent D was replaced with adsorbent M.

[0162] Comparative Examples 2-4

[0163] The method for removing N-methylpyrrolidone from wastewater was followed as described in Examples 2-4, except that adsorbent D was replaced with adsorbent N.

[0164] Test Example 2

[0165] The adsorption rates of the adsorbents and the regenerated adsorbents in Examples 2-1 to 2-12 and Comparative Examples 2-1 to 2-4 were tested, and the results are shown in Table 2.

[0166] Table 2

[0167]

[0168] As can be seen from the results in Table 2, compared with Comparative Examples 2-1 to 2-4, the adsorbent obtained by the preparation method provided by this invention can more effectively remove organic pollutants from wastewater. Furthermore, the adsorbent provided by this invention can cyclically adsorb organic pollutants from wastewater without generating solid waste that pollutes the environment, thus reducing production costs and demonstrating significant economic benefits.

[0169] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A composite material adsorbent, characterized in that, The adsorbent contains activated alumina and carbon nitride, wherein the content of aluminum in the adsorbent is 9-26 wt%, the content of nitrogen is 15-30 wt%, and the content of carbon is 24-40 wt%. Under the adsorption conditions where the mass ratio of the adsorbent to the solution containing 5000 mg / L N-methylpyrrolidone is 0.1:1, the adsorption rate of the adsorbent for N-methylpyrrolidone is greater than 85%.

2. The adsorbent according to claim 1, characterized in that, After five adsorption-desorption cycles, the adsorbent was adsorbed onto a solution containing 5000 mg / L N-methylpyrrolidone at a mass ratio of 0.1:1, and the adsorption rate of N-methylpyrrolidone was greater than 80%.

3. The adsorbent according to claim 1 or 2, characterized in that, The specific surface area of ​​the adsorbent is 300-600 m². 2 / g, with a pore size of 0.8-1.5nm.

4. A method for preparing a composite material adsorbent, characterized in that, The process includes the following steps: mixing an activated alumina precursor, a carbon nitride precursor, and an additive and then heating them to react.

5. The preparation method according to claim 4, characterized in that, The active alumina precursor is an aluminum salt and / or an aluminum oxide; Preferably, the aluminum salt is selected from at least one of aluminum nitrate, aluminum sulfate, and aluminum stearate; the aluminum oxide is aluminum oxide. Preferably, the carbon nitride precursor is a compound represented by formula (I) and / or a compound represented by formula (II); (CH2N2) n Formula (I); CH4N2X Formula (II); Where n is an integer between 2 and 4, and X is 0 or S; Preferably, the adjuvant is selected from at least one of starch, glucose, cotton, rice husk, and cellulose; Preferably, the activated alumina precursor is aluminum stearate, the carbon nitride precursor is melamine, and the auxiliary agent is cellulose.

6. The preparation method according to claim 4 or 5, characterized in that, The mass ratio of the activated alumina precursor, the carbon nitride precursor, and the additive is 1:0.1-0.5:0.1-0.5; Preferably, the conditions for the heating reaction include at least: a temperature of 500-650°C and a time of 2-6 hours.

7. The application of the adsorbent according to any one of claims 1 to 3 and / or the adsorbent obtained by the preparation method according to any one of claims 4 to 6 in the removal of organic pollutants from wastewater; Preferably, the organic pollutant is selected from at least one of N-methylpyrrolidone, phenol, cresol, dibromochloromethane, dibromochloromethane, dichloromethane, tribromomethane, chloroform, and carbon tetrachloride, and more preferably N-methylpyrrolidone.

8. A method for removing N-methylpyrrolidone from wastewater, characterized in that, The process includes the following steps: using the adsorbent described in any one of claims 1 to 3 and / or the adsorbent obtained by the preparation method described in any one of claims 4 to 6, and mixing it with wastewater containing N-methylpyrrolidone for adsorption.

9. The method according to claim 8, characterized in that, The mass ratio of the adsorbent to the wastewater containing N-methylpyrrolidone is 0.03-0.15:1; Preferably, the concentration of N-methylpyrrolidone in the wastewater is 100-10000 mg / L; Preferably, the adsorption conditions include at least the following: a temperature of 40-90°C and a time of 30-120 min.

10. The method according to claim 8 or 9, characterized in that, The method further includes: separating the adsorbed product to obtain a solid adsorbed product, using a desorbent to desorb the solid adsorbed product to obtain a regenerated adsorbent, and continuing to mix the regenerated adsorbent with the wastewater for cyclic adsorption; Preferably, the desorbent is ethanol and / or methanol, more preferably ethanol; Preferably, the mass ratio of the solid adsorption product to the desorbent is 1:1-5; Preferably, the number of times the cycle is used is 1-5 times.

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