Method for deeply removing phosphorus-containing organic matters from high-salinity wastewater or feed liquid

Abstract

The invention discloses a method for deeply removing phosphorus-containing organic matters from high-salinity wastewater or feed liquid obtained in a metal extraction process, and belongs to the technical field of organic matter removal. Comprising the following steps: filtering high-salinity wastewater or feed liquid, then entering a regulation and control process, and adding a regulation and control agent to regulate and control the existence form or hydrophilicity of phosphorus-containing organic matters; after regulation and control, entering an oil-water separation process, so that phosphorus-containing organic matters in a non-dissolved state are separated from the wastewater or feed liquid; then entering a primary adsorption phosphorus removal process, wherein non-polar or weak-polar phosphorus-containing organic matters are adsorbed and removed by a non-polar phosphorus removal agent 1; the removed high-salinity wastewater or feed liquid enters a secondary adsorption phosphorus removal process, and residual polar phosphorus-containing organic matters with hydroxyl are adsorbed and removed by using a polar phosphorus removal agent 2; according to the method, the problems that phosphorus-containing organic matters cannot be thoroughly removed and adsorption materials are not thoroughly desorbed in the current adsorption treatment process of high-salinity wastewater or feed liquid are solved by utilizing a strategy of solution regulation and grading adsorption phosphorus removal of the targeted phosphorus removal agent.

Description

Technical Field

[0001] This invention relates to the field of organic matter removal technology, and in particular to a method for deep removal of phosphorus-containing organic matter from high-salt wastewater or feed liquid. Background Technology

[0002] Phosphorus-containing organic compounds can be classified into six categories based on the characteristics of their functional groups: phosphine compounds, phosphonic acids, hydroxyl-containing phospho(phosphonic) esters, non-hydroxyl-containing phospho(phosphonic) esters, phosphoroyl-containing heterophosphine compounds, and thiophosphine compounds. Phosphorus-containing organic compounds can be used as insecticides (such as trichlorfon, dichlorvos, malathion, and phoxim), herbicides (such as glyphosate, trichlorfon, and glufosinate), metal chelating agents (such as aminotrimethylphosphonic acid (ATMP), hydroxyethylidene diphosphonic acid (HEDP), sodium ethylenediaminetetramethylidene phosphonate (EDTMPS), ethylenediaminetetramethylidene phosphonate (EDTMPA), etc.), metal extractants (such as di(2-ethylhexyl) phosphate, 2-ethylhexyl phosphate mono-2-ethylhexyl ester, di(2-trimethylpentyl)phosphonic acid, and tributyl phosphate), antioxidants (such as triphenylphosphonate (TPP), tri(2-hydroxyethyl) phosphate (TEP), and tributylphosphonate (TBP), flame retardants (such as triphenyl phosphate, xylene phosphate, alkyl phosphonates, and aryl phosphonates), and surfactants (such as alkyl polyoxyethylene ether phosphate salts and alkyl phosphate salts). The production and use of phosphorus-containing organic compounds generate large amounts of wastewater or liquids containing these compounds, primarily including pesticide wastewater, metal extraction wastewater or liquids, electrolytes, and surfactant wastewater. Direct discharge of this phosphorus-containing wastewater into the environment causes phosphorus pollution, resulting in irreversible toxicity to aquatic bodies and aquatic plants and animals. Phosphorus-containing organic compounds in metal extraction solutions (such as lithium sulfate, nickel sulfate, cobalt sulfate, and manganese sulfate solutions used in the production of ternary battery precursors) not only cause adverse phenomena such as evaporator foaming during subsequent evaporation and crystallization processes but also affect the safety performance of the final product, the power battery. Therefore, efficient removal of phosphorus-containing organic compounds from wastewater or liquids is essential.

[0003] Methods for removing phosphorus-containing organic matter from wastewater or liquid mainly include chemical oxidation, acid hydrolysis, biodegradation, stripping, extraction, chemical coagulation, membrane separation, and adsorption.

[0004] Advanced oxidation technologies such as ozone catalytic oxidation and Fenton oxidation can degrade phosphorus-containing organic compounds with aromatic hydrocarbon structures into long-chain saturated hydrocarbon structures, but further oxidation and degradation are extremely difficult and require huge amounts of reagents. Ultraviolet photocatalysis technology can completely degrade phosphorus-containing organic compounds into inorganic phosphorus, but its operation and investment costs are high, making industrialization impossible.

[0005] Acidification hydrolysis technology is suitable for treating wastewater with high concentrations of organophosphorus compounds, but it generally only converts them into phosphorus-containing organic intermediates and cannot achieve the purpose of organophosphorus removal. Wastewater with high concentrations of phosphorus-containing organic matter cannot be directly treated by biodegradation processes and requires pretreatment to increase its biodegradability. In addition, wastewater generated from metal extraction processes often has a complex composition, and the metals and salts in the wastewater can cause microbial poisoning, making biodegradation technology difficult to apply.

[0006] Stripping is a process that strips and condenses phosphorus-containing organic compounds for recovery. However, phosphorus-containing organic compounds generally have high boiling points, and the energy required for vaporization is very high. Extraction is a process that utilizes the difference in solubility of phosphorus-containing organic compounds between two phases to separate them from water using a solvent. However, this process introduces another type of organic compound into the wastewater, making the wastewater more complex.

[0007] Coagulation involves adding chemicals to wastewater to disrupt the state of organic matter and remove it. However, this method can only remove undissolved phosphorus-containing organic matter in emulsified or dispersed states, and cannot remove dissolved phosphorus-containing organic matter. It also introduces new impurities into the system. Membrane separation technologies such as ultrafiltration, nanofiltration, and reverse osmosis rely on external pressure and membrane pore size characteristics to separate organic matter from water. However, phosphorus-containing organic matter often has surface activity, easily causing membrane surface fouling, making it impossible to separate using membrane filtration technology.

[0008] Compared to the processes described above, adsorption technology relies on electrostatic attraction, hydrogen bonding, and van der Waals forces between solid-phase adsorbent materials and the adsorbate in solution to adsorb the adsorbate from the solution onto the surface and pores of the adsorbent material, achieving separation of organic matter and solution. Therefore, adsorption technology can simultaneously adsorb suspended, dispersed, emulsified, and dissolved organic matter in wastewater or feed solutions without introducing impurities into the system. Simultaneously, adsorbent materials loaded with phosphorus-containing organic matter can be regenerated using effective solvent desorption, allowing for recycling. Furthermore, the type of adsorbent material can be targeted and adjusted according to the type and characteristics of phosphorus-containing organic matter in the wastewater or feed solution, resulting in high adsorption efficiency. For example, researchers have used activated carbon and polystyrene-divinylbenzene macroporous resins as adsorbent materials to treat extractant wastewater from organophosphate extractants for nickel and cobalt extraction, achieving a phosphorus-containing organic matter removal rate exceeding 90%. Chinese patent CN 110523381B discloses the preparation of a urea-functionalized magnetic adsorbent material, Urea-Fe3O4@LDH, and its application in the adsorption and removal of organophosphorus compounds from water. The magnetic adsorbent material can adsorb and remove more than 90% of triphenyl phosphate and more than 85% of dimethoate from water (organophosphorus concentration below 10 mg / L). Chinese patent CN 116474713A discloses a highly efficient magnetic nano-adsorbent material, its preparation method, and its application. This highly efficient magnetic nano-adsorbent material exhibits good dispersibility and chemical stability, achieving an adsorption and removal rate of over 80% for various organophosphorus pesticides at low doses, short times, and various pH ranges. Chinese patent CN 112495349A discloses a cellulose nanocrystal-supported sodium alginate phosphorus removal agent and its application in enriching organophosphorus compounds in wastewater. The provided alginate-cellulose nanocrystals, when mixed with 50 ml of dyeing and printing wastewater, achieve an equilibrium adsorption capacity of 35.7 mg / g for tris(2-carboxyethyl)phosphine (TCEP), with an enrichment rate exceeding 85%. Chinese patent CN116832791B discloses a magnetic covalent organic framework material with a core-shell structure. This material achieves an adsorption and removal rate of over 90% for pyridafenthion, phorate, phoxim, or pyrimitate in wastewater with an initial organophosphorus concentration of 2 mg / L. This example demonstrates that selecting suitable adsorption materials can achieve highly efficient removal of phosphorus-containing organic matter from wastewater.

[0009] Currently, adsorption technology performs excellently in treating wastewater containing simple phosphorus-containing organic compounds. For example, when using macroporous adsorption resins to treat low-concentration pharmaceutical wastewater, the removal rate of phosphorus-containing organic compounds reaches over 99.5%. However, for high-salt wastewater or feed solutions (salt content ≥2%) containing multiple components such as phosphorus-containing organic compounds and inorganic salts, especially high-salt wastewater or feed solutions generated during metal extraction processes, the application of adsorption technology to remove phosphorus-containing organic compounds faces several challenges. First, it is difficult to completely remove phosphorus-containing organic compounds; the concentration of organic phosphorus in the wastewater or feed solution still exceeds 1 mg / L after adsorption treatment. For example, in the aforementioned case of using polystyrene-divinylbenzene framework macroporous resin to treat extractant wastewater from nickel and cobalt extracted with organophosphate extractants, the removal rate of phosphorus-containing organic compounds in the extraction wastewater was only slightly over 90%, failing to achieve complete removal. This may be because there is an interaction between the inorganic components in the wastewater or feed solution and the phosphorus-containing organic compounds, increasing the hydrophilicity of the phosphorus-containing organic compounds. Second, the reusability of adsorption materials continuously declines. For example, a company used a polystyrene-divinylbenzene framework adsorption resin to adsorb and remove phosphorus-containing organic matter from ammonium sulfate wastewater (ammonium sulfate concentration ≥5%) generated during the nickel-cobalt extraction process. After the adsorption resin was recycled 15 times, the adsorption capacity decreased by 30%. This may be because various components in the wastewater or feed liquid are simultaneously adsorbed, and the inorganic or organic components that are not desorbed continuously accumulate inside the adsorption material, occupying adsorption sites.

[0010] To achieve efficient removal of phosphorus-containing organic matter from high-salt wastewater or feed solutions and ensure the reusability of adsorption materials, reducing the hydrophilicity of phosphorus-containing organic matter in the wastewater or feed solution and improving the adsorption selectivity of the adsorption materials are feasible strategies. Summary of the Invention

[0011] To achieve efficient separation of phosphorus-containing organic compounds from high-salinity wastewater or feed solutions, the adsorption force of the adsorbent material for phosphorus-containing organic compounds should be greater than the interaction force between phosphorus-containing organic compounds and water, allowing the phosphorus-containing organic compounds to overcome the binding force of water and achieve phase migration. Furthermore, the adsorbent material should possess a suitable pore structure, enabling phosphorus-containing organic compounds that have migrated to the surface of the adsorbent material to enter the interior of the pores. For phosphorus-containing organic compounds, a relatively small interaction force with water lowers the energy barrier for phase migration. Additionally, a suitable spatial structure size for phosphorus-containing organic compounds also reduces the difficulty of their entry into the pores of the adsorbent material. Therefore, to improve the adsorption efficiency of phosphorus-containing organic compounds in high-salinity wastewater or feed solutions, controlling the structural morphology of phosphorus-containing organic compounds, reducing the interaction force between phosphorus-containing organic compounds and water, and increasing the adsorption force of the adsorbent material for phosphorus-containing organic compounds are effective strategies.

[0012] In order to achieve deep removal of phosphorus-containing organic matter from high-salt wastewater or feed liquid, the present invention provides a method for deep removal of phosphorus-containing organic matter from high-salt wastewater or feed liquid.

[0013] To achieve the above-mentioned technical objectives, the technical solution of the present invention is as follows: A method for deep removal of phosphorus-containing organic matter from high-salinity wastewater or liquid feed includes the following steps: (1): After high-salt wastewater or liquid is precisely filtered, it enters the conditioning process. A conditioning agent is added to regulate the form or hydrophilicity of phosphorus-containing organic matter. The working mechanism of the conditioning agent is to directly change the structural form of phosphorus-containing organic matter or reduce the interaction force between phosphorus-containing organic matter and water through its own hydration and electrostatic shielding. (2): After regulation, the wastewater or liquid enters the oil-water separation process, so that the non-dissolved phosphorus-containing organic matter is separated from the wastewater or liquid; (3): The wastewater or liquid after removing non-dissolved organic matter enters the primary adsorption phosphorus removal process, where non-polar or weakly polar phosphorus-containing organic matter is adsorbed and removed by non-polar phosphorus removal agent 1. (4): The high-salt wastewater or liquid after the removal of non-polar and weakly polar phosphorus-containing organic matter enters the secondary adsorption phosphorus removal process, and the residual polar phosphorus-containing organic matter with hydroxyl groups is adsorbed and removed by polar phosphorus removal agent 2, which has both electrostatic shielding and adsorption functions. (5): After removing phosphorus-containing organic matter, the high-salt wastewater or feed liquid is adjusted and then enters the subsequent valuable component recovery process. The recovered valuable components are used to prepare products or recycled as regulators.

[0014] The concentration of organic phosphorus in the high-salt wastewater or feed liquid is 1-100 mg / L, and the phosphorus-containing organic matter is an organophosphorus oxide compound, including organophosphonic acid, acidic phosphonate, neutral phosphonate and their hydrolysis or degradation products.

[0015] Wherein, the salt concentration in the high-salt wastewater or feed liquid is >2%, and the inorganic cations include, but are not limited to, alkali metal ions, alkaline earth metal ions, ammonium ions, transition metal ions and rare earth metal ions; the anions include, but are not limited to, halogen anions, oxyacid anions, thiocyanate ions and cyanide ions.

[0016] The regulator component is consistent with or corresponds to the main inorganic salt component in the high-salt wastewater or feed solution; the regulator dosage is 0.1–2.0 mol / L, the stirring time is 40–60 min, and the pH of the solution after regulation is <7. The regulator's regulation principle is to directly change the structural morphology of phosphorus-containing organic matter in the wastewater or feed solution or to reduce the hydrophilicity of phosphorus-containing organic matter through its own hydration and electrostatic shielding effects.

[0017] The phosphorus removal agent 1 is a desorbable and regenerable nonpolar material that adsorbs nonpolar or weakly polar phosphorus-containing organic matter through hydrophobic interactions or van der Waals forces. Its framework structure is polystyrene-divinylbenzene, with a crosslinking degree >75%, an average pore size of 5–7 nm, and a specific surface area of ​​600–900 m². 2 / g. The phosphorus removal agent 1 is prepared by free radical suspension polymerization of styrene as monomer, divinylbenzene as crosslinking agent, xylene as porogen, and benzoyl peroxide as initiator, followed by post-crosslinking under the action of FeCl2 catalyst; The phosphorus removal agent 1 adsorbs non-polar or weakly polar phosphorus-containing organic matter, and the influent flow rate for phosphorus removal is 1-5 BV / h. The phosphorus removal agent 1 is desorbed and regenerated using organic solvents such as methanol, ethanol and acetone, with a desorption rate greater than 99.5%.

[0018] The phosphorus removal agent 2 is a desorbable and regenerable polar adsorbent material with dual functions of electrostatic shielding and adsorption. The functional groups loaded in the phosphorus removal agent 2 can shield the charge carried by hydroxyl-containing polar phosphorus-containing organic compounds through electrostatic shielding, reducing the interaction force between the polar phosphorus-containing organic compounds and water. Simultaneously, it can directly associate with hydroxyl-containing polar phosphorus-containing organic compounds via hydrogen bonds, adsorbing and separating the polar phosphorus-containing organic compounds from the solution. The framework structure of the phosphorus removal agent 2 includes, but is not limited to, polystyrene-type and acrylate-type, with an effective functional group content of 10%–40%, an average pore size of 4–10 nm, and a specific surface area of ​​100–600 m². 2 / g; The supported functional groups include, but are not limited to, carbonyl (-C=O), ether (-O-), nitro (-NO2), fluorine (-F), thiocyanate (-SCN) and cyano (-CN).

[0019] The preparation process of the phosphorus removal agent 2 includes three steps: (1) The skeleton monomer and crosslinking agent are first subjected to free radical suspension polymerization at 80℃~90℃ for 8h~10h to obtain a copolymer; then, it is swollen with dichloroethane, heated to 80℃~90℃ under the action of FeCl2 catalyst, kept at the temperature for 8h~12h, and then crosslinked to obtain an ultra-high crosslinked adsorption material; (2) Chloromethylated polystyrene microspheres are reacted with diethylenetriamine at 85℃~95℃ for 12h~15h to generate polystyrene-diethylenetriamine polymer; then, the polystyrene-diethylenetriamine polymer is reacted with glycidol at 105℃~110℃ for 18h~2h. After 4 hours, polystyrene adsorbent material containing a multi-hydroxyl structure was obtained; finally, the compound containing the target functional group was reacted with the polystyrene adsorbent material containing the multi-hydroxyl structure to obtain a polystyrene skeleton adsorbent material containing the target functional group; (3) Styrene and crosslinking agent divinylbenzene first undergo a polymerization reaction at 85℃~90℃ under the action of an initiator to form linear polystyrene, then swelled with dichloroethane, and then crosslinked at 80℃~90℃ under the action of FeCl2 catalyst to obtain ultra-high crosslinked polystyrene resin, and finally reacted with nitrifying agent (a mixture of nitric acid and sulfuric acid) to generate polystyrene resin containing nitro (-NO2).

[0020] The phosphorus removal agent 2 adsorbs polar phosphorus-containing organic matter with hydroxyl groups but does not adsorb inorganic ions; the influent flow rate of the secondary adsorption phosphorus removal process is 1-2 BV / h, and the total phosphorus in the adsorbed effluent is <0.2 mg / L; the phosphorus removal agent 2 is desorbed and regenerated using sodium hydroxide, and the desorption rate is greater than 99.5%.

[0021] In this process, phosphorus removal agent 1 is desorbed and regenerated using an organic solvent after adsorption and penetration, wherein the organic solvent is methanol, ethanol or acetone; phosphorus removal agent 2 is desorbed and regenerated using sodium hydroxide after adsorption and penetration.

[0022] Compared with existing technologies, this technical solution has the following technical effects: (1) Before adsorption and phosphorus removal, add regulators to high-salt wastewater or feed liquid to transform the structural form of phosphorus-containing organic matter into a form that is conducive to adsorption, or use the hydration or electrostatic shielding effect of regulators to reduce the hydrophilicity of phosphorus-containing organic matter in solution and reduce the load of subsequent adsorption and phosphorus removal.

[0023] (2) Using non-polar phosphorus removal agent 1 for primary adsorption phosphorus removal, selectively adsorbing and removing non-polar or weakly polar phosphorus-containing organic matter in the solution, realizing graded treatment of different polar organic matter, so that phosphorus removal agent 1 maintains a desorption efficiency of more than 99.5%. (3) Polar phosphorus removal agent 2, which has both electrostatic shielding and adsorption functions, is used to target and remove residual hydroxyl-containing polar phosphorus-containing organic matter in the solution, so that the total phosphorus in the adsorbed water is less than 0.2 mg / L and the desorption rate of phosphorus removal agent 2 exceeds 99.5%.

[0024] (4) This technical solution utilizes the strategy of solution regulation and targeted phosphorus removal agent staged adsorption to remove phosphorus, which solves the current problem that phosphorus-containing organic matter cannot be completely removed and adsorption materials are not completely desorbed during the adsorption treatment of high-salt wastewater or liquid. Attached Figure Description

[0025] Figure 1 This is a schematic flowchart of a reagent and method for extracting phosphorus-containing organic matter from high-salt wastewater or liquid according to the present invention. Detailed Implementation

[0026] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0027] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance, quantity, or position.

[0028] In the following embodiments, the phosphorus removal agent 1 is made of styrene as monomer, divinylbenzene as crosslinking agent, xylene as porogen, and benzoyl peroxide as initiator, and is subjected to free radical suspension polymerization at a mass ratio of 100:(30-42):(30-50):0.92. Then, it is swollen with dichloroethane, and 16-20 g / L of FeCl2 catalyst is added to the mixed system. The temperature is raised to 80℃~90℃ and kept at that temperature for 8h-12h. The crosslinking reaction is then carried out to obtain an ultra-high crosslinked adsorption material.

[0029] The preparation process of the phosphorus removal agent 2 includes three steps: (1) The skeleton monomer and crosslinking agent are first subjected to free radical suspension polymerization at 80℃~90℃ for 8h~10h to obtain a copolymer; then, the copolymer is swollen with dichloroethane, and 16-20g / L of catalyst FeCl2 is added to the mixed system. The temperature is raised to 80℃~90℃ and kept for 8h-12h. Then, the crosslinking reaction is carried out to obtain an ultra-high crosslinking adsorption material; (2) Chloromethylated polystyrene microspheres and diethylenetriamine are reacted at 85℃~95℃ for 12h~15h at a mass ratio of 100:(22-25) to generate a polystyrene-diethylenetriamine polymer; then, the polystyrene-diethylenetriamine polymer is reacted with glycidol at a mass ratio of 100:(12-15). The reaction was carried out at 105℃~110℃ for 18h~24h to obtain polystyrene adsorbent material containing a multi-hydroxyl structure; finally, the compound containing the target functional group was reacted with the polystyrene adsorbent material containing the multi-hydroxyl structure to obtain a polystyrene skeleton adsorbent material containing the target functional group; (3) Styrene and crosslinking agent divinylbenzene first under the action of an initiator at 85℃~90℃ to form linear polystyrene, then swollen with dichloroethane, and under the action of FeCl2 catalyst at 80℃~90℃ to carry out post-crosslinking to obtain ultra-high crosslinked polystyrene resin, and finally reacted with nitrifying agent (a mixture of nitric acid and sulfuric acid) to generate polystyrene resin containing nitro (-NO2). Example 1

[0030] The extraction wastewater obtained by a metallurgical enterprise from cobalt extraction has a pH of 5-7, with ammonium sulfate as the main salt at a concentration of 10%. The phosphorus-containing organic components are complexes of the extractant di(2-ethylhexyl) phosphate, 2-ethylhexyl phosphate mono-2-ethylhexyl ester, ammonium ions, and cobalt ions, with a total phosphorus content of 100 mg / L.

[0031] Step (1): After filtration, the cobalt extraction wastewater enters the conditioning process. 0.1 mol / L sulfuric acid is added and stirred for 40 minutes to adjust the pH of the solution to <1.0. All complexed phosphorus-containing organic compounds in the wastewater are converted to free states. Simultaneously, both types of phosphorus-containing organic molecules carry a positive charge on their surface, resulting in electrostatic attraction with water. Sulfate ions utilize hydrogen bonds with the phosphorus-containing organic compounds to shield the positive charge carried by the phosphorus-containing organic compounds, reducing their hydrophilicity. Step (2): Adjust the effluent to enter the oil-water separator, let it stand for 2 hours to separate the phases, and the total phosphorus content in the water phase obtained from the oil-water separation is 47.5 mg / L; Step (3): After oil-water separation, the aqueous phase enters the primary adsorption phosphorus removal process, where non-polar phosphorus-containing organic matter (mainly dispersed phosphate esters) in the wastewater is adsorbed and removed using non-polar phosphorus removal agent 1. The influent flow rate is 1 BV / h, and the total phosphorus in the effluent is 1.5 mg / L. The phosphorus removal agent 1 has a polystyrene-divinylbenzene framework structure with a crosslinking degree >75%, an average pore size of 5.6 nm, and a specific surface area of ​​900 m². 2 / g. Preparation process: Styrene as monomer, divinylbenzene as crosslinking agent, xylene as porogen, and benzoyl peroxide as initiator are subjected to free radical suspension polymerization at 80℃ in a mass ratio of 100:40:50:0.92 to form a copolymer; then, the copolymer is mixed with dichloroethane at a mass ratio of 15:100 and swelled for 8 hours; finally, 20 g / L FeCl2 catalyst is added to the mixture, the temperature is raised to 80℃, and held for 12 hours to complete crosslinking. After the phosphorus removal agent 1 is adsorbed and penetrated, it is regenerated by desorption with ethanol, and the desorption rate is >99.5%.

[0032] Step (4) The effluent from the primary adsorption process enters the secondary adsorption phosphorus removal process, where the residual polar phosphorus-containing organic matter (mainly organic acids and fatty alcohols generated from the hydrolysis of phosphate esters) in the wastewater is adsorbed and removed using polar phosphorus removal agent 2. The influent flow rate is 2 BV / h, and the total phosphorus in the adsorbed effluent is 0.1 mg / L. Phosphorus removal agent 2 is a polymethyl acrylate framework adsorption resin with dual functions of electrostatic shielding and adsorption. It carries carbonyl (-C=O) and ether (-O-) functional groups, with an effective functional group content of 10%, an average pore size of 4 nm, and a specific surface area of ​​600 m². 2 / g. The functional groups supported on phosphorus remover 2 can shield the charge carried by hydroxyl-containing polar phosphorus-containing organic compounds through hydrogen bonding, reducing the interaction force between polar phosphorus-containing organic compounds and water. Simultaneously, it can also directly associate with hydroxyl-containing polar phosphorus-containing organic compounds via hydrogen bonding, adsorbing and separating the polar phosphorus-containing organic compounds from the solution. The preparation process of phosphorus remover 2 is as follows: Methyl acrylate monomer and N,N'-methylenebisacrylamide are mixed at a mass ratio of 100:15, firstly, free radical suspension polymerization is carried out at 90℃ to obtain a copolymer. Then, the copolymer and dichloroethane are mixed at a mass ratio of 15:100 and swelled for 8 hours. Finally, 20 g / L of catalyst FeCl2 is added to the mixture, the temperature is raised to 90℃, and held for 8 hours to complete cross-linking and obtain an ultra-highly cross-linked adsorbent material.

[0033] Step (5): After removing phosphorus-containing organic matter, the high-salt wastewater is adjusted to neutral by adding ammonia water and then evaporated and crystallized to produce ammonium sulfate. Example 2

[0034] A metallurgical enterprise extracts sodium chloride wastewater from cobalt. The solution has a pH of 5.5, sodium chloride is the main salt with a concentration of 2%, and the phosphorus-containing organic component is a complex of 2-ethylhexyl phosphate mono-2-ethylhexyl ester and cobalt ions. The total phosphorus content is 85 mg / L.

[0035] Step (1): After filtration, the sodium chloride wastewater enters the conditioning process. 0.1 mol / L hydrochloric acid is added and stirred for 60 min to adjust the pH of the solution to < 1.0. All the complexed phosphorus-containing organic matter in the wastewater is converted into free 2-ethylhexyl phosphate mono-2-ethylhexyl ester molecules. Simultaneously, the added chloride ions reduce the hydrophilicity of the phosphorus-containing organic matter through their own hydration. Step (2): Adjust the effluent to enter the oil-water separator, let it stand for 2 hours to separate the phases, and the total phosphorus content in the aqueous phase obtained from the oil-water separation is 23.5 mg / L; Step (3): After oil-water separation, the aqueous phase enters the primary adsorption phosphorus removal process, where non-polar phosphorus-containing organic matter (mainly dispersed phosphate esters) in the wastewater is adsorbed and removed using non-polar phosphorus removal agent 1. The influent flow rate is 5 BV / h, and the total phosphorus in the effluent is 3.5 mg / L. The phosphorus removal agent 1 has a polystyrene-divinylbenzene framework structure with a crosslinking degree >75%, an average pore size of 7 nm, and a specific surface area of ​​600 m². 2 / g. Preparation process: Styrene as monomer, divinylbenzene as crosslinking agent, xylene as porogen, and benzoyl peroxide as initiator were subjected to free radical suspension polymerization at 90℃ in a mass ratio of 100:30:40:0.92. Then, the copolymer and dichloroethane were mixed at a mass ratio of 15:100 and allowed to swell for 8 hours. Finally, 16 g / L of FeCl2 catalyst was added to the mixture, and the temperature was raised to 90℃ and held for 8 hours to complete crosslinking. After adsorption and penetration, the phosphorus removal agent 1 was regenerated by desorption with ethanol, achieving a desorption rate >99.5%.

[0036] Step (4) The effluent from the primary adsorption stage enters the secondary adsorption phosphorus removal process, where the residual polar phosphorus-containing organic matter (mainly organic acids and fatty alcohols generated from the hydrolysis of phosphate esters) in the wastewater is adsorbed and removed using polar phosphorus removal agent 2. The influent flow rate is 1 BV / h, and the total phosphorus in the adsorbed effluent is 0.12 mg / L. Phosphorus removal agent 2 is a polystyrene framework adsorption resin with dual functions of electrostatic shielding and adsorption. It carries nitro (-NO2) functional groups, has an effective functional group content of 15%, an average pore size of 6 nm, and a specific surface area of ​​500 m². 2 / g. The functional groups loaded with phosphorus removal agent 2 can shield the charge carried by polar phosphorus-containing organic compounds with hydroxyl groups through hydrogen bonding, reducing the interaction force between polar phosphorus-containing organic compounds and water. At the same time, it can also directly associate with polar phosphorus-containing organic compounds with hydroxyl groups through hydrogen bonding, adsorbing and separating polar phosphorus-containing organic compounds from the solution. The preparation process of phosphorus removal agent 2 is as follows: styrene monomer, divinylbenzene crosslinking agent, toluene porogen, and benzoyl peroxide initiator are polymerized at 90℃ in a mass ratio of 100:20:30:0.92 to form linear polystyrene; then, the copolymer and dichloroethane are mixed at a mass ratio of 15:100 and swelled for 8 hours; 20 g / L FeCl2 catalyst is added to the mixture, the temperature is raised to 80℃ and held for 12 hours to complete crosslinking and obtain ultra-high crosslinked polystyrene resin; finally, the ultra-high crosslinked polystyrene resin is reacted with a nitrating agent (a mixture of nitric acid and sulfuric acid) at a mass ratio of 100:30 to generate polystyrene resin containing nitro groups (-NO2).

[0037] Step (5): After removing phosphorus-containing organic matter, add sodium hydroxide to the high-salt wastewater to adjust it to neutral, then evaporate and crystallize to produce sodium chloride. Example 3

[0038] A lithium-rich solution obtained by a salt lake enterprise from lithium extraction has a pH of 2.2, with lithium chloride as the main salt at a concentration of 3.5%, and the phosphorus-containing organic components being tributyl phosphate and its derivatives, with a total phosphorus content of 1 mg / L.

[0039] Step (1): After the lithium chloride solution is filtered, it enters the conditioning process. 2 mol / L lithium chloride is added and stirred for 40 min. The added lithium chloride reduces the hydrophilicity of phosphorus-containing organic matter through its own hydration. Step (2): Adjust the effluent to enter the oil-water separator, let it stand for 2 hours to separate the phases, and the total phosphorus content in the water phase obtained from the oil-water separation is 0.85 mg / L; Step (3): After oil-water separation, the aqueous phase enters the primary adsorption phosphorus removal process, where non-polar phosphorus-containing organic matter (mainly dispersed phosphate esters) in the feed solution is adsorbed and removed using non-polar phosphorus removal agent 1. The influent flow rate is 2 BV / h, and the total phosphorus in the adsorbed effluent is 0.42 mg / L. The phosphorus removal agent 1 has a polystyrene-divinylbenzene skeleton structure with a crosslinking degree >75%, an average pore size of 7 nm, and a specific surface area of ​​740 m². 2 / g. Preparation process: Styrene as monomer, divinylbenzene as crosslinking agent, xylene as porogen, and benzoyl peroxide as initiator are subjected to free radical suspension polymerization at 85℃ in a mass ratio of 100:35:40:0.92 to form a copolymer; then, the copolymer is mixed with dichloroethane at a mass ratio of 15:100 and swelled for 8 hours; finally, 18 g / L FeCl2 catalyst is added to the mixture, the temperature is raised to 85℃ and held for 10 hours, and crosslinking is completed. After the phosphorus removal agent 1 is adsorbed and penetrated, it is regenerated by desorption with ethanol, and the desorption rate is >99.5%.

[0040] Step (4) The effluent from the primary adsorption process enters the secondary adsorption phosphorus removal process, where the residual polar phosphorus-containing organic matter (mainly organic acids and fatty alcohols generated from the hydrolysis of phosphate esters) in the feed solution is adsorbed and removed using polar phosphorus removal agent 2. The influent flow rate is 1 BV / h, and the total phosphorus in the adsorbed effluent is 0.16 mg / L. Phosphorus removal agent 2 is a polystyrene framework adsorption resin with dual functions of electrostatic shielding and adsorption. It carries fluorine (-F) functional groups, has an effective functional group content of 40%, an average pore size of 10 nm, and a specific surface area of ​​100 m². 2 / g. The functional groups loaded in phosphorus removal agent 2 can shield the charge carried by polar phosphorus-containing organic compounds with hydroxyl groups through hydrogen bonding, reducing the interaction force between polar phosphorus-containing organic compounds and water. Simultaneously, it can also directly associate with polar phosphorus-containing organic compounds with hydroxyl groups through hydrogen bonding, adsorbing and separating the polar phosphorus-containing organic compounds from the solution. The preparation process of phosphorus removal agent 2 is as follows: chloromethylated polystyrene microspheres are reacted with diethylenetriamine at a mass ratio of 100:22 at 85℃ for 15 h to generate a polystyrene-diethylenetriamine polymer. Next, the polystyrene-diethylenetriamine polymer is reacted with glycidol at a mass ratio of 100:12 at 105℃ for 24 h to obtain a polystyrene adsorbent material containing a multi-hydroxyl structure. Finally, potassium fluoride is reacted with the polystyrene adsorbent material containing the multi-hydroxyl structure at a mass ratio of 14.5:100 to obtain a polystyrene framework adsorbent material containing fluorine groups (-F).

[0041] Step (5): After removing phosphorus-containing organic matter, sodium carbonate is added to the feed solution to precipitate lithium, and lithium carbonate product is obtained. Example 4

[0042] A metallurgical company extracted magnesium to obtain a magnesium sulfate solution with a pH of 2.1. Magnesium sulfate was the main salt with a concentration of 12%. The phosphorus-containing organic components were di(2-ethylhexyl) phosphate, 2-ethylhexyl phosphate mono-2-ethylhexyl ester, and their hydrolyzed derivatives, with a total phosphorus content of 34.5 mg / L.

[0043] Step (1): After the magnesium sulfate solution is filtered, it enters the conditioning process. 1 mol / L magnesium sulfate is added and stirred for 50 min. Magnesium sulfate reduces the hydrophilicity of phosphorus-containing organic matter by its own hydration. Step (2): Adjust the effluent to enter the oil-water separator, let it stand for 2 hours to separate the phases, and the total phosphorus content in the water phase obtained from the oil-water separation is 17.4 mg / L; Step (3): After oil-water separation, the aqueous phase enters the primary adsorption phosphorus removal process, where non-polar phosphorus-containing organic matter (mainly dispersed phosphate esters) in the feed solution is adsorbed and removed using non-polar phosphorus removal agent 1. The influent flow rate is 2 BV / h, and the total phosphorus in the adsorbed effluent is 4.3 mg / L. The phosphorus removal agent 1 has a polystyrene-divinylbenzene framework structure with a crosslinking degree >75%, an average pore size of 7.5 nm, and a specific surface area of ​​680 m². 2 / g. Preparation process: Styrene as monomer, divinylbenzene as crosslinking agent, xylene as porogen, and benzoyl peroxide as initiator are subjected to free radical suspension polymerization at 80℃ in a mass ratio of 100:32:40:0.92 to form a copolymer; then, the copolymer is mixed with dichloroethane at a mass ratio of 15:100 and swelled for 8 hours; finally, 20 g / L FeCl2 catalyst is added to the mixture, the temperature is raised to 90℃ and held for 9 hours, and crosslinking is completed. After the phosphorus removal agent 1 is adsorbed and penetrated, it is regenerated by desorption with ethanol, and the desorption rate is >99.5%.

[0044] Step (4) The effluent from the primary adsorption process enters the secondary adsorption phosphorus removal process, where the residual polar phosphorus-containing organic matter (mainly organic acids and fatty alcohols generated from the hydrolysis of phosphate esters) in the feed solution is adsorbed and removed using polar phosphorus removal agent 2. The influent flow rate is 1 BV / h, and the total phosphorus in the adsorbed effluent is 0.09 mg / L. Phosphorus removal agent 2 is a polystyrene skeleton resin with both electrostatic shielding and adsorption functions. It carries thiocyanate groups (-SCN) as its functional group, has an effective functional group content of 30%, an average pore size of 8 nm, and a specific surface area of ​​400 m². 2 / g. The functional groups loaded in phosphorus removal agent 2 can shield the charge carried by polar phosphorus-containing organic compounds with hydroxyl groups through hydrogen bonding, reducing the interaction force between polar phosphorus-containing organic compounds and water. Simultaneously, it can also directly associate with polar phosphorus-containing organic compounds with hydroxyl groups via hydrogen bonding, adsorbing and separating the polar phosphorus-containing organic compounds from the solution. The preparation process of phosphorus removal agent 2 is as follows: chloromethylated polystyrene microspheres are reacted with diethylenetriamine at a mass ratio of 100:25 at 95℃ for 12 h to generate a polystyrene-diethylenetriamine polymer. Next, the polystyrene-diethylenetriamine polymer is reacted with glycidol at a mass ratio of 100:15 at 110℃ for 18 h to obtain a polystyrene adsorbent material containing a multi-hydroxyl structure. Finally, potassium thiocyanate is reacted with the polystyrene adsorbent material containing the multi-hydroxyl structure at a mass ratio of 16:100 to obtain a polystyrene framework adsorbent material containing thiocyanate groups (-SCN).

[0045] Step (5): After removing phosphorus-containing organic matter, the magnesium sulfate solution is evaporated and crystallized to produce magnesium sulfate. Part of the magnesium sulfate is returned to the control process as a control agent. Example 5

[0046] A rare earth company extracted cerium nitrate solution from praseodymium and neodymium. The solution had a pH of 1.3, with cerium nitrate as the main salt at a concentration of 5.3%. The phosphorus-containing organic components were 2-ethylhexyl phosphate mono-2-ethylhexyl ester and its derivatives, with a total phosphorus content of 12.3 mg / L.

[0047] Step (1): After filtration, the cerium nitrate solution enters the conditioning process. 0.5 mol / L cerium nitrate is added and stirred for 60 min. The added cerium nitrate reduces the hydrophilicity of phosphorus-containing organic matter through its own hydration. Step (2): Adjust the effluent to enter the oil-water separator, let it stand for 2 hours to separate the phases, and the total phosphorus content in the water phase obtained from the oil-water separation is 8.3 mg / L; Step (3): After oil-water separation, the aqueous phase enters the primary adsorption phosphorus removal process, where non-polar phosphorus-containing organic matter (mainly dispersed phosphate esters) in the feed solution is adsorbed and removed using non-polar phosphorus removal agent 1. The influent flow rate is 3 BV / h, and the total phosphorus in the adsorbed effluent is 3.7 mg / L. The phosphorus removal agent 1 has a polystyrene-divinylbenzene framework structure with a crosslinking degree >75%, an average pore size of 6.5 nm, and a specific surface area of ​​810 m². 2 / g. Preparation process: Styrene as monomer, divinylbenzene as crosslinking agent, xylene as porogen, and benzoyl peroxide as initiator are used in a free radical suspension polymerization at 85℃ in a mass ratio of 100:40:35:0.92 to form a copolymer. Then, the copolymer is mixed with dichloroethane at a mass ratio of 15:100 and allowed to swell for 8 hours. Finally, 20 g / L of FeCl2 catalyst is added to the mixture, and the temperature is raised to 85℃ and held for 11 hours to complete crosslinking. After adsorption and penetration, phosphorus removal agent 1 is regenerated by desorption with ethanol, achieving a desorption rate >99.5%.

[0048] Step (4) The effluent from the primary adsorption process enters the secondary adsorption phosphorus removal process, where the residual polar phosphorus-containing organic matter (mainly organic acids and fatty alcohols generated from the hydrolysis of phosphate esters) in the feed solution is adsorbed and removed using polar phosphorus removal agent 2. The influent flow rate is 2 BV / h, and the total phosphorus in the adsorbed effluent is 0.11 mg / L. Phosphorus removal agent 2 is a polystyrene framework adsorption resin with both electrostatic shielding and adsorption functions. It carries cyano (-CN) functional groups, has an effective functional group content of 20%, an average pore size of 7.4 nm, and a specific surface area of ​​510 m². 2 / g. The functional groups loaded in phosphorus removal agent 2 can shield the charge carried by polar phosphorus-containing organic compounds with hydroxyl groups through hydrogen bonding, reducing the interaction force between polar phosphorus-containing organic compounds and water. Simultaneously, it can also directly associate with polar phosphorus-containing organic compounds with hydroxyl groups via hydrogen bonding, adsorbing and separating the polar phosphorus-containing organic compounds from the solution. The preparation process of phosphorus removal agent 2 is as follows: chloromethylated polystyrene microspheres are reacted with diethylenetriamine at a mass ratio of 100:24 at 90℃ for 14 h to generate a polystyrene-diethylenetriamine polymer. Next, the polystyrene-diethylenetriamine polymer is reacted with glycidol at a mass ratio of 100:13 at 108℃ for 20 h to obtain a polystyrene adsorbent material containing a multi-hydroxyl structure. Finally, potassium cyanide is reacted with the polystyrene adsorbent material containing the multi-hydroxyl structure at a mass ratio of 15:100 to obtain a polystyrene framework adsorbent material containing cyano groups (-CN).

[0049] Step (5): After removing phosphorus-containing organic matter, sodium carbonate is added to the liquid to precipitate cerium, and cerium carbonate product is obtained. Example 6

[0050] A nickel-cobalt company extracted cobalt and obtained cobalt sulfate solution. The solution pH was 2.4, cobalt sulfate was the main salt with a concentration of 12%, and the phosphorus-containing organic components were 2-ethylhexyl phosphate mono-2-ethylhexyl ester and its derivatives. The total phosphorus content was 14.3 mg / L.

[0051] Step (1): After the cobalt sulfate solution is filtered, it enters the conditioning process. 1 mol / L cobalt sulfate is added and stirred for 60 min. The added cobalt sulfate reduces the hydrophilicity of phosphorus-containing organic matter through its own hydration. Step (2): Adjust the effluent to enter the oil-water separator, let it stand for 2 hours to separate the phases, and the total phosphorus content in the water phase obtained from the oil-water separation is 7.6 mg / L; Step (3): After oil-water separation, the aqueous phase enters the primary adsorption phosphorus removal process, where non-polar phosphorus-containing organic matter (mainly dispersed phosphate esters) in the feed solution is adsorbed and removed using non-polar phosphorus removal agent 1. The influent flow rate is 3 BV / h, and the total phosphorus in the adsorbed effluent is 3.6 mg / L. The phosphorus removal agent 1 has a polystyrene-divinylbenzene framework structure with a crosslinking degree >75%, an average pore size of 5 nm, and a specific surface area of ​​830 m².2 / g. Preparation process: Styrene as monomer, divinylbenzene as crosslinking agent, xylene as porogen, and benzoyl peroxide as initiator are subjected to free radical suspension polymerization at 90℃ in a mass ratio of 100:42:30:0.92 to form a copolymer; then, the copolymer is mixed with dichloroethane at a mass ratio of 15:100 and swelled for 8 hours; finally, 20 g / L FeCl2 catalyst is added to the mixture, the temperature is raised to 80℃ and held for 12 hours, and crosslinking is completed. After the phosphorus removal agent 1 is adsorbed and penetrated, it is regenerated by desorption with ethanol, and the desorption rate is >99.5%.

[0052] Step (4) The effluent from the primary adsorption process enters the secondary adsorption phosphorus removal process, where the residual polar phosphorus-containing organic matter (mainly organic acids and fatty alcohols generated from the hydrolysis of phosphate esters) in the feed solution is adsorbed and removed using polar phosphorus removal agent 2. The influent flow rate is 1 BV / h, and the total phosphorus in the adsorbed effluent is 0.11 mg / L. Phosphorus removal agent 2 is a polymethyl acrylate framework adsorption resin with dual functions of electrostatic shielding and adsorption. It carries carbonyl (-C=O) and ether (-O-) functional groups, with an effective functional group content of 10%, an average pore size of 4 nm, and a specific surface area of ​​600 m². 2 / g. The functional groups supported on phosphorus remover 2 can shield the charge carried by polar phosphorus-containing organic compounds with hydroxyl groups through hydrogen bonding, reducing the interaction force between polar phosphorus-containing organic compounds and water. Simultaneously, it can also directly associate with polar phosphorus-containing organic compounds with hydroxyl groups through hydrogen bonding, adsorbing and separating the polar phosphorus-containing organic compounds from the solution. The preparation process of phosphorus remover 2 is as follows: methyl acrylate monomer and N,N'-methylenebisacrylamide are first subjected to free radical suspension polymerization at 80℃ to obtain a copolymer; then, the copolymer and dichloroethane are mixed at a mass ratio of 15:100 and swelled for 8 hours; finally, 16 g / L of catalyst FeCl2 is added to the mixture, the temperature is raised to 90℃, and held for 8 hours to carry out a post-crosslinking reaction to obtain an ultra-highly crosslinked adsorbent material.

[0053] Step (5): The cobalt sulfate solution after removing phosphorus-containing organic matter is added to the evaporation crystallization process to produce cobalt sulfate product.

[0054] Although embodiments of the present invention have been shown and described above, it is understood that these embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and alterations to the above embodiments within the scope of the present invention without departing from its principles and spirit. The scope of protection of the present invention is defined by the claims and their equivalents.

Claims

1. A method for deep removal of phosphorus-containing organic matter from high-salinity wastewater or liquid feed, characterized in that, Includes the following steps: (1): After high-salt wastewater or liquid is finely filtered, it enters the conditioning process, where conditioning agents are added to regulate the form or hydrophilicity of phosphorus-containing organic matter. (2): After regulation, the wastewater or liquid enters the oil-water separation process, so that the non-dissolved phosphorus-containing organic matter is separated from the wastewater or liquid; (3): The wastewater or liquid after removing non-dissolved organic matter enters the primary adsorption phosphorus removal process, where non-polar or weakly polar phosphorus-containing organic matter is adsorbed and removed by non-polar phosphorus removal agent 1. (4): The high-salt wastewater or liquid after the removal of non-polar and weakly polar phosphorus-containing organic matter enters the secondary adsorption phosphorus removal process, and the residual polar phosphorus-containing organic matter with hydroxyl groups is adsorbed and removed by polar phosphorus removal agent 2, which has both electrostatic shielding and adsorption functions. (5): After removing phosphorus-containing organic matter, the high-salt wastewater or feed liquid is adjusted and then enters the subsequent valuable component recovery process. The recovered valuable components are used to prepare products or recycled as regulators.

2. The method according to claim 1, characterized in that, The concentration of organic phosphorus in the high-salt wastewater or feed liquid is 1-100 mg / L, and the phosphorus-containing organic matter is an organophosphorus oxide compound, including organophosphonic acid, acidic phosphonate, neutral phosphonate and their hydrolysis or degradation products.

3. The method according to claim 1, characterized in that, The salt concentration in the high-salt wastewater or feed solution is >2%, wherein the inorganic cations include, but are not limited to, alkali metal ions, alkaline earth metal ions, ammonium ions, transition metal ions and rare earth metal ions; and the anions include, but are not limited to, halogen anions, oxyacid anions, thiocyanate ions and cyanide ions.

4. The method according to claim 1, characterized in that, The regulator component is consistent with or corresponds to the main inorganic salt component in the high-salt wastewater or feed solution; the amount of regulator added is 0.1-2.0 mol / L, the stirring time is 40-60 min, and the pH of the solution after regulation is <7.

5. The method according to claim 1, characterized in that, The phosphorus removal agent 1 is a desorbable and regenerable nonpolar material that adsorbs nonpolar or weakly polar phosphorus-containing organic matter through hydrophobic interactions or van der Waals forces. Its framework structure is polystyrene-divinylbenzene, with a crosslinking degree >75%, an average pore size of 5–7 nm, and a specific surface area of ​​600–900 m². 2 / g; The phosphorus removal agent 1 is prepared by free radical suspension polymerization of styrene as monomer, divinylbenzene as crosslinking agent, xylene as porogen, and benzoyl peroxide as initiator, followed by post-crosslinking under the action of FeCl2 catalyst.

6. The method according to claim 5, characterized in that, The phosphorus removal agent 1 adsorbs non-polar or weakly polar phosphorus-containing organic matter, and the influent flow rate for phosphorus removal is 1-5 BV / h. The phosphorus removal agent 1 is desorbed and regenerated using organic solvents such as methanol, ethanol and acetone, with a desorption rate greater than 99.5%.

7. The method according to claim 1, characterized in that, The phosphorus removal agent 2 has a skeleton structure including, but not limited to, polystyrene and acrylate types, with an effective functional group content of 10%–40%, an average pore size of 4–10 nm, and a specific surface area of ​​100–600 m². 2 / g; The supported functional groups include, but are not limited to, carbonyl, ether, nitro, fluorine, thiocyanate, and cyano.

8. The method according to claim 7, characterized in that, The preparation process of the phosphorus removal agent 2 includes three steps: (1) The skeleton monomer and crosslinking agent are first subjected to free radical suspension polymerization at 80℃~90℃ for 8h~10h to obtain a copolymer; then, it is swollen with dichloroethane, heated to 80℃~90℃ under the action of FeCl2 catalyst, kept at the temperature for 8h~12h, and then crosslinked to obtain an ultra-high crosslinked adsorption material; (2) Chloromethylated polystyrene microspheres are reacted with diethylenetriamine at 85℃~95℃ for 12h~15h to generate polystyrene-diethylenetriamine polymer; then, the polystyrene-diethylenetriamine polymer is reacted with glycidol at 105℃~110℃. After 18h to 24h, a polystyrene adsorbent material containing a multi-hydroxyl structure is obtained; finally, the compound containing the target functional group is reacted with the polystyrene adsorbent material containing the multi-hydroxyl structure to obtain a polystyrene skeleton adsorbent material containing the target functional group; (3) Styrene and crosslinking agent divinylbenzene first undergo a polymerization reaction at 85℃ to 90℃ under the action of an initiator to form linear polystyrene, then swells with dichloroethane, and undergoes post-crosslinking at 80℃ to 90℃ under the action of FeCl2 catalyst to obtain ultra-high crosslinked polystyrene resin, and finally reacts with a nitrifying agent to generate a nitro-containing polystyrene resin.

9. The method according to claim 7, characterized in that, The phosphorus removal agent 2 adsorbs polar phosphorus-containing organic matter with hydroxyl groups, but does not adsorb inorganic ions; the influent flow rate of the secondary adsorption phosphorus removal process is 1-2 BV / h, and the total phosphorus in the adsorbed effluent is <0.2 mg / L; the phosphorus removal agent 2 is desorbed and regenerated using sodium hydroxide, and the desorption rate is greater than 99.5%.

10. The method according to claim 1, characterized in that, After the phosphorus removal agent 1 is adsorbed and penetrated, it is desorbed and regenerated using an organic solvent, such as methanol, ethanol, or acetone; after the phosphorus removal agent 2 is adsorbed and penetrated, it is desorbed and regenerated using sodium hydroxide.

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