CN115073669B - Preparation method of cellulose-based adsorption flocculation material for wastewater treatment - Google Patents
Preparation method of cellulose-based adsorption flocculation material for wastewater treatment Download PDFInfo
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- CN115073669B CN115073669B CN202210760391.1A CN202210760391A CN115073669B CN 115073669 B CN115073669 B CN 115073669B CN 202210760391 A CN202210760391 A CN 202210760391A CN 115073669 B CN115073669 B CN 115073669B
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- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F251/00—Macromolecular compounds obtained by polymerising monomers on to polysaccharides or derivatives thereof
- C08F251/02—Macromolecular compounds obtained by polymerising monomers on to polysaccharides or derivatives thereof on to cellulose or derivatives thereof
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- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/28—Treatment of water, waste water, or sewage by sorption
- C02F1/286—Treatment of water, waste water, or sewage by sorption using natural organic sorbents or derivatives thereof
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
- C02F1/54—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using organic material
- C02F1/56—Macromolecular compounds
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Abstract
The application relates to a preparation method of a cellulose-based adsorption flocculation material for wastewater treatment. The method comprises the following steps: adding cellulose into a sodium hydroxide/urea water dissolution system, stirring to obtain a cellulose solution, adding acrylamide, an initiator and a cross-linking agent, stirring for reaction, adding formaldehyde, continuously stirring, adding epichlorohydrin, stirring again, dialyzing, drying and crushing. The method has the advantages of quick reaction, low cost, cleanness, environmental protection and simple preparation process, and the constructed cellulose-based material can realize the efficient purification treatment of the wastewater.
Description
Technical Field
The application belongs to the field of functional polymer preparation, and in particular relates to a preparation method of a cellulose-based adsorption flocculation material for wastewater treatment.
Background
In nature, cellulose is a polymer material with the most extensive distribution and huge reserves, has the characteristics of wide sources, low price, recycling, easy natural degradation, chemical modification and the like, and has huge application potential in the fields of energy and chemical industry. However, because the special chemical structural unit of the cellulose leads to strong hydrogen bond network action among cellulose molecular chains and high crystal structure, the cellulose is difficult to dissolve in water and common chemical reagents, and the processability of the cellulose material is severely limited, so that the cellulose-based water-soluble polymer material applicable to wastewater purification treatment has slow and single development. At present, in the field of wastewater treatment, carboxylated cellulose and carboxylated cellulose-based modified polymer materials are mainly used, the hydrophilicity of carboxyl is utilized to improve the water solubility and liquid-phase dispersibility of cellulose materials, and meanwhile, the carboxyl is easy to ionize and produce adsorption effect with other charged particles, so that the aim of removing wastewater impurities is fulfilled. However, the products have single variety, little industrialized application, low waste water purification efficiency and great progress space. In addition, the preparation process of carboxylated cellulose has the defects of severe reaction, poor controllability, incomplete chemical modification and the like, and simultaneously, serious chemical pollution is caused. Therefore, how to prepare the adsorption flocculation functional material by using the natural cellulose has practical significance, not only can promote the development of the adsorption flocculant towards the direction of cleaning and environmental protection, but also can enrich the application way of the cellulose material.
The sodium hydroxide/urea water dissolution system can realize the effective dissolution of cellulose, and also creates conditions for modifying cellulose in a liquid phase system; however, the cellulose dissolved by the system only has a certain flocculation effect and has poor adsorption effect on pollutants in wastewater. To increase the adsorptive flocculation functionality of cellulose, the cellulose must be chemically modified.
As the amide group has excellent adsorption flocculation performance, the polyacrylamide is widely applied to wastewater treatment, and has the characteristics of high purification efficiency, safety, no toxicity, natural degradation, wide application range and the like. However, in the dissolution and dispersion process, polyacrylamide has the problem of easy agglomeration and agglomeration, and the use cost is high. In order to exert the ability of amide groups to purify wastewater, improvement of acrylamide binding targets is demanded. The combination of acrylamide and cellulose material is realized through chemical reaction, which is an important mode for endowing the cellulose material with adsorption flocculation function.
Disclosure of Invention
The application aims to provide a preparation method of a cellulose-based adsorption flocculation material for wastewater treatment, so as to fill the blank of the prior art.
The application provides a preparation method of a cellulose-based adsorption flocculation material, which comprises the following steps:
(1) Adding cellulose into a sodium hydroxide/urea water dissolution system, and stirring to obtain a cellulose solution;
(2) Adding acrylamide, an initiator and a cross-linking agent into the cellulose solution in the step (1), stirring for reaction, adding formaldehyde, continuously stirring, adding epichlorohydrin, stirring again, dialyzing, drying and crushing to obtain the cellulose-based adsorption flocculation material.
Preferably, in the step (1), the mass fraction of sodium hydroxide in the sodium hydroxide/urea water dissolution system is 6-9%, the mass fraction of urea is 10-13%, and the balance is water.
Preferably, the mass fraction of cellulose in the cellulose solution in the step (1) is 2-4%.
Preferably, the cellulose in the step (1) comprises one or more of cotton linters, cotton pulp, bamboo fibers and bagasse.
Preferably, in the step (1), the stirring temperature is-20 to-10 ℃ and the stirring time is 0.5 to 1h.
Preferably, the initiator in the step (2) comprises one or more of ammonium persulfate, potassium persulfate and sodium persulfate; the cross-linking agent is N, N' -methylene bisacrylamide.
Preferably, the initiator in the step (2) accounts for 0.1-5% of the total weight of the cellulose and the acrylamide.
Preferably, the cross-linking agent in the step (2) accounts for 0.1-2% of the total weight of the cellulose and the acrylamide.
Preferably, the mass ratio of cellulose to acrylamide in the step (2) is 1:1-20.
Preferably, the concentration of formaldehyde in step (2) is 36-40%.
Preferably, the mass ratio of formaldehyde to acrylamide in the step (2) is 1:10-50.
Preferably, the epichlorohydrin in the step (2) accounts for 0.1 to 10 percent of the total weight of the cellulose and the acrylamide.
Preferably, the stirring reaction in the step (2) is as follows: reacting for 0.5-1h at 40-80 ℃ under nitrogen.
Preferably, the continuous stirring time in the step (2) is 1-2 h; stirring again for 1-4 h.
Preferably, the dialysis in the step (2) is as follows: the molecular weight cut-off interval of the dialysis bag is 3000-100000, and water is changed once every 10h in the dialysis process until the solution is neutral.
Preferably, the drying temperature in the step (2) is 20-50 ℃.
Preferably, in the step (2), a high-speed shearing machine is adopted for smashing, the rotating speed of the high-speed shearing machine is 1500-10000 r/min, and the shearing time is 1-60 min.
The application also provides the cellulose-based adsorption flocculation material prepared by the preparation method.
The application also provides application of the cellulose-based adsorption flocculation material prepared by the preparation method in wastewater treatment.
The application prepares the cellulose solution with uniform dispersion by the characteristic that the sodium hydroxide/urea water dissolution system can dissolve cellulose. The dissolution system has the advantages of environmental protection, low cost, safety and innocuity, simple operation process and good dissolution effect. The initiator can be used for realizing the homopolymerization reaction between acrylamide monomers, and can also generate chemical grafting reaction with a cellulose glucose long chain to construct a cellulose-based grafting material. The inclusion of acrylamide may also improve the aqueous dispersion stability of cellulose. N, N' -methylene bisacrylamide can form a three-dimensional cross-linked network structure among grafted products, so that the stability of the grafted products is enhanced. By utilizing the methylolation treatment characteristic of formaldehyde on the amide groups, adsorption agglomeration among the amide groups can be inhibited, and the liquid phase dispersion capability of the material is improved. In addition, through the crosslinking characteristic of epoxy chloropropane, the binding fastness of cellulose and acrylamide is further enhanced, and the adsorption flocculation effect of the material is improved. The cellulose-based adsorption flocculation material prepared by the method has good liquid phase dispersion stability, and has the advantages of high speed, high efficiency and repeated utilization in the process of being applied to wastewater purification, thereby effectively reducing the use cost. Furthermore, the cellulose-based adsorption flocculation material shows good biodegradability and compatibility, so that the application belongs to the field of sustainable development, and the product belongs to a green environment-friendly material.
Advantageous effects
The application has the advantages of quick reaction, low cost, cleanness, environmental protection and simple preparation process, and the constructed cellulose-based material can realize the efficient purification treatment of wastewater. And the acrylamide is introduced to break the hydrogen bond structure among the celluloses, so that the effective liquid-phase dispersion of the celluloses is realized.
Detailed Description
The application will be further illustrated with reference to specific examples. It is to be understood that these examples are illustrative of the present application and are not intended to limit the scope of the present application. Furthermore, it should be understood that various changes and modifications can be made by one skilled in the art after reading the teachings of the present application, and such equivalents are intended to fall within the scope of the application as defined in the appended claims.
Example 1
(1) Preparation of cellulose solutions
98g of sodium hydroxide/urea water dissolution system (7% sodium hydroxide, 10% urea and the balance water) is prepared, fully stirred, 2g of cotton pulp is put into the sodium hydroxide/urea water dissolution system at a constant speed, and the mixture is placed at the temperature of minus 12 ℃ and stirred uniformly, so that the cellulose solution with the mass fraction of 2% is prepared.
(2) Preparation of crude cellulose microgel product
At 50 ℃, pure nitrogen is filled into a reaction container, air is removed, 10g of acrylamide is added into a cellulose solution at a constant speed, and the mixture is fully stirred; respectively adding 0.3g of ammonium persulfate and 0.1g of N, N' -methylene bisacrylamide, and continuously stirring for 1h; adding 2.77g of formaldehyde solution (36% by mass) and stirring for 1h; finally, adding 1g of epichlorohydrin, and fully stirring for 1h to prepare a crude product of the cellulose-based adsorption flocculation material.
(3) Dialysis-drying-pulverizing
The crude product of the cellulose-based adsorption flocculation material was transferred to a dialysis membrane (molecular weight cut-off 100000) at room temperature and stirred thoroughly, changing water every 10 hours until the pH of the reaction system was 7. And transferring the product to a constant temperature oven at 30 ℃ for drying, and treating for 30min by using a high-speed shearing machine (the rotating speed is 1000 r/min) to obtain the cellulose-based adsorption flocculation material.
The cellulose-based adsorption and flocculation material is placed in 100ml of water, and is kept stand for 1 week, and no precipitate is separated out, so that the cellulose-based adsorption and flocculation material has good liquid phase stability.
Example 2
(1) Preparation of cellulose solutions
97g of sodium hydroxide/urea water dissolving system (8% sodium hydroxide, 12% urea and the balance water) is prepared, fully stirring is carried out, 3g of cotton pulp is put into the sodium hydroxide/urea water dissolving system at a constant speed, and the mixture is placed under the condition of-15 ℃ and uniformly stirred, thus obtaining the cellulose solution with the mass fraction of 3%.
(2) Preparation of crude cellulose microgel product
At 60 ℃, pure nitrogen is filled into a reaction container, air is removed, 20g of acrylamide is added into a cellulose solution at a constant speed, and the mixture is fully stirred; respectively adding 0.5g of ammonium persulfate and 0.2g of N, N' -methylene bisacrylamide, and continuously stirring for 1h; adding 1.5g of formaldehyde solution (36% by mass) and stirring for 1.5h; finally, adding 1.2g of epichlorohydrin, and fully stirring for 2 hours to prepare a crude product of the cellulose-based adsorption flocculation material.
(3) Dialysis-drying-pulverizing
The crude product of the cellulose-based adsorption flocculation material was transferred to a dialysis membrane (molecular weight cut-off 100000) at room temperature and stirred thoroughly, changing water every 10 hours until the pH of the reaction system was 7. And transferring the product to a constant temperature oven at 30 ℃ for drying, and treating for 30min by using a high-speed shearing machine (the rotating speed is 800 r/min) to obtain the cellulose-based adsorption flocculation material.
The cellulose-based adsorption and flocculation material is placed in 100ml of water, and is kept stand for 1 week, and no precipitate is separated out, so that the cellulose-based adsorption and flocculation material has good liquid phase stability.
Example 3
(1) Preparation of cellulose solutions
96g of sodium hydroxide/urea water dissolving system (9% sodium hydroxide, 13% urea and the balance water) is prepared, fully stirring is carried out, 4g of cotton pulp is put into the sodium hydroxide/urea water dissolving system at a constant speed, and the mixture is placed at the temperature of minus 20 ℃ and is uniformly stirred, thus obtaining the cellulose solution with the mass fraction of 4%.
(2) Preparation of crude cellulose microgel product
At 70 ℃, pure nitrogen is filled into a reaction container, air is removed, 30g of acrylamide is added into a cellulose solution at a constant speed, and the mixture is fully stirred; respectively adding 1g of ammonium persulfate and 0.3g of N, N' -methylene bisacrylamide, and continuously stirring for 1h; adding 2.5g of formaldehyde solution (36% by mass) and stirring for 1.5h; finally, adding 2.3g of epichlorohydrin, and fully stirring for 3 hours to prepare a crude product of the cellulose-based adsorption flocculation material.
(3) Dialysis-drying-pulverizing
The crude product of the cellulose-based adsorption flocculation material was transferred to a dialysis membrane (molecular weight cut-off 100000) at room temperature and stirred thoroughly, changing water every 10 hours until the pH of the reaction system was 7. And transferring the product to a constant temperature oven at 30 ℃ for drying, and treating for 30min by using a high-speed shearing machine (the rotating speed is 1200 r/min) to obtain the cellulose-based adsorption flocculation material.
The cellulose-based adsorption and flocculation material is placed in 100ml of water, and is kept stand for 1 week, and no precipitate is separated out, so that the cellulose-based adsorption and flocculation material has good liquid phase stability.
Example 4
Preparing kaolin solution with mass fraction of 2% to simulate sewage, and respectively adding the products prepared in examples 1, 2 and 3 to perform adsorption flocculation experiments. In addition, comparative examples 1, 2 and 3, in which formaldehyde was not added and the other components were the same as those of examples 1, 2 and 3, were prepared, and adsorption flocculation experiments were performed. The experimental contents are as follows: at room temperature, 500mL of kaolin solution was sucked up, placed in a beaker, 10mg of the sample prepared in the example was uniformly applied, stirred at a constant speed of 150r/min for 5min, left to stand for 5min, and the liquid at a position 1cm below the liquid surface was sucked up, and the ultraviolet penetration effect was measured by an ultraviolet spectrophotometer (wavelength: 550 nm). The experimental results are shown in table 1. As can be seen from table 1, after the cellulose-based adsorptive flocculation material prepared by the present application was added, the kaolin solution was significantly layered, and a good adsorptive flocculation function was exhibited. The amide bond has an excellent adsorption flocculation function, so that adsorption bridging action can be generated with kaolin suspended particles, and further, the sedimentation of impurities in water is promoted. As the impurity content in the water decreases, the permeation effect through the solution increases. Further, by comparison analysis with the comparative example, it is possible to obtain: the formaldehyde can promote the adsorption flocculation function of the cellulose-based adsorption flocculation material. This is mainly due to the fact that the incorporation of formaldehyde can improve the binding of acrylamide to cellulosic material, reducing the loss of acrylamide components during dialysis. Furthermore, the crosslinking can also improve the effective components of the adsorption flocculation material in unit volume, form more effective adsorption bridging structures and improve the sedimentation efficiency of suspended particles in sewage.
Table 1 examples, comparative examples and adsorption effects
Claims (9)
1. A method for preparing a cellulose-based adsorptive flocculation material, comprising:
(1) Adding cellulose into a sodium hydroxide/urea water dissolution system, and stirring to obtain a cellulose solution, wherein the cellulose comprises one or more of cotton linters, cotton pulp, bamboo fibers and bagasse;
(2) Adding acrylamide, an initiator and a cross-linking agent into the cellulose solution in the step (1), stirring for reaction, adding formaldehyde, continuously stirring, adding epichlorohydrin, stirring again, dialyzing, drying and crushing to obtain a cellulose-based adsorption flocculation material, wherein the cross-linking agent is N, N' -methylene bisacrylamide, and stirring for reaction is as follows: reacting for 0.5-1h at the temperature of 40-80 ℃ under nitrogen; continuing stirring for 1-2 hours; stirring again for 1-4 hours.
2. The preparation method according to claim 1, wherein the mass fraction of sodium hydroxide in the sodium hydroxide/urea aqueous solution system in the step (1) is 6 to 9%, the mass fraction of urea is 10 to 13%, and the balance is water.
3. The method according to claim 1, wherein the mass fraction of cellulose in the cellulose solution in the step (1) is 2 to 4%.
4. The method according to claim 1, wherein the stirring temperature in the step (1) is-20 to-10 ℃ and the stirring time is 0.5 to 1h.
5. The method according to claim 1, wherein the initiator in the step (2) comprises one or more of ammonium persulfate, potassium persulfate and sodium persulfate.
6. The preparation method according to claim 1, wherein the initiator in the step (2) accounts for 0.1-5% of the total weight of cellulose and acrylamide; the cross-linking agent accounts for 0.1 to 2 percent of the total weight of cellulose and acrylamide; the mass ratio of the cellulose to the acrylamide is 1:1-20.
7. The method according to claim 1, wherein the concentration of formaldehyde in the step (2) is 36-40%; the mass ratio of formaldehyde to acrylamide is 1:10-50; the epichlorohydrin accounts for 0.1 to 10 percent of the total weight of the cellulose and the acrylamide.
8. A cellulose-based adsorptive flocculation material prepared by the preparation method of claim 1.
9. Use of a cellulose-based adsorptive flocculation material prepared by the preparation method of claim 1 in wastewater treatment.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103183780A (en) * | 2013-04-03 | 2013-07-03 | 浙江理工大学 | Preparation method for cellulose-based wastewater flocculating agent |
| CN103788381A (en) * | 2014-01-21 | 2014-05-14 | 浙江理工大学 | Preparation method of cationized cellulose-based flocculating agent |
| CN107082894A (en) * | 2017-06-02 | 2017-08-22 | 湖南大学 | A kind of double-network hydrogel adsorbent and preparation method thereof and it is used as the application of heavy metal absorbent |
| CN109205748A (en) * | 2018-10-30 | 2019-01-15 | 成都其其小数科技有限公司 | A kind of flocculant and preparation method for heavy metal-polluted water process |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103183780A (en) * | 2013-04-03 | 2013-07-03 | 浙江理工大学 | Preparation method for cellulose-based wastewater flocculating agent |
| CN103788381A (en) * | 2014-01-21 | 2014-05-14 | 浙江理工大学 | Preparation method of cationized cellulose-based flocculating agent |
| CN107082894A (en) * | 2017-06-02 | 2017-08-22 | 湖南大学 | A kind of double-network hydrogel adsorbent and preparation method thereof and it is used as the application of heavy metal absorbent |
| CN109205748A (en) * | 2018-10-30 | 2019-01-15 | 成都其其小数科技有限公司 | A kind of flocculant and preparation method for heavy metal-polluted water process |
Non-Patent Citations (1)
| Title |
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| Ghada Kadry.Cellulosic-based hydrogel from biomass material for removal of metals from waste water .《JOURNAL OF MACROMOLECULAR SCIENCE, PART A: PURE AND APPLIED CHEMISTRY》.2019,1-14. * |
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