CN104525227A - Preparation method for environment-friendly advanced water treatment agent by combining carbon nano tube and Ag/BiOX - Google Patents

Abstract

The invention relates to a preparation method of carbon nanotube composite Ag/BiOX green deep water treatment agent, comprising: (1) sequentially carboxylating carbon nanotubes, amination modification, 2,4,6-trifluoro-5- Preparation of reactive carbon nanotubes by chloropyrimidine modification; (2) adding Ag/BiOX (X=Cl, Br, I), stabilizer, template and reactive carbon nanotubes to phosphate buffer, stirring for 30- After 60 minutes, a suspension is formed; (3) filter and dry to obtain the product. The invention has the advantages of low cost, simple preparation method, low requirements on equipment, and good operability; the water treatment agent of the invention can remove high-concentration organic pollutants in water, is suitable for advanced treatment of various waste water, and is environmentally friendly without secondary pollution , and has the advantages of antibacterial, deodorizing, and can adsorb other heavy metal ions.

Description

A preparation method of carbon nanotube composite Ag/BiOX green deep water treatment agent

technical field

The invention belongs to the field of water treatment agents, in particular to a preparation method of a carbon nanotube composite Ag/BiOX green deep water treatment agent.

Background technique

Only about 10% of the world's water is directly used by humans. The largest share, 70%, is used in agriculture, and the remaining 20% is used in industry. China's sewage is about 20% of the world's, but it only gets 5% of the world's fresh water. Therefore, solving the pollution problem is on the agenda. In the processing of textile printing and dyeing, leather, and papermaking industries, a large number of additives that pollute the environment and are harmful to the human body are used. Most of these additives are discharged in the form of liquid and pollute the environment. They have poor biodegradability, high toxicity, and high content of free formaldehyde. The content of heavy metal ions exceeds the standard. Among them, printing and dyeing wet finishing is indisputably a major water polluter. From sizing to desizing, washing, bleaching, mercerizing, dyeing and printing, and possibly coating, each process involves washing, and each process requires 20L of water per kilogram of material. The result is up to 200 liters of water per kilogram of raw cotton added up during wet finishing. When a standard men's shirt is customized and displayed in the shop window, more than 2000L of water is used in the production and processing of it (fabric: pure cotton, 125g/m).

The methods currently used to treat wastewater mainly include: physical separation, biodegradation, and chemical decomposition, but these methods have certain limitations and are not conducive to sustainable development. Therefore, people began to devote themselves to the development of pollutant removal technology with high efficiency, low energy consumption, wide application range and deep oxidation ability. In recent years, many scholars have used Ag/BiOX (X=Cl, Br, I) for photocatalytic degradation of organic pollutants in water, and loaded Ag/BiOX (X=Cl, Br, I) on carbon nanotubes to prepare high-efficiency Photocatalysts have become a hot research topic.

Contents of the invention

The technical problem to be solved by the present invention is to provide a preparation method of carbon nanotube composite Ag/BiOX green advanced water treatment agent, the method is simple to operate, low in cost, and has low requirements on equipment; the water treatment agent is suitable for the treatment of various waste water Advanced treatment, environmental protection and no secondary pollution.

A kind of preparation method of carbon nanotube composite Ag/BiOX green advanced water treatment agent of the present invention comprises:

(1) Ultrasonically react the carbon nanotubes in a mixture of H ₂ SO ₄ and HNO ₃ at room temperature for 30-60 minutes, wash with water until neutral, and dry in vacuum at room temperature to obtain carboxylated carbon nanotubes; then disperse the carboxylated carbon nanotubes Add 2-(7-azobenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate to excess diethylenetriamine, react at 40~50℃ for 5~6h , washed with ethanol, and vacuum-dried at room temperature to obtain aminated carbon nanotubes; then ultrasonically disperse the aminated carbon nanotubes into a mixture of water and acetone, adjust the pH value to 5-6, add 2,4, 6-trifluoro-5-chloropyrimidine, adjust the pH value to 6-6.5, ultrasonically react at 20-30°C for 24-48 hours, wash with ethanol, wash with water, dry in vacuum at room temperature, and irradiate (irradiate under 222nm excimer ultraviolet light source 3min) to obtain reactive carbon nanotubes;

(2) Add Ag/BiOX, stabilizer, template agent and reactive carbon nanotubes in step (1) to phosphate buffer, stir for 30-60min to form a suspension; wherein, Ag/BiOX reacts with The mass ratio of type carbon nanotubes is 1:5～1:20; X is Cl, Br or I;

(3) Adjust the pH value to 5-6 with an alkaline solution, heat to 80-100° C. to reflux for 6-24 hours, and filter to obtain a carbon nanotube composite Ag/BiOX green advanced water treatment agent.

The ratio of carbon nanotubes to H ₂ SO ₄ and HNO ₃ mixture in the step (1) is 10-20g:4L; wherein, the volume ratio of H ₂ SO ₄ and HNO ₃ is 1:1-5:1 .

The mass ratio of the carboxylated carbon nanotubes in the step (1) to 2-(7-azobenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphoric acid is 5 ~8:0.1~0.6.

The ratio of the aminated carbon nanotube to the mixture of water and acetone in the step (1) is 4-4.5g:1L; wherein, the volume ratio of water and acetone is 3:1-5:1.

The mass ratio of the aminated carbon nanotubes to 2,4,6-trifluoro-5-chloropyrimidine in the step (1) is 4-4.5:4-6.

In the step (1), sodium carbonate solution is used to adjust the pH value.

The Ag/BiOX concentration in the step (2) is 0.01-0.2 mol/L.

The stabilizer in the step (2) is one of disodium edetate, tetrasodium edetate, sodium gluconate, butane tetracarboxylic acid; the concentration of stabilizer is 0.01～0.1mol/ L.

The template in the step (2) is a mixture of tri-block polyether P123 and tri-block copolymer F127 with a mass ratio of 1:3; the template concentration is 0.01-0.1 mol/L.

The phosphate buffer in the step (2) is composed of 0.025-0.05 mol/L sodium dihydrogen phosphate and 0.05-0.1 mol/L sodium hydrogen phosphate.

The alkaline solution in the step (3) is an aqueous solution of sodium hydroxide or potassium hydroxide with a concentration of 0.5mol/L˜1.5mol/L.

As a porous substance, carbon nanotubes have special interlayer characteristics, and Ag/BiOX particles can be loaded on the surface to prepare supported catalysts. The supported photocatalyst can improve the dispersibility of the photocatalyst, which is beneficial to recycling and reuse.

The present invention combines the characteristics of porous carbon nanotubes, strong adsorption capacity, and easy separation from water with the photocatalytic activity of Ag/BiOX, and successfully loads nano Ag/BiOX (X=Cl, Br, I) on carbon nanotubes. On the tube, a visible light photocatalytic material with high catalytic activity that can be suspended in wastewater and can be successfully separated from water is prepared, and it is applied to the advanced treatment of wastewater, which can realize the oxidation and removal of high-concentration organic pollutants in water, while It is not transferred to other places, it is an environmentally friendly process technology.

Beneficial effect

(1) The present invention has low cost, simple preparation method, low requirement on equipment, and good operability;

(2) The water treatment agent of the present invention can remove high-concentration organic pollutants in water, is suitable for advanced treatment of various waste water, is environmentally friendly without secondary pollution, and has the advantages of antibacterial, deodorizing, and can adsorb other heavy metal ions;

(3) The water treatment agent of the present invention can overcome the deficiency of the existing bismuth-based water treatment agent, has good water treatment effect and can be recycled.

Detailed ways

Below in conjunction with specific embodiment, further illustrate the present invention. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

Example 1

(1) 10 g of carbon nanotubes were ultrasonically reacted at room temperature for 30 min in 4 L of H ₂ SO ₄ and HNO ₄ mixed solution with a volume ratio of 1:1, washed with water until neutral, and vacuum-dried at room temperature for 48 h to obtain 5 g of carboxylated carbon nanotubes ; Then the above-mentioned 5g carboxylated carbon nanotubes were dispersed in excess diethylenetriamine, and 100mg 2-(7-azobenzotriazole)-N,N,N',N'-tetramethylurea hexa Fluorophosphate, reacted at 40°C for 5 hours, washed with ethanol, and dried in vacuum at room temperature for 48 hours to obtain 4g of aminated carbon nanotubes; finally, 4g of aminated carbon nanotubes were ultrasonically dispersed in 1L of a mixture of water and acetone with a volume ratio of 3:1 In the solution, use sodium carbonate solution to adjust the pH value to 5, add 4 g of 2,4,6-trifluoro-5-chloropyrimidine dropwise in an ice-water bath, use sodium carbonate solution to adjust the pH value to 6, perform ultrasonic reaction at 20°C for 24 hours, and wash with ethanol , washed with water, vacuum-dried at room temperature for 48 hours, and irradiated under a 222nm excimer ultraviolet light source for 3 minutes to obtain reactive carbon nanotubes;

(2) the mixture of Ag/BiOCl, disodium edetate, mass ratio of triblock polyether P123 and triblock copolymer F127 of 1:3 and reactive carbon nanotubes in the above step (1) Add to the buffer solution composed of 0.025mol/L sodium dihydrogen phosphate and 0.05mol/L sodium hydrogen phosphate, stir for 30min to form a suspension; the concentration of Ag/BiOCl is 0.01mol/L, the concentration of stabilizer is 0.01mol/L, and the concentration of template agent is 0.05mol/L.

(3) Adjust the pH value of the above-mentioned suspension to 5 with an aqueous sodium hydroxide solution with a concentration of 0.5mol/L, heat at 80°C, reflux for 6h, and filter to obtain a reaction product; wherein the mass ratio of Ag/BiOCl to carbon nanotubes 1:5.

Example 2

(1) 10 g of carbon nanotubes were ultrasonically reacted at room temperature for 45 min in 4 L of H ₂ SO ₄ and HNO ₄ mixed solution with a volume ratio of 3:1, washed with water until neutral, and vacuum-dried at room temperature for 54 h to obtain 6.5 g of carboxylated carbon nanotubes. tube; then the above 5g carboxylated carbon nanotubes were dispersed into excess diethylenetriamine, and 300mg 2-(7-azobenzotriazole)-N,N,N',N'-tetramethylurea was added Hexafluorophosphate, reacted at 45°C for 5 hours, washed with ethanol, and dried in vacuum at room temperature for 48 hours to obtain 4.2 g of aminated carbon nanotubes; finally, ultrasonically dispersed 4.2 g of aminated carbon nanotubes in 1 L of water with a volume ratio of 4:1 and In the mixed solution of acetone, use sodium carbonate solution to adjust the pH value to 5.5, add 5g of 2,4,6-trifluoro-5-chloropyrimidine dropwise in an ice-water bath, use sodium carbonate solution to adjust the pH value to 6.2, and conduct ultrasonic reaction at 25°C for 36 hours , washed with ethanol, washed with water, dried in vacuum at room temperature for 48 hours, and irradiated for 3 minutes under a 222nm excimer ultraviolet light source to obtain reactive carbon nanotubes;

(2) Ag/BiOBr, sodium gluconate, a mixture of triblock polyether P123 and triblock copolymer F127 with a mass ratio of 1:3 and reactive carbon nanotubes in the above step (1) are added to a concentration of In the buffer composed of 0.03mol/L sodium dihydrogen phosphate and 0.05mol/L sodium hydrogen phosphate, stir for 45min to form a suspension; the concentration of Ag/BiOBr is 0.01mol/L, and the concentration of stabilizer is 0.03mol/L L, the concentration of template agent is 0.07mol/L.

(3) Adjust the pH value of the above-mentioned suspension to 7 with an aqueous sodium hydroxide solution with a concentration of 0.5mol/L, heat at 90°C, reflux for 16h, and filter to obtain a reaction product; wherein the mass ratio of Ag/BiOBr to carbon nanotubes for 1:15.

Example 3

(1) 10 g of carbon nanotubes were ultrasonically reacted at room temperature for 60 min in 4 L of H ₂ SO ₄ and HNO ₄ mixed solution with a volume ratio of 5:1, washed with water until neutral, and vacuum-dried at room temperature for 60 h to obtain 8 g of carboxylated carbon nanotubes ; Then the above-mentioned 8g carboxylated carbon nanotubes were dispersed in excess diethylenetriamine, and 600mg 2-(7-azobenzotriazole)-N,N,N',N'-tetramethylurea hexa Fluorophosphate, reacted at 50°C for 5h, washed with ethanol, and dried in vacuum at room temperature for 48h to obtain 4.5g of aminated carbon nanotubes; finally, 4.5g of aminated carbon nanotubes were ultrasonically dispersed in 1L of water and acetone with a volume ratio of 5:1 In the mixed solution, adjust the pH value to 6 with sodium carbonate solution, add 6 g of 2,4,6-trifluoro-5-chloropyrimidine dropwise in an ice-water bath, adjust the pH value to 6.5 with sodium carbonate solution, and perform ultrasonic reaction at 30°C for 48 hours. Washing with ethanol, washing with water, vacuum drying at room temperature for 48 hours, and irradiating for 3 minutes under a 222nm excimer ultraviolet light source to obtain reactive carbon nanotubes;

(2) Ag/BiOI, butane tetracarboxylic acid, a mixture of triblock polyether P123 and triblock copolymer F127 with a mass ratio of 1:3 and reactive carbon nanotubes in the above step (1) were added to In the buffer solution composed of 0.05mol/L sodium dihydrogen phosphate and 0.1mol/L sodium hydrogen phosphate, stir for 60min to form a suspension; the concentration of Ag/BiOI is 0.15mol/L, and the concentration of stabilizer is 0.05mol /L, the concentration of template agent is 0.1mol/L.

(3) Adjust the pH value of the above-mentioned suspension to 9 with an aqueous potassium hydroxide solution with a concentration of 1.5mol/L, heat at 100°C, reflux for 24h, and filter to obtain a reaction product; wherein the mass ratio of Ag/BiOI to carbon nanotubes for 1:20.

Taking the printing and dyeing wastewater of the printing and dyeing factory sampled at the same time as the treatment object, adding different concentrations of the water treatment agents obtained in Examples 1 to 3 to the wastewater, after 6 hours of sunlight, the decolorization rate of the water treatment agent on the printing and dyeing wastewater is as follows As shown in the table:

Decolorization rate COD removal rate Example 1 99.4% 91.2% Example 2 99.3% 91.3% Example 3 99.5% 92.6%

Claims (10)

1. A preparation method of carbon nanotube composite Ag/BiOX green deep water treatment agent, comprising: (1) Ultrasonically react the carbon nanotubes in a mixture of H ₂ SO ₄ and HNO ₃ at room temperature for 30-60 minutes, wash with water until neutral, and dry in vacuum at room temperature to obtain carboxylated carbon nanotubes; then disperse the carboxylated carbon nanotubes Add 2-(7-azobenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate to excess diethylenetriamine, react at 40~50℃ for 5~6h , washed with ethanol, and vacuum-dried at room temperature to obtain aminated carbon nanotubes; then ultrasonically disperse the aminated carbon nanotubes into a mixture of water and acetone, adjust the pH value to 5-6, add 2,4, 6-trifluoro-5-chloropyrimidine, adjust the pH value to 6-6.5, ultrasonically react at 20-30°C for 24-48 hours, wash with ethanol, wash with water, dry in vacuum at room temperature, and irradiate to obtain reactive carbon nanotubes; (2) Add Ag/BiOX, stabilizer, template agent and reactive carbon nanotubes in step (1) to phosphate buffer, stir for 30-60min to form a suspension; wherein, Ag/BiOX reacts with The mass ratio of type carbon nanotubes is 1:5～1:20; X is Cl, Br or I; (3) adjusting the pH value to 5-6 with an alkaline solution, heating to reflux and filtering to obtain a carbon nanotube composite Ag/BiOX green advanced water treatment agent. 2. the preparation method of a kind of carbon nanotube composite Ag/BiOX green deep water treatment agent according to claim 1, is characterized in that: the carbon nanotube in the described step (1) and H ₂ SO ₄ and HNO ₃ The ratio of the mixed liquid is 10-20g:4L; wherein, the volume ratio of H ₂ SO ₄ and HNO ₃ is 1:1-5:1. 3. the preparation method of a kind of carbon nanotube composite Ag/BiOX green depth water treatment agent according to claim 1, is characterized in that: the carboxylated carbon nanotube in the described step (1) and 2-(7- The mass ratio of azobenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphoric acid is 5-8:0.1-0.6. 4. the preparation method of a kind of carbon nanotube composite Ag/BiOX green depth water treatment agent according to claim 1, is characterized in that: the mixing of the aminated carbon nanotube in the described step (1) and water and acetone The liquid ratio is 4-4.5g:1L; wherein, the volume ratio of water and acetone is 3:1-5:1. 5. the preparation method of a kind of carbon nanotube composite Ag/BiOX green depth water treatment agent according to claim 1, is characterized in that: the aminated carbon nanotube in the described step (1) and 2,4,6 - The mass ratio of trifluoro-5-chloropyrimidine is 4-4.5:4-6. 6. The preparation method of a kind of carbon nanotube composite Ag/BiOX green deep water treatment agent according to claim 1, it is characterized in that: adopt sodium carbonate solution to adjust pH value in described step (1). 7. the preparation method of a kind of carbon nanotube composite Ag/BiOX green depth water treatment agent according to claim 1, is characterized in that: the stabilizing agent in the described step (2) is disodium edetate, One of tetrasodium edetate, sodium gluconate, butane tetracarboxylic acid; the concentration of the stabilizer is 0.01-0.1mol/L. 8. The preparation method of a kind of carbon nanotube composite Ag/BiOX green deep water treatment agent according to claim 1, it is characterized in that: the template agent in the described step (2) is the triembedding agent of mass ratio 1:3 A mixture of segmented polyether P123 and tri-block copolymer F127; the template concentration is 0.01-0.1mol/L. 9. The preparation method of a carbon nanotube composite Ag/BiOX green deep water treatment agent according to claim 1, characterized in that: the phosphate buffer in the step (2) has a concentration of 0.025～0.05mol/ L sodium dihydrogen phosphate and 0.05-0.1mol/L sodium hydrogen phosphate. 10. The preparation method of a carbon nanotube composite Ag/BiOX green deep water treatment agent according to claim 1, characterized in that: the alkaline solution in the step (3) has a concentration of 0.5mol/L～1.5 mol/L aqueous solution of sodium hydroxide or potassium hydroxide.