Water treatment agent as well as preparation method and application thereof

Abstract

The invention relates to a water treatment agent and a preparation method and application thereof, and the preparation method comprises the following steps: (1) adding an organic additive and hydrogen peroxide into an ammonia water solution to prepare a mixed solution I, carrying out electrolytic reaction, and aging to obtain sol; (2) dissolving acrylamide and a cationic monomer in water to obtain a mixed solution II; (3) adding the mixed solution II into the sol in the step (1) to obtain a mixed solution III; and (4) adding an initiator into the mixed solution III, and carrying out polymerization reaction to prepare the water treatment agent. According to the method disclosed by the invention, introduction of heteroanions is avoided, efficient in-situ polymerization of organic components on inorganic components is improved, the problem of low molecular weight of the medicament caused by initiation of an anion inhibition chain is solved, and the prepared medicament has excellent defluorination and flocculation capabilities.

Description

Technical Field

[0001] This invention belongs to the field of water pollution control technology, specifically relating to a water treatment agent, its preparation method, and its application. Background Technology

[0002] With the further development of the photovoltaic industry, the generation of fluoride-containing wastewater has brought new problems. Flocculation technology is one of the methods for treating this type of wastewater, and it is currently an economical and simple water treatment technology widely used both domestically and internationally to improve water quality treatment efficiency. Highly efficient and safe water treatment agents play an irreplaceable role in the entire water treatment process; therefore, many researchers are dedicated to the formulation and research and development of water treatment agents.

[0003] CN103351047A discloses an organic-inorganic hybrid ionic bond high-efficiency flocculant, which involves adding ammonium persulfate as an initiator during the polymerization of dimethyl diallyl ammonium chloride (DMDAAC). This results in the synthesized polymer, poly(dimethyl diallyl ammonium chloride) (PDMDAAC), having sulfate ions at the molecular chain ends. These sulfate ions then bond with positively charged aluminum hydroxide ions via ionic bonds, yielding the PAC-PDMDAAC organic-inorganic hybrid ionic bond high-efficiency flocculant. This allows the flocculant to fully utilize the excellent charge neutralization ability of PAC and the adsorption bridging effect of PDMDAAC. In water treatment, the PAC-PDMDAAC hybrid flocculant requires a small dosage, produces large and dense flocs, and settles quickly, significantly improving water treatment efficiency. However, the inorganic chloride ions present in the PAC component introduced during the synthesis process can react with sulfate free radicals, thereby inhibiting the initiation of chain free radicals and leading to a significant reduction in the molecular weight of the agent.

[0004] In existing technologies, the process of introducing cations into inorganic components of inorganic-organic hybrid reagents usually involves the simultaneous introduction of a large number of inorganic anions, such as sulfate ions, chloride ions, peroxide ions, and phosphate ions. The introduction of these heterogeneous anions can cause secondary pollution of water quality during reagent addition. Furthermore, for the removal of some anions in water, such as fluoride ions and phosphate ions, the introduced anions occupy the vacancies of the cation nuclei due to their coordination effect, thus inhibiting the adsorption performance of the reagent on anions in the water.

[0005] In conclusion, it is essential to develop water treatment agents that are cost-effective, have simple preparation processes, and exhibit superior performance. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a water treatment agent, its preparation method, and its application. The method of this invention avoids the introduction of heterogeneous anions, improves the efficient in-situ polymerization of organic components on inorganic components, solves the problem of low molecular weight caused by anion-inhibited chain initiation, and the prepared agent possesses both excellent defluorination and flocculation capabilities.

[0007] The first aspect of this invention provides a method for preparing a water treatment agent, comprising the following steps:

[0008] (1) Organic additives and hydrogen peroxide were added to an ammonia solution to prepare a mixture I. The mixture was then subjected to an electrolytic reaction and aged to obtain a sol.

[0009] (2) Dissolve acrylamide and cationic monomer in water to obtain mixture II;

[0010] (3) Add mixture II to the sol in step (1) to obtain mixture III;

[0011] (4) Add an initiator to the mixture III to carry out a polymerization reaction to obtain a water treatment agent.

[0012] In this invention, the mass concentration of the ammonia solution in step (1) is 5%-25%.

[0013] In this invention, the organic additive mentioned in step (1) is at least one of 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA), iminodiacetic acid (IDA), potassium sodium tartrate, etc.

[0014] In this invention, the mass concentration of the organic additive added in step (1) is 2%-8%, preferably 3%-5%.

[0015] In this invention, the mass concentration of hydrogen peroxide added in step (1) is 1.0%-5.0%.

[0016] In this invention, the electrolysis in step (1) can be performed using conventional electrolysis methods. Preferably, a sacrificial electrode is used as the anode and a mesh-shaped stable electrode is used as the cathode. The sacrificial electrode includes one or more of aluminum electrodes, zinc electrodes, etc.; the mesh-shaped stable electrode includes one or more of ruthenium-iridium electrodes, ruthenium-titanium electrodes, ruthenium-iridium-tantalum electrodes, ruthenium-iridium-tin electrodes, etc.

[0017] In this invention, the electrolysis conditions in step (1) are: temperature of 30-80℃ and current density of 2-10 mA / cm². -2 The time is 20-60 minutes, and the stirring rate is 100-600 rpm. -1 .

[0018] In this invention, after electrolysis in step (2), aging is carried out for 12-48 hours to obtain a sol.

[0019] In this invention, the cationic monomer in step (3) includes at least one of N,N,N-trimethyl-3-allylamino-1-chloropropylamine (APTAC), methacryloyloxyethyltrimethylammonium chloride (DMC), acryloyloxyethylmethylammonium chloride (DAC), and [2-(acryloyloxy)ethyl]trimethylammonium chloride (AETAC).

[0020] In this invention, the sum of the mass concentrations of acrylamide and cationic monomer in the mixture in step (3) is 10%-25%, preferably 15%-20%; wherein the mass ratio of cationic monomer to acrylamide is 1:1-1:8, preferably 1:4-1:6.

[0021] In this invention, in step (3), mixture II is added according to the mass ratio of the sum of the cationic monomer and acrylamide to the sol of 3:7-7:3, and after mixing, mixture III is obtained.

[0022] In this invention, the initiator in step (4) is potassium persulfate. Based on the sum of the masses of acrylamide and cationic monomer, the amount of initiator is 1.0‰-5.0‰, preferably 2.0‰-4.0‰.

[0023] In this invention, the polymerization reaction described in step (4) is carried out in a vacuum distillation apparatus, such as a rotary evaporator, with a rotation speed of 100-300 r / min. Preferably, the polymerization reaction is carried out in a water bath.

[0024] In this invention, the conditions for the polymerization reaction in step (4) are: the reaction temperature is 20-50℃, preferably 30-40℃; the reaction time is 1-6h, preferably 2-3h.

[0025] A second aspect of this invention provides a water treatment agent prepared using the method described above. The prepared agent has an intrinsic viscosity of 1000-2000 mL / g. -1 When the drug is formulated to a concentration of 1‰, the zeta potential is 20-50 mV.

[0026] A third aspect of the present invention provides the application of the water treatment agent described herein for wastewater defluorination and flocculation.

[0027] In this invention, the fluoride ion content in the wastewater is 10-200 mg / L. -1 The suspended solids content in the wastewater is between 50-5000 mg / L. -1 .

[0028] In this invention, the dosage of the agent is 50-2000 mg / L. -1 Preferred dosage: 200-1000 mg / L -1 .

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The method of the present invention avoids the introduction of heterogeneous anions, improves the efficient in-situ polymerization of organic components on inorganic components, and the grafting rate can reach more than 80%. At the same time, it avoids the problem of the reduction of molecular weight of the agent caused by the initiation of free radicals of anion inhibition chain. The prepared agent can efficiently remove fluoride ions and make particulate matter aggregate and settle quickly, with excellent defluorination and flocculation performance.

[0031] (2) The inorganic components in the reagent of the present invention are mainly sols formed by anodic dissolution of cations, without the introduction of other impurities, thus realizing the in-situ generation of cation groups and avoiding the secondary pollution problem caused by the introduction of anions; at the same time, the coordination effect of anions is avoided, which helps to improve the removal effect of fluoride ions.

[0032] (3) The reagent of the present invention has excellent defluorination and turbidity removal properties, is stable for long-term storage, and will not exhibit phase separation within six months. It has stable effects and broad application prospects. Attached Figure Description

[0033] Figure 1 This is a transmission electron microscope image of the synthesized drug in Example 1 of the present invention. Detailed Implementation

[0034] The technical solution and its effects of the present invention will be further described in detail below through embodiments. These embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0035] Unless otherwise specified, the experimental methods used in the following examples are conventional methods in the art. Unless otherwise specified, the experimental materials used in the following examples were purchased from conventional biochemical reagent stores.

[0036] In this invention, the fluoride content of the water sample is detected by ion-selective electrode method. Suspended solids are detected by filtration and weighing method. Molecular weight is determined by viscosity, which is measured using an Ubbelohde viscometer.

[0037] The analysis and calculation method of grafting rate is as follows: the product is extracted by washing with acetone multiple times, and the obtained substance is dried to obtain a solid product. Let the initial amount of inorganic component added be m0, and the actual amount of inorganic component obtained by extraction be m1. Grafting rate = (m1 / m0) × 100%.

[0038] Example 1

[0039] (1) Prepare a 15% ammonia solution. Add potassium sodium tartrate to achieve a 4% ammonia concentration after addition, and add hydrogen peroxide to achieve a 3% ammonia concentration, thus obtaining mixture I. Using an aluminum sheet as the anode and a mesh ruthenium-titanium electrode as the cathode, place the mixture in mixture I at a temperature of 50℃ and a current density of 5 mA / cm². -2 The stirring speed is 300 rpm. -1 Electrolyze for 40 minutes, and after the reaction is complete, age for 18 hours to obtain a sol.

[0040] (2) Acrylamide and methacryloyloxyethyltrimethylammonium chloride were dissolved in deionized water to obtain mixture II. The sum of their mass concentrations in mixture II was 15%, and the mass ratio of the cationic monomer to the acrylamide monomer was 1:6.

[0041] (3) Slowly add mixture II to the sol, wherein the mass ratio of the sum of the mass of acrylamide and cationic monomer to the mass of the sol is 6:4, and stir evenly to obtain mixture III.

[0042] (4) Place mixture III in a vacuum distillation apparatus at a rotation speed of 200 r / min. Add potassium persulfate at a mass fraction of 2.0‰ based on the sum of the masses of acrylamide and cationic monomer, and carry out a polymerization reaction at a polymerization temperature of 30°C for a reaction time of 3 h to obtain the reagent.

[0043] Figure 1 The transmission electron microscope (TEM) image of the synthesized drug shows that the inorganic sol is dispersed in the organic phase. Analysis revealed that the intrinsic viscosity of the prepared drug is 1480 mL g. -1 When prepared at a concentration of 1‰, the zeta potential is 36mV and the grafting rate is 90%.

[0044] The water treatment agent was used for fluoride removal and flocculation in wastewater with a fluoride ion content of 100 mg / L. -1 The suspended solids content is 1000 mg / L. -1 The dosage of the drug is 300 mg / L. -1 The removal rate of suspended solids was 92.4%, and the removal rate of fluoride ions was 86.0%.

[0045] Example 2

[0046] (1) Prepare a 25% ammonia solution. Add potassium sodium tartrate to achieve an 8% ammonia concentration after addition, and add hydrogen peroxide to achieve a 5% ammonia concentration, thus obtaining mixture I. Using a zinc sheet as the anode and a mesh ruthenium-iridium electrode as the cathode, place the mixture in mixture I at a temperature of 80℃ and a current density of 10 mA / cm². -2 The stirring speed is 600 rpm. -1Electrolyze for 60 minutes, and after the reaction is complete, age for 24 hours to obtain a sol.

[0047] (2) Acrylamide and acryloyloxyethyl methyl ammonium chloride are dissolved in deionized water to obtain mixture II. The sum of their mass concentrations in mixture II is 25%, and the mass ratio of the cationic monomer to the acrylamide monomer is 1:8.

[0048] (3) Slowly add mixture II to the sol, wherein the mass ratio of the sum of the mass of acrylamide and cationic monomer to the mass of the sol is 7:3, and stir evenly to obtain mixture III.

[0049] (4) Place mixture III in a vacuum distillation apparatus and rotate at a speed of 300 r / min. Add potassium persulfate at a mass fraction of 5.0‰ based on the sum of the masses of acrylamide and cationic monomer, and carry out a polymerization reaction at a polymerization temperature of 50°C for 2 hours to obtain the reagent.

[0050] Analysis showed that the intrinsic viscosity of the prepared reagent was 1278 mL g. -1 When prepared at a concentration of 1‰, the zeta potential is 32mV and the grafting rate is 86%.

[0051] The water treatment agent was used for fluoride removal and flocculation in wastewater with a fluoride ion content of 100 mg / L. -1 The suspended solids content is 1000 mg / L. -1 The dosage of the agent is 400 mg / L. -1 The removal rate of suspended solids was 94.7%, and the removal rate of fluoride ions was 88.6%.

[0052] Example 3

[0053] (1) Prepare a 5% ammonia solution by adding potassium sodium tartrate to achieve a 2% concentration and hydrogen peroxide to achieve a 1% concentration, thus obtaining mixture I. Using a zinc sheet as the anode and a mesh ruthenium-iridium-tantalum electrode as the cathode, place the mixture in mixture I at a temperature of 30℃ and a current density of 3 mA / cm². -2 The stirring speed is 100 rpm. -1 Electrolysis for 20 minutes, followed by aging for 12 hours after the reaction, yields a sol.

[0054] (2) Acrylamide and N,N,N-trimethyl-3-allylamino-1-chloropropane were dissolved in deionized water to obtain mixture II. The sum of their mass concentrations in mixture II was 10%, and the mass ratio of the cationic monomer to the acrylamide monomer was 1:2.

[0055] (3) Slowly add mixture II to the sol, wherein the mass ratio of the sum of the mass of acrylamide and cationic monomer to the mass of the sol is 3:7, and stir evenly to obtain mixture III.

[0056] (4) Place mixture III in a vacuum distillation apparatus and rotate at a speed of 100 r / min. Add potassium persulfate with a mass fraction of 1.0‰ based on the sum of the masses of acrylamide and cationic monomer, and carry out a polymerization reaction at a polymerization temperature of 20°C for a reaction time of 6 h to obtain the reagent.

[0057] Analysis showed that the intrinsic viscosity of the prepared reagent was 1163 mL g. -1 When prepared at a concentration of 1‰, the zeta potential is 29mV, and the grafting rate is 84%.

[0058] The water treatment agent was used for fluoride removal and flocculation in wastewater with a fluoride ion content of 100 mg / L. -1 The suspended solids content is 1000 mg / L. -1 The dosage of the agent is 600 mg / L. -1 The removal rate of suspended solids was 97.4%, and the removal rate of fluoride ions was 94.6%.

[0059] Example 4

[0060] Same as Example 1, except that the organic additive is 2-phosphonobutane-1,2,4-tricarboxylic acid, and the final water treatment agent is obtained. Analysis showed that the intrinsic viscosity of the prepared agent was 1530 mL g. -1 When prepared at a concentration of 1‰, the zeta potential is 37mV, and the grafting rate is 91%.

[0061] The water treatment agent was used for fluoride removal and flocculation in wastewater with a fluoride ion content of 100 mg / L. -1 The suspended solids content is 1000 mg / L. -1 The dosage of the drug is 300 mg / L. -1 The removal rate of suspended solids was 93.7%, and the removal rate of fluoride ions was 88.8%.

[0062] Example 5

[0063] Same as Example 1, except that the organic additive is iminodiacetic acid, and the final water treatment agent is prepared. Analysis showed that the intrinsic viscosity of the prepared agent was 1638 mL g. -1 When prepared at a concentration of 1‰, the zeta potential is 40mV and the grafting rate is 93%.

[0064] The water treatment agent was used for fluoride removal and flocculation in wastewater with a fluoride ion content of 100 mg / L. -1 The suspended solids content is 1000 mg / L.-1 The dosage of the drug is 300 mg / L. -1 The removal rate of suspended solids was 95.6%, and the removal rate of fluoride ions was 91.2%.

[0065] Example 6

[0066] Same as Example 1, except that the cationic monomer is [2-(acryloyloxy)ethyl]trimethylammonium chloride, and the final water treatment agent is prepared. Analysis showed that the intrinsic viscosity of the prepared agent was 1466 mL g. -1 When prepared at a concentration of 1‰, the zeta potential is 36mV, and the grafting rate is 89%.

[0067] The water treatment agent was used for fluoride removal and flocculation in wastewater with a fluoride ion content of 100 mg / L. -1 The suspended solids content is 1000 mg / L. -1 The dosage of the drug is 300 mg / L. -1 The removal rate of suspended solids was 91.7%, and the removal rate of fluoride ions was 85.2%.

[0068] Comparative Example 1

[0069] Similar to Example 1, except that no organic additives were used in the preparation process, resulting in a water treatment agent. Analysis showed that the intrinsic viscosity of the prepared agent was 932 mL g. -1 When prepared at a concentration of 1‰, the zeta potential is 28 mV, and the grafting rate is 78%. This water treatment agent was used for fluoride removal flocculation in wastewater, achieving a suspended solids removal rate of 76.5% and a fluoride ion removal rate of 73.4%.

[0070] Comparative Example 2

[0071] Similar to Example 1, except that hydrogen peroxide was not used in the preparation process, resulting in a water treatment agent. Analysis showed that the intrinsic viscosity of the prepared agent was 1058 mL g. -1 When prepared at a concentration of 1‰, the zeta potential is 31 mV, and the grafting rate is 79%. This water treatment agent was used for fluoride removal flocculation in wastewater, achieving a suspended solids removal rate of 79.1% and a fluoride ion removal rate of 76.4%.

[0072] Comparative Example 3

[0073] Same as Example 1, except that: the anode of the electrolysis is an iron sheet, which produces a brown suspension and makes it impossible to obtain the reagent.

[0074] Comparative Example 4

[0075] Similar to Example 1, except that the process was carried out in a conventional closed reactor, not in a vacuum distillation apparatus, ultimately yielding the water treatment agent. Analysis showed that the intrinsic viscosity of the prepared agent was 1178 mL g. -1 When prepared at a concentration of 1‰, the zeta potential is 30mV, and the grafting rate is 82%. When the above water treatment agent was used for fluoride removal flocculation in wastewater, the suspended solids removal rate was 85.3%, and the fluoride ion removal rate was 79.2%.

[0076] Comparative Example 5

[0077] For comparison with Example 1, aluminum chloride was used as the aluminum source to prepare the sol, and all other steps were the same. Analysis showed that the intrinsic viscosity of the water treatment agent was 1120 mL g. -1 When prepared at a concentration of 1‰, the zeta potential is 21 mV. Using the above water treatment agent for fluoride removal, the suspended solids removal rate reached 78.2%, and the fluoride ion removal rate reached 58.5%. Chloride ions, acting as free radical scavengers, inhibited organic chain growth and hindered molecular weight increase. Furthermore, the introduced chloride ions competed with fluoride ions for adsorption, leading to a decrease in the fluoride ion removal rate.

Claims

1. A method for preparing a water treatment agent, characterized in that... Includes the following steps: (1) Add organic additives and hydrogen peroxide to an ammonia solution to prepare a mixture I, carry out an electrolytic reaction, and after aging, obtain a sol; (2) Dissolve acrylamide and cationic monomer in water to obtain mixture II; (3) Add mixture II to the sol in step (1) to obtain mixture III; (4) Add an initiator to the mixture III to carry out a polymerization reaction and obtain a water treatment agent.

2. The method according to claim 1, characterized in that: The mass concentration of the ammonia solution in step (1) is 5%-25%.

3. The method according to claim 1, characterized in that: The organic additive mentioned in step (1) is at least one of 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA), iminodiacetic acid (IDA), and potassium sodium tartrate.

4. The method according to claim 1 or 3, characterized in that: The mass concentration of the organic additive added in step (1) is 2%-8%, preferably 3%-5%.

5. The method according to claim 1, characterized in that: The mass concentration of hydrogen peroxide added in step (1) is 1.0%-5.0%.

6. The method according to claim 1, characterized in that: The electrolysis in step (1) uses a sacrificial electrode as the anode and a mesh-shaped stable electrode as the cathode. The sacrificial electrode is selected from one or more of aluminum electrodes and zinc electrodes. The mesh-shaped stable electrode is selected from one or more of ruthenium-iridium electrodes, ruthenium-titanium electrodes, ruthenium-iridium-tantalum electrodes, and ruthenium-iridium-tin electrodes.

7. The method according to claim 1, characterized in that: The electrolysis conditions described in step (1) are: temperature 30-80℃, current density 2-10 mA cm⁻¹. -2 The time is 20-60 minutes, and the stirring rate is 100-600 r / min. -1 .

8. The method according to claim 1, characterized in that: After electrolysis in step (2), the aging process is carried out for 12-48 hours to obtain a sol.

9. The method according to claim 1, characterized in that: The cationic monomer in step (3) includes at least one of N,N,N-trimethyl-3-allylamino-1-chloropropylamine (APTAC), methacryloyloxyethyltrimethylammonium chloride (DMC), acryloyloxyethylmethylammonium chloride (DAC), and [2-(acryloyloxy)ethyl]trimethylammonium chloride (AETAC).

10. The method according to claim 1 or 9, characterized in that: In step (3), the sum of the mass concentrations of acrylamide and cationic monomer in the mixture is 10%-25%, preferably 15%-20%; The mass ratio of cationic monomer to acrylamide is 1:1-1:8, preferably 1:4-1:

6.

11. The method according to claim 1 or 9, characterized in that: Step (3) Mixture II is added according to the mass ratio of the sum of the cationic monomer and acrylamide to the sol of 3:7-7:3, and after mixing, mixture III is obtained.

12. The method according to claim 1, characterized in that: The initiator in step (4) is potassium persulfate. Based on the sum of the masses of acrylamide and cationic monomer, the amount of initiator is 1.0‰-5.0‰, preferably 2.0‰-4.0‰.

13. The method according to claim 1, characterized in that: The polymerization reaction described in step (4) is carried out in a vacuum distillation apparatus; a rotary evaporator is preferred, with a rotation speed of 100-300 r / min.

14. The method according to claim 1 or 13, characterized in that: In this invention, the conditions for the polymerization reaction in step (4) are: the reaction temperature is 20-50℃, preferably 30-40℃; the reaction time is 1-6h, preferably 2-3h.

15. A water treatment agent, characterized in that... It is prepared by the method described in any one of claims 1-14.

16. The pharmaceutical preparation according to claim 15, characterized in that: The intrinsic viscosity of the prepared reagent is 1000-2000 mL / g. -1 When the drug is prepared at a concentration of 1‰, the zeta potential is 20-50mV.

17. The application of a water treatment agent prepared by the method according to any one of claims 1-14 or the water treatment agent according to any one of claims 15-16, characterized in that: Used for fluoride removal and flocculation in wastewater.

18. The application according to claim 17, characterized in that: The fluoride ion content in the wastewater is 10-200 mg / L. -1 The suspended solids content in the wastewater is between 50-5000 mg / L. -1 .

19. The application according to claim 17, characterized in that: The dosage of the agent is 50-2000 mg / L. -1 Preferred dosage: 200-1000 mg / L -1 .

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