Salt-tolerant chelating resin suitable for high-salinity wastewater and preparation method thereof

Abstract

The invention belongs to the technical field of chelating resin, and relates to salt-tolerant chelating resin suitable for high-salinity wastewater and a preparation method thereof. The salt-tolerant chelating resin suitable for the high-salinity wastewater is prepared from chloromethylated spherical porous polystyrene resin, a functional monomer and iminodisuccinic acid through a reaction; the functional monomers are glycidyl methacrylate and vinyl phosphoric acid. The salt-tolerant chelating resin provided by the invention solves the problem that the adsorption effect of calcium and magnesium ions is poor when the traditional chelating resin is under a high-salt condition.

Description

Technical Field

[0001] This invention belongs to the field of chelating resin technology, specifically relating to a salt-resistant chelating resin suitable for high-salt wastewater and its preparation method. Background Technology

[0002] High-salinity wastewater typically refers to wastewater with a total salt content of 1% or higher, equivalent to more than 10,000 milligrams of salts per liter. It contains high levels of soluble inorganic ions such as calcium, magnesium, sodium, chloride, and sulfate, and primarily originates from seawater desalination, chemical plants, and the oil and gas industries. Direct discharge of high-salinity wastewater causes severe environmental pollution, such as soil compaction and impaired plant growth. Therefore, the treatment and resource recovery of high-salinity wastewater is a necessary trend for environmental protection and sustainable development.

[0003] Currently, the main process flow for treating high-salt wastewater includes the following: sequentially performing biochemical treatment on the wastewater to remove organic matter and obtain wastewater with high salt content, membrane concentration, salt separation, chelating resin to remove calcium and magnesium ions, and bipolar membrane treatment to generate NaOH and HCl from Na2SO4.

[0004] In high-salt environments, sodium ions compete with calcium and magnesium ions for adsorption, causing the active sites of the chelating resin to be non-selectively occupied, reducing the effective exchange capacity. On the other hand, sodium ions also inhibit the adsorption rate of calcium and magnesium ions, thus severely affecting the adsorption effect of calcium and magnesium ions. Therefore, salt separation treatment is required before using chelating resins for adsorption processes. Thus, providing a salt-tolerant chelating resin that can be directly used for high-salt wastewater and simplifying the treatment process of high-salt wastewater is of great significance.

[0005] There are few reports on salt-resistant chelating resins in the prior art. Chinese patent publication number CN1143876C discloses an improved chelating resin, a macroporous aminoalkylphosphonic acid or iminodiacetic acid chelating resin with improved stability and capacity in removing cations (e.g., calcium, magnesium, barium, and strontium) from brine and metals (e.g., nickel, copper, and zinc) from waste streams. However, this technical solution is suitable for low concentrations of calcium and magnesium ions. Summary of the Invention

[0006] Therefore, it is necessary to provide a salt-tolerant chelating resin suitable for high-salt wastewater and its preparation method to solve the problem of poor calcium and magnesium ion adsorption effect of traditional chelating resins under high-salt conditions.

[0007] The above-mentioned objective of this invention is achieved through the following technical solution: In a first aspect, the present invention provides a salt-resistant chelating resin suitable for high-salt wastewater, which is prepared by reacting chloromethylated spherical porous polystyrene resin, functional monomers, and iminodisuccinic acid; wherein the functional monomers are glycidyl methacrylate and vinyl phosphate.

[0008] In the salt-resistant chelating resin provided by this invention, the structural formula of the vinyl phosphate is as follows: .

[0009] In some preferred embodiments, the method for preparing the chloromethylated spherical porous polystyrene resin includes the following steps: mixing a dispersant, deionized water and sodium chloride to obtain an aqueous phase; mixing p-chloromethylstyrene, styrene, divinylbenzene, styrene-based phosphoric acid, an initiator and a porogen to obtain an oil phase; adding the aqueous phase to the oil phase to carry out a polymerization reaction; and removing the porogen after the polymerization reaction is completed to obtain the chloromethylated spherical porous polystyrene resin.

[0010] In some preferred embodiments, the dispersant is selected from at least one of polyvinyl alcohol, hydroxymethyl cellulose, hydroxypropyl methyl cellulose, and hydroxyethyl cellulose.

[0011] In some preferred embodiments, the initiator is selected from at least one of azobisisobutyronitrile, benzoyl peroxide, azobisisoheptanenitrile, and dilauryl peroxide.

[0012] In some preferred embodiments, the pore-forming agent is selected from at least one of gasoline, isobutanol, and toluene.

[0013] In the salt-resistant chelating resin provided by this invention, the structural formula of the styrene-based phosphoric acid is as follows: .

[0014] In some preferred embodiments, the amounts of each material in the oil phase, by weight, are: 20-30 parts of p-chloromethylstyrene, 10-15 parts of styrene, 15-25 parts of divinylbenzene, 5-10 parts of styrene-based phosphoric acid, 0.5-1 part of initiator, and 40-70 parts of pore-forming agent.

[0015] In some preferred embodiments, the amounts of each material in the aqueous phase, by mass, are: 1-2 parts dispersant, 4-6 parts sodium chloride, and 100 parts deionized water.

[0016] In some preferred embodiments, the volume ratio of the oil phase to the water phase is 4-7:1.

[0017] In some preferred embodiments, the preparation method of the chloromethylated spherical porous polystyrene resin includes the following steps: mixing a dispersant, deionized water, and sodium chloride, heating and stirring until completely dissolved to obtain an aqueous phase; mixing p-chloromethylstyrene, styrene, styrene-based phosphoric acid, divinylbenzene, an initiator, and a porogen to obtain an oil phase; adding the aqueous phase to the oil phase and carrying out a polymerization reaction at 60-85°C for 6-12 hours; removing the porogen after the polymerization reaction is completed to obtain the chloromethylated spherical porous polystyrene resin.

[0018] A second aspect of the present invention provides a method for preparing a salt-tolerant chelating resin suitable for high-salinity wastewater, comprising the following steps: Chloromethyl spherical porous polystyrene resin, functional monomers, cuprous bromide, 2,2-bipyridine and N,N-dimethylformamide were mixed, wherein the functional monomers were glycidyl methacrylate and vinyl phosphoric acid. The reaction was carried out under nitrogen protection. After the reaction was completed, the mixture was filtered, washed and dried to obtain an intermediate product. The intermediate product was mixed with N-methyl-2-pyrrolidone, soaked and swollen, and then tetrasodium iminodisuccinate and sodium carbonate were added. After the reaction was completed, the mixture was filtered, washed, and dried to obtain a salt-resistant chelating resin suitable for high-salt wastewater.

[0019] In some preferred embodiments, the mass ratio of the chloromethyl spherical porous polystyrene resin, vinyl phosphoric acid, glycidyl methacrylate, cuprous bromide, 2,2-bipyridine, and N,N-dimethylformamide is 40-60:70-90:10-15:1-3:3-8:100-120.

[0020] In some preferred embodiments, the mass ratio of the intermediate product, N-methyl-2-pyrrolidone, tetrasodium iminodisuccinate, and sodium carbonate is 1:5-10:2-3:4-5.

[0021] In some preferred embodiments, the preparation method of the salt-tolerant chelating resin suitable for high-salinity wastewater includes the following steps: Chloromethyl spherical porous polystyrene resin, functional monomers, cuprous bromide, 2,2-bipyridine and N,N-dimethylformamide were mixed and reacted at 40-60℃ for 8-12 h under nitrogen protection. After the reaction was completed, the mixture was filtered, washed and dried to obtain the intermediate product. The intermediate product and N-methyl-2-pyrrolidone were mixed and soaked to swell for 10-12 hours. Then, tetrasodium iminodisuccinate and sodium carbonate were added, and the mixture was reacted at 60-70°C for 10-12 hours. After the reaction was completed, the mixture was filtered, washed, and dried to obtain a salt-resistant chelating resin suitable for high-salt wastewater.

[0022] Compared with the prior art, the present invention has the following advantages: The salt-tolerant chelating resin for high-salt wastewater provided by this invention is a chloromethylated spherical porous polystyrene resin grafted with vinyl phosphate and iminodisuccinic acid. Vinyl phosphate and iminodisuccinic acid are suspended on the side chains, exhibiting a higher coordination capacity for calcium and magnesium ions than for sodium ions. This avoids the influence of sodium ions in high-salt wastewater on the adsorption effect of calcium and magnesium ions. Simultaneously, they can form stable chelates with calcium and magnesium ions, enhancing the adsorption capacity. Specifically, in the preparation process of the chloromethylated spherical porous polystyrene resin, styrene-phosphate directly participates in the polymerization, acting as part of the chloromethylated spherical porous polystyrene resin, further improving the adsorption effect of the salt-tolerant chelating resin on calcium and magnesium ions. The styrene-phosphate on the chloromethylated spherical porous polystyrene resin, together with the vinyl phosphate and iminodisuccinic acid grafted onto the salt-tolerant chelating resin, achieves the adsorption effect of calcium and magnesium ions in a high-salt environment. Attached Figure Description

[0023] Figure 1 The images show SEM images of the chloromethylated spherical porous polystyrene resin and the salt-resistant chelating resin in Example 1. A represents the chloromethylated spherical porous polystyrene resin, and B represents the salt-resistant chelating resin. Detailed Implementation

[0024] To enable those skilled in the art to more clearly understand the technical solutions described in this invention, the following embodiments are provided for illustration. It should be noted that the following embodiments do not constitute a limitation on the scope of protection claimed by this invention.

[0025] Unless otherwise specified, the raw materials, reagents or apparatus used in the following examples and comparative examples are available from conventional commercial sources or can be obtained by existing known methods.

[0026] Example 1: A salt-tolerant chelating resin suitable for high-salinity wastewater: (1) Preparation of chloromethylated spherical porous polystyrene resin: Dispersant, deionized water, and sodium chloride were mixed in a mass ratio of 2:5:100 and heated and stirred until completely dissolved to obtain an aqueous phase. Chloromethylstyrene, styrene, styrene-based phosphoric acid, divinylbenzene, initiator, and porogen were mixed in a mass ratio of 24:15:6:15:60:0.6 to obtain an oil phase. The aqueous phase was added to the oil phase in a volume ratio of 5:1, and polymerization was carried out at 70°C for 10 hours. After polymerization, the porogen was removed to obtain chloromethylated spherical porous polystyrene resin.

[0027] The dispersant is polyvinyl alcohol with a degree of polymerization of 1000±50 and a degree of alcoholysis of 98-99 mol%, manufactured by Shanghai Yingjia Industrial Development Co., Ltd., model: PVA10-99.

[0028] The initiator is benzoyl peroxide.

[0029] The porogen is toluene.

[0030] (2) Preparation of salt-tolerant chelating resin suitable for high-salt wastewater: Chloromethyl spherical porous polystyrene resin, vinyl phosphoric acid, glycidyl methacrylate, cuprous bromide, 2,2-bipyridine and N,N-dimethylformamide were mixed in a mass ratio of 50:70:15:2:5:120 and reacted at 50°C for 10 h under nitrogen protection. After the reaction was completed, the mixture was filtered, washed and dried to obtain the intermediate product. The intermediate product and N-methyl-2-pyrrolidone were mixed at a mass ratio of 1:8:3:4, soaked and swollen for 10 h, and then tetrasodium iminodisuccinate and sodium carbonate were added. The mixture was reacted at 65 °C for 12 h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain a salt-resistant chelating resin suitable for high-salt wastewater.

[0031] SEM images of the chloromethylated spherical porous polystyrene resin and the salt-resistant chelating resin in this embodiment are shown below. Figure 1 As shown, A represents chloromethylated spherical porous polystyrene resin, and B represents salt-resistant chelating resin.

[0032] Example 2: A salt-tolerant chelating resin suitable for high-salinity wastewater: (1) Preparation of chloromethylated spherical porous polystyrene resin: Dispersant, deionized water, and sodium chloride were mixed in a mass ratio of 2:5:100 and heated and stirred until completely dissolved to obtain an aqueous phase. Chloromethylstyrene, styrene, styrene-based phosphoric acid, divinylbenzene, initiator, and porogen were mixed in a mass ratio of 25:12:8:20:65:0.7 to obtain an oil phase. The aqueous phase was added to the oil phase in a volume ratio of 6:1, and the polymerization reaction was carried out at 70°C for 10 hours. After the polymerization reaction was completed, the porogen was removed to obtain chloromethylated spherical porous polystyrene resin.

[0033] The dispersant is polyvinyl alcohol with a degree of polymerization of 1000±50 and a degree of alcoholysis of 98-99 mol%, manufactured by Shanghai Yingjia Industrial Development Co., Ltd., model: PVA10-99.

[0034] The initiator is benzoyl peroxide.

[0035] The porogen is toluene.

[0036] (2) Preparation of salt-tolerant chelating resin suitable for high-salt wastewater: Chloromethyl spherical porous polystyrene resin, vinyl phosphoric acid, glycidyl methacrylate, cuprous bromide, 2,2-bipyridine and N,N-dimethylformamide were mixed in a mass ratio of 50:80:12:2:5:120 and reacted at 50°C for 10 h under nitrogen protection. After the reaction was completed, the mixture was filtered, washed and dried to obtain the intermediate product. The intermediate product and N-methyl-2-pyrrolidone were mixed at a mass ratio of 1:8:2:4, soaked and swollen for 10 h, and then tetrasodium iminodisuccinate and sodium carbonate were added. The mixture was reacted at 65 °C for 12 h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain a salt-resistant chelating resin suitable for high-salt wastewater.

[0037] Example 3: A salt-tolerant chelating resin suitable for high-salinity wastewater: (1) Preparation of chloromethylated spherical porous polystyrene resin: Dispersant, deionized water, and sodium chloride were mixed in a mass ratio of 2:5:100 and heated and stirred until completely dissolved to obtain an aqueous phase. Chloromethylstyrene, styrene, styrene-based phosphoric acid, divinylbenzene, initiator, and porogen were mixed in a mass ratio of 30:10:10:20:70:0.7 to obtain an oil phase. The aqueous phase was added to the oil phase in a volume ratio of 7:1, and the polymerization reaction was carried out at 70°C for 10 hours. After the polymerization reaction was completed, the porogen was removed to obtain chloromethylated spherical porous polystyrene resin.

[0038] The dispersant is polyvinyl alcohol with a degree of polymerization of 1000±50 and a degree of alcoholysis of 98-99 mol%, manufactured by Shanghai Yingjia Industrial Development Co., Ltd., model: PVA10-99.

[0039] The initiator is benzoyl peroxide.

[0040] The porogen is toluene.

[0041] (2) Preparation of salt-tolerant chelating resin suitable for high-salt wastewater: Chloromethyl spherical porous polystyrene resin, vinyl phosphoric acid, glycidyl methacrylate, cuprous bromide, 2,2-bipyridine and N,N-dimethylformamide were mixed in a mass ratio of 50:90:10:2:5:120 and reacted at 50°C for 10 h under nitrogen protection. After the reaction was completed, the mixture was filtered, washed and dried to obtain the intermediate product. The intermediate product and N-methyl-2-pyrrolidone were mixed at a mass ratio of 1:8:2:4, soaked and swollen for 10 h, and then tetrasodium iminodisuccinate and sodium carbonate were added. The mixture was reacted at 65 °C for 12 h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain a salt-resistant chelating resin suitable for high-salt wastewater.

[0042] Comparative Example 1: A salt-tolerant chelating resin suitable for high-salinity wastewater: (1) Preparation of chloromethylated spherical porous polystyrene resin: Dispersant, deionized water, and sodium chloride were mixed in a mass ratio of 2:5:100 and heated and stirred until completely dissolved to obtain an aqueous phase. Chloromethylstyrene, styrene, divinylbenzene, initiator, and porogen were mixed in a mass ratio of 25:20:20:65:0.7 to obtain an oil phase. The aqueous phase was added to the oil phase in a volume ratio of 6:1, and the polymerization reaction was carried out at 70°C for 10 hours. After the polymerization reaction was completed, the porogen was removed to obtain chloromethylated spherical porous polystyrene resin.

[0043] The dispersant is polyvinyl alcohol with a degree of polymerization of 1000±50 and a degree of alcoholysis of 98-99 mol%, manufactured by Shanghai Yingjia Industrial Development Co., Ltd., model: PVA10-99.

[0044] The initiator is benzoyl peroxide.

[0045] The porogen is toluene.

[0046] (2) Preparation of salt-resistant chelating resin suitable for high-salt wastewater: Same as in Example 1.

[0047] Comparative Example 2: A salt-tolerant chelating resin suitable for high-salinity wastewater: (1) Preparation of chloromethylated spherical porous polystyrene resin: Same as in Example 1; (2) Preparation of salt-tolerant chelating resin suitable for high-salt wastewater: Chloromethyl spherical porous polystyrene resin, vinyl phosphoric acid, glycidyl methacrylate, cuprous bromide, 2,2-bipyridine and N,N-dimethylformamide were mixed in a mass ratio of 50:80:12:2:5:120 and reacted at 50°C for 10 h under nitrogen protection. After the reaction was completed, the mixture was filtered, washed and dried to obtain the intermediate product. The intermediate product and N-methyl-2-pyrrolidone were mixed in a mass ratio of 1:8:2:4 and soaked and swollen for 10 h. Then, sodium iminodiacetic acid solution (obtained by mixing iminodiacetic acid, sodium hydroxide and water in a mass ratio of 1.5:1:50) and sodium carbonate were added. The mixture was reacted at 65 °C for 12 h. After the reaction was completed, the mixture was filtered, washed and dried to obtain a salt-resistant chelating resin suitable for high-salt wastewater.

[0048] Comparative Example 3: A salt-tolerant chelating resin suitable for high-salinity wastewater: (1) Preparation of chloromethylated spherical porous polystyrene resin: Same as in Example 1.

[0049] (2) Preparation of salt-tolerant chelating resin suitable for high-salt wastewater: Chloromethyl spherical porous polystyrene resin, vinyl phosphoric acid, cuprous bromide, 2,2-bipyridine and N,N-dimethylformamide were mixed in a mass ratio of 50:12:2:5:120 and reacted at 50°C for 10 hours under nitrogen protection. After the reaction was completed, the mixture was filtered, washed and dried to obtain a salt-resistant chelating resin suitable for high-salt wastewater.

[0050] Comparative Example 4: A salt-tolerant chelating resin suitable for high-salinity wastewater: (1) Preparation of chloromethylated spherical porous polystyrene resin: Same as in Example 1; (2) Preparation of salt-tolerant chelating resin suitable for high-salt wastewater: Chloromethyl spherical porous polystyrene resin, glycidyl methacrylate, cuprous bromide, 2,2-bipyridine and N,N-dimethylformamide were mixed in a mass ratio of 50:100:2:5:120 and reacted at 50°C for 10 h under nitrogen protection. After the reaction was completed, the mixture was filtered, washed and dried to obtain the intermediate product. The intermediate product and N-methyl-2-pyrrolidone were mixed at a mass ratio of 1:8:2:4, soaked and swollen for 10 h, and then tetrasodium iminodisuccinate and sodium carbonate were added. The mixture was reacted at 65 °C for 12 h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain a salt-resistant chelating resin suitable for high-salt wastewater.

[0051] Test case The following performance tests were conducted on the salt-resistant chelating resins of Examples 1-3 and Comparative Examples 1-4: (1) Prepare high-content saline: The calcium ion content in the saline is 600 mg / L, the magnesium ion content is 600 mg / L, and the sodium ion content is 50 g / L; (2) Take 10 mL of each of the salt-tolerant chelating resins obtained in Examples 1-3 and Comparative Examples 1-4, fill them into ion exchange columns, add 100 mL of high-content saline solution for adsorption treatment, the flow rate is 2 BV / h, the adsorption time is 8 h, and the adsorption is performed using ICP. The calcium and magnesium contents of high-content brine before and after adsorption treatment were determined by MS method, and the results are shown in Table 1. (3) After adsorption treatment, the calcium-magnesium resin is regenerated using a 5% HCl solution at a flow rate of 2 BV / h for 2 hours; then, adsorption treatment is performed again according to step (2) for a total of 3 adsorption-regeneration cycles. After 3 adsorption-regeneration cycles, step (2) is performed again for adsorption treatment using ICP. The calcium and magnesium contents of high-concentration brine before and after adsorption treatment were determined by MS method, and the results are shown in Table 1.

[0052] Table 1 Test Results

[0053] As can be seen from Table 1, the salt-resistant chelating resins of Examples 1-3 still have excellent adsorption effects on calcium and magnesium ions in high-content salt water, and have excellent recycling performance.

[0054] The chloromethylated spherical porous polystyrene resin in Comparative Example 1 does not contain styrene-phosphate. The salt-resistant chelating resin in Comparative Example 2 uses iminodiacetic acid instead of tetrasodium iminodisuccinate. The salt-resistant chelating resin in Comparative Example 3 is only grafted with vinyl phosphate. The salt-resistant chelating resin in Comparative Example 4 is only grafted with tetrasodium iminodisuccinate. The adsorption effect and recycling performance of calcium and magnesium ions decreased. This indicates that the styrene-phosphate in the chloromethylated spherical porous polystyrene resin, the vinyl phosphate grafted in the salt-resistant chelating resin, and the tetrasodium iminodisuccinate work together to give the chelating resin excellent salt resistance and avoid the influence of sodium ions.

[0055] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A salt-tolerant chelating resin suitable for high-salinity wastewater, characterized in that, The salt-resistant chelating resin is prepared by reacting chloromethylated spherical porous polystyrene resin, functional monomers, and iminodisuccinic acid; the functional monomers are glycidyl methacrylate and vinyl phosphate.

2. The salt-tolerant chelating resin suitable for high-salinity wastewater according to claim 1, characterized in that, The preparation method of the chloromethylated spherical porous polystyrene resin includes the following steps: mixing a dispersant, deionized water and sodium chloride to obtain an aqueous phase; mixing p-chloromethylstyrene, styrene, divinylbenzene, styrene-based phosphoric acid, an initiator and a porogen to obtain an oil phase; adding the aqueous phase to the oil phase to carry out a polymerization reaction; removing the porogen after the polymerization reaction is completed to obtain the chloromethylated spherical porous polystyrene resin.

3. The salt-tolerant chelating resin suitable for high-salinity wastewater according to claim 2, characterized in that, The dispersant is selected from at least one of polyvinyl alcohol, hydroxymethyl cellulose, hydroxypropyl methyl cellulose, and hydroxyethyl cellulose; the initiator is selected from at least one of azobisisobutyronitrile, benzoyl peroxide, azobisisobutyronitrile, and dilauryl peroxide.

4. The salt-tolerant chelating resin suitable for high-salinity wastewater according to claim 3, characterized in that, The pore-forming agent is selected from at least one of gasoline, isobutanol, and toluene.

5. The salt-tolerant chelating resin suitable for high-salinity wastewater according to claim 4, characterized in that, The amounts of each material in the oil phase, by weight, are as follows: 20-30 parts of p-chloromethylstyrene, 10-15 parts of styrene, 15-25 parts of divinylbenzene, 5-10 parts of styrene-based phosphoric acid, 0.5-1 part of initiator, and 40-70 parts of pore-forming agent.

6. The salt-tolerant chelating resin suitable for high-salinity wastewater according to claim 5, characterized in that, By mass, the amounts of each material in the aqueous phase are: 1-2 parts dispersant, 4-6 parts sodium chloride, and 100 parts deionized water.

7. The salt-tolerant chelating resin suitable for high-salinity wastewater according to claim 6, characterized in that, The volume ratio of the oil phase to the water phase is 4-7:

1.

8. The method for preparing the salt-tolerant chelating resin suitable for high-salinity wastewater according to any one of claims 1-7, characterized in that, Includes the following steps: Chloromethyl spherical porous polystyrene resin, functional monomers, cuprous bromide, 2,2-bipyridine and N,N-dimethylformamide were mixed, wherein the functional monomers were glycidyl methacrylate and vinyl phosphoric acid. The reaction was carried out under nitrogen protection. After the reaction was completed, the mixture was filtered, washed and dried to obtain an intermediate product. The intermediate product was mixed with N-methyl-2-pyrrolidone, soaked and swollen, and then tetrasodium iminodisuccinate and sodium carbonate were added. After the reaction was completed, the mixture was filtered, washed, and dried to obtain a salt-resistant chelating resin suitable for high-salt wastewater.

9. The method for preparing a salt-tolerant chelating resin suitable for high-salinity wastewater according to claim 8, characterized in that, The mass ratio of the chloromethyl spherical porous polystyrene resin, vinyl phosphoric acid, glycidyl methacrylate, cuprous bromide, 2,2-bipyridine, and N,N-dimethylformamide is 40-60:70-90:10-15:1-3:3-8:100-120.

10. The method for preparing a salt-tolerant chelating resin suitable for high-salinity wastewater according to claim 8, characterized in that, The mass ratio of the intermediate product, N-methyl-2-pyrrolidone, tetrasodium iminodisuccinate, and sodium carbonate is 1:5-10:2-3:4-5.

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