A flocculant containing polyacrylamide and preparation method thereof

Abstract

The invention relates to the technical field of sewage treatment, and discloses a flocculant containing polyacrylamide and a preparation method thereof. The invention provides a flocculant containing polyacrylamide by adding amino acid-modified graphene oxide, triazine amino acid, polyacrylamide and sodium laurate coagulant into a stirrer for stirring. Graphene has an extremely high specific surface area, can provide more active sites for adsorbing suspended particles, and can also promote the aggregation of suspended particles through an adsorption bridging mechanism; the cationic groups contained in the quaternary ammonium salt molecules can bridge between particles, capture tiny particles, and accelerate sedimentation; the acylamino group can form hydrogen bonds with water molecules, combine with other particles or ions, and promote aggregation and sedimentation between particles; the hydrophilicity of the hydroxyl group makes the anionic flocculant more easily soluble in water, which helps the flocculant to fully contact and react with the suspended particles; the carboxyl group has a negative charge, which can attract positively charged metal ions, and further enhance the adsorption effect.

Description

Technical Field

[0001] The invention relates to the technical field of sewage treatment, in particular to a flocculant containing polyacrylamide and a preparation method thereof. Background Art

[0002] Flocculants are a type of agent used to promote the aggregation and enlargement of particles in a suspension, forming flocs to accelerate particle sedimentation and achieve solid-liquid separation. They are widely used to remove pollutants such as suspended matter, organic matter and heavy metal ions in water. With the development of industrialization, the treatment of sewage has become increasingly important, and how to use flocculants efficiently plays a key role.

[0003] Polyacrylamide is a water-soluble high molecular polymer with good flocculation effect. In terms of flocculants, polyacrylamide contains a large number of chemically active groups and can form larger floccules through chemical adsorption and physical networks, but the effect is single, so how to avoid this phenomenon is the key to solving the problem. For example, patent CN115321653A discloses an environmentally friendly sewage flocculant and its preparation method, which has the characteristics of green environmental protection and solid state of flocculant, but the flocculation effect needs to be improved. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the deficiencies of the prior art, the present invention provides a flocculant containing polyacrylamide and a preparation method thereof, which has good flocculation effect.

[0006] (II) Technical solution

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical scheme: a flocculant containing polyacrylamide and a preparation method thereof, comprising the following components by weight: 6-8 parts by weight of cardanol-modified graphene oxide, 2-4 parts by weight of polyacrylamide, 10-16 parts by weight of triazine amino acid, and 1-2 parts by weight of sodium laurate coagulant.

[0008] Preferably, the preparation method of the cardanol-modified graphene oxide is:

[0009] (1) ultrasonically dispersing 4-8 parts by weight of graphene oxide into 60-100 parts by weight of thionyl chloride, and after the dispersion is uniform, reacting at 75-80° C., and after the reaction, filtering, washing, and drying to obtain chlorinated graphene;

[0010] (2) adding chlorinated graphene to ether solvent, stirring and dispersing, and continuing to add L-histidine and triethylamine catalyst, reacting at 65-80° C. for 7-12 hours. After the reaction is completed, washing and drying are performed to obtain L-histidine-modified graphene oxide;

[0011] (3) Add 4-8 parts by weight of cardanol and 2-3 parts by weight of 2,2-bis(bromomethyl)-1,3-propylene glycol to an acetone solvent, stir to dissolve, then continue to add an aqueous sodium hydroxide solution, react at 60-85° C. for 5-8 hours, and after reaction, dropwise add dilute hydrochloric acid to neutralize, concentrate to remove the solvent, filter, wash and dry to obtain an intermediate 1;

[0012] (4) Add L-histidine modified graphene oxide and intermediate 1 to N,N-dimethylformamide solvent, stir evenly, continue to add p-toluenesulfonic acid catalyst, react at 75-90° C. for 6-10 h, and then perform reduced pressure distillation, wash and dry to obtain cardanol modified graphene oxide.

[0013] Preferably, the reaction time in (1) is 18-24 hours.

[0014] Preferably, the mass ratio of the acyl chloride graphene, L-histidine and triethylamine catalyst in (2) is 1:1.2-1.5:0.01-0.03.

[0015] Preferably, the molar concentration of sodium hydroxide in (3) is 5-6 mol / L.

[0016] Preferably, in said (4), the mass ratio of L-histidine modified graphene oxide, intermediate 1, and p-toluenesulfonic acid catalyst is 0.8-1.3:1:0.02-0.05.

[0017] Preferably, the preparation method of the triazine amino acid is:

[0018] S1. Add 3-6 parts by weight of L-histidine-modified graphene oxide to N,N-dimethylformamide solvent, stir and disperse, continue to add 5-8 parts by weight of vinyl chloride, heat to 70-90° C. and react for 5-10 hours, then perform vacuum distillation and wash to obtain intermediate 2;

[0019] S2. Add 5-10 parts by weight of intermediate 2, 5-9 parts by weight of allyltrimethylammonium chloride, and 2-5 parts by weight of 1,3,5-triacryloylhexahydro-1,3,5-triazine to N,N-dimethylformamide solvent, stir to dissolve, and then add 0.5-1 parts by weight of azobisisobutyronitrile initiator to carry out polymerization reaction, react at 90-115°C for 10-14h, wash and dry after completion to obtain triazine amino acid.

[0020] Preferably, the preparation method of the polyacrylamide-containing flocculant comprises the following steps: adding amino acid-modified graphene oxide, triazine amino acid, polyacrylamide, and sodium laurate coagulant aid into a stirrer, stirring at room temperature for 10-15 minutes, and obtaining the polyacrylamide-containing flocculant after the stirring.

[0021] 3. Beneficial technical effects

[0022] The present invention obtains a flocculant containing polyacrylamide by adding amino acid-modified graphene oxide, triazine amino acid, polyacrylamide and sodium laurate coagulant aid into a stirrer for stirring.

[0023] The carboxyl group in graphene oxide reacts with the chlorine atom in thionyl chloride to obtain acyl chloride graphene, the acyl chloride group in the acyl chloride graphene reacts with the amino group in L-histidine to introduce the amide group and the carboxyl group to obtain L-histidine modified graphene oxide; the bromine atom of 2,2-di(bromomethyl)-1,3-propanediol reacts with the phenolic hydroxyl group in cardanol to obtain intermediate 1, the intermediate 1 undergoes an esterification reaction with L-histidine modified graphene oxide to obtain cardanol modified graphene oxide; the L-histidine modified graphene oxide undergoes a quaternization reaction with vinyl chloride to generate a quaternary ammonium salt and introduce a carbon-carbon double bond to obtain intermediate 2, the intermediate 2 undergoes a polymerization reaction with allyltrimethylammonium chloride and 1,3,5-triacryloylhexahydro-1,3,5-triazine to obtain a triazine amino acid.

[0024] Cardanol-modified graphene oxide provides amide and ester groups, and the ester groups are hydrolyzed into hydroxyl and carboxyl groups in water. The hydrophilicity of the hydroxyl group can effectively promote the dissolution of anionic flocculants such as polyacrylamide in water, which helps the flocculant to fully contact and react with suspended particles; the carboxyl group carries a negative charge and can attract positively charged metal ions, further enhancing the adsorption effect; the hydrogen bonds formed by the amide group can combine with other particles or ions to promote the aggregation and sedimentation of particles; graphene has an extremely high specific surface area, which can provide more active sites for adsorbing suspended particles, and can also promote the aggregation of suspended particles through adsorption bridging mechanism; cardanol has a longer carbon chain and can also provide more adsorption sites; the polymer triazine amino acid provides a triazine group, which can interact with charged particles, promote aggregation of particles, and accelerate the sedimentation process; the cationic groups contained in the quaternary ammonium salt molecules can bridge between particles, capture tiny particles, and accelerate sedimentation. DETAILED DESCRIPTION Example 1

[0025] (1) ultrasonically dispersing 4 parts by weight of graphene oxide into 60 parts by weight of thionyl chloride, and after being evenly dispersed, reacting at 75° C. for 18 hours, and after the reaction, filtering, washing, and drying to obtain chlorinated graphene;

[0026] (2) adding acylated graphene to ether solvent, stirring and dispersing, and continuing to add L-histidine and triethylamine catalyst, wherein the mass ratio of acylated graphene, L-histidine, and triethylamine catalyst is 1:1.2:0.01, reacting at 65°C for 7h, and after completion, washing and drying to obtain L-histidine modified graphene oxide;

[0027] (3) Add 4 parts by weight of cardanol and 2 parts by weight of 2,2-bis(bromomethyl)-1,3-propylene glycol to an acetone solvent, stir to dissolve, then continue to add a 5 mol / L sodium hydroxide aqueous solution, react at 60°C for 5 h, and then dropwise add dilute hydrochloric acid to neutralize, concentrate to remove the solvent, filter, wash and dry to obtain intermediate 1;

[0028] (4) Add L-histidine modified graphene oxide and intermediate 1 to N,N-dimethylformamide solvent, stir evenly, and continue to add p-toluenesulfonic acid catalyst, wherein the mass ratio of L-histidine modified graphene oxide, intermediate 1, and p-toluenesulfonic acid catalyst is 0.8:1:0.02, react at 75°C for 6h, and then distill under reduced pressure, wash and dry to obtain cardanol modified graphene oxide;

[0029] (5) Add 3 parts by weight of L-histidine-modified graphene oxide to N,N-dimethylformamide solvent, stir and disperse, continue to add 5 parts by weight of vinyl chloride, heat to 70° C. and react for 5 h. After the reaction, perform vacuum distillation and wash to obtain intermediate 2;

[0030] (6) Add 5 parts by weight of intermediate 2, 5 parts by weight of allyltrimethylammonium chloride, and 2 parts by weight of 1,3,5-triacryloylhexahydro-1,3,5-triazine to N,N-dimethylformamide solvent, stir to dissolve, and then add 0.5 parts by weight of azobisisobutyronitrile initiator to carry out polymerization reaction at 90° C. for 10 hours. After completion, wash and dry to obtain triazine amino acid;

[0031] (7) 6 parts by weight of cardanol-modified graphene oxide, 2 parts by weight of polyacrylamide, 10 parts by weight of triazine amino acid, and 1 part by weight of sodium laurate coagulant were stirred at room temperature for 10 minutes to obtain a flocculant containing polyacrylamide. Example 2

[0032] (1) ultrasonically dispersing 6 parts by weight of graphene oxide into 80 parts by weight of thionyl chloride, and after being evenly dispersed, reacting at 78° C. for 21 hours, and after the reaction, filtering, washing, and drying to obtain chlorinated graphene;

[0033] (2) adding chlorinated graphene to ether solvent, stirring and dispersing, and continuing to add L-histidine and triethylamine catalyst, wherein the mass ratio of chlorinated graphene, L-histidine, and triethylamine catalyst is 1:1.3:0.02, reacting at 70°C for 10 hours, and after completion, washing and drying to obtain L-histidine modified graphene oxide;

[0034] (3) Add 6 parts by weight of cardanol and 3 parts by weight of 2,2-di(bromomethyl)-1,3-propylene glycol to an acetone solvent, stir to dissolve, then continue to add a 6 mol / L sodium hydroxide aqueous solution, react at 70°C for 6 hours, and then dropwise add dilute hydrochloric acid to neutralize, concentrate to remove the solvent, filter, wash and dry to obtain intermediate 1;

[0035] (4) Add L-histidine modified graphene oxide and intermediate 1 to N,N-dimethylformamide solvent, stir evenly, and continue to add p-toluenesulfonic acid catalyst, wherein the mass ratio of L-histidine modified graphene oxide, intermediate 1, and p-toluenesulfonic acid catalyst is 1.1:1:0.03, react at 85°C for 8h, and then distill under reduced pressure, wash and dry to obtain cardanol modified graphene oxide;

[0036] (5) Add 5 parts by weight of L-histidine-modified graphene oxide to N,N-dimethylformamide solvent, stir and disperse, continue to add 7 parts by weight of vinyl chloride, heat to 80° C. and react for 7 h. After the reaction, perform vacuum distillation and wash to obtain intermediate 2;

[0037] (6) Add 8 parts by weight of the intermediate 2, 7 parts by weight of allyltrimethylammonium chloride, and 3 parts by weight of 1,3,5-triacryloylhexahydro-1,3,5-triazine to N,N-dimethylformamide solvent, stir to dissolve, and then add 0.7 parts by weight of azobisisobutyronitrile initiator to carry out polymerization reaction at 100° C. for 12 hours. After completion, wash and dry to obtain triazine amino acid;

[0038] (7) 7 parts by weight of cardanol-modified graphene oxide, 3 parts by weight of polyacrylamide, 13 parts by weight of triazine amino acid, and 1.5 parts by weight of sodium laurate coagulant were stirred at room temperature for 12 minutes to obtain a polyacrylamide-containing flocculant. Example 3

[0039] (1) ultrasonically dispersing 7 parts by weight of graphene oxide into 90 parts by weight of thionyl chloride, and after being evenly dispersed, reacting at 80° C. for 22 hours, and after the reaction, filtering, washing, and drying to obtain chlorinated graphene;

[0040] (2) adding chlorinated graphene to ether solvent, stirring and dispersing, and continuing to add L-histidine and triethylamine catalyst, wherein the mass ratio of chlorinated graphene, L-histidine, and triethylamine catalyst is 1:1.4:0.01, reacting at 75°C for 11 hours, and after completion, washing and drying to obtain L-histidine modified graphene oxide;

[0041] (3) Add 7 parts by weight of cardanol and 3 parts by weight of 2,2-di(bromomethyl)-1,3-propylene glycol to an acetone solvent, stir to dissolve, then continue to add a 5 mol / L sodium hydroxide aqueous solution, react at 80°C for 7 hours, and then dropwise add dilute hydrochloric acid to neutralize, concentrate to remove the solvent, filter, wash and dry to obtain intermediate 1;

[0042] (4) Add L-histidine modified graphene oxide and intermediate 1 to N,N-dimethylformamide solvent, stir evenly, and continue to add p-toluenesulfonic acid catalyst, wherein the mass ratio of L-histidine modified graphene oxide, intermediate 1, and p-toluenesulfonic acid catalyst is 1.2:1:0.04, react at 80°C for 9h, and then distill under reduced pressure, wash and dry to obtain cardanol modified graphene oxide;

[0043] (5) Add 6 parts by weight of L-histidine-modified graphene oxide to N,N-dimethylformamide solvent, stir and disperse, continue to add 8 parts by weight of vinyl chloride, heat to 85° C. and react for 8 h. After the reaction, perform vacuum distillation and wash to obtain intermediate 2;

[0044] (6) 9 parts by weight of the intermediate 2, 8 parts by weight of allyltrimethylammonium chloride, and 4 parts by weight of 1,3,5-triacryloylhexahydro-1,3,5-triazine were added to N,N-dimethylformamide solvent, stirred to dissolve, and then 0.8 parts by weight of azobisisobutyronitrile initiator was added to carry out polymerization reaction at 110° C. for 12 hours. After completion, the reaction mixture was washed and dried to obtain a triazine amino acid;

[0045] (7) 7 parts by weight of cardanol-modified graphene oxide, 3 parts by weight of polyacrylamide, 15 parts by weight of triazine amino acid, and 2 parts by weight of sodium laurate coagulant were stirred at room temperature for 13 minutes to obtain a polyacrylamide-containing flocculant. Example 4

[0046] (1) ultrasonically dispersing 5 parts by weight of graphene oxide into 70 parts by weight of thionyl chloride, and after being evenly dispersed, reacting at 77° C. for 20 hours, and after the reaction, filtering, washing, and drying to obtain chlorinated graphene;

[0047] (2) adding acylated graphene to ether solvent, stirring and dispersing, and continuing to add L-histidine and triethylamine catalyst, wherein the mass ratio of acylated graphene, L-histidine, and triethylamine catalyst is 1:1.3:0.01, reacting at 70°C for 9h, and after completion, washing and drying to obtain L-histidine modified graphene oxide;

[0048] (3) Add 6 parts by weight of cardanol and 2 parts by weight of 2,2-di(bromomethyl)-1,3-propylene glycol to an acetone solvent, stir to dissolve, then continue to add a 6 mol / L sodium hydroxide aqueous solution, react at 65°C for 6 hours, and then add dilute hydrochloric acid dropwise to neutralize, concentrate to remove the solvent, filter, wash and dry to obtain intermediate 1;

[0049] (4) Add L-histidine modified graphene oxide and intermediate 1 to N,N-dimethylformamide solvent, stir evenly, and continue to add p-toluenesulfonic acid catalyst, wherein the mass ratio of L-histidine modified graphene oxide, intermediate 1, and p-toluenesulfonic acid catalyst is 1.1:1:0.03, react at 78°C for 7h, and then distill under reduced pressure, wash and dry to obtain cardanol modified graphene oxide;

[0050] (5) Add 4 parts by weight of L-histidine-modified graphene oxide to N,N-dimethylformamide solvent, stir and disperse, continue to add 6 parts by weight of vinyl chloride, heat to 80° C. and react for 7 h. After the reaction, perform vacuum distillation and wash to obtain intermediate 2;

[0051] (6) Add 7 parts by weight of the intermediate 2, 6 parts by weight of allyltrimethylammonium chloride, and 3 parts by weight of 1,3,5-triacryloylhexahydro-1,3,5-triazine to N,N-dimethylformamide solvent, stir to dissolve, and then add 0.6 parts by weight of azobisisobutyronitrile initiator to carry out polymerization reaction at 95° C. for 13 hours. After completion, wash and dry to obtain triazine amino acid;

[0052] (7) 6 parts by weight of cardanol-modified graphene oxide, 2 parts by weight of polyacrylamide, 13 parts by weight of triazine amino acid, and 1 part by weight of sodium laurate coagulant were stirred at room temperature for 14 minutes to obtain a flocculant containing polyacrylamide. Example 5

[0053] (1) ultrasonically dispersing 8 parts by weight of graphene oxide into 100 parts by weight of thionyl chloride, and after being evenly dispersed, reacting at 80° C. for 24 hours, and after the reaction, filtering, washing, and drying to obtain chlorinated graphene;

[0054] (2) adding chlorinated graphene to ether solvent, stirring and dispersing, and continuing to add L-histidine and triethylamine catalyst, wherein the mass ratio of chlorinated graphene, L-histidine, and triethylamine catalyst is 1:1.5:0.03, reacting at 80°C for 12 hours, and after completion, washing and drying to obtain L-histidine modified graphene oxide;

[0055] (3) Add 8 parts by weight of cardanol and 3 parts by weight of 2,2-bis(bromomethyl)-1,3-propylene glycol to an acetone solvent, stir to dissolve, then continue to add a 6 mol / L sodium hydroxide aqueous solution, react at 85°C for 8 hours, and then dropwise add dilute hydrochloric acid to neutralize, concentrate to remove the solvent, filter, wash and dry to obtain intermediate 1;

[0056] (4) Add L-histidine modified graphene oxide and intermediate 1 to N,N-dimethylformamide solvent, stir evenly, and continue to add p-toluenesulfonic acid catalyst, wherein the mass ratio of L-histidine modified graphene oxide, intermediate 1, and p-toluenesulfonic acid catalyst is 1.3:1:0.05, react at 90°C for 10 hours, and then distill under reduced pressure, wash and dry to obtain cardanol modified graphene oxide;

[0057] (5) Add 6 parts by weight of L-histidine-modified graphene oxide to N,N-dimethylformamide solvent, stir and disperse, continue to add 8 parts by weight of vinyl chloride, heat to 90° C. and react for 10 h. After the reaction, perform vacuum distillation and wash to obtain intermediate 2;

[0058] (6) Add 10 parts by weight of the intermediate 2, 9 parts by weight of allyltrimethylammonium chloride, and 5 parts by weight of 1,3,5-triacryloylhexahydro-1,3,5-triazine to N,N-dimethylformamide solvent, stir to dissolve, and then add 1 part by weight of azobisisobutyronitrile initiator to carry out polymerization reaction at 115° C. for 14 hours. After completion, wash and dry to obtain triazine amino acid;

[0059] (7) 8 parts by weight of cardanol-modified graphene oxide, 4 parts by weight of polyacrylamide, 16 parts by weight of triazine amino acid, and 2 parts by weight of sodium laurate coagulant were stirred at room temperature for 15 minutes to obtain a flocculant containing polyacrylamide.

[0060] Comparative Example 1

[0061] 6 parts by weight of cardanol-modified graphene oxide, 2 parts by weight of polyacrylamide, and 1 part by weight of sodium laurate coagulant were stirred at room temperature for 10 minutes to obtain a flocculant containing polyacrylamide.

[0062] Comparative Example 2

[0063] 2 parts by weight of polyacrylamide, 10 parts by weight of triazine amino acid and 1 part by weight of sodium laurate coagulant were stirred at room temperature for 10 minutes to obtain a flocculant containing polyacrylamide.

[0064] Take 500mL of wastewater into a beaker. 2+ and Pb 2+ The initial concentration of the polyacrylamide flocculant was 100 mg / L. The wastewater was added with the polyacrylamide flocculant of the present application. After ultrasonic dispersion for 6 minutes, the wastewater was placed on a shaker for 10 hours. The supernatant was taken and the Cd content in the supernatant was determined by ICP. 2+ and Pb 2+ The concentration after adsorption, the removal rate of heavy metal ions w = (initial concentration-concentration after adsorption) / initial concentration, the test results are shown in Table 1.

[0065] Table 1: Heavy metal ion removal rate test.

[0066] project <![CDATA[Cd 2+ Removal rate (%)]]> <![CDATA[Pb 2+ Removal rate (%)]]> Example 1 87.5 86.7 Example 2 91.7 90.8 Example 3 90.6 91.3 Example 4 82.9 89.4 Example 5 89.7 90.8 Comparative Example 1 52.3 51.4 Comparative Example 2 50.8 52.7

[0067] It can be seen from Table 1 that Examples 1-5 of the present invention have better removal effects on heavy metal ions than Comparative Examples 1-2, indicating that the flocculation effect is better.

[0068] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A flocculant containing polyacrylamide, characterized in that: The invention comprises the following components by weight: 6-8 parts by weight of cardanol-modified graphene oxide, 2-4 parts by weight of polyacrylamide, 10-16 parts by weight of triazine amino acid, and 1-2 parts by weight of sodium laurate coagulant; The preparation method of the cardanol-modified graphene oxide is: (1) ultrasonically dispersing 4-8 parts by weight of graphene oxide into 60-100 parts by weight of thionyl chloride, and after the dispersion is uniform, reacting at 75-80° C., and after the reaction, filtering, washing, and drying to obtain chlorinated graphene; (2) adding chlorinated graphene to ether solvent, stirring and dispersing, and continuing to add L-histidine and triethylamine catalyst, reacting at 65-80° C. for 7-12 hours. After the reaction is completed, washing and drying are performed to obtain L-histidine-modified graphene oxide; (3) Add 4-8 parts by weight of cardanol and 2-3 parts by weight of 2,2-bis(bromomethyl)-1,3-propylene glycol to an acetone solvent, stir to dissolve, then continue to add an aqueous sodium hydroxide solution, react at 60-85° C. for 5-8 hours, and after reaction, dropwise add dilute hydrochloric acid to neutralize, concentrate to remove the solvent, filter, wash and dry to obtain an intermediate 1; (4) Add L-histidine modified graphene oxide and intermediate 1 to N,N-dimethylformamide solvent, stir evenly, continue to add p-toluenesulfonic acid catalyst, react at 75-90°C for 6-10h, and then perform reduced pressure distillation after reaction, wash and dry to obtain cardanol modified graphene oxide; The preparation method of the triazine amino acid is: S1. Add 3-6 parts by weight of L-histidine-modified graphene oxide to N,N-dimethylformamide solvent, stir and disperse, continue to add 5-8 parts by weight of vinyl chloride, heat to 70-90° C. and react for 5-10 hours, then perform vacuum distillation and wash to obtain intermediate 2; S2. Add 5-10 parts by weight of intermediate 2, 5-9 parts by weight of allyltrimethylammonium chloride, and 2-5 parts by weight of 1,3,5-triacryloylhexahydro-1,3,5-triazine to N,N-dimethylformamide solvent, stir to dissolve, and then add 0.5-1 parts by weight of azobisisobutyronitrile initiator to carry out polymerization reaction, react at 90-115°C for 10-14h, wash and dry after completion to obtain triazine amino acid.

2. The polyacrylamide-containing flocculant according to claim 1, characterized in that: The reaction time in (1) is 18-24 hours.

3. The polyacrylamide-containing flocculant according to claim 1, characterized in that: The mass ratio of the acyl chloride graphene, L-histidine and triethylamine catalyst in (2) is 1:1.2-1.5:0.01-0.

03.

4. The polyacrylamide-containing flocculant according to claim 1, characterized in that: The molar concentration of sodium hydroxide in (3) is 5-6 mol / L.

5. The polyacrylamide-containing flocculant according to claim 1, characterized in that: The mass ratio of L-histidine modified graphene oxide, intermediate 1, and p-toluenesulfonic acid catalyst in (4) is 0.8-1.3:1:0.02-0.

05.

6. A method for preparing a polyacrylamide-containing flocculant according to any one of claims 1 to 5, characterized in that: The preparation method of the polyacrylamide-containing flocculant comprises the following steps: adding amino acid-modified graphene oxide, triazine amino acid, polyacrylamide and sodium laurate coagulant aid into a stirrer, stirring at room temperature for 10-15 minutes, and obtaining the polyacrylamide-containing flocculant after stirring.