Filler for sewage treatment and preparation method thereof

Abstract

The invention discloses a filler for sewage treatment and a preparation method thereof, and belongs to the technical field of sewage treatment.The cotton fiber has good hydrophilicity and certain mechanical strength, can effectively resist impact caused by sewage flowing, ensures stability of internal modified activated carbon, facilitates transmission of sewage in the filler, and improves the sewage treatment efficiency. Meanwhile, a good environment for attachment growth is provided for microorganisms, the biodegradation effect is promoted, the filler is filled with modified activated carbon, a compact and efficient sewage treatment structure is formed, the sewage treatment efficiency is effectively improved, the sewage treatment time is shortened, and the prepared filler for sewage treatment is high in mechanical strength, good in stability, long in service life and suitable for popularization and application. Meanwhile, the composite material has relatively large specific surface area, rich adsorption capacity and specific reaction activity of functional groups on the polymer, and has strong removal capacity on pollutants in water.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment, and in particular is a filler for sewage treatment and a preparation method thereof. Background Art

[0002] Sewage is the water discharged during human production and life activities. Water pollution not only harms human health, but also seriously harms the ecosystem. Therefore, it needs to be treated to meet the emission standards. Sewage treatment fillers are used to treat sewage in a certain way to meet the set emission standards. At present, sewage treatment fillers can be divided into inorganic fillers, organic fillers and composite fillers. The main working principle is that the fillers provide the surface area for reaction, enhance adsorption capacity and promote microbial growth, thereby reducing the degree of pollution in sewage.

[0003] In recent years, the water pollution problem in the Yellow River Delta has become increasingly prominent, mainly due to industrial, agricultural and domestic pollution. The chemical oxygen demand, ammonia nitrogen, total phosphorus and other indicators in the water body are generally exceeded. The wastewater discharged by many heavy polluting enterprises such as chemical, papermaking, and textile in the surrounding area also contains a large amount of metal ions, organic matter and other pollutants, which seriously affect the water environment quality of the Yellow River. The traditional sewage treatment filler has a small specific surface area and limited adsorption capacity for pollutants, resulting in low treatment efficiency; the chemical properties are unstable and prone to degradation, which affects the service life of the filler; and the filler has a relatively simple nature and is difficult to adapt to the complex sewage environment. The treatment effect of sewage containing multiple pollutants is not good, and it is difficult to achieve efficient and comprehensive purification treatment. Therefore, it is of great significance to develop a new filler for sewage treatment to achieve efficient and stable purification treatment of sewage, meet the treatment needs of different types of sewage, and improve the service life of the filler. Summary of the invention

[0004] To solve the above problems, the object of the present invention is to provide a filler for sewage treatment and a preparation method thereof.

[0005] In order to achieve the above object, the present invention is implemented through the following technical solutions: A filler for sewage treatment, comprising cotton fiber and modified activated carbon, wherein the modified activated carbon is filled in the cotton fiber; The modified activated carbon is prepared by grafting a cross-linked network polymer onto the surface of the activated carbon; wherein the cross-linked network polymer contains carboxyl groups, amino groups, sulfonic acid groups and long-chain alkyl groups.

[0006] The modified activated carbon is prepared according to the following steps: 1) Under nitrogen protection, acrylic acid, acrylamide, 2-acrylamide-2-methylpropanesulfonic acid and dodecyl acrylate are added to an organic solvent, stirred and dissolved, heated to 60-80°C, and then an initiator is added to continue the reaction for 3-5 hours. After the reaction is completed, the temperature is lowered to 25-30°C to obtain a polymer reaction solution; 2) Under nitrogen protection, add activated carbon to dilute nitric acid solution, heat to 80-90°C, filter after 2-3 hours, wash the filter cake with deionized water until neutral, and then dry at 100-105°C for 5-8 hours to obtain activated activated carbon; 3) Add the activated carbon prepared in step 2) to the polymer reaction solution prepared in step 1), then add 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 4-dimethylaminopyridine, stir and mix evenly, react at 50-70° C. for 8-12 hours, add N,N-methylenebisacrylamide and continue stirring and reacting for 3-10 hours. After the reaction is completed, filter, wash with deionized water for 3-5 times, and dry to obtain modified activated carbon.

[0007] The initiator in step 1) is azobisisobutyronitrile, azobisisoheptanenitrile and dibenzoyl peroxide.

[0008] The organic solvent in step 1) is toluene, ethyl acetate or acetone.

[0009] The mass ratio of acrylic acid, acrylamide, 2-acrylamide-2-methylpropanesulfonic acid, dodecyl acrylate, organic solvent and initiator in step 1) is 1:0.5~0.8:0.3~0.5:0.3~0.5:8~10:0.01~0.03.

[0010] The mass volume ratio of the activated carbon and the dilute nitric acid solution in step 2) is 1g:5~10ml.

[0011] The mass ratio of the activated carbon, the polymer reaction solution, 1-ethyl-(3-dimethylaminopropyl)carbodiimide, 4-dimethylaminopyridine and N,N-methylenebisacrylamide in step 3) is 1:15~30:5~10:3.5~6.5:0.02~0.05.

[0012] The method for preparing the filler for sewage treatment comprises the following steps: Cotton fibers are woven into a cylindrical structure and placed in a high-temperature steam environment of 120-150°C for treatment for 0.5-1h to obtain a cotton fiber cylinder. The modified activated carbon is then evenly filled into the cotton fiber cylinder, and finally hot-melt sealed to obtain a filler for sewage treatment.

[0013] The thickness of the cotton fiber tube is 0.1-0.5 cm.

[0014] The packing density of the modified activated carbon in the cotton fiber cylinder is 0.5-0.8 g / cm 3 .

[0015] Compared with the prior art, the present invention has the following advantages: The filler for sewage treatment of the present invention has cotton fibers with good hydrophilicity and certain mechanical strength, can effectively resist the impact caused by sewage flow, ensure the stability of the internal modified activated carbon, help the transmission of sewage inside the filler, and at the same time provide a good environment for the attachment and growth of microorganisms, promote biodegradation, fill the middle with modified activated carbon, form a compact and efficient sewage treatment structure, and combine physical adsorption with chemical adsorption, effectively improve the sewage treatment efficiency and shorten the sewage treatment time.

[0016] The activated carbon of the present invention is grafted with polymers containing multiple functional groups on its surface, and the polymers are further cross-linked into a network structure, which increases the effective specific surface area of ​​the activated carbon, enhances the mechanical strength and chemical stability of the activated carbon, and further enhances its adsorption and reaction activity to different pollutants; at the same time, the cross-linked network structure can provide attachment points for microorganisms and enhance biodegradation. The long-chain alkyl group increases the hydrophobicity of the filler and enhances the adsorption capacity of non-polar organic matter; the carboxyl group can react with metal ions to effectively remove heavy metals in sewage; the amino group can form hydrogen bonds or ionic bonds with organic matter in sewage to enhance the removal of organic matter; the sulfonic acid group has a good adsorption capacity for anions and is suitable for removing organic matter and heavy metal ions.

[0017] The filler for sewage treatment prepared by the present invention has high mechanical strength, good stability and long service life, and at the same time has a large specific surface area, rich adsorption capacity and specific reaction activity of functional groups on the polymer, and has a strong ability to remove pollutants in water. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the cross-sectional structure of the filler for sewage treatment of the present invention; Among them, 1-cotton fiber, 2-modified activated carbon. DETAILED DESCRIPTION

[0019] In order to better understand the technical solution of the present invention, the above content of the present invention is further described in detail below through specific implementation methods in the form of embodiments, but this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples. All technologies realized based on the above content of the present invention belong to the scope of the present invention.

[0020] Example 1 Preparation of modified activated carbon 1) Under nitrogen protection, 1 kg of acrylic acid, 0.5 kg of acrylamide, 0.3 kg of 2-acrylamide-2-methylpropanesulfonic acid and 0.3 kg of dodecyl acrylate were added to 8 kg of toluene, stirred and dissolved, and then heated to 60 ° C, and then 0.01 kg of azobisisobutyronitrile was added, and the reaction was continued for 5 hours. After the reaction was completed, the temperature was lowered to 25 ° C to obtain a polymer reaction solution; 2) Under nitrogen protection, add 1 kg of activated carbon to 5 L of dilute nitric acid solution, heat to 80 ° C, filter after 3 hours, wash the filter cake with deionized water until neutral, and then dry at 100 ° C for 5 hours to obtain activated activated carbon; 3) Add 0.1 kg of the activated carbon prepared in step 2) to 1.5 kg of the polymer reaction solution prepared in step 1), then add 0.5 kg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 0.35 kg of 4-dimethylaminopyridine, stir and mix evenly, react at 50°C for 12 h, add 0.002 kg of N,N-methylenebisacrylamide and continue stirring and reacting for 3 h. After the reaction is completed, filter, wash 3 times with deionized water, and dry to obtain modified activated carbon.

[0021] Preparation of fillers for sewage treatment Cotton fibers were woven into a 0.1 cm thick cylindrical structure and placed in a 120 ° C high temperature steam environment for 0.5 h to obtain a cotton fiber cylinder. The modified activated carbon was then evenly filled into the cotton fiber cylinder with a filling density of 0.5 g / cm 3 , and finally hot-melt sealed to obtain the filler for sewage treatment. Its cross-sectional structure diagram is shown in Figure 1 shown.

[0022] Example 2 Preparation of modified activated carbon 1) Under nitrogen protection, 1 kg of acrylic acid, 0.6 kg of acrylamide, 0.35 kg of 2-acrylamide-2-methylpropanesulfonic acid and 0.4 kg of dodecyl acrylate were added to 8.5 kg of ethyl acetate, stirred and dissolved, and then heated to 65 ° C, and then 0.015 kg of azobisisoheptanenitrile was added, and the reaction was continued for 4.5 hours. After the reaction was completed, the temperature was lowered to 27 ° C to obtain a polymer reaction solution; 2) Under nitrogen protection, add 1 kg of activated carbon to 6 L of dilute nitric acid solution, heat to 85 ° C, filter after 2.5 hours, wash the filter cake with deionized water until neutral, and then dry at 105 ° C for 8 hours to obtain activated activated carbon; 3) Add 0.5 kg of the activated carbon prepared in step 2) to 9 kg of the polymer reaction solution prepared in step 1), then add 3 kg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 1.9 kg of 4-dimethylaminopyridine, stir and mix evenly, react at 55°C for 10 h, add 0.015 kg of N,N-methylenebisacrylamide and continue stirring and reacting for 5 h. After the reaction is completed, filter, wash 4 times with deionized water, and dry to obtain modified activated carbon.

[0023] Preparation of fillers for sewage treatment Cotton fibers were woven into a 0.2 cm thick cylindrical structure and placed in a high temperature steam environment at 130 °C for 0.6 h to obtain a cotton fiber cylinder. The modified activated carbon was then evenly filled into the cotton fiber cylinder with a filling density of 0.6 g / cm 3 , and finally hot-melt sealed to obtain filler for sewage treatment.

[0024] Example 3 Preparation of modified activated carbon 1) Under nitrogen protection, add 1 kg of acrylic acid, 0.65 kg of acrylamide, 0.4 kg of 2-acrylamide-2-methylpropanesulfonic acid and 0.4 kg of dodecyl acrylate into 9 kg of acetone, stir and dissolve, heat to 70 °C, add 0.02 kg of dibenzoyl peroxide, continue to react for 4 hours, and after the reaction is completed, cool to 28 °C to obtain a polymer reaction solution; 2) Under nitrogen protection, add 1 kg of activated carbon to 7.5 L of dilute nitric acid solution, heat to 88 ° C, filter after 2.8 hours, wash the filter cake with deionized water until neutral, and then dry at 105 ° C for 7 hours to obtain activated activated carbon; 3) Add 0.5 kg of the activated carbon prepared in step 2) to 12 kg of the polymer reaction solution prepared in step 1), then add 3.5 kg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 2.5 kg of 4-dimethylaminopyridine, stir and mix evenly, react at 60°C for 9 hours, add 0.02 kg of N,N-methylenebisacrylamide and continue stirring and reacting for 6 hours. After the reaction is completed, filter, wash 5 times with deionized water, and dry to obtain modified activated carbon.

[0025] Preparation of fillers for sewage treatment Cotton fibers were woven into a 0.3 cm thick cylindrical structure and placed in a high temperature steam environment at 135 °C for 0.75 h to obtain a cotton fiber cylinder. The modified activated carbon was then evenly filled into the cotton fiber cylinder with a filling density of 0.7 g / cm 3 , and finally hot-melt sealed to obtain filler for sewage treatment.

[0026] Example 4 Preparation of modified activated carbon 1) Under nitrogen protection, add 1 kg of acrylic acid, 0.75 kg of acrylamide, 0.45 kg of 2-acrylamide-2-methylpropanesulfonic acid and 0.45 kg of dodecyl acrylate into 9.5 kg of toluene, stir and dissolve, heat to 75 °C, add 0.025 kg of azobisisobutyronitrile, continue to react for 3.5 hours, and after the reaction is completed, cool to 26 °C to obtain a polymer reaction solution; 2) Under nitrogen protection, add 1 kg of activated carbon to 8.5 L of dilute nitric acid solution, heat to 84 ° C, filter after 2.5 hours, wash the filter cake with deionized water until neutral, and then dry at 105 ° C for 6 hours to obtain activated activated carbon; 3) Add 0.5 kg of the activated carbon prepared in step 2) to 14 kg of the polymer reaction solution prepared in step 1), then add 4.5 kg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 3 kg of 4-dimethylaminopyridine, stir and mix evenly, react at 65°C for 8.5 h, add 0.022 kg of N,N-methylenebisacrylamide and continue stirring and reacting for 8 h. After the reaction is completed, filter, wash 5 times with deionized water, and dry to obtain modified activated carbon.

[0027] Preparation of fillers for sewage treatment Cotton fibers were woven into a 0.4 cm thick cylindrical structure and placed in a high temperature steam environment at 140 °C for 0.9 h to obtain a cotton fiber cylinder. The modified activated carbon was then evenly filled into the cotton fiber cylinder with a filling density of 0.75 g / cm 3 , and finally hot-melt sealed to obtain filler for sewage treatment.

[0028] Example 5 Preparation of modified activated carbon 1) Under nitrogen protection, add 1 kg of acrylic acid, 0.8 kg of acrylamide, 0.5 kg of 2-acrylamide-2-methylpropanesulfonic acid and 0.5 kg of dodecyl acrylate into 10 kg of acetone, stir and dissolve, heat to 80 ° C, add 0.03 kg of azobisisobutyronitrile, continue to react for 3 hours, and after the reaction is completed, cool to 30 ° C to obtain a polymer reaction solution; 2) Under nitrogen protection, add 1 kg of activated carbon to 10 L of dilute nitric acid solution, heat to 90 ° C, filter after 2 hours, wash the filter cake with deionized water until neutral, and then bake at 100 ° C for 8 hours to obtain activated activated carbon; 3) Add 0.5 kg of the activated carbon prepared in step 2) to 15 kg of the polymer reaction solution prepared in step 1), then add 5 kg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 3.25 kg of 4-dimethylaminopyridine, stir and mix evenly, react at 70°C for 8 h, add 0.025 kg of N,N-methylenebisacrylamide and continue stirring and reacting for 10 h. After the reaction is completed, filter, wash 5 times with deionized water, and dry to obtain modified activated carbon.

[0029] Preparation of fillers for sewage treatment Cotton fibers were woven into a 0.5 cm thick cylindrical structure and placed in a high temperature steam environment at 150 °C for 1 h to obtain a cotton fiber cylinder. The modified activated carbon was then evenly filled into the cotton fiber cylinder with a filling density of 0.8 g / cm 3 , and finally hot-melt sealed to obtain filler for sewage treatment.

[0030] Example 6 Preparation of modified activated carbon 1) Under nitrogen protection, 1 kg of acrylic acid, 0.5 kg of acrylamide, 0.5 kg of 2-acrylamide-2-methylpropanesulfonic acid and 0.3 kg of dodecyl acrylate were added to 10 kg of ethyl acetate, stirred and dissolved, heated to 70 ° C, and then 0.03 kg of azobisisobutyronitrile was added, and the reaction was continued for 5 hours. After the reaction was completed, the temperature was lowered to 30 ° C to obtain a polymer reaction solution; 2) Under nitrogen protection, add 1 kg of activated carbon to 8 L of dilute nitric acid solution, heat to 90 ° C, filter after 3 hours, wash the filter cake with deionized water until neutral, and then bake at 105 ° C for 7 hours to obtain activated activated carbon; 3) Add 0.5 kg of the activated carbon prepared in step 2) to 12 kg of the polymer reaction solution prepared in step 1), then add 4 kg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 3 kg of 4-dimethylaminopyridine, stir and mix evenly, react at 60°C for 10 h, add 0.02 kg of N,N-methylenebisacrylamide and continue stirring and reacting for 8 h. After the reaction is completed, filter, wash with deionized water 5 times, and dry to obtain modified activated carbon.

[0031] Preparation of fillers for sewage treatment Cotton fibers were woven into a 0.3 cm thick cylindrical structure and placed in a high temperature steam environment at 150 °C for 0.5 h to obtain a cotton fiber cylinder. The modified activated carbon was then evenly filled into the cotton fiber cylinder with a filling density of 0.6 g / cm 3 , and finally hot-melt sealed to obtain filler for sewage treatment.

[0032] The fillers for sewage treatment prepared in Examples 1 to 6 of the present invention were used in an experiment to treat fermentation wastewater. The mass ratio of fermentation wastewater to the fillers for sewage treatment was 1:0.2, and the treatment time was 6 hours. The test results are shown in Table 1.

[0033] It can be seen from the results in Table 1 that all indicators of the fermentation wastewater treated with the filler for sewage treatment of the present invention can meet the discharge standards.

[0034] Table 1 Treatment results of fermentation wastewater by fillers for sewage treatment

[0035] The fillers for sewage treatment prepared in Examples 1 to 6 of the present invention were used to treat electroplating industrial wastewater containing heavy metals. The mass ratio of industrial wastewater to the fillers for sewage treatment was 1:0.2, and the treatment time was 6 hours. The test results are shown in Table 2.

[0036] Table 2 Treatment results of industrial wastewater by fillers for sewage treatment

[0037] It can be seen from the results in Table 2 that the filler for sewage treatment of the present invention can effectively remove heavy metals in sewage, and the treated industrial wastewater can meet the discharge standards.

[0038] Although the above describes the specific implementation methods of the present invention, it does not limit the scope of protection of the present invention. Based on the technical solution of the present invention, various modifications or variations that can be made by those skilled in the art without creative work are still within the scope of protection of the present invention.

Claims

1. A filler for sewage treatment, comprising cotton fiber and modified activated carbon, characterized in that: The modified activated carbon is filled in the cotton fiber; The modified activated carbon is prepared by grafting a cross-linked network polymer onto the surface of the activated carbon; wherein the cross-linked network polymer contains carboxyl groups, amino groups, sulfonic acid groups and long-chain alkyl groups.

2. The filler for sewage treatment according to claim 1, characterized in that: The modified activated carbon is prepared according to the following steps: 1) Under nitrogen protection, acrylic acid, acrylamide, 2-acrylamide-2-methylpropanesulfonic acid and dodecyl acrylate are added to an organic solvent, stirred and dissolved, heated to 60-80°C, and then an initiator is added to continue the reaction for 3-5 hours. After the reaction is completed, the temperature is lowered to 25-30°C to obtain a polymer reaction solution; 2) Under nitrogen protection, add activated carbon to dilute nitric acid solution, heat to 80-90°C, filter after 2-3 hours, wash the filter cake with deionized water until neutral, and then dry at 100-105°C for 5-8 hours to obtain activated activated carbon; 3) Add the activated carbon prepared in step 2) to the polymer reaction solution prepared in step 1), then add 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 4-dimethylaminopyridine, stir and mix evenly, react at 50-70° C. for 8-12 hours, add N,N-methylenebisacrylamide and continue stirring and reacting for 3-10 hours. After the reaction is completed, filter, wash with deionized water for 3-5 times, and dry to obtain modified activated carbon.

3. The filler for sewage treatment according to claim 2, characterized in that: The initiator in step 1) is azobisisobutyronitrile, azobisisoheptanenitrile and dibenzoyl peroxide.

4. The filler for sewage treatment according to claim 2, characterized in that: The organic solvent in step 1) is toluene, ethyl acetate or acetone.

5. The filler for sewage treatment according to claim 2, characterized in that: The mass ratio of acrylic acid, acrylamide, 2-acrylamide-2-methylpropanesulfonic acid, dodecyl acrylate, organic solvent and initiator in step 1) is 1:0.5~0.8:0.3~0.5:0.3~0.5:8~10:0.01~0.

03.

6. The filler for sewage treatment according to claim 2, characterized in that: The mass volume ratio of the activated carbon and the dilute nitric acid solution in step 2) is 1g:5~10ml.

7. The filler for sewage treatment according to claim 2, characterized in that: The mass ratio of the activated carbon, the polymer reaction solution, 1-ethyl-(3-dimethylaminopropyl)carbodiimide, 4-dimethylaminopyridine and N,N-methylenebisacrylamide in step 3) is 1:15~30:5~10:3.5~6.5:0.02~0.

05.

8. The method for preparing the filler for sewage treatment according to claim 1, characterized in that: The following steps are involved: Cotton fibers are woven into a cylindrical structure and placed in a high-temperature steam environment of 120-150°C for treatment for 0.5-1h to obtain a cotton fiber cylinder. The modified activated carbon is then evenly filled into the cotton fiber cylinder, and finally hot-melt sealed to obtain a filler for sewage treatment.

9. The method for preparing a filler for sewage treatment according to claim 8, characterized in that: The thickness of the cotton fiber tube is 0.1-0.5 cm; the packing density of the modified activated carbon in the cotton fiber tube is 0.5-0.8 g / cm 3 .

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