A filler for sewage treatment and its preparation method

Abstract

The present invention discloses a filler for sewage treatment and its preparation method, belonging to the technical field of sewage treatment. Cotton fibers have good hydrophilicity and certain mechanical strength, can effectively resist the impact brought by the flow of sewage, ensure the stability of the internal modified activated carbon, contribute to the transmission of sewage inside the filler, and at the same time provide a good environment for the attachment and growth of microorganisms, promoting biodegradation. The middle is filled with modified activated carbon to form a tight and efficient sewage treatment structure, effectively improving the sewage treatment efficiency and shortening the sewage treatment time. The filler for sewage treatment prepared by the present invention has high mechanical strength, good stability and long service life. At the same time, it 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.

Description

Technical Field

[0001] The present invention belongs to the technical field of sewage treatment, and specifically relates to a filler for sewage treatment and a preparation method thereof. Background Technique

[0002] Sewage is the water discharged during the process of human production and living activities. Water pollution not only endangers human health, but also seriously harms the ecological system. Therefore, it is necessary to treat it to meet the discharge standards. The sewage treatment filler is to make the sewage reach the set discharge standards after being treated by a certain method. At present, sewage treatment fillers can be divided into inorganic fillers, organic fillers and composite fillers. Their main working principles are that the fillers provide the surface area of the reaction, enhance the adsorption capacity and promote the growth of microorganisms, etc., thereby reducing the pollution degree in the 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 indicators such as chemical oxygen demand, ammonia nitrogen and total phosphorus in the water body generally exceed the standards. The waste water discharged from many surrounding heavily polluting enterprises such as chemical industry, papermaking and textile also contains a large amount of pollutants such as metal ions and organic substances, 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; its chemical properties are unstable and it is easy to degrade, affecting the service life of the filler; and the properties of the filler are relatively single, making it difficult to adapt to complex sewage environments, and the treatment effect on sewage containing various 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 sewage treatment filler to achieve efficient and stable purification treatment of sewage, meet the treatment requirements of different sewage types, and improve the service life of the filler. Summary of the Invention

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

[0005] The present invention achieves the above purpose through the following technical solutions:

[0006] A filler for sewage treatment includes cotton fibers and modified activated carbon, and the modified activated carbon is filled in the cotton fibers;

[0007] The modified activated carbon is prepared by grafting a cross-linked network polymer on the surface of activated carbon; wherein the cross-linked network polymer contains carboxyl groups, amino groups, sulfonic acid groups and long-chain alkyl groups.

[0008] The modified activated carbon is prepared according to the following steps:

[0009] 1) Under nitrogen protection, acrylic acid, acrylamide, 2-acrylamido-2-methylpropanesulfonic acid and dodecyl acrylate are added to an organic solvent. After stirring and dissolving, it is heated to 60-80 °C, and then an initiator is added. The reaction continues for 3-5 h. After the reaction is completed, the temperature is lowered to 25-30 °C to obtain a polymer reaction solution;

[0010] 2) Under nitrogen protection, activated carbon is added to a dilute nitric acid solution and heated to 80-90 °C. After 2-3 h, it is filtered. The obtained filter cake is washed with deionized water until neutral, and then dried at 100-105 °C for 5-8 h to obtain activated activated carbon;

[0011] 3) The activated activated carbon prepared in step 2) is added to the polymer reaction solution prepared in step 1), and then 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 4-dimethylaminopyridine are added thereto. After stirring and mixing evenly, the reaction is carried out at 50-70 °C for 8-12 h, and then N,N-methylenebisacrylamide is added and the stirring reaction continues for 3-10 h. After the reaction is completed, it is filtered, washed 3-5 times with deionized water, and dried to obtain modified activated carbon.

[0012] The initiator described in step 1) is azobisisobutyronitrile, azobisisoheptonitrile and benzoyl peroxide.

[0013] The organic solvent described in step 1) is toluene, ethyl acetate or acetone.

[0014] The mass ratio of acrylic acid, acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, dodecyl acrylate, organic solvent and initiator described in step 1) is 1:0.5-0.8:0.3-0.5:0.3-0.5:8-10:0.01-0.03.

[0015] The mass-volume ratio of the activated carbon and the dilute nitric acid solution described in step 2) is 1 g:5-10 ml.

[0016] The mass ratio of the activated activated carbon, polymer reaction solution, 1-ethyl-(3-dimethylaminopropyl)carbodiimide, 4-dimethylaminopyridine and N,N-methylenebisacrylamide described in step 3) is 1:15-30:5-10:3.5-6.5:0.02-0.05.

[0017] The preparation method of the filler for sewage treatment includes the following steps:

[0018] The cotton fiber is woven into a tubular structure and placed in a high-temperature steam environment at 120-150 °C for 0.5-1 h to obtain a cotton fiber tube. Then the modified activated carbon is evenly filled into the cotton fiber tube, and finally heat-sealed to obtain the filler for sewage treatment.

[0019] The thickness of the cotton fiber tube is 0.1-0.5 cm.

[0020] The packing density of the modified activated carbon in the cotton fiber cylinder is 0.5 - 0.8 g / cm 3 .

[0021] The present invention has the following advantages compared with the prior art:

[0022] For the packing material for sewage treatment of the present invention, the cotton fiber has good hydrophilicity and certain mechanical strength, can effectively resist the impact brought by the sewage flow, ensure the stability of the internal modified activated carbon, contribute to the transmission of sewage inside the packing material, and at the same time provide a good environment for the attachment and growth of microorganisms, promote the biodegradation effect. The middle is filled with modified activated carbon to form a tight and efficient sewage treatment structure, combining physical adsorption with chemical adsorption, effectively improving the sewage treatment efficiency and shortening the sewage treatment time.

[0023] For the activated carbon of the present invention, a polymer containing various functional groups is grafted on its surface, and the polymer is further crosslinked into a network structure, increasing the effective specific surface area of the activated carbon, enhancing the mechanical strength and chemical stability of the activated carbon, and further enhancing its adsorption and reaction activities for different pollutants; at the same time, the crosslinked network structure can provide attachment points for microorganisms and enhance the biodegradation effect. The long-chain alkyl group increases the hydrophobicity of the packing material and at the same time enhances the adsorption capacity for non-polar organic substances; the carboxyl group can undergo a complexation reaction with metal ions to effectively remove heavy metals in the sewage; the amino group can form hydrogen bonds or ionic bonds with the organic substances in the sewage to enhance the removal of organic substances, and the sulfonic acid group has good adsorption capacity for anions and is suitable for removing organic substances and heavy metal ions.

[0024] The packing material for sewage treatment prepared by the present invention has high mechanical strength, good stability and long service life. At the same time, it has a large specific surface area, rich adsorption capacity and specific reaction activity of the functional groups on the polymer, and has a strong ability to remove pollutants in water. Description of the Drawings

[0025] Figure 1 It is a schematic cross-sectional structure diagram of the packing material for sewage treatment of the present invention;

[0026] Among them, 1 - cotton fiber, 2 - modified activated carbon. Detailed Embodiments

[0027] In order to better understand the technical solution of the present invention, the following provides a more detailed description of the above content of the present invention in the form of specific embodiments of examples, but this should not be construed as limiting the scope of the above subject matter of the present invention to the following examples. All technologies implemented based on the above content of the present invention belong to the scope of the present invention.

[0028] Example 1 Preparation of Modified Activated Carbon

[0029] 1) Under nitrogen protection, 1 kg of acrylic acid, 0.5 kg of acrylamide, 0.3 kg of 2-acrylamido-2-methylpropanesulfonic acid and 0.3 kg of dodecyl acrylate were added to 8 kg of toluene. After stirring and dissolving, it was heated to 60 °C, and then 0.01 kg of azobisisobutyronitrile was added. The reaction continued for 5 h. After the reaction was completed, the temperature was lowered to 25 °C to obtain a polymer reaction solution;

[0030] 2) Under nitrogen protection, 1 kg of activated carbon was added to 5 L of dilute nitric acid solution and heated to 80 °C. After 3 h, filtration was carried out. The obtained filter cake was washed with deionized water until neutral, and then dried at 100 °C for 5 h to obtain activated carbon;

[0031] 3) 0.1 kg of the activated carbon prepared in step 2) was added to 1.5 kg of the polymer reaction solution prepared in step 1), and then 0.5 kg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 0.35 kg of 4-dimethylaminopyridine were added thereto. After stirring and mixing evenly, the reaction was carried out at 50 °C for 12 h. Then, 0.002 kg of N,N-methylenebisacrylamide was added and the stirring reaction continued for 3 h. After the reaction was completed, filtration was carried out, and it was washed 3 times with deionized water and dried to obtain modified activated carbon.

[0032] Preparation of filler for sewage treatment

[0033] The cotton fiber was woven into a cylindrical structure with a thickness of 0.1 cm and placed in a high-temperature steam environment at 120 °C for 0.5 h to obtain a cotton fiber cylinder. Then, the modified activated carbon was evenly filled into the cotton fiber cylinder, and the filling density was 0.5 g / cm 3 , and finally heat-sealed to obtain a filler for sewage treatment, and its cross-sectional structure schematic diagram is as Figure 1 shown.

[0034] Example 2 Preparation of modified activated carbon

[0035] 1) Under nitrogen protection, 1 kg of acrylic acid, 0.6 kg of acrylamide, 0.35 kg of 2-acrylamido-2-methylpropanesulfonic acid and 0.4 kg of dodecyl acrylate were added to 8.5 kg of ethyl acetate. After stirring and dissolving, it was heated to 65 °C, and then 0.015 kg of azobisisoheptonitrile was added. The reaction continued for 4.5 h. After the reaction was completed, the temperature was lowered to 27 °C to obtain a polymer reaction solution;

[0036] 2) Under nitrogen protection, 1 kg of activated carbon was added to 6 L of dilute nitric acid solution and heated to 85 °C. After 2.5 h, filtration was carried out. The obtained filter cake was washed with deionized water until neutral, and then dried at 105 °C for 8 h to obtain activated carbon;

[0037] 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 thereto, stir and mix evenly, react at 55 °C for 10 h, then add 0.015 kg of N,N-methylenebisacrylamide and continue to stir and react for 5 h. After the reaction is completed, filter, wash 4 times with deionized water, and dry to obtain modified activated carbon.

[0038] Preparation of Filler for Sewage Treatment

[0039] Weave cotton fibers into a cylindrical structure with a thickness of 0.2 cm, and place it in a high-temperature steam environment at 130 °C for 0.6 h to obtain a cotton fiber cylinder. Then evenly fill the modified activated carbon into the cotton fiber cylinder, and the filling density is 0.6 g / cm 3 , and finally seal it by hot melting to obtain the filler for sewage treatment.

[0040] Example 3 Preparation of Modified Activated Carbon

[0041] 1) Under nitrogen protection, add 1 kg of acrylic acid, 0.65 kg of acrylamide, 0.4 kg of 2-acrylamido-2-methylpropanesulfonic acid and 0.4 kg of dodecyl acrylate to 9 kg of acetone, stir and dissolve, heat to 70 °C, then add 0.02 kg of benzoyl peroxide, and continue to react for 4 h. After the reaction is completed, cool down to 28 °C to obtain a polymer reaction solution;

[0042] 2) Under nitrogen protection, add 1 kg of activated carbon to 7.5 L of dilute nitric acid solution, heat to 88 °C, after 2.8 h, filter, wash the obtained filter cake with deionized water until neutral, and then dry it at 105 °C for 7 h to obtain activated carbon;

[0043] 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 thereto, stir and mix evenly, react at 60 °C for 9 h, then add 0.02 kg of N,N-methylenebisacrylamide and continue to stir and react for 6 h. After the reaction is completed, filter, wash 5 times with deionized water, and dry to obtain modified activated carbon.

[0044] Preparation of Filler for Sewage Treatment

[0045] Weave cotton fibers into a cylindrical structure with a thickness of 0.3 cm, and place it in a high-temperature steam environment at 135 °C for 0.75 h to obtain a cotton fiber cylinder. Then evenly fill the modified activated carbon into the cotton fiber cylinder, and the filling density is 0.7 g / cm 3, and finally heat-seal to obtain the filler for sewage treatment.

[0046] Example 4 Preparation of Modified Activated Carbon

[0047] 1) Under nitrogen protection, add 1 kg of acrylic acid, 0.75 kg of acrylamide, 0.45 kg of 2-acrylamido-2-methylpropanesulfonic acid, and 0.45 kg of dodecyl acrylate to 9.5 kg of toluene. After stirring and dissolving, heat to 75 °C, then add 0.025 kg of azobisisobutyronitrile, and continue to react for 3.5 h. After the reaction is completed, cool to 26 °C to obtain the polymer reaction solution;

[0048] 2) Under nitrogen protection, add 1 kg of activated carbon to 8.5 L of dilute nitric acid solution, heat to 84 °C, after 2.5 h, filter, wash the obtained filter cake with deionized water until neutral, and then dry at 105 °C for 6 h to obtain activated activated carbon;

[0049] 3) Add 0.5 kg of the activated 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, then add 0.022 kg of N,N-methylenebisacrylamide and continue to stir and react for 8 h. After the reaction is completed, filter, wash with deionized water 5 times, and dry to obtain modified activated carbon.

[0050] Preparation of Filler for Sewage Treatment

[0051] Weave cotton fibers into a cylindrical structure with a thickness of 0.4 cm, and place it in a high-temperature steam environment at 140 °C for 0.9 h to obtain a cotton fiber cylinder. Then evenly fill the modified activated carbon into the cotton fiber cylinder, and the filling density is 0.75 g / cm 3 , and finally heat-seal to obtain the filler for sewage treatment.

[0052] Example 5 Preparation of Modified Activated Carbon

[0053] 1) Under nitrogen protection, add 1 kg of acrylic acid, 0.8 kg of acrylamide, 0.5 kg of 2-acrylamido-2-methylpropanesulfonic acid, and 0.5 kg of dodecyl acrylate to 10 kg of acetone. After stirring and dissolving, heat to 80 °C, then add 0.03 kg of azobisisobutyronitrile, and continue to react for 3 h. After the reaction is completed, cool to 30 °C to obtain the polymer reaction solution;

[0054] 2) Under nitrogen protection, add 1 kg of activated carbon to 10 L of dilute nitric acid solution, heat to 90 °C, after 2 h, filter, wash the obtained filter cake with deionized water until neutral, and then dry at 100 °C for 8 h to obtain activated activated carbon;

[0055] 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 thereto, stir and mix evenly, react at 70 °C for 8 h, then add 0.025 kg of N,N-methylenebisacrylamide and continue to stir and react for 10 h. After the reaction is completed, filter, wash 5 times with deionized water, and dry to obtain modified activated carbon.

[0056] Preparation of Filler for Sewage Treatment

[0057] Weave the cotton fiber into a cylindrical structure with a thickness of 0.5 cm, and place it in a high-temperature steam environment at 150 °C for 1 h to obtain a cotton fiber cylinder. Then evenly fill the modified activated carbon into the cotton fiber cylinder, and the filling density is 0.8 g / cm 3 , and finally seal it by hot melting to obtain the filler for sewage treatment.

[0058] Example 6 Preparation of Modified Activated Carbon

[0059] 1) Under nitrogen protection, add 1 kg of acrylic acid, 0.5 kg of acrylamide, 0.5 kg of 2-acrylamido-2-methylpropanesulfonic acid and 0.3 kg of dodecyl acrylate to 10 kg of ethyl acetate, stir and dissolve, heat to 70 °C, then add 0.03 kg of azobisisobutyronitrile, and continue to react for 5 h. After the reaction is completed, cool to 30 °C to obtain a polymer reaction solution;

[0060] 2) Under nitrogen protection, add 1 kg of activated carbon to 8 L of dilute nitric acid solution, heat to 90 °C, after 3 h, filter, wash the obtained filter cake with deionized water until neutral, and then dry at 105 °C for 7 h to obtain activated carbon;

[0061] 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 thereto, stir and mix evenly, react at 60 °C for 10 h, then add 0.02 kg of N,N-methylenebisacrylamide and continue to stir and react for 8 h. After the reaction is completed, filter, wash 5 times with deionized water, and dry to obtain modified activated carbon.

[0062] Preparation of Filler for Sewage Treatment

[0063] Weave the cotton fiber into a cylindrical structure with a thickness of 0.3 cm, and place it in a high-temperature steam environment at 150 °C for 0.5 h to obtain a cotton fiber cylinder. Then evenly fill the modified activated carbon into the cotton fiber cylinder, and the filling density is 0.6 g / cm 3, finally, heat-seal it to obtain the filler for sewage treatment.

[0064] The fillers for sewage treatment prepared in Examples 1-6 of the present invention were used in the experiment for treating fermentation wastewater. The mass ratio of the fermentation wastewater to the filler for sewage treatment was 1:0.2, and the treatment time was 6 h. The test results are shown in Table 1.

[0065] It can be seen from the results in Table 1 that all the indexes of the fermentation wastewater treated with the filler for sewage treatment of the present invention can reach the discharge standard.

[0066] Table 1 Treatment results of the filler for sewage treatment on fermentation wastewater

[0067]

[0068] The fillers for sewage treatment prepared in Examples 1-6 of the present invention were used in the experiment for treating electroplating industrial wastewater containing heavy metals. The mass ratio of the industrial wastewater to the filler for sewage treatment was 1:0.2, and the treatment time was 6 h. The test results are shown in Table 2.

[0069] Table 2 Treatment results of the filler for sewage treatment on industrial wastewater

[0070]

[0071] 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 the sewage, and the treated industrial wastewater can reach the discharge standard.

[0072] Although the specific embodiments of the present invention are described above, it is not a limitation on the protection scope of the present invention. Based on the technical solutions of the present invention, various modifications or deformations that can be made by those skilled in the art without creative labor are still within the protection scope of the present invention.

Claims

1. A method for preparing a filler for sewage treatment, the filler 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; 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.

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

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

4. The method for preparing a filler for sewage treatment according to claim 1, 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.

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

6. The method for preparing a filler for sewage treatment according to claim 1, 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.

7. 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.

8. The method for preparing a filler for sewage treatment according to claim 7, 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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