Preparation method and system of natural high molecular flocculant

Abstract

The present application relates to a kind of natural polymer flocculants preparation method and preparation system, wherein preparation method steps are: blending paste;Blending paste material transfer;Graft copolymerization modification;Crosslinking modification;Cooling and drying;Crushing powder;Preparation system includes thermostatic mixer, the thermostatic mixer is connected with modular laboratory reactor, the modular laboratory reactor is connected with dryer, crusher, pulverizer in sequence.The present application is studied by physical, chemical and other modification methods, proposes new natural polymer flocculants synthesis technology route, develops new efficient stable low-cost degradable flocculant with the dual structure characteristics of starch flocculant and cellulose flocculant, and plays a good flocculation dewatering treatment effect to handle high turbidity acidic heavy metal fine particle tailing waste liquid, solves the environmental pollution problems such as toxic monomer and metal produced in the process of residual and natural degradation in the process of flocculant production.

Description

Technical Field

[0001] This invention belongs to the field of industrial wastewater treatment technology, specifically relating to a method and system for preparing a natural polymeric flocculant. Background Technology

[0002] Polymer flocculants play an irreplaceable role in wastewater treatment. Flocculants are the core of coagulation and sedimentation methods, acting as coagulants that transform sols into flocculent precipitates. Flocculants used in petrochemical, metallurgical, mineral processing, and other wastewater treatment processes are mainly classified into inorganic and organic types based on their molecular composition. Inorganic flocculants have a long history of application, but their use is limited due to large dosages and low efficiency. Organic flocculants can be further divided into synthetic polymer flocculants and natural polymer flocculants. Synthetic polymer flocculants, with polyacrylamide (PAM) as a typical example, suffer from drawbacks such as residues from production and toxic monomers and metal residues generated during natural degradation, which do not meet environmental protection requirements, leading to increasingly limited applications.

[0003] my country's flocculant production lacks standardization and large-scale production. There are many small-scale manufacturers with limited product variety and outdated production processes, resulting in inconsistent flocculant quality. The research, production, and application of organic polymer flocculants are still in the development stage and remain a weak link. Basic theoretical guidance for production and equipment design has not yet been applied. my country lags significantly behind foreign countries in the technology of organic polymer flocculants. Taking polyacrylamide flocculants, a major product, as an example, there is a significant gap in terms of product variety, product form, production process, and production scale.

[0004] Natural polymeric flocculants possess characteristics such as a wide relative molecular mass distribution, numerous active groups, diverse structures, abundant raw material sources, and high mechanical strength. In particular, they are safe, non-toxic, and completely biodegradable, exhibiting excellent "environmental acceptability" and are known as "green flocculants," thus securing a place in the industrial wastewater treatment field. However, currently, natural polymeric flocculants suffer from unstable performance and high prices, and cannot completely replace inorganic and synthetic polymeric flocculants. Therefore, developing stable and economical natural polymeric flocculants is of great significance and holds considerable market potential.

[0005] The development of highly safe and biodegradable polymeric flocculants has always been a focus of attention. Natural polymers (such as starch, cellulose, and other polysaccharides) have advantages such as low cost, easy availability, non-toxicity, and biodegradability. Their chemical structures contain functional groups such as hydroxyl, amino, and carbonyl groups. Through reactions such as esterification, etherification, oxidation, and cross-linking of these hydroxyl groups, the properties of starch and cellulose can be modified, resulting in higher selective removal rates of heavy metal ions in wastewater. Modified natural polymeric flocculants can remove heavy metal ions from wastewater through multiple mechanisms including chelation, electrostatic attraction, ion exchange, and adsorption bridging, facilitating the effective adsorption of various pollutants during the flocculation process. Expanding the application scope of natural polymeric flocculants by combining them with other technologies, and improving the flocculation and dewatering of fine-grained tailings in flocculation substrates, will be an important direction for future research on the treatment of high-turbidity acidic heavy metal fine-grained tailings wastewater from industries such as petrochemicals, metallurgy, mineral processing, and mineral beneficiation. Summary of the Invention

[0006] To address the above problems, this invention provides a method and system for preparing a natural polymeric flocculant.

[0007] The specific technical solution is as follows:

[0008] A method for preparing a natural polymeric flocculant includes the following steps:

[0009] Step 1: Blend and gelatinize. Weigh out corn starch and straw according to the ratio and put them into a constant temperature mixer. Add a measured amount of water and stir to gelatinize.

[0010] Step 2: Transfer the blended gelatinized material, cool it to room temperature, transfer it to a modular laboratory reactor, add a measured amount of warm water, and turn on the reactor stirrer to prevent clumping;

[0011] Step 3: Graft copolymerization modification. Weigh the initiator—potassium persulfate—in a beaker, and weigh N,N-methylenebisacrylamide and ethyl acrylate into another beaker. Add a measured amount of water to each beaker and heat to dissolve. Cool to room temperature and pour into a modular laboratory reactor. The modular laboratory reactor is set to a specific temperature for the reaction. The reaction principle is as follows:

[0012] Chain trigger:

[0013]

[0014] Chain growth:

[0015]

[0016] Chain transfer:

[0017]

[0018] Chain termination:

[0019]

[0020] Where: M is N-methylenebisacrylamide

[0021]

[0022] Step 4: Crosslinking modification. Weigh epichlorohydrin into a beaker, add an appropriate amount of water, heat to dissolve, cool to room temperature, and transfer to a modular laboratory reactor. Then add emulsifier (OP-10), silicone-based waterproofing agent, and acetic acid. Set the temperature in the modular laboratory reactor for the reaction. The reaction principle is as follows:

[0023] Step 4.1: (1)

[0024] Step 4.2: (2)

[0025] (a)

[0026] (b)

[0027] Under alkaline conditions, starch and cellulose act as weak acid and base, respectively, to generate sodium starch cellulose salt; epichlorohydrin is affected by the anion of sodium starch cellulose salt, and the original epoxy ring breaks to form a new epoxy ring; in step 4.2, (a) and (b) are two simultaneous reactions between another sodium starch salt molecule and the product of (2) to obtain cross-linked starch cellulose.

[0028] Step 5: Cooling and drying. After the reaction product has cooled, it is poured out from the modular laboratory reactor to obtain the starch and cellulose blended flocculant, which is then dried using a general-purpose oven.

[0029] Step 6: Crushing and pulverizing. The dried reaction product is crushed and pulverized using a multi-functional crusher to obtain a natural polymer flocculant.

[0030] Further, in step 1, 10g of corn starch and 3g of straw are weighed, and 30ml of a measured amount of water is added. The temperature of the constant temperature mixer is set to 65℃, and the reaction time is 30min. In step 2, 15ml of a measured amount of warm water is added. In step 3, 0.5g of potassium persulfate, 0.015g of NN methylenebisacrylamide, and 30ml of ethyl acrylate are weighed, and 10ml of a measured amount of water is added to each. The temperature of the modular laboratory reactor is set to 85℃, and the reaction time is 2h. In step 4, 5g of epichlorohydrin is weighed, and 20ml of water is added and heated to dissolve. 2ml of emulsifier (OP-10), 8ml of silicone-based waterproofing agent, and 10ml of acetic acid are added. The temperature of the modular laboratory reactor is set to 85℃, and the reaction time is 2h. In step 5, the oven temperature is set to 60℃, and the drying time is 8h.

[0031] The present invention also provides a preparation system for a method of preparing a natural polymeric flocculant, including a constant temperature mixer connected to a modular laboratory reactor, which is sequentially connected to a dryer, a crusher, and a pulverizer.

[0032] Furthermore, the pulverizer is connected to the crusher via a sieve to achieve repeated crushing and pulverization of the polymer flocculant.

[0033] Furthermore, the constant temperature mixer and the modular laboratory reactor are also connected to cooling water pipes for cooling the reactants.

[0034] The beneficial effects of this invention are:

[0035] This invention proposes a new synthetic route for natural polymeric flocculants through physical and chemical modification methods. By introducing different functional groups, the water solubility, molecular weight range, charge density, and multifunctionality of starch and cellulose are improved, giving them two or more functional groups. These flocculants possess high processing strength, high acid and alkali stability, and are not easily gelatinized. A novel, highly efficient, stable, inexpensive, and biodegradable flocculant with the dual structural characteristics of starch and cellulose flocculants has been developed. This flocculant effectively treats high-turbidity, acidic, heavy metal fine-particle tailings wastewater through flocculation and dehydration, solving the environmental pollution problems caused by residues during flocculant production and the generation of toxic monomers and metals during natural degradation. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the process flow of the present invention;

[0037] Figure 2 This is a schematic diagram of the preparation system of the present invention;

[0038] In the diagram: 1-Thermostatic mixer, 2-Modular laboratory reactor, 3-Dryer, 4-Crusher, 5-Pulverizer, 6-Sieve. Detailed Implementation

[0039] To make the technical problems and solutions solved by the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention. Example 1

[0040] This embodiment provides a method for preparing a natural polymeric flocculant, comprising the following steps:

[0041] Step 1: Blending and gelatinization. Weigh 6g of corn starch and 3g of straw according to the ratio and put them into a constant temperature mixer. Then add 30ml of quantitative water and put it into the constant temperature mixer to blend and gelatinize. Set the temperature to 65℃ and the reaction time to 30min.

[0042] Step 2: Transfer the blended gelatinized material, cool it to room temperature, transfer it to a modular laboratory reactor, add a measured amount of 15ml of warm water, turn on the reactor stirrer to prevent clumping;

[0043] Step 3: Graft copolymerization modification. Weigh 0.3g of potassium persulfate into a beaker, weigh 0.02g of N-N-methylenebisacrylamide and 25ml of ethyl acrylate into another beaker, add 10ml of measured amount of water to each beaker and heat to dissolve. Cool to room temperature and pour into a modular laboratory reactor. Set the temperature of the modular laboratory reactor to 80℃ and the reaction time to 2h.

[0044] Step 4: Crosslinking modification. After the graft copolymerization modification reaction is completed, weigh 5g of epichlorohydrin into a beaker, add 20ml of water and heat to dissolve. Cool to room temperature and transfer to a modular laboratory reactor. Then add 1ml of emulsifier (OP-10), 6ml of silicone waterproofing agent, and 10ml of acetic acid. Set the temperature of the modular laboratory reactor to 80℃ and the reaction time to 2h.

[0045] Step 5: Cooling and drying. After the reaction product has cooled, pour it out from the modular laboratory reactor to obtain the starch and cellulose blended flocculant. Dry it using a general-purpose oven set at 60°C for 8 hours.

[0046] Step 6: Crushing and pulverizing. The dried reaction product is crushed and pulverized using a multi-functional crusher to obtain environmentally friendly flocculant 1.

[0047] Experimental Example 2

[0048] This embodiment provides a method for preparing a natural polymeric flocculant, comprising the following steps:

[0049] Step 1: Blending and gelatinization. Weigh 9g of corn starch and 3g of straw according to the ratio and put them into a constant temperature mixer. Add 30ml of quantitative water and put it into the constant temperature mixer to blend and gelatinize. Set the temperature to 65℃ and the reaction time to 30min.

[0050] Step 2: Transfer the blended gelatinized material, cool it to room temperature, transfer it to a modular laboratory reactor, add a measured amount of 15ml of warm water, turn on the reactor stirrer to prevent clumping;

[0051] Step 3: Graft copolymerization modification. Weigh 0.35g of potassium persulfate into a beaker, weigh 0.025g of N-N-methylenebisacrylamide and 30ml of ethyl acrylate into another beaker, add 10ml of measured amount of water to each beaker and heat to dissolve. Cool to room temperature and pour into a modular laboratory reactor. Set the temperature of the modular laboratory reactor to 80℃ and the reaction time to 2h.

[0052] Step 4: Crosslinking modification. After the graft copolymerization modification reaction is completed, weigh 4g of epichlorohydrin into a beaker, add 20ml of water and heat to dissolve. Cool to room temperature and transfer to a modular laboratory reactor. Then add 2ml of emulsifier (OP-10), 6ml of silicone waterproofing agent, and 8ml of acetic acid. Set the temperature of the modular laboratory reactor to 80℃ and the reaction time to 2h.

[0053] Step 5: Cooling and drying. After the reaction product has cooled, pour it out from the modular laboratory reactor to obtain the starch and cellulose blended flocculant. Dry it using a general-purpose oven set at 60°C for 8 hours.

[0054] Step 6: Crushing and pulverizing. The dried reaction product is crushed and pulverized using a multi-functional crusher to obtain environmentally friendly flocculant 2.

[0055] Experimental Example 3

[0056] This embodiment provides a method for preparing a natural polymeric flocculant, comprising the following steps:

[0057] Step 1: Blending and gelatinization. Weigh 10g of corn starch and 3g of straw according to the ratio and put them into a constant temperature mixer. Add 30ml of quantitative water and put it into the constant temperature mixer to blend and gelatinize. Set the temperature to 65℃ and the reaction time to 30min.

[0058] Step 2: Transfer of blended gelatinized material: After cooling to room temperature, transfer the blended gelatinized material to a modular laboratory reactor, add a measured amount of 15ml of warm water, and turn on the reactor stirrer to prevent clumping;

[0059] Step 3: Graft copolymerization modification. Weigh 0.45g of potassium persulfate into a beaker, weigh 0.02g of N-N-methylenebisacrylamide and 30ml of ethyl acrylate into another beaker, add 10ml of measured water to each beaker and heat to dissolve. Cool to room temperature and pour into a modular laboratory reactor. Set the temperature of the modular laboratory reactor to 80℃ and the reaction time to 2h.

[0060] Step 4: Crosslinking modification. After the graft copolymerization modification reaction is complete, weigh 5g of epichlorohydrin into a beaker, add 20ml of water, heat to dissolve, cool to room temperature, and then transfer to a modular laboratory reactor. Then add 2ml of emulsifier (OP-10), 8ml of silicone-based waterproofing agent, and 9ml of acetic acid. Set the temperature of the modular laboratory reactor to 80℃ and the reaction time to 2 hours.

[0061] Step 5: Cooling and drying. After the reaction product has cooled, pour it out from the modular laboratory reactor to obtain the starch and cellulose blended flocculant. Dry it using a general-purpose oven (IKA OVEN 125) set at 60℃ for 8 hours.

[0062] Step 6: Crushing and pulverizing. The dried reaction product is crushed and pulverized using a multi-functional crusher to obtain environmentally friendly flocculant 3.

[0063] Experiment Example 4:

[0064] Step 1: Blending and gelatinization. Weigh 10g of corn starch and 3g of straw according to the ratio and put them into a constant temperature mixer. Add 30ml of quantitative water and put it into the constant temperature mixer to blend and gelatinize. Set the temperature to 65℃ and the reaction time to 30min.

[0065] Step 2: Transfer the blended gelatinized material, cool it to room temperature, transfer it to a modular laboratory reactor, add a measured amount of 15ml of warm water, turn on the reactor stirrer to prevent clumping;

[0066] Step 3: Graft copolymerization modification. Weigh 0.5g of potassium persulfate into a beaker, weigh 0.015g of N-N-methylenebisacrylamide and 30ml of ethyl acrylate into another beaker, add 10ml of measured amount of water to each beaker and heat to dissolve. Cool to room temperature and pour into a modular laboratory reactor. Set the temperature of the modular laboratory reactor to 80℃ and the reaction time to 2h.

[0067] Step 4: Crosslinking Modification. After the graft copolymerization modification reaction is complete, weigh 5g of epichlorohydrin into a beaker, add 20ml of water, heat to dissolve, cool to room temperature, and then transfer to a modular laboratory reactor. Then add 2ml of emulsifier (OP-10), 8ml of silicone-based waterproofing agent, and 10ml of acetic acid. Set the temperature of the modular laboratory reactor to 80℃ and the reaction time to 2 hours.

[0068] Step 5: Cooling and drying. After the reaction product has cooled, pour it out from the modular laboratory reactor to obtain the starch and cellulose blended flocculant. Dry it using a general-purpose oven set at 60°C for 8 hours.

[0069] Step 6: Crushing and pulverizing. The dried reaction product is crushed and pulverized using a multi-functional crusher to obtain environmentally friendly flocculant 4.

[0070] Experimental Example 5:

[0071] This embodiment provides a method for preparing a natural polymeric flocculant, comprising the following steps:

[0072] Step 1: Blending and gelatinization. Weigh 10g of corn starch and 3g of straw according to the ratio and put them into a constant temperature mixer. Add 30ml of quantitative water and put it into the constant temperature mixer to blend and gelatinize. Set the temperature to 65℃ and the reaction time to 30min.

[0073] Step 2: Transfer the blended gelatinized material, cool it to room temperature, transfer it to a modular laboratory reactor, add a measured amount of 15ml of warm water, turn on the reactor stirrer to prevent clumping;

[0074] Step 3: Graft copolymerization modification. Weigh 0.5g of potassium persulfate into a beaker, weigh 0.015g of N-N-methylenebisacrylamide and 30ml of ethyl acrylate into another beaker, add 10ml of measured amount of water to each beaker and heat to dissolve. Cool to room temperature and pour into a modular laboratory reactor. Set the temperature of the modular laboratory reactor to 85℃ and the reaction time to 2h.

[0075] Step 4: Crosslinking modification. After the graft copolymerization modification reaction is complete, weigh 5g of epichlorohydrin into a beaker, add 20ml of water, heat to dissolve, cool to room temperature, and then transfer to a modular laboratory reactor. Then add 2ml of emulsifier (OP-10), 8ml of silicone-based waterproofing agent, and 10ml of acetic acid. Set the temperature of the modular laboratory reactor to 85℃ and the reaction time to 2 hours.

[0076] Step 5: Cooling and drying. After the reaction product has cooled, pour it out from the modular laboratory reactor to obtain the starch and cellulose blended flocculant. Dry it using a general-purpose oven set at 60°C for 8 hours.

[0077] Step 6: Crushing and pulverizing. The dried reaction product is crushed and pulverized using a multi-functional crusher to obtain environmentally friendly flocculant 5.

[0078] Experimental Example 6:

[0079] This embodiment provides a method for preparing a natural polymeric flocculant, comprising the following steps:

[0080] Step 1: Blending and gelatinization. Weigh 10g of corn starch and 3g of straw according to the ratio and put them into a constant temperature mixer. Add 30ml of quantitative water and put it into the constant temperature mixer to blend and gelatinize. Set the temperature to 65℃ and the reaction time to 30min.

[0081] Step 2: Transfer the blended gelatinized material, cool it to room temperature, transfer it to a modular laboratory reactor, add a measured amount of 15ml of warm water, turn on the reactor stirrer to prevent clumping;

[0082] Step 3: Graft copolymerization modification. Weigh 0.5g of potassium persulfate into a beaker, weigh 0.015g of N-N-methylenebisacrylamide and 30ml of ethyl acrylate into another beaker, add 10ml of measured amount of water to each beaker and heat to dissolve. Cool to room temperature and pour into a modular laboratory reactor. Set the temperature of the modular laboratory reactor to 90℃ and the reaction time to 2h.

[0083] Step 4: Crosslinking Modification. After the graft copolymerization modification reaction is complete, weigh 5g of epichlorohydrin into a beaker, add 20ml of water, heat to dissolve, cool to room temperature, and then transfer to a modular laboratory reactor. Add 2ml of emulsifier (OP-10), 8ml of silicone-based waterproofing agent, and 10ml of acetic acid. Set the temperature of the modular laboratory reactor to 90℃ and the reaction time to 2 hours.

[0084] Step 5: Cooling and drying. After the reaction product has cooled, pour it out from the modular laboratory reactor to obtain the starch and cellulose blended flocculant. Dry it using a general-purpose oven set at 60°C for 8 hours.

[0085] Step 6: Crushing and pulverizing. The dried reaction product is crushed and pulverized using a multi-functional crusher to obtain environmentally friendly flocculant 6.

[0086] Comparative experiment: The sedimentation experiments of fine-grained calcined sand tailings were carried out using natural sedimentation, PAM sedimentation, and environmentally friendly flocculants 1, 2, 3, 4, 5, and 6. The elemental detection results of water samples of fine-grained calcined sand tailings are shown in Table 1, the sedimentation experimental conditions of fine-grained calcined sand tailings are shown in Table 2, and the sedimentation experimental results of fine-grained calcined sand tailings are shown in Table 3.

[0087] Table 1. Elemental analysis results of water samples from fine-grained calcined cyanide tailings.

[0088]

[0089] Table 2 Settling test conditions for fine-grained calcined cyanide tailings

[0090]

[0091] Table 3. Settling test results of fine-grained calcined cyanide tailings

[0092]

[0093] As can be seen from Table 3, adding flocculant 5 to the calcined cyanide fine-grained tailings slurry has the best flocculation effect, and the slurry sedimentation effect is closest to that of adding polyacrylamide (PAM) flocculant. Therefore, the optimal preparation method for natural polymeric flocculant is the scheme in Example 5.

[0094] This invention utilizes starch and cellulose, two natural polymer materials with different structures, for blending and gelatinization. Following chemical modification through graft copolymerization and cross-linking, the mixture is then copolymerized with acrylamide using a water-phase polymerization process to prepare a highly efficient, safe, and biodegradable natural polymeric flocculant tailings for various wastewater conditions. Comparative experiments comparing the natural polymeric flocculant with natural sedimentation and organic synthetic polyacrylamide (PAM) flocculants in the treatment of roasted cyanide fine-grained tailings slurry revealed that the natural polymeric flocculant exhibits higher processing strength and acid-base stability. It demonstrates better treatment efficacy than PAM for high-turbidity acidic heavy metal fine-grained tailings wastewater. Furthermore, cellulose and starch are abundant, renewable, and inexpensive, and the natural polymeric flocculant is selective, non-toxic, and biodegradable, thus broadening its applicability in treating high-turbidity acidic heavy metal fine-grained tailings wastewater from the petrochemical, metallurgical, mineral processing, and other industries. Example 7

[0095] like Figure 2 As shown, this embodiment provides a preparation system for a natural polymeric flocculant, including a thermostatic mixer 1 connected to a modular laboratory reactor 2. The modular laboratory reactor 2 is sequentially connected to a dryer 3, a crusher 4, and a pulverizer 5. The pulverizer 5 is connected to the crusher 4 via a sieve 6 to achieve repeated crushing and pulverizing of the polymeric flocculant. The thermostatic mixer 1 and the modular laboratory reactor 2 are also connected to cooling water pipes for cooling the reactants.

[0096] In this specific application, the corn starch and straw, weighed according to the specified ratio, are placed in a constant-temperature mixer 1, and then a measured amount of water is added to the mixer 1 for blending and gelatinization. After the blending and gelatinization is completed, the material is cooled to room temperature and then transferred to a modular laboratory reactor 2. A measured amount of warm water is added, and the reactor stirrer is turned on to prevent clumping. At the same time, potassium persulfate is weighed into a beaker, and N,N-methylenebisacrylamide and ethyl acrylate are weighed into another beaker. Measured amounts of water are added to each beaker, and the mixture is heated to dissolve. After cooling to room temperature, the solutions are poured into the modular laboratory reactor 2 for graft copolymerization modification reaction. After the graft copolymerization modification reaction is completed... Weigh epichlorohydrin into a beaker, add water and heat to dissolve. Cool to room temperature and transfer to modular laboratory reactor 2. Then add emulsifier (OP-10), silicone-based waterproofing agent, and acetic acid to carry out cross-linking modification reaction. After the reaction product cools, pour it out of modular laboratory reactor 2 and transfer it to desiccator 3 for drying. Transfer the dried reaction product to crusher 4 for preliminary crushing, and then to pulverizer 5 for further pulverization. After pulverization, it enters sieve 6 for sieving. Fine particles are directly used as the finished product - natural polymer flocculant, while coarse particles are returned to crusher 4 and pulverizer 5 for further pulverization.

[0097] In this embodiment, the constant temperature mixer is IKA MATRIX, the modular laboratory reactor is IKA LR 1000, the dryer is IKA OVEN 125 universal drying oven, the crusher is IKA Multidrive multi-functional crusher, the pulverizer is IKA Multidrive multi-functional crusher, and the sieve size of the sieve is 0.0750mm.

[0098] The present invention has been described in detail above through specific and preferred embodiments. However, those skilled in the art should understand that the present invention is not limited to the embodiments described above. Any modifications, equivalent substitutions, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for producing a natural high molecular flocculant, characterized by, Includes the following steps: Step 1: Blend and gelatinize. Weigh out corn starch and straw according to the ratio and put them into a constant temperature mixer. Add a measured amount of water and stir to gelatinize. Step 2: Transfer the blended gelatinized material, cool it to room temperature, transfer it to a modular laboratory reactor, add a measured amount of warm water, and turn on the reactor stirrer to prevent clumping; Step 3: Graft copolymerization modification. Weigh the initiator—potassium persulfate—in a beaker, and weigh NN methylenebisacrylamide and ethyl acrylate into another beaker. Add a measured amount of water to each beaker and heat to dissolve. Cool to room temperature and pour into a modular laboratory reactor. Set the temperature in the modular laboratory reactor for reaction. Step 4: Crosslinking modification. Weigh epichlorohydrin into a beaker, add an appropriate amount of water, heat to dissolve, cool to room temperature, and transfer to a modular laboratory reactor. Then add emulsifier (OP-10), silicone-based waterproofing agent, and acetic acid. Set the temperature in the modular laboratory reactor for the reaction. The reaction principle is as follows: Step 4.1: (1) Step 4.2: (2) （a） （b） Under alkaline conditions, starch and cellulose act as weak acid and base, respectively, to generate sodium starch cellulose salt; epichlorohydrin is affected by the anion of sodium starch cellulose salt, and the original epoxy ring breaks to form a new epoxy ring; in step 4.2, (a) and (b) are two simultaneous reactions between another sodium starch salt molecule and the product of (2) to obtain cross-linked starch cellulose. Step 5: Cooling and drying. After the reaction product has cooled, it is poured out from the modular laboratory reactor to obtain the starch and cellulose blended flocculant, which is then dried using a general-purpose oven. Step 6: Crushing and pulverizing. The dried reaction product is crushed and pulverized using a multi-functional crusher to obtain a natural polymer flocculant.

2. The method for preparing a natural polymeric flocculant according to claim 1, characterized in that, In step 1, weigh 10g of corn starch and 3g of straw, add 30ml of a measured amount of water, set the temperature of the constant temperature mixer to 65℃, and the reaction time to 30min; in step 2, add 15ml of a measured amount of warm water; in step 3, weigh 0.5g of potassium persulfate, 0.015g of NN methylenebisacrylamide, and 30ml of ethyl acrylate, add 10ml of a measured amount of water to each, set the temperature of the modular laboratory reactor to 85℃, and the reaction time to 2h; in step 4, weigh 5g of epichlorohydrin, add 20ml of water and heat to dissolve, add 2ml of emulsifier (OP-10), 8ml of silicone-based waterproofing agent, and 10ml of acetic acid, set the temperature of the modular laboratory reactor to 85℃, and the reaction time to 2h; in step 5, set the oven temperature to 60℃ and the drying time to 8h.

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