A wastewater treatment flocculant and a preparation method thereof

Abstract

The application belongs to the technical field of flocculants, and specifically provides a wastewater treatment flocculant and a preparation method thereof. The preparation method of the wastewater treatment flocculant comprises the following steps: 1) reacting guar gum with isopropyl acrylamide to obtain precursor A; reacting guar gum with sodium methacrylate to obtain precursor B; 2) uniformly mixing deionized water, the precursor A, the precursor B and a dextran derivative polymer, then adding monomers and an initiator, performing photoinitiated reaction, and performing purification and drying to obtain the flocculant. The flocculant prepared by the application has the advantages of good flocculation effect and suitability for complex sewage systems.

Description

Technical Field

[0001] This application belongs to the field of flocculant technology, and in particular relates to a wastewater treatment flocculant and its preparation method. Background Technology

[0002] Flocculation technology is one of the most widely used and cost-effective solid-liquid separation technologies in the water treatment field. Its core lies in using flocculants to aggregate suspended colloidal particles and fine suspended solids in water into large flocs, thereby accelerating the sedimentation or filtration separation process. The selection and performance of flocculants directly determine the water treatment effect, treatment cost, and effluent quality; therefore, flocculant research and development has always been a research hotspot in the water treatment field.

[0003] With the increasing complexity of industrial wastewater composition, single-type flocculants often fall short of meeting the demands for efficient treatment, leading to widespread attention on the research and application of composite flocculants. By compounding different types of flocculants or introducing multiple functional groups into the same molecule through chemical modification, the synergistic effect between components can be fully utilized, significantly improving flocculation performance. For example, multi-ion composite flocculants prepared using coal gasification slag contain iron, aluminum, and calcium ions simultaneously. When treating complex wastewater, the synergistic effect of these multiple ions effectively improves the coagulation performance of the flocculant.

[0004] Furthermore, chemical modification can endow flocculants with special responsive properties. For example, by synthesizing temperature-sensitive starch and pH-responsive etherifying agents, flocculants with unidirectional temperature memory function can be prepared. These flocculants can achieve temperature-triggered dye-directed flocculation, and after flocculation, their unique unidirectional temperature memory ability enables irreversible fixation of the floc conformation, effectively avoiding the re-electrostatic restabilization phenomenon of colloidal particles caused by reversible dissolution of flocculants, and significantly reducing the residual amount of flocculants in recycled water.

[0005] Despite significant progress in flocculant research, several pressing issues remain: the secondary pollution risk of traditional flocculants, the stability of natural polymeric flocculants, the industrialization cost of microbial flocculants, and the synergistic mechanism of composite flocculants. Therefore, developing novel, environmentally friendly, efficient, economical, and stable flocculants, conducting in-depth research on their mechanisms of action, and exploring targeted design strategies for specific pollutants are of significant scientific and practical value for achieving efficient industrial wastewater treatment, sustainable resource utilization, protecting the water environment, and reducing environmental pollution. Summary of the Invention

[0006] To address the above problems, this application provides a wastewater treatment flocculant and its preparation method.

[0007] This application first provides a method for preparing a wastewater treatment flocculant, comprising the following steps:

[0008] 1) Precursor A was prepared by reacting guar gum with isopropylacrylamide; Precursor B was prepared by reacting guar gum with sodium methacrylate.

[0009] 2) Take deionized water, precursor A, precursor B, and dextran-derived polymer, mix them evenly, then add monomers and initiators, photo-initiate the reaction, purify and dry to obtain the final product.

[0010] Furthermore, in step 1), the mass ratio of guar gum to sodium methacrylate is 1:(1-1.5).

[0011] Furthermore, in step 1), the mass ratio of guar gum to isopropylacrylamide is 1:(0.75-1).

[0012] Furthermore, in step 2), the monomers are acrylamide monomer and acryloyloxyethyltrimethylammonium chloride, and the initiator is azobisisobutyramidine hydrochloride.

[0013] Furthermore, in step 2), the dextran-derived polymer is prepared using the following steps:

[0014] S1: Sodium caseinate and dextran were dissolved in deionized water and stirred overnight. Then, the mixture was freeze-dried. The resulting freeze-dried powder was spread in a glass dish and kept moist with potassium bromide solution. The temperature was controlled at 55-65℃ to react and obtain dextran derivatives.

[0015] S2: Dissolve zein in an ethanol solution, add sodium thiocate and stir until homogeneous to obtain a base solution; dissolve the dextran derivative in deionized water to obtain an aqueous solution of the dextran derivative; slowly disperse the base solution into the dextran derivative solution, stir thoroughly, evaporate to remove ethanol, and freeze-dry to obtain the final product.

[0016] Furthermore, in step S1, the mass ratio of sodium caseinate to dextran is 1:(1.5-2.5).

[0017] Furthermore, in step S2, the mass concentration of zein in the base solution is 2-3.5%.

[0018] Furthermore, in step S2, the volume ratio of the base liquid to the dextran derivative solution is 1:(4-6).

[0019] Furthermore, in step 2), the mass ratio of precursor A, precursor B, and dextran-derived polymer is 1:(0.15-2):(0.1-0.15).

[0020] This application also provides a wastewater treatment flocculant, which is prepared by the above-described preparation method.

[0021] Compared with the prior art, this application has the following beneficial effects:

[0022] This application utilizes guar gum, a natural polysaccharide, grafted with two monomers to prepare a pH- and temperature-responsive polymeric flocculant. This material exhibits high solubility in wastewater systems, particularly in complex wastewater environments where it undergoes a phase transition. It captures micro- and nano-particles and oily substances through charge neutralization, while the hydrophobic chains provide adsorption, effectively enhancing the capture of hydrophobic particles and demonstrating superior flocculation and removal performance. Furthermore, the dextran-derived polymer enhances the regeneration performance of the flocs through coiling and stretching transformations, significantly improving the overall removal efficiency of pollutants in the wastewater system. Additionally, the dextran-derived polymer, as an unreacted base chain, can intercalate within the guar gum grafted structure, forming a more stable network structure within the system. This enhances bridging and trapping efficiency, resists the physicochemical impacts of complex water bodies, and improves the overall flocculation effect. Attached Figure Description

[0023] Figure 1 This is a schematic diagram showing the flocculant turbidity removal rate data of Examples 1-2 and Control Groups 1-2 of this application.

[0024] Figure 2 These are microscopic images of the flocculant state in Examples 1-2 and Control Groups 1-2 of this application. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0027] When using “including,” “having,” and “contains” as described herein, the intention is to cover non-exclusive inclusion, unless an explicit qualifying term such as “only,” “consisting of,” etc., is used, in which case another component may be added.

[0028] The terms "preferred," "more preferably," "better," and "even better" used in this application refer to embodiments of this application that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this application. That is, in this application, "preferred," "more preferably," "better," and "even better" are merely descriptions of implementations or embodiments with better effects, but do not constitute a limitation on the scope of protection of this application.

[0029] In this application, terms such as "further," "even more," and "particularly" are used for descriptive purposes and indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0030] In this application, "at least one" means one or more, such as one, two, or more. "Multiple" or "several" means at least two, such as two, three, etc., and "multi-layered" means at least two layers, such as two layers, three layers, etc., unless otherwise explicitly specified. In the description of this application, "several" means at least one, such as one, two, etc., unless otherwise explicitly specified.

[0031] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0032] Unless otherwise specified, all steps in this application may be performed sequentially or randomly. For example, the method comprising steps (a) and (b) indicates that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order; for example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc. Unless otherwise stated, singular terms may include plural forms and should not be construed as having a quantity of one.

[0033] In this application, "above" or "below" includes the number itself. For example, "below 1" includes 1.

[0034] In this application, room temperature refers to 0~40℃, including but not limited to 10~40℃, or further to 20~30℃.

[0035] Based on extensive experimental research, this application provides a method for preparing a wastewater treatment flocculant, comprising the following steps:

[0036] 1) Precursor A was prepared by reacting guar gum with isopropylacrylamide; Precursor B was prepared by reacting guar gum with sodium methacrylate.

[0037] 2) Take deionized water, precursor A, precursor B, and dextran-derived polymer, mix them evenly, then add monomers and initiators, photo-initiate the reaction, purify and dry to obtain the final product.

[0038] Furthermore, in step 1), the mass ratio of guar gum to sodium methacrylate is 1:(1-1.5).

[0039] In some specific embodiments, in step 1), the mass ratio of guar gum to sodium methacrylate can be 1:1, 1:1.05, 1:1.1, 1:1.15, 1:1.2, 1:1.25, 1:1.3, 1:1.35, 1:1.4, 1:1.45, or 1:1.5. Generally, a mass ratio of guar gum to sodium methacrylate of 1:1.2 in step 1) yields better experimental results.

[0040] Furthermore, in step 1), the mass ratio of guar gum to isopropylacrylamide is 1:(0.75-1).

[0041] In some specific embodiments, in step 1), the mass ratio of guar gum to isopropylacrylamide can be 1:0.75, 1:0.8, 1:0.85, 1:0.9, 1:0.95, or 1:1. Generally, a mass ratio of guar gum to isopropylacrylamide of 1:0.85 in step 1) yields better technical results.

[0042] Furthermore, in step 2), the monomers are acrylamide monomer and acryloyloxyethyltrimethylammonium chloride, and the initiator is azobisisobutyramidine hydrochloride.

[0043] Furthermore, in step 2), the dextran-derived polymer is prepared using the following steps:

[0044] S1: Sodium caseinate and dextran were dissolved in deionized water and stirred overnight. Then, the mixture was freeze-dried. The resulting freeze-dried powder was spread in a glass dish and kept moist with potassium bromide solution. The temperature was controlled at 55-65℃ to react and obtain dextran derivatives.

[0045] S2: Dissolve zein in an ethanol solution, add sodium thiocate and stir until homogeneous to obtain a base solution; dissolve the dextran derivative in deionized water to obtain an aqueous solution of the dextran derivative; slowly disperse the base solution into the dextran derivative solution, stir thoroughly, evaporate to remove ethanol, and freeze-dry to obtain the final product.

[0046] Furthermore, in step S1, the mass ratio of sodium caseinate to dextran is 1:(1.5-2.5).

[0047] In some specific embodiments, in step S1, the mass ratio of sodium caseinate to dextran can be 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2, 1:2.1, 1:2.2, 1:2.3, 1:2.4, or 1:2.5. Generally, a mass ratio of 1:2 for sodium caseinate to dextran in step S1 yields the best technical results.

[0048] Furthermore, in step S2, the mass concentration of zein in the base solution is 2-3.5%.

[0049] In some specific embodiments, in step S2, the mass concentration of zein in the base solution can be 2%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3%, 3.1%, 3.2%, 3.3%, 3.4%, or 3.5%. Generally, a mass concentration of 3% of zein in the base solution in step S2 yields better experimental results.

[0050] Furthermore, in step S2, the volume ratio of the base liquid to the dextran derivative solution is 1:(4-6).

[0051] In some specific embodiments, in step S2, the volume ratio of the base solution to the dextran derivative solution can be 1:4, 1:4.1, 1:4.2, 1:4.3, 1:4.4, 1:4.5, 1:4.6, 1:4.7, 1:4.8, 1:4.9, 1:5, 1:5.1, 1:5.2, 1:5.3, 1:5.4, 1:5.5, 1:5.6, 1:5.7, 1:5.8, 1:5.9, or 1:6. Generally, a volume ratio of 1:5 for the base solution to the dextran derivative solution in step S2 yields better technical results.

[0052] Furthermore, in step 2), the mass ratio of precursor A, precursor B, and dextran-derived polymer is 1:(0.15-2):(0.1-0.15).

[0053] In some specific embodiments, in step 2), the mass ratio of precursor A, precursor B, and dextran-derived polymer can be 1:0.15:0.1, 1:0.16:0.1, 1:0.17:0.1, 1:0.18:0.1, 1:0.19:0.1, 1:0.2:0.1, 1:0.15:0.1, 1:0.16:0.11, 1:0.17:0.12, 1:0.18:0.13, 1:0.19:0.14, or 1:0.2:0.15. Generally, in step 2), a mass ratio of 1:0.16:0.11 or 1:0.17:0.12 yields better results.

[0054] This application also provides a wastewater treatment flocculant, which is prepared by the above-described preparation method.

[0055] The present application will be further illustrated by the following examples, but these examples do not limit the scope of the present application.

[0056] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in this application, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. All reagents or instruments whose manufacturers are not specified are conventional products that can be purchased commercially. In addition to the specific methods, equipment, and materials used in the embodiments, based on the knowledge of the prior art possessed by one of ordinary skill in the art and the description in this application, any prior art methods, equipment, and materials similar to or equivalent to those described, used, or made by the methods, equipment, and materials in the embodiments of this application may be used to implement this application.

[0057] Example 1

[0058] The preparation method of the wastewater treatment flocculant in this embodiment includes the following steps:

[0059] 1) Dissolve 3g of guar gum in 200mL of 0.1mol / L citric acid solution, then add 2.55g of isopropylacrylamide, stir thoroughly, add potassium persulfate, and react under nitrogen protection in a 60℃ constant temperature water bath for 2.5h. Wash with anhydrous ethanol, and then vacuum dry at 60℃ to obtain precursor A; Dissolve 1g of guar gum in 100mL of 0.1mol / L citric acid solution, add 1.2g of sodium methacrylate, stir thoroughly, add potassium persulfate, and react under nitrogen protection in a 60℃ constant temperature water bath for 2.5h. Wash with anhydrous ethanol, and then vacuum dry at 60℃ to obtain precursor B;

[0060] 2) Add 1.5L of deionized water, 10g of precursor A, 2g of precursor B, and 1.5g of dextran-derived polymer to the reactor and mix thoroughly. Then add 5g of acrylamide, 3.5g of acryloyloxyethyltrimethylammonium chloride, and azobisisobutyramidine hydrochloride. Adjust the pH of the system to 5. After mixing thoroughly at room temperature, place the mixture under a 24W UV lamp to initiate the reaction. Maintain the temperature below 30°C during the reaction. Aging the reaction product overnight, washing it with anhydrous ethanol, and then vacuum drying it at 60°C to obtain the final product.

[0061] The dextran-derived polymer in this embodiment was prepared using the following steps:

[0062] S1: Dissolve 10g sodium caseinate and 20g β-glucan in deionized water, stir overnight, then freeze dry. Spread the resulting freeze-dried powder in a glass dish, maintain the humidity at 78% with saturated potassium bromide solution, control the temperature at 60℃, and react for 24h to obtain the glucan derivative.

[0063] S2: Dissolve zein in an 80% ethanol solution, add sodium thiocate and stir until homogeneous to obtain a base solution. Control the mass concentration of zein in the base solution to 3% and the mass concentration of thiocate in the base solution to 0.3%. Dissolve 1g of dextran derivative in deionized water and adjust the pH to 6 to obtain an aqueous solution of dextran derivative. Slowly disperse 100mL of the base solution into 500mL of the dextran derivative solution, stir thoroughly at 800r / min for 45min, remove ethanol by rotary evaporation at 35℃, centrifuge, and freeze-dry the supernatant to obtain the final product.

[0064] Example 2

[0065] The preparation method of the wastewater treatment flocculant in this embodiment includes the following steps:

[0066] 1) Dissolve 3g of guar gum in 200mL of 0.1mol / L citric acid solution, then add 2.55g of isopropylacrylamide, stir thoroughly, add potassium persulfate, and react under nitrogen protection in a 60℃ constant temperature water bath for 2.5h. Wash with anhydrous ethanol, and then vacuum dry at 60℃ to obtain precursor A; Dissolve 1g of guar gum in 100mL of 0.1mol / L citric acid solution, add 1.2g of sodium methacrylate, stir thoroughly, add potassium persulfate, and react under nitrogen protection in a 60℃ constant temperature water bath for 2.5h. Wash with anhydrous ethanol, and then vacuum dry at 60℃ to obtain precursor B;

[0067] 2) Add 1.5L of deionized water, 10g of precursor A, 1.6g of precursor B, and 1.1g of dextran-derived polymer to the reactor and mix thoroughly. Then add 5g of acrylamide, 3.5g of acryloyloxyethyltrimethylammonium chloride, and azobisisobutyramidine hydrochloride. Adjust the pH of the system to 5. After mixing thoroughly at room temperature, place the mixture under a 24W UV lamp to initiate the reaction. Maintain the temperature below 30°C during the reaction. Aging the reaction product overnight, washing it with anhydrous ethanol, and then vacuum drying it at 60°C to obtain the final product.

[0068] The dextran-derived polymer in this embodiment was prepared using the following steps:

[0069] S1: Dissolve 10g sodium caseinate and 20g β-glucan in deionized water, stir overnight, then freeze dry. Spread the resulting freeze-dried powder in a glass dish, maintain the humidity at 78% with saturated potassium bromide solution, control the temperature at 60℃, and react for 24h to obtain the glucan derivative.

[0070] S2: Dissolve zein in an 80% ethanol solution, add sodium thiocate and stir until homogeneous to obtain a base solution. Control the mass concentration of zein in the base solution to 3% and the mass concentration of thiocate in the base solution to 0.3%. Dissolve 1g of dextran derivative in deionized water and adjust the pH to 6 to obtain an aqueous solution of dextran derivative. Slowly disperse 100mL of the base solution into 500mL of the dextran derivative solution, stir thoroughly at 800r / min for 45min, remove ethanol by rotary evaporation at 35℃, centrifuge, and freeze-dry the supernatant to obtain the final product.

[0071] Control group 1

[0072] The preparation method of the wastewater treatment flocculant in this control group includes the following steps:

[0073] 1) Dissolve 3g of guar gum in 200mL of 0.1mol / L citric acid solution, then add 2.55g of isopropylacrylamide, stir thoroughly, add potassium persulfate, and react under nitrogen protection in a 60℃ constant temperature water bath for 2.5h. Wash with anhydrous ethanol, and then vacuum dry at 60℃ to obtain precursor A; Dissolve 1g of guar gum in 100mL of 0.1mol / L citric acid solution, add 1.2g of sodium methacrylate, stir thoroughly, add potassium persulfate, and react under nitrogen protection in a 60℃ constant temperature water bath for 2.5h. Wash with anhydrous ethanol, and then vacuum dry at 60℃ to obtain precursor B;

[0074] 2) Add 1.5L of deionized water, 10g of precursor A, and 2g of precursor B to the reactor and mix thoroughly. Then add 5g of acrylamide, 3.5g of acryloyloxyethyltrimethylammonium chloride, and azobisisobutyramidine hydrochloride. Adjust the pH of the system to 5. After mixing thoroughly at room temperature, place the mixture under a 24W UV lamp to initiate the reaction. Maintain the temperature below 30°C during the reaction. Aging the reaction product overnight, washing it with anhydrous ethanol, and then vacuum drying it at 60°C to obtain the final product.

[0075] Control group 2

[0076] The preparation method of the wastewater treatment flocculant in this control group includes the following steps:

[0077] 1) Dissolve 3g of guar gum in 200mL of 0.1mol / L citric acid solution, then add 2.55g of isopropylacrylamide, stir thoroughly, add potassium persulfate, and react under nitrogen protection in a 60℃ constant temperature water bath for 2.5h. Wash with anhydrous ethanol, and then vacuum dry at 60℃ to obtain precursor A; Dissolve 1g of guar gum in 100mL of 0.1mol / L citric acid solution, add 1.2g of sodium methacrylate, stir thoroughly, add potassium persulfate, and react under nitrogen protection in a 60℃ constant temperature water bath for 2.5h. Wash with anhydrous ethanol, and then vacuum dry at 60℃ to obtain precursor B;

[0078] 2) Add 1.5L of deionized water, 10g of precursor A, 2g of precursor B, and 1.5g of β-glucan to the reactor and mix thoroughly. Then add 5g of acrylamide, 3.5g of acryloyloxyethyltrimethylammonium chloride, and azobisisobutyramidine hydrochloride. Adjust the pH of the system to 5. After mixing thoroughly at room temperature, place the mixture under a 24W UV lamp to initiate the reaction. Maintain the temperature below 30°C during the reaction. Aging the reaction product overnight, washing it with anhydrous ethanol, and then vacuum drying it at 60°C to obtain the final product.

[0079] Performance testing

[0080] 1000 mL of wastewater from a wastewater treatment plant was placed in a container. The wastewater parameters were: turbidity 186.32, COD 358.29 mg / L, pH 6.51, TP 35.18 mg / L, and oil content 3.51 mg / L. Flocculants from Examples 1-2 and Control Groups 1-2 were added to the container at dosages of 0.5 wt%, 1 wt%, and 1.5 wt% L. The mixture was stirred at 250 rpm for 3 minutes, then allowed to stand for 20 minutes. The turbidity removal rate at different dosages was tested. The test results are as follows: Figure 1 As shown. Water samples were taken after flocculation, and the flocculation morphology was observed under a microscope. The test results are as follows. Figure 2 As shown.

[0081] analyze Figures 1-2 It can be seen that the flocculant of this application has a high flocculation effect on bridges, a high flocculation effect on complex water bodies, strong adsorption and trapping performance and charge neutralization effect, and high application value.

[0082] Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for preparing a wastewater treatment flocculant, characterized in that: Includes the following steps: 1) Precursor A was prepared by reacting guar gum with isopropylacrylamide; Precursor B was prepared by reacting guar gum with sodium methacrylate. 2) Take deionized water, precursor A, precursor B, and dextran-derived polymer, mix them evenly, then add monomer and initiator, photo-initiate the reaction, purify and dry to obtain the product; The dextran-derived polymer was prepared using the following steps: S1: Sodium caseinate and dextran are dissolved in deionized water at a mass ratio of 1:(1.5-2.5), stirred overnight, and then freeze-dried. The resulting freeze-dried powder is spread in a glass dish, kept moist with potassium bromide solution, and the temperature is controlled at 55-65℃ to obtain dextran derivatives. S2: Dissolve zein in an ethanol solution, add sodium thiocate and stir until homogeneous to obtain a base solution. The mass concentration of zein in the base solution is 2-3.5%. Dissolve the dextran derivative in deionized water to obtain an aqueous solution of the dextran derivative. Slowly disperse the base solution into the dextran derivative solution. The volume ratio of the base solution to the dextran derivative solution is 1:(4-6). After thorough stirring, evaporate to remove the ethanol and freeze-dry to obtain the final product.

2. The method for preparing the wastewater treatment flocculant according to claim 1, characterized in that: In step 1), the mass ratio of guar gum to sodium methacrylate is 1:(1-1.5).

3. The method for preparing the wastewater treatment flocculant according to claim 1, characterized in that: In step 1), the mass ratio of guar gum to isopropylacrylamide is 1:(0.75-1).

4. The method for preparing the wastewater treatment flocculant according to claim 1, characterized in that: In step 2), the monomers are acrylamide monomer and acryloyloxyethyltrimethylammonium chloride, and the initiator is azobisisobutyramidine hydrochloride.

5. The method for preparing the wastewater treatment flocculant according to claim 1, characterized in that: In step 2), the mass ratio of precursor A, precursor B, and dextran-derived polymer is 1:(0.15-2):(0.1-0.15).

6. A wastewater treatment flocculant, characterized in that: It is prepared by any one of the preparation methods described in claims 1-5.

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