A composite material for industrial wastewater treatment and its preparation method and application

Abstract

The invention discloses a composite material for industrial wastewater treatment and its preparation method and application, the preparation method comprises the following steps: S1, carbon nanotubes are added to ferrous sulfate and zinc chloride, tetrabutyl titanate solution is added dropwise, heating, NaOH solution is added, and stirring is continued, then filtering, washing, drying, roasting to obtain iron, zinc and titanium modified carbon nanotubes; S2, iron, zinc and titanium modified carbon nanotubes are placed in hydrogen peroxide solution, carboxymethyl chitosan, dicyclohexylcarbodiimide and N-hydroxysuccinimide are added, ultrasonic treatment, washing, drying to obtain modified carbon nanotubes; S3, attapulgite is dispersed in deionized water, stirred under heating to obtain attapulgite suspension, modified carbon nanotubes are added to attapulgite suspension to obtain mixed suspension; S4, the mixed suspension is subjected to vacuum filtration to induce self-assembly molding process, drying to obtain composite material. The composite material preparation method provided by the present invention is simple and easy to operate.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental protection, and in particular to a composite material for industrial sewage treatment, a preparation method and an application thereof. Background Art

[0002] Industrial wastewater often contains large amounts of organic matter, heavy metal ions, suspended solids, and other substances harmful to the ecological environment. If discharged directly without treatment, this wastewater can cause serious water pollution, damage the ecosystem, and endanger human health. Therefore, the development and application of efficient and economical wastewater treatment methods are crucial to achieving sustainable development and improving water resource utilization.

[0003] The application of composite materials in industrial wastewater treatment stems from their superior physical and chemical properties and good adaptability. By rationally designing the composition and structure of composite materials, wastewater treatment efficiency can be significantly improved. For example, pollutants can be removed from water through various methods such as adsorption, catalysis, and membrane separation. This new material, when applied to wastewater treatment, not only improves pollutant removal capabilities but also reduces energy consumption and operating costs during the treatment process, aligning with the current trend of energy conservation and emission reduction.

[0004] Composite materials are increasingly being used in industrial wastewater treatment, demonstrating unique advantages in heavy metal ion removal, organic matter degradation, and microbial degradation. In recent years, researchers have developed a variety of composite materials, such as polymer-inorganic composites, activated carbon composites, and porous materials, tailored to different types of wastewater. These composites, thanks to their excellent adsorption properties and large specific surface area, are capable of effectively removing pollutants from wastewater.

[0005] While composite materials have made significant progress in industrial wastewater treatment, they still face numerous challenges and issues in practical application. For example, the cost of composite material preparation, the difficulty of large-scale production, stability and regeneration during the treatment process, and low wastewater treatment efficiency are all technical bottlenecks that urgently need to be overcome. Green and sustainable development will become key considerations. During the material preparation process, the use of environmentally harmful chemicals must be avoided, and efforts must be made to develop environmentally friendly materials to reduce negative impacts on the ecosystem. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a composite material for industrial wastewater treatment and its preparation method and application, so as to solve the technical problems of low wastewater treatment efficiency and high material and preparation costs of current composite materials.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] The present invention provides a method for preparing a composite material for industrial wastewater treatment, comprising the following steps:

[0009] S1. Adding carbon nanotubes to a mixed solution of ferrous sulfate and zinc chloride, then dropwise adding tetrabutyl titanate solution, heating, adding NaOH solution under stirring, and continuing stirring for a period of time, then filtering, washing, drying, and calcining to obtain iron-zinc-titanium modified carbon nanotubes;

[0010] S2, soaking the iron-zinc-titanium modified carbon nanotubes in a hydrogen peroxide solution for a period of time, then adding carboxymethyl chitosan, dicyclohexylcarbodiimide and N-hydroxysuccinimide, ultrasonically treating the solution, washing the generated product, and drying the product to obtain modified carbon nanotubes;

[0011] S3, dispersing attapulgite in deionized water, stirring while heating in a water bath to obtain a attapulgite suspension, adding the modified carbon nanotubes to the attapulgite suspension, stirring while heating in a water bath to obtain a mixed suspension;

[0012] S4. The mixed suspension is subjected to vacuum filtration to induce self-assembly molding, and then dried to obtain an attapulgite-based composite material, i.e., a composite material for industrial wastewater treatment.

[0013] Preferably, in step S1, the molar concentration of the ferrous sulfate is 15 to 18 mmol / L, and the molar concentration of the zinc chloride is 12 to 15 mmol / L;

[0014] The usage ratio of the carbon nanotubes, ferrous sulfate, zinc chloride and tetrabutyl titanate solution is (1-3 g): (80-120 mL): (60-80 mL): (20-50 mL).

[0015] Preferably, in step S1, the heating temperature is 70-80°C;

[0016] The calcination temperature is 600-800°C.

[0017] Preferably, in step S2, the mass concentration of the hydrogen peroxide solution is 25-35%;

[0018] Preferably, in step S2, the usage ratio of the iron-zinc-titanium modified carbon nanotubes, carboxymethyl chitosan, dicyclohexylcarbodiimide and N-hydroxysuccinimide is (2-4 g): (3-9 g): (0.05-0.5 g): (0.01-0.2 g).

[0019] Preferably, in step S3, the water bath heating temperature is 55-65°C.

[0020] Preferably, in step S3, the usage ratio of the attapulgite and the modified carbon nanotubes is (4-8 g): (1-2 g).

[0021] Preferably, in step S4, the vacuum degree is 0.04-0.07 MPa;

[0022] The drying temperature is 40-50°C.

[0023] The present invention also provides a composite material prepared by the above-mentioned preparation method.

[0024] The present invention further proposes an application of the composite material as above, which is applied in industrial wastewater treatment.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The composite material for industrial wastewater treatment provided by the present invention is prepared from low-cost, renewable raw materials such as carbon nanotubes, chitosan and attapulgite, and the preparation method is simple and easy to operate, and is suitable for large-scale production.

[0027] (2) The preparation method of the composite material provided by the present invention comprises the following steps: firstly reacting carbon nanotubes with a metal salt solution to obtain iron-zinc-titanium modified carbon nanotubes, then grafting them onto chitosan, and then mixing with attapulgite and subjecting to self-assembly treatment to obtain the composite material. Carbon nanotubes have a high specific surface area and can effectively adsorb pollutants in water. The modification with iron, zinc and titanium further enhances their adsorption properties, especially for heavy metal ions such as lead, cadmium and mercury, thereby improving the efficiency of sewage treatment. The iron, zinc and titanium composite material can also act as a catalyst to promote the degradation reaction of organic pollutants in water, especially in redox reactions, accelerating the decomposition of pollutants and reducing the concentration of harmful substances in water. The carboxymethyl chitosan modification not only increases the dispersibility of the composite material in sewage, but also introduces amino, carboxyl and hydroxyl groups. These functional groups can form hydrogen bonds and electrostatic interactions with pollutants in water such as heavy metal ions and organic matter, significantly improving the removal rate of pollutants in sewage. At the same time, the hydrophobicity and surface activity provided by the polymer chain can promote the aggregation of particulate matter in sewage, thereby improving the sedimentation of sewage, reducing the time required for flocculation, and effectively improving the removal of suspended solids in sewage. Finally, through the hydrogen bond self-assembly process, the carbon nanotubes that are difficult to recycle can be attached to the attapulgite, improving its recyclability and maintaining its function in complex sewage environments, ensuring long-term and effective pollutant treatment capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a process flow chart of the preparation method of the composite material for industrial wastewater treatment provided by the present invention. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below through specific preferred embodiments, but the present invention is not limited to the following embodiments.

[0030] It should be noted that, unless otherwise specified, all chemical reagents involved in the present invention were purchased through commercial channels.

[0031] Example 1

[0032] A method for preparing a composite material for industrial wastewater treatment comprises the following steps:

[0033] (1) 2 g of carbon nanotubes were added to a mixed solution of 100 mL of ferrous sulfate with a molar concentration of 16 mmol / L and 70 mL of zinc chloride with a molar concentration of 17 mmol / L, and then 35 mL of tetrabutyl titanate solution was added dropwise. The mixture was heated to 75° C., and 10 mL of a 2% NaOH solution was added under stirring. The mixture was stirred for a period of time, and then filtered, washed, dried, and calcined at 700° C. to obtain iron-zinc-titanium modified carbon nanotubes.

[0034] (2) 3 g of iron-zinc-titanium-modified carbon nanotubes were placed in 20 mL of 30% hydrogen peroxide solution and soaked for a period of time. Then, 6 g of carboxymethyl chitosan, 0.2 g of dicyclohexylcarbodiimide, and 0.1 g of N-hydroxysuccinimide were added and ultrasonically treated. The resulting product was washed and dried to obtain modified carbon nanotubes.

[0035] (3) 6 g of attapulgite was dispersed in 10 mL of deionized water, and the mixture was heated in a water bath at 60° C. with stirring to obtain a attapulgite suspension. 1.5 g of modified carbon nanotubes was added to the attapulgite suspension, and the mixture was heated in a water bath at 60° C. with stirring to obtain a mixed suspension.

[0036] (4) The mixed suspension is subjected to vacuum filtration to induce self-assembly molding, and then dried at 45° C. to obtain a attapulgite-based composite material, i.e., a composite material for industrial wastewater treatment.

[0037] Example 2

[0038] A method for preparing a composite material for industrial wastewater treatment comprises the following steps:

[0039] (1) 1 g of carbon nanotubes was added to a mixed solution of 80 mL of 16 mmol / L ferrous sulfate and 60 mL of 17 mmol / L zinc chloride, and then 20 mL of tetrabutyl titanate solution was added dropwise. The mixture was heated to 75° C., and 10 mL of 2% NaOH solution was added under stirring. The mixture was stirred for a period of time, and then filtered, washed, dried, and calcined at 600° C. to obtain iron-zinc-titanium modified carbon nanotubes.

[0040] (2) 2 g of iron-zinc-titanium modified carbon nanotubes were placed in 20 mL of 30% hydrogen peroxide solution and soaked for a period of time. Then, 3 g of carboxymethyl chitosan, 0.05 g of dicyclohexylcarbodiimide, and 0.01 g of N-hydroxysuccinimide were added and ultrasonically treated. The resulting product was washed and dried to obtain modified carbon nanotubes.

[0041] (3) 4 g of attapulgite was dispersed in 10 mL of deionized water, and the mixture was heated in a water bath at 60° C. with stirring to obtain a attapulgite suspension. 1 g of modified carbon nanotubes was added to the attapulgite suspension, and the mixture was heated in a water bath at 60° C. with stirring to obtain a mixed suspension.

[0042] (4) The mixed suspension is subjected to vacuum filtration to induce self-assembly molding, and then dried at 40° C. to obtain a attapulgite-based composite material, that is, a composite material for industrial wastewater treatment.

[0043] Example 3

[0044] A method for preparing a composite material for industrial wastewater treatment comprises the following steps:

[0045] (1) 3 g of carbon nanotubes were added to a mixed solution of 120 mL of ferrous sulfate with a molar concentration of 16 mmol / L and 80 mL of zinc chloride with a molar concentration of 17 mmol / L, and then 50 mL of tetrabutyl titanate solution was added dropwise. The mixture was heated to 80° C., and 10 mL of a 2% NaOH solution was added under stirring. The mixture was stirred for a period of time, and then filtered, washed, dried, and calcined at 800° C. to obtain iron-zinc-titanium modified carbon nanotubes.

[0046] (2) 4 g of iron-zinc-titanium-modified carbon nanotubes were placed in 20 mL of 30% hydrogen peroxide solution and soaked for a period of time. Then, 9 g of carboxymethyl chitosan, 0.5 g of dicyclohexylcarbodiimide, and 0.2 g of N-hydroxysuccinimide were added and ultrasonically treated. The resulting product was washed and dried to obtain modified carbon nanotubes.

[0047] (3) 8 g of attapulgite was dispersed in 10 mL of deionized water, and the mixture was heated in a water bath at 60° C. with stirring to obtain a attapulgite suspension. 2 g of modified carbon nanotubes was added to the attapulgite suspension, and the mixture was heated in a water bath at 60° C. with stirring to obtain a mixed suspension.

[0048] (4) The mixed suspension is subjected to vacuum filtration to induce self-assembly molding, and then dried at 50° C. to obtain a attapulgite-based composite material, that is, a composite material for industrial wastewater treatment.

[0049] Comparative Example 1

[0050] A method for preparing a composite material for industrial wastewater treatment comprises the following steps:

[0051] (1) 2 g of carbon nanotubes were added to a mixed solution of 100 mL of 16 mmol / L ferrous sulfate and 70 mL of 17 mmol / L zinc chloride, and heated to 75° C. 10 mL of 2% NaOH solution was added under stirring, and stirring was continued for a period of time. The mixture was then filtered, washed, dried, and calcined at 700° C. to obtain iron-zinc-modified carbon nanotubes.

[0052] (2) 3 g of iron-zinc-modified carbon nanotubes were placed in 20 mL of 30% hydrogen peroxide solution and soaked for a period of time. Then, 6 g of carboxymethyl chitosan, 0.2 g of dicyclohexylcarbodiimide, and 0.1 g of N-hydroxysuccinimide were added and ultrasonically treated. The resulting product was washed and dried to obtain modified carbon nanotubes.

[0053] (3) 6 g of attapulgite was dispersed in 10 mL of deionized water, and the mixture was heated in a water bath at 60° C. with stirring to obtain a attapulgite suspension. 1.5 g of modified carbon nanotubes was added to the attapulgite suspension, and the mixture was heated in a water bath at 60° C. with stirring to obtain a mixed suspension.

[0054] (4) The mixed suspension is subjected to vacuum filtration to induce self-assembly molding, and then dried at 45° C. to obtain a attapulgite-based composite material, i.e., a composite material for industrial wastewater treatment.

[0055] Compared with Example 1, the carbon nanotubes of Comparative Example 1 were not mixed with the tetrabutyl titanate solution.

[0056] Comparative Example 2

[0057] A method for preparing a composite material for industrial wastewater treatment comprises the following steps:

[0058] (1) 3 g of carbon nanotubes were placed in 20 mL of 30% hydrogen peroxide solution and soaked for a period of time. Then, 6 g of carboxymethyl chitosan, 0.2 g of dicyclohexylcarbodiimide, and 0.1 g of N-hydroxysuccinimide were added and ultrasonicated. The resulting product was washed and dried to obtain modified carbon nanotubes.

[0059] (2) 6 g of attapulgite was dispersed in 10 mL of deionized water, and the mixture was heated in a water bath at 60° C. with stirring to obtain a attapulgite suspension. 1.5 g of modified carbon nanotubes was added to the attapulgite suspension, and the mixture was heated in a water bath at 60° C. with stirring to obtain a mixed suspension.

[0060] (3) The mixed suspension is subjected to vacuum filtration to induce self-assembly molding, and then dried at 45° C. to obtain a attapulgite-based composite material, that is, a composite material for industrial wastewater treatment.

[0061] Compared with Example 1, the carbon nanotubes in Comparative Example 2 were not modified with iron, zinc and titanium.

[0062] Comparative Example 3

[0063] A method for preparing a composite material for industrial wastewater treatment comprises the following steps:

[0064] (1) 2 g of carbon nanotubes were added to a mixed solution of 100 mL of ferrous sulfate with a molar concentration of 16 mmol / L and 70 mL of zinc chloride with a molar concentration of 17 mmol / L, and then 35 mL of tetrabutyl titanate solution was added dropwise. The mixture was heated to 75° C., and 10 mL of a 2% NaOH solution was added under stirring. The mixture was stirred for a period of time, and then filtered, washed, dried, and calcined at 700° C. to obtain iron-zinc-titanium modified carbon nanotubes.

[0065] (2) 3 g of iron-zinc-titanium modified carbon nanotubes were placed in 20 mL of a 30% hydrogen peroxide solution and soaked for a period of time. 0.2 g of dicyclohexylcarbodiimide and 0.1 g of N-hydroxysuccinimide were then added and ultrasonicated. The resulting product was washed and dried to obtain a solid.

[0066] (3) 6 g of attapulgite was dispersed in 10 mL of deionized water, and the mixture was heated in a water bath at 60° C. with stirring to obtain a attapulgite suspension. 1.5 g of the solid was added to the attapulgite suspension, and the mixture was heated in a water bath at 60° C. with stirring to obtain a mixed suspension.

[0067] (4) The mixed suspension is subjected to vacuum filtration to induce self-assembly molding, and then dried at 45° C. to obtain a attapulgite-based composite material, i.e., a composite material for industrial wastewater treatment.

[0068] Compared with Example 1, the iron-zinc-titanium modified carbon nanotubes of Comparative Example 3 did not react with chitosan.

[0069] Comparative Example 4

[0070] A method for preparing a composite material for industrial wastewater treatment comprises the following steps:

[0071] (1) 2 g of carbon nanotubes were added to a mixed solution of 100 mL of ferrous sulfate with a molar concentration of 16 mmol / L and 70 mL of zinc chloride with a molar concentration of 17 mmol / L, and then 35 mL of tetrabutyl titanate solution was added dropwise. The mixture was heated to 75° C., and 10 mL of a 2% NaOH solution was added under stirring. The mixture was stirred for a period of time, and then filtered, washed, dried, and calcined at 700° C. to obtain iron-zinc-titanium modified carbon nanotubes.

[0072] (2) 3 g of iron-zinc-titanium modified carbon nanotubes were placed in 20 mL of 30% hydrogen peroxide solution and soaked for a period of time. Then, 6 g of carboxymethyl chitosan, 0.2 g of dicyclohexylcarbodiimide and 0.1 g of N-hydroxysuccinimide were added and ultrasonically treated. The resulting product was washed and dried to obtain modified carbon nanotubes.

[0073] Compared with Example 1, the modified carbon nanotubes in Comparative Example 4 were not subjected to self-assembly molding treatment with attapulgite.

[0074] Test methods and results

[0075] Test Example 1

[0076] Prepare As with an initial concentration of 500 mg / L 3+ Cr 3+ , Pb 2+ 、Ni + 、Hg 2+ The metal ion aqueous solution was used to simulate chemical heavy metal wastewater, and then the composite materials obtained in Examples 1 to 3 and Comparative Examples 1 to 4 were used for treatment (the mass volume ratio of the composite material to the heavy metal wastewater was 1 g:1 L). After the treatment was completed (temperature 25°C, treatment time 30 minutes), the filtrate was filtered to obtain the filtrate. The metal ion concentration of the filtrate and the heavy metal wastewater before treatment was analyzed and detected by flame atomic absorption spectrophotometry, and the adsorption capacity of the composite material, that is, the mass of metal ions adsorbed by the unit mass of the composite material, was calculated. The results are shown in Table 1.

[0077] Table 1 Adsorption statistics

[0078]

[0079] Test Example 2

[0080] Take the wastewater of a metallurgical chemical plant as an example. The water quality is as follows: the chemical oxygen demand (COD) concentration is 4259 mg / L, the metal ions (including As 3+ Cr 3+ , Pb 2+ 、Ni + 、Hg 2+ ) with a total content of 23535 mg / L. Treatment was performed using the composite materials of Examples 1-3 and Comparative Examples 1-3, respectively (composite material to wastewater mass volume ratio of 1 g:1 L, temperature 25°C, treatment time 30 minutes). The effluent quality is shown in Table 2. The metal ion content before treatment was determined by EDTA complexometric titration, and the metal ion content after treatment was determined by atomic absorption spectroscopy.

[0081] Table 2 Water quality of effluent

[0082]

[0083]

[0084] Test Example 3

[0085] The reaction solution of Experiment 2 was allowed to settle, and then solid-liquid separation was performed to separate the composite material solid adsorbed with heavy metal ions and dried at 80°C for 36 hours to constant weight. The composite material solid was then washed with a disodium salt solution of ethylenediaminetetraacetic acid having a molar concentration of 0.02 mol / L to desorb the heavy metal ions. The solid was then precipitated again to separate the solid and dried at 80°C for 36 hours. The recovery rate was calculated by weighing to obtain Table 3.

[0086] Table 3 Recovery rate

[0087] Group Recovery rate (%) Example 1 92％ Example 2 89％ Example 3 90％ Comparative Example 1 72％ Comparative Example 2 68％ Comparative Example 3 31％ Comparative Example 4 19％

[0088] As shown in Table 1, compared with Comparative Examples 1 to 4, the composite materials provided by Examples 1 to 3 of the present invention have a high 3+ Cr 3+ , Pb 2+ 、Ni + 、Hg 2+ All have good adsorption capacity; as shown in Table 2, the composite materials provided by Examples 1 to 3 of the present invention can effectively reduce COD and metal ion content; as shown in Table 3, the composite materials provided by Examples 1 to 3 of the present invention have a high recovery rate and can be reused.

[0089] Finally, it should be noted that the above embodiments do not limit the present invention in any form. Those skilled in the art will appreciate that modifications and improvements can be made based on the present invention. Therefore, any modifications or improvements made without departing from the spirit of the present invention are intended to fall within the scope of protection claimed in the present invention.

Claims

1. A method for preparing a composite material for industrial wastewater treatment, characterized in that: The following steps are involved: S1. Adding carbon nanotubes to a mixed solution of ferrous sulfate and zinc chloride, then dropwise adding tetrabutyl titanate solution, heating, adding NaOH solution under stirring, and continuing stirring for a period of time, then filtering, washing, drying, and calcining to obtain iron-zinc-titanium modified carbon nanotubes; S2, soaking the iron-zinc-titanium modified carbon nanotubes in a hydrogen peroxide solution for a period of time, then adding carboxymethyl chitosan, dicyclohexylcarbodiimide and N-hydroxysuccinimide, ultrasonically treating the solution, washing the generated product, and drying the product to obtain modified carbon nanotubes; S3, dispersing attapulgite in deionized water, stirring while heating in a water bath to obtain a attapulgite suspension, adding the modified carbon nanotubes to the attapulgite suspension, stirring while heating in a water bath to obtain a mixed suspension; S4. The mixed suspension is subjected to vacuum filtration to induce self-assembly molding, and then dried to obtain an attapulgite-based composite material, i.e., a composite material for industrial wastewater treatment.

2. The method for preparing a composite material for industrial wastewater treatment according to claim 1, characterized in that: In step S1, the heating temperature is 70-80°C; The calcination temperature is 600-800°C.

3. The method for preparing a composite material for industrial wastewater treatment according to claim 1, characterized in that: In step S2, the mass concentration of the hydrogen peroxide solution is 25-35%.

4. The method for preparing a composite material for industrial wastewater treatment according to claim 1, characterized in that: In step S2, the usage ratio of the iron-zinc-titanium modified carbon nanotubes, carboxymethyl chitosan, dicyclohexylcarbodiimide and N-hydroxysuccinimide is (2-4 g): (3-9 g): (0.05-0.5 g): (0.01-0.2 g).

5. The method for preparing a composite material for industrial wastewater treatment according to claim 1, characterized in that: In step S3, the water bath is heated at a temperature of 55-65°C.

6. The method for preparing a composite material for industrial wastewater treatment according to claim 1, characterized in that: In step S3, the usage ratio of attapulgite and modified carbon nanotubes is (4-8 g): (1-2 g).

7. The method for preparing a composite material for industrial wastewater treatment according to claim 1, characterized in that: In step S4, the vacuum degree of vacuum filtration is 0.04-0.07 MPa; The drying temperature is 40-50°C.

8. A composite material prepared by the preparation method according to any one of claims 1 to 7.

9. Use of the composite material according to claim 8, characterized in that: Used in industrial wastewater treatment.

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