A highly adaptable defluorination agent and its preparation method and use

Abstract

The invention discloses a highly adaptable defluoridation agent and a preparation method and usage thereof, wherein the defluoridation agent comprises, by weight, 280-500 parts of humic acid copolymers, 420-600 parts of environmentally responsive polyurethanes, and 80-120 parts of dendritic cationic polymers. The defluoridation agent of the present application can be widely used in acidic, neutral, and alkaline industrial fluoride-containing wastewaters, and can stabilize the fluoride ion concentration below 5 mg / L, meeting the discharge standards. At the same time, the humic acid copolymer in the defluoridation agent can adsorb high-priced toxic metal ions in the fluoride-containing wastewater, and the formed cationic bridge can adsorb more fluoride ions. Environmentally responsive polyurethanes and dendritic cationic polymers rely on their molecular chain characteristics at different pH values ​​to improve the adaptability of the defluoridation agent.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, in particular to a highly adaptable defluorination agent and a preparation method and usage thereof. Background Art

[0002] With the continuous development of the current society, more fluorine resources are being applied to modern industry, which will inevitably lead to the generation of a large amount of fluorine-containing wastewater, such as chemical production, semiconductors, electroplating, metallurgy and ceramics. Therefore, fluoride pollution in natural water has become a global problem. The national comprehensive sewage discharge standard stipulates that the direct discharge limit of fluoride ion concentration in wastewater should be less than 10.0 mg / L, and some policies even require fluoride concentration to be less than 1.0 mg / L. However, due to the imperfect treatment technology and equipment of some factories involving fluorine wastewater, the mass concentration of fluoride ions in the discharged wastewater is far higher than the national emission standards. Fluoride wastewater discharged in excess of the standard enters the surface water through the flushing of surface runoff, and pollutes groundwater through infiltration, which not only harms human life, but also endangers the ecosystem.

[0003] Chemical defluorination technology is an important means of treating fluoride ions in industrial wastewater, which can effectively control the fluoride concentration in industrial wastewater and meet the requirements for industrial wastewater discharge. At present, commonly used chemical defluorination technologies include electrochemical method, chemical precipitation method, adsorption method, etc. The principles of chemical defluorination in different processes are different, and the applicable environment and effect are also very different. CN114212867A discloses a liquid defluoridation agent for fluorine-containing wastewater and its preparation method and application. An organic polymer flocculant is introduced into the defluoridation agent, including polyaluminum chloride, polyaluminum sulfate, and polyferric sulfate, which enhances the adsorption and bridging ability of polyaluminum, thereby improving the removal rate of chloride ions. CN114890493A discloses a carbon-coated magnesium oxide adsorption coagulant defluoridation agent and its preparation method and application, using porous carbon-coated magnesium oxide to achieve rapid adsorption and sedimentation of fluoride ions. CN116062941A discloses a method for synergistic defluorination and dechlorination of high-fluorine and chlorine-containing wastewater in the photovoltaic industry, using a capacitive deionization device for deep defluorination and dechlorination.

[0004] Industrial fluoride wastewater comes from all walks of life, resulting in great differences in its composition and environment. The main characteristics include: ① The amount of fluoride-containing industrial wastewater is large, and the fluoride ion concentration varies, with the highest reaching 8000mg / L and the lowest being 30mg / L; ② Fluoride-containing industrial wastewater is acidic, alkaline, and highly corrosive; ③ It has certain toxicity; ④ The fluoride ions in the wastewater exist in the form of ions, complexes, and chelates. Therefore, the adaptability of the defluoridation agent is extremely high. Summary of the invention

[0005] Under the above background, the technical problem to be solved by the present invention is to provide a highly adaptable defluorination agent and a preparation method and usage thereof, which can be widely used in acidic, neutral and alkaline industrial fluoride-containing wastewater and has the characteristics of high fluoride ion removal rate and wide adaptability.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A highly adaptable defluorination agent comprises, by weight, 280-500 parts of humic acid copolymer, 420-600 parts of environmentally responsive polyurethane, and 80-120 parts of dendritic cationic polymer.

[0008] Furthermore, the raw materials for preparing the humic acid copolymer include the following components in parts by weight: 40-60 parts of aromatic humic acid, 60-90 parts of acrylic acid, 90-140 parts of acrylamide, 12-20 parts of N-vinyl-2-pyrrolidone, 1-5 parts of N,N-methylenebisacrylamide, 26-40 parts of hydrophobic monomer, 0.5-3 parts of ammonium persulfate, 0.1-2 parts of bleaching powder, 1- 8-12 parts of allyloxy-3-(4-nonylphenol)-2-propanol polyoxyethylene and 628-762.4 parts of water; the hydrophobic monomer comprises one or more of styrene, α-methylstyrene, 2-ethylhexyl acrylate, octyl acrylate, lauryl acrylate, stearyl acrylate, 2-ethylhexyl methacrylate, octyl methacrylate, lauryl methacrylate, stearyl methacrylate, 2-ethylhexyl acrylamide, octylacrylamide, propyl acrylate, butyl acrylate, pentyl acrylate, hexyl acrylate, 1-vinylnaphthalene, 2-vinylnaphthalene and 3-methylstyrene.

[0009] Furthermore, the raw materials for preparing the environmentally responsive polyurethane include the following components in parts by weight: 70-130 parts of polyethylene glycol, 70-92 parts of polycaprolactone, 60-80 parts of 2,2-dihydroxymethylpropionic acid, 40-100 parts of 1,6-hexamethylene diisocyanate, 20-40 parts of hydroxyl-terminated polydimethylsiloxane, 24-36 parts of 1,6-hexanediamine, 1-5 parts of 1-hydroxybenzotriazole, 1-4 parts of N,N'-dicyclohexylcarbodiimide, 10-30 parts of aluminum sulfate, and 483-704 parts of water.

[0010] Furthermore, the raw materials for preparing the dendritic cationic polymer include the following components in parts by weight: 120-160 parts of polyethyleneimine, 200-300 parts of epichlorohydrin, 1-4 parts of a crosslinking agent, and 536-679 parts of water; the crosslinking agent includes one of glucose, piperazine, and sodium oleate.

[0011] A method for preparing a highly adaptable defluorination agent comprises the following steps:

[0012] (1) Preparation method of humic acid copolymer:

[0013] S1. At room temperature, water and 1-allyloxy-3-(4-nonylphenol)-2-propanol polyoxyethylene are added to a reaction kettle and stirred until uniform and transparent;

[0014] S2. Under nitrogen protection, aromatic humic acid, acrylic acid, acrylamide, N-vinyl-2-pyrrolidone, and hydrophobic monomers were added to the solution of step S1, stirred for 30-120 min, and then added to the bleaching block, and continued to stir for 10-20 min. After that, the ammonium persulfate was added within 2-3 h, and the reaction was continued to stir for 2-6 h;

[0015] S3. Add N,N-methylenebisacrylamide into step S2 and stir for 1-3 hours to obtain a humic acid copolymer.

[0016] (2) Synthesis of environmentally responsive polyurethane:

[0017] S11. Under nitrogen protection, polyethylene glycol, polycaprolactone and 1,6-hexamethylene diisocyanate were dissolved in dry tetrahydrofuran, stirred for 30 minutes, and then heated to 90-120°C for 4 hours; then 2,2-dihydroxymethylpropionic acid and hydroxyl-terminated polydimethylsiloxane were added in sequence, and the reaction was continued at 90-120°C for 4 hours; wherein, the amount of tetrahydrofuran used was 1 times the total mass of polyethylene glycol, polycaprolactone and 1,6-hexamethylene diisocyanate;

[0018] S12. At 0-5° C., 1,6-hexanediamine and 1-hydroxybenzotriazole are added to the product of step S11 and stirred for reaction for 10-40 min, and then N,N'-dicyclohexylcarbodiimide is added and stirred for reaction for 24-48 h, and then dispersed dropwise in water;

[0019] S13. Dissolving aluminum sulfate in water to obtain a solution having a mass fraction of 18%-25%;

[0020] S14. The aluminum sulfate solution obtained in step S13 is mixed with the solution obtained in step S12 and stirred for 10-180 minutes to obtain an environmentally responsive polyurethane.

[0021] (3) Preparation method of dendritic cationic polymer:

[0022] Polyethyleneimine and water are put into a reaction kettle, and after stirring for 30 minutes, epichlorohydrin and a cross-linking agent are added in sequence. After reacting for 4-10 hours, the mixture is cooled to room temperature to obtain a dendritic cationic polymer.

[0023] Usage of a highly adaptable defluorination agent:

[0024] When the pH of the fluorine-containing wastewater is greater than 6.5, humic acid copolymer is first added, and after reacting for 20 minutes, environmentally responsive polyurethane is added, and the reaction is continued for 20 minutes. Then, the dendritic cationic polymer is added, and the reaction is continued for 20 minutes. The pH of the wastewater is adjusted to 5.0-6.5, and the reaction is continued for more than 10 minutes for solid-liquid separation.

[0025] When the pH value of the fluorine-containing wastewater is less than 6.5, humic acid copolymer is first added, and after reacting for 20 minutes, environmentally responsive polyurethane is added, and after continuing the reaction for 20 minutes, the pH value of the wastewater is adjusted to 7.0-8.0, and then the dendritic cationic polymer is added. After reacting for 20 minutes, the pH value of the wastewater is adjusted to 5.0-6.5 for solid-liquid separation.

[0026] Mechanism of the present invention:

[0027] Humic acid is an amorphous high molecular organic compound formed by the polymerization of polyphenols and polyquinones. It has a huge specific surface area and hydrophilic groups, and can form bridges with high-valent cations. The introduction of humic acid into polymers can adsorb high-valent toxic metal ions in fluoride-containing wastewater. At the same time, the formed cationic bridge can adsorb more fluoride ions. N-vinyl-2-pyrrolidone and N,N-methylenebisacrylamide can reduce the hydrolysis of humic acid polymers in strong acid, strong alkali, and high-salt environments; hydrophobic monomers can greatly improve the viscosity of humic acid polymers in strong acid, strong alkali, and high-salt environments, and enhance the flocculent precipitation effect of the defluoridation agent.

[0028] The surface of environmentally responsive polyurethane has a large number of hydroxyl groups, amine groups, silicon oxygen bonds, and carboxyl groups that can complex aluminum ions at the same time, so that the surface of environmentally responsive polyurethane has a large number of adsorption sites, making it have a higher fluorine adsorption performance. In alkaline wastewater, the protonated amine groups fully extend on the surface of polyurethane and combine with the hydrogen bonds of fluoride ions; in acidic wastewater, the carboxyl groups fully extend on the surface of polyurethane, and the complexed aluminum ions react with fluoride ions to form aluminum fluoride precipitation and thus detach from the polyurethane.

[0029] In an alkaline environment in the solution, the dendritic cationic polymer will present a fully extended network structure, which can adsorb more fluoride ions, but in an acidic environment it will quickly compress the volume and wrap the humic acid polymer and environmentally responsive polyurethane therein, having an adsorption and precipitation effect.

[0030] Beneficial effects of the present invention:

[0031] (1) The highly adaptable defluoridation agent prepared by the present invention can be widely used in acidic, neutral and alkaline industrial fluoride-containing wastewaters, and can stabilize the fluoride ion concentration of the effluent at below 5 mg / L.

[0032] (2) The highly adaptable defluoridation agent prepared by the present invention can not only reduce the concentration of fluoride ions, but also effectively remove high-valent toxic metal ions in fluoride-containing wastewater. DETAILED DESCRIPTION

[0033] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments, but the present invention is not limited to the following technical solution.

[0034] Example 1

[0035] This embodiment provides a highly adaptable defluorination agent and a preparation method thereof, comprising:

[0036] (1) Preparation method of humic acid copolymer:

[0037] S1. At room temperature, 669.9 g of water and 8 g of 1-allyloxy-3-(4-nonylphenol)-2-propanol polyoxyethylene were added to a reaction vessel and stirred until uniform and transparent;

[0038] S2. Under nitrogen protection, 60g of aromatic humic acid, 80g of acrylic acid, 140g of acrylamide, 12g of N-vinyl-2-pyrrolidone, 10g of styrene, and 16g of propyl acrylate were added to the solution of step S1, and 0.1g of bleaching block was added after stirring for 60min. Stirring was continued for 20min, and 1g of ammonium persulfate was added within 2h, and the reaction was continued to stir for 6h;

[0039] S3. Add 3 g of N,N-methylenebisacrylamide into step S2 and stir for 2 h to obtain humic acid copolymer A1.

[0040] (2) Synthesis of environmentally responsive polyurethane:

[0041] S11. Under nitrogen protection, 130 g of polyethylene glycol, 70 g of polycaprolactone, and 76 g of 1,6-hexamethylene diisocyanate were dissolved in 276 g of dry tetrahydrofuran, stirred for 30 min, and then heated to 100 ° C and stirred for 4 h; then 60 g of 2,2-dihydroxymethylpropionic acid and 40 g of hydroxy-terminated polydimethylsiloxane were added in sequence, and the reaction was continued at 100 ° C for 4 h;

[0042] S12. Control the temperature in the range of 0-5 ° C, add 24g of 1,6-hexanediamine and 1g of 1-hydroxybenzotriazole to the product of step S11 and stir for 20min, then add 2g of N,N'-dicyclohexylcarbodiimide and stir for 24h, and then disperse dropwise in 522g of water;

[0043] S13. Dissolve 15 g of aluminum sulfate in 60 g of water;

[0044] S14. The aluminum sulfate solution obtained in step S13 and the solution obtained in step S12 are mixed and stirred for 80 minutes to obtain environmentally responsive polyurethane B1.

[0045] (3) Preparation method of dendritic cationic polymer:

[0046] 160 g of polyethyleneimine and 536 g of water were added to a reactor, and after stirring for 30 min, 300 g of epichlorohydrin and 4 g of glucose were added in sequence. After reacting for 4 h, the mixture was cooled to room temperature to obtain a dendritic cationic polymer C1.

[0047] Usage is as follows:

[0048] When the pH of the fluorine-containing wastewater is greater than 6.5, 500 parts of humic acid copolymer A1 are first added, and after reacting for 20 minutes, 420 parts of environmentally responsive polyurethane B1 are added, and the reaction is continued for 20 minutes. Then, 80 parts of dendritic cationic polymer C1 are added, and after reacting for 20 minutes, the pH of the wastewater is adjusted to 5.0-6.5, and the reaction is continued for more than 10 minutes for solid-liquid separation.

[0049] When the pH value of the fluorine-containing wastewater is less than 6.5, 400 parts of humic acid copolymer A1 are first added, and after reacting for 20 minutes, 500 parts of environmentally responsive polyurethane B1 are added, and after continuing the reaction for 20 minutes, the pH value of the wastewater is adjusted to 7.0-8.0, and then 100 parts of dendritic cationic polymer C1 are added, and the reaction is continued for more than 10 minutes, and the pH value of the wastewater is adjusted to 5.0-6.5 for solid-liquid separation.

[0050] Example 2

[0051] This embodiment provides a highly adaptable defluorination agent and a preparation method thereof, comprising:

[0052] (1) Preparation method of humic acid copolymer:

[0053] S1. At room temperature, 704.8 g of water and 10 g of 1-allyloxy-3-(4-nonylphenol)-2-propanol polyoxyethylene were added to a reaction vessel and stirred until uniform and transparent;

[0054] S2. Under nitrogen protection, 40g of aromatic humic acid, 90g of acrylic acid, 90g of acrylamide, 16g of N-vinyl-2-pyrrolidone, 20g of α-methylstyrene, 10g of octyl acrylate, 10g of 2-ethylhexyl methacrylate were added to the solution in step S1, stirred for 120min, and then 1.2g of bleaching block was added. After stirring for 20min, 3g of ammonium persulfate was added within 3h, and the reaction was stirred for 2h;

[0055] S3. Add 5 g of N,N-methylenebisacrylamide into step S2 and stir for 1 hour to obtain humic acid copolymer A2.

[0056] (2) Synthesis of environmentally responsive polyurethane:

[0057] S11. Under nitrogen protection, 70 g of polyethylene glycol, 80 g of polycaprolactone, and 100 g of 1,6-hexamethylene diisocyanate were dissolved in 250 g of dry tetrahydrofuran, stirred for 30 min, and then heated to 120° C. and stirred for 4 h; then 80 g of 2,2-dihydroxymethylpropionic acid and 20 g of hydroxyl-terminated polydimethylsiloxane were added in sequence, and the reaction was continued at 120° C. for 4 h;

[0058] S12. The temperature was controlled within the range of 0-5°C, 36 g of 1,6-hexanediamine and 2 g of 1-hydroxybenzotriazole were added to the product of step S11 and stirred for 40 min, followed by addition of 2 g of N,N'-dicyclohexylcarbodiimide and stirring for 48 h, and then dispersed dropwise in 444 g of water;

[0059] S13. Dissolve 30 g of aluminum sulfate in 136 g of water;

[0060] S14. The aluminum sulfate solution obtained in step S13 and the solution obtained in step S12 are mixed and stirred for 180 minutes to obtain an environmentally responsive polyurethane B2.

[0061] (3) Preparation method of dendritic cationic polymer:

[0062] 120 g of polyethyleneimine and 639 g of water were added to a reactor, and after stirring for 30 min, 240 g of epichlorohydrin and 1 g of piperazine were added in sequence. After reacting for 6 h, the mixture was cooled to room temperature to obtain a dendritic cationic polymer C2.

[0063] Usage is as follows:

[0064] When the pH of the fluorine-containing wastewater is greater than 6.5, 280 parts of humic acid copolymer A2 are first added, and after reacting for 20 minutes, 600 parts of environmentally responsive polyurethane B2 are added, and the reaction is continued for 20 minutes. Then, 120 parts of dendritic cationic polymer C2 are added, and after reacting for 20 minutes, the pH of the wastewater is adjusted to 5.0-6.5, and the reaction is continued for more than 10 minutes for solid-liquid separation.

[0065] When the pH value of the fluorine-containing wastewater is less than 6.5, 400 parts of humic acid copolymer A2 are first added, and after reacting for 20 minutes, 520 parts of environmentally responsive polyurethane B2 are added, and after continuing the reaction for 20 minutes, the pH value of the wastewater is adjusted to 7.0-8.0, and then 80 parts of dendritic cationic polymer C2 are added, and the reaction is continued for more than 10 minutes, and the pH value of the wastewater is adjusted to 5.0-6.5 for solid-liquid separation.

[0066] Example 3

[0067] This embodiment provides a highly adaptable defluorination agent and a preparation method thereof, comprising:

[0068] (1) Preparation method of humic acid copolymer:

[0069] S1. At room temperature, 702.5 g of water and 12 g of 1-allyloxy-3-(4-nonylphenol)-2-propanol polyoxyethylene were added to a reaction vessel and stirred until uniform and transparent;

[0070] S2. Under nitrogen protection, 50g of aromatic humic acid, 60g of acrylic acid, 120g of acrylamide, 20g of N-vinyl-2-pyrrolidone and 32g of octyl acrylate were added to the solution in step S1, stirred for 30min, and then 2g of bleaching block was added. Stirring was continued for 20min, and then 0.5g of ammonium persulfate was added within 2h, and the reaction was continued with stirring for 4h.

[0071] S3. Add 1 g of N,N-methylenebisacrylamide into step S2 and stir for 3 h to obtain humic acid copolymer A3.

[0072] (2) Synthesis of environmentally responsive polyurethane:

[0073] S11. Under nitrogen protection, 100 g of polyethylene glycol, 90 g of polycaprolactone, and 40 g of 1,6-hexamethylene diisocyanate were dissolved in 230 g of dry tetrahydrofuran, stirred for 30 min, and then heated to 90° C. for 4 h; then 68 g of 2,2-dihydroxymethylpropionic acid and 32 g of hydroxyl-terminated polydimethylsiloxane were added in sequence, and the reaction was continued at 90° C. for 4 h;

[0074] S12. At 5°C, 36 g of 1,6-hexanediamine and 5 g of 1-hydroxybenzotriazole were added to the product of step S11 and stirred for 20 min, followed by the addition of 4 g of N,N'-dicyclohexylcarbodiimide and stirring for 36 h, and then dispersed dropwise in 575 g of water;

[0075] S13. Dissolve 10 g of aluminum sulfate in 40 g of water;

[0076] S14. The aluminum sulfate solution obtained in step S13 and the solution obtained in step S12 are mixed and stirred for 20 minutes to obtain an environmentally responsive polyurethane B3.

[0077] (3) Preparation method of dendritic cationic polymer:

[0078] 140 g of polyethyleneimine and 656 g of water were added to a reactor, and after stirring for 30 min, 200 g of epichlorohydrin and 4 g of sodium oleate were added in sequence. After reacting for 10 h, the mixture was cooled to room temperature to obtain a dendritic cationic polymer C3.

[0079] Usage is as follows:

[0080] When the pH value of the fluorine-containing wastewater is greater than 6.5, 340 parts of humic acid copolymer A3 are first added, and after reacting for 20 minutes, 540 parts of environmentally responsive polyurethane B3 are added, and the reaction is continued for 20 minutes. Then, 120 parts of dendritic cationic polymer C3 are added, and after reacting for 20 minutes, the pH value of the wastewater is adjusted to 5.0-6.5, and the reaction is continued for more than 10 minutes for solid-liquid separation.

[0081] When the pH value of the fluorine-containing wastewater is less than 6.5, 400 parts of humic acid copolymer A3 are first added, and after reacting for 20 minutes, 520 parts of environmentally responsive polyurethane B3 are added, and after continuing the reaction for 20 minutes, the pH value of the wastewater is adjusted to 7.0-8.0, and then 80 parts of dendritic cationic polymer C3 are added, and the reaction is continued for more than 10 minutes, and the pH value of the wastewater is adjusted to 5.0-6.5 for solid-liquid separation.

[0082] Comparative Example 1

[0083] This comparative example provides a highly adaptable defluorination agent, which is used as follows:

[0084] When the pH of the fluorine-containing wastewater is greater than 6.5, humic acid copolymer A1 is first added, and after reacting for 20 minutes, the pH of the wastewater is adjusted to 5.0-6.5, and reacted for more than 10 minutes for solid-liquid separation.

[0085] When the pH of the fluorine-containing wastewater is less than 6.5, humic acid copolymer A1 is first added, and after reacting for 20 minutes, solid-liquid separation is performed.

[0086] Comparative Example 2

[0087] This comparative example provides a highly adaptable defluorination agent, which is used as follows:

[0088] When the pH of the fluorine-containing wastewater is greater than 6.5, the environmentally responsive polyurethane B1 is first added. After reacting for 20 minutes, the pH of the wastewater is adjusted to 5.0-6.5, and the reaction is continued for more than 10 minutes for solid-liquid separation.

[0089] When the pH of the fluorine-containing wastewater is less than 6.5, environmentally responsive polyurethane B1 is first added. After reacting for 20 minutes, the pH of the wastewater is adjusted to 7.0-8.0. After reacting for more than 10 minutes, the pH of the wastewater is adjusted to 5.0-6.5 for solid-liquid separation.

[0090] Comparative Example 3

[0091] This comparative example provides a highly adaptable defluorination agent, which is used as follows:

[0092] When the pH of the fluorine-containing wastewater is greater than 6.5, the dendritic cationic polymer C1 is added and reacted for 20 minutes, and then the pH of the wastewater is adjusted to 5.0-6.5, and the reaction is continued for more than 10 minutes for solid-liquid separation.

[0093] When the pH of the fluorine-containing wastewater is less than 6.5, the pH of the wastewater is adjusted to 7.0-8.0, and then the dendritic cationic polymer C1 is added to react for more than 10 minutes, and the pH of the wastewater is adjusted to 5.0-6.5 for solid-liquid separation.

[0094] Comparative Example 4

[0095] This comparative example provides a highly adaptable defluorination agent:

[0096] Preparation method of humic acid copolymer:

[0097] S1. At room temperature, 669.9 g of water and 8 g of 1-allyloxy-3-(4-nonylphenol)-2-propanol polyoxyethylene were added to a reaction vessel and stirred until uniform and transparent;

[0098] S2. Under nitrogen protection, 80g of acrylic acid, 140g of acrylamide, 12g of N-vinyl-2-pyrrolidone, 10g of styrene, and 16g of propyl acrylate were added to the solution of step S1, and 0.1g of bleaching block was added after stirring for 60min. Stirring was continued for 20min, and 1g of ammonium persulfate was added within 2h, and the reaction was continued with stirring for 6h;

[0099] S3. Add 3 g of N,N-methylenebisacrylamide into step S2 and stir for 2 h to obtain humic acid copolymer A4.

[0100] Usage is as follows:

[0101] When the pH of the fluorine-containing wastewater is greater than 6.5, 500 parts of humic acid copolymer A4 are first added, and after reacting for 20 minutes, 420 parts of environmentally responsive polyurethane B1 are added, and the reaction is continued for 20 minutes. Then, 80 parts of dendritic cationic polymer C1 are added, and after reacting for 20 minutes, the pH of the wastewater is adjusted to 5.0-6.5, and the reaction is continued for more than 10 minutes for solid-liquid separation.

[0102] When the pH value of the fluorine-containing wastewater is less than 6.5, 400 parts of humic acid copolymer A4 are first added, and after reacting for 20 minutes, 500 parts of environmentally responsive polyurethane B1 are added, and after continuing the reaction for 20 minutes, the pH value of the wastewater is adjusted to 7.0-8.0, and then 100 parts of dendritic cationic polymer C1 are added, and the reaction is continued for more than 10 minutes, and the pH value of the wastewater is adjusted to 5.0-6.5, and solid-liquid separation is performed.

[0103] Comparative Example 5

[0104] This comparative example provides a highly adaptable defluorination agent:

[0105] Synthesis of Environmentally Responsive Polyurethanes:

[0106] S11. Under nitrogen protection, 130 g of polyethylene glycol, 70 g of polycaprolactone, and 76 g of 1,6-hexamethylene diisocyanate were dissolved in 276 g of dry tetrahydrofuran, stirred for 30 min, and then heated to 100 ° C and stirred for 4 h; then 60 g of 2,2-dihydroxymethylpropionic acid and 40 hydroxyl-terminated polydimethylsiloxane were added in sequence, and the reaction was continued at 100 ° C for 4 h, and then dispersed dropwise in 522 g of water;

[0107] S12. Dissolve 15 g of aluminum sulfate in 60 g of water;

[0108] S13. The aluminum sulfate solution obtained in step S12 and the solution obtained in step S11 are mixed and stirred for 80 minutes to obtain environmentally responsive polyurethane B4.

[0109] Usage is as follows:

[0110] When the pH of the fluorine-containing wastewater is greater than 6.5, 500 parts of humic acid copolymer A1 are first added, and after reacting for 20 minutes, 420 parts of environmentally responsive polyurethane B4 are added, and the reaction is continued for 20 minutes. Then, 80 parts of dendritic cationic polymer C1 are added, and after reacting for 20 minutes, the pH of the wastewater is adjusted to 5.0-6.5, and the reaction is continued for more than 10 minutes for solid-liquid separation.

[0111] When the pH value of the fluorine-containing wastewater is less than 6.5, 400 parts of humic acid copolymer A1 are first added, and after reacting for 20 minutes, 500 parts of environmentally responsive polyurethane B4 are added, and after continuing the reaction for 20 minutes, the pH value of the wastewater is adjusted to 7.0-8.0, and then 100 parts of dendritic cationic polymer C1 are added, and the reaction is continued for more than 10 minutes, and the pH value of the wastewater is adjusted to 5.0-6.5, and solid-liquid separation is performed.

[0112] Comparative Example 6

[0113] This comparative example provides a highly adaptable defluorination agent, which is used as follows:

[0114] When the pH of the fluorine-containing wastewater is greater than 6.5, 500 parts of humic acid copolymer A1 are first added, and after reacting for 20 minutes, 420 parts of environmentally responsive polyurethane B4 are added, and the reaction is continued for 20 minutes. Then, 80 parts of dendritic cationic polymer C1 are added, and the reaction is continued for more than 10 minutes for solid-liquid separation.

[0115] Comparative Example 7

[0116] This comparative example provides a highly adaptable defluorination agent, which is used as follows:

[0117] When the pH of the fluorine-containing wastewater is less than 6.5, 400 parts of humic acid copolymer A1 are first added, and after reacting for 20 minutes, 500 parts of environmentally responsive polyurethane B4 are added, and the reaction is continued for 20 minutes. Then, 100 parts of dendritic cationic polymer C1 are added, and the reaction is continued for more than 10 minutes, and solid-liquid separation is performed.

[0118] A certain alkaline process smelting plant collected fluoride-containing wastewater, the pH value of the fluoride-containing wastewater was 11.8, and the fluoride ion concentration was 164.36 mg / L.

[0119]

[0120] The acid wastewater from a copper industry has a fluoride-containing wastewater pH of 3.5, a fluoride ion concentration of 23.50 mg / L, an arsenic ion concentration of 0.1463 mg / L, and a zinc ion concentration of 1.2103 mg / L.

[0121]

[0122] From the treatment data of fluorine-containing wastewater of a certain alkaline process smelter, it can be seen that the highly adaptable defluorination agent prepared by the present invention can reduce the fluoride ion content in alkaline fluorine-containing wastewater to below 5 mg / L, while the humic acid copolymer, environmentally responsive polyurethane or dendritic cationic polymer alone cannot achieve this effect. The data of Comparative Example 6 shows that after adding the dendritic cationic polymer to the alkaline wastewater, if the environmental pH is not adjusted, the dendritic cationic polymer may not shrink, thereby affecting the sedimentation.

[0123] From the treatment data of acid wastewater from a copper industry, it can be seen that the highly adaptable defluoridation agent prepared by the present invention can reduce the fluoride ion content in the acidic fluoride-containing wastewater to below 5 mg / L, and effectively remove metal ions in the wastewater, while the humic acid copolymer, environmentally responsive polyurethane or dendritic cationic polymer alone cannot achieve this effect. The data of Comparative Example 7 show that directly adding dendritic cationic polymers to acidic wastewater will also affect sedimentation.

Claims

1. A highly adaptable defluorination agent, characterized in that: The invention comprises, by weight, 280-500 parts of humic acid copolymer, 420-600 parts of environmentally responsive polyurethane, and 80-120 parts of dendritic cationic polymer; the raw materials for preparing the humic acid copolymer include aromatic humic acid, acrylic acid, acrylamide, N-vinyl-2-pyrrolidone, N,N-methylenebisacrylamide, hydrophobic monomer, ammonium persulfate, bleaching agent, 1-allyloxy-3-(4-nonylphenol)-2-propanol polyoxyethylene, and water; the raw materials for preparing the environmentally responsive polyurethane include polyethylene glycol, polycaprolactone, 2,2-dihydroxymethylpropionic acid, 1,6-hexamethylene diisocyanate, hydroxyl-terminated polydimethylsiloxane, 1,6-hexanediamine, 1-hydroxybenzotriazole, N,N'-dicyclohexylcarbodiimide, aluminum sulfate, and water; the raw materials for preparing the dendritic cationic polymer include polyethyleneimine, epichlorohydrin, a crosslinking agent, and water; The raw materials for preparing the humic acid copolymer include the following components in parts by weight: 40-60 parts of aromatic humic acid, 60-90 parts of acrylic acid, 90-140 parts of acrylamide, 12-20 parts of N-vinyl-2-pyrrolidone, 1-5 parts of N,N-methylenebisacrylamide, 26-40 parts of hydrophobic monomer, 0.5-3 parts of ammonium persulfate, 0.1-2 parts of bleaching powder, 1- 8-12 parts of allyloxy-3-(4-nonylphenol)-2-propanol polyoxyethylene, 628-762.4 parts of water; the hydrophobic monomer includes one or more of styrene, α-methylstyrene, 2-ethylhexyl acrylate, octyl acrylate, lauryl acrylate, stearyl acrylate, 2-ethylhexyl methacrylate, octyl methacrylate, lauryl methacrylate, stearyl methacrylate, 2-ethylhexyl acrylamide, octylacrylamide, propyl acrylate, butyl acrylate, pentyl acrylate, hexyl acrylate, 1-vinylnaphthalene, 2-vinylnaphthalene, and 3-methylstyrene; The raw materials for preparing the environmentally responsive polyurethane include the following components in parts by weight: 70-130 parts of polyethylene glycol, 70-92 parts of polycaprolactone, 60-80 parts of 2,2-dihydroxymethylpropionic acid, 40-100 parts of 1,6-hexamethylene diisocyanate, 20-40 parts of hydroxyl-terminated polydimethylsiloxane, 24-36 parts of 1,6-hexanediamine, 1-5 parts of 1-hydroxybenzotriazole, 1-4 parts of N,N'-dicyclohexylcarbodiimide, 10-30 parts of aluminum sulfate, and 483-704 parts of water; The raw materials for preparing the dendritic cationic polymer include the following components in parts by weight: 120-160 parts of polyethyleneimine, 200-300 parts of epichlorohydrin, 1-4 parts of a crosslinking agent, and 536-679 parts of water; the crosslinking agent includes one of glucose, piperazine, and sodium oleate.

2. The method for preparing a highly adaptable defluorination agent according to claim 1, characterized in that: The following steps are involved: (1) Preparation method of humic acid copolymer: S1. At room temperature, water and 1-allyloxy-3-(4-nonylphenol)-2-propanol polyoxyethylene are added to a reaction kettle and stirred until uniform and transparent; S2. Under nitrogen protection, aromatic humic acid, acrylic acid, acrylamide, N-vinyl-2-pyrrolidone, and hydrophobic monomers were added to the solution of step S1, stirred for 30-120 min, and then added to the bleaching block, and continued to stir for 10-20 min. After that, the ammonium persulfate was added within 2-3 h, and the reaction was continued to stir for 2-6 h; S3. Add N,N-methylenebisacrylamide into step S2 and stir for 1-3h to obtain a humic acid copolymer; (2) Synthesis of environmentally responsive polyurethane: S11. Under nitrogen protection, polyethylene glycol, polycaprolactone and 1,6-hexamethylene diisocyanate were dissolved in dry tetrahydrofuran, stirred for 30 minutes, and then heated to 90-120°C for 4 hours; then 2,2-dihydroxymethylpropionic acid and hydroxyl-terminated polydimethylsiloxane were added in sequence, and the reaction was continued at 90-120°C for 4 hours; wherein, the amount of tetrahydrofuran used was 1 times the total mass of polyethylene glycol, polycaprolactone and 1,6-hexamethylene diisocyanate; S12. At 0-5° C., 1,6-hexanediamine and 1-hydroxybenzotriazole are added to the product of step S11 and stirred for reaction for 10-40 min, and then N,N'-dicyclohexylcarbodiimide is added and stirred for reaction for 24-48 h, and then dispersed dropwise in water; S13. Dissolving aluminum sulfate in water to obtain a solution having a mass fraction of 18%-25%; S14. The aluminum sulfate solution obtained in step S13 is mixed with the solution obtained in step S12 and stirred for 10-180 min to obtain an environmentally responsive polyurethane; (3) Preparation method of dendritic cationic polymer: Polyethyleneimine and water are put into a reaction kettle, and after stirring for 30 minutes, epichlorohydrin and a cross-linking agent are added in sequence. After reacting for 4-10 hours, the mixture is cooled to room temperature to obtain a dendritic cationic polymer.

3. The method for using a highly adaptable defluorination agent according to claim 1, characterized in that: When the pH of the fluorine-containing wastewater is greater than 6.5, first add the humic acid copolymer, react for 20 minutes, then add the environmentally responsive polyurethane, continue to react for 20 minutes, then add the dendritic cationic polymer, continue to react for 20 minutes, adjust the wastewater pH to 5.0-6.5, react for more than 10 minutes, and perform solid-liquid separation; When the pH value of the fluorine-containing wastewater is less than 6.5, humic acid copolymer is first added, and after reacting for 20 minutes, environmentally responsive polyurethane is added, and after continuing the reaction for 20 minutes, the pH value of the wastewater is adjusted to 7.0-8.0, and then the dendritic cationic polymer is added. After reacting for 20 minutes, the pH value of the wastewater is adjusted to 5.0-6.5 for solid-liquid separation.

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