A lanthanum-modified phosphorus removal agent and its preparation method

Abstract

The present invention discloses a lanthanum-modified phosphorus removal agent and a preparation method thereof, belonging to the technical field of phosphorus removal. The preparation raw materials include the following parts by mass: 40-60 parts of lanthanum-loaded zeolite, 20-45 parts of porous aluminosilicate microspheres, 2-3 parts of sodium carboxymethylcellulose, and 3-5 parts of ferrous sulfate. The preparation method of the porous aluminosilicate microspheres includes the following steps: sodium silicate and aluminum sulfate are co-precipitated in water, and the pH of the co-precipitation is controlled at 10.1-10.7, and the reaction is carried out at 55-65 °C for 5-8 h to obtain a gel; the gel is spray granulated and then sintered and activated to obtain the porous aluminosilicate microspheres. The lanthanum-modified phosphorus removal agent prepared by the present invention has a large phosphorus removal capacity and a high capacity retention rate after multiple phosphorus removals, and is expected to be applied to the deep phosphorus removal of sewage treatment plants.

Description

Technical Field

[0001] The present invention belongs to the technical field of phosphorus removal, and specifically relates to a lanthanum-modified phosphorus remover and a preparation method thereof. Background Art

[0002] Phosphorus element (P) is a key limiting factor leading to water eutrophication. Excessive phosphorus can trigger ecological disasters such as algal blooms and dissolved oxygen depletion. Treatment methods for phosphorus element include chemical precipitation method. Traditional chemical precipitation methods (such as aluminum salts and iron salts) have the advantage of low cost, but there are problems such as large sludge production and excessive residual metal ions, which are difficult to meet the increasingly strict emission standards.

[0003] Due to its high affinity with phosphate ions and wide pH adaptability, lanthanum has become a research hotspot for new phosphorus removers. Although using pure lanthanum compounds has a high adsorption capacity, the nanoparticles are prone to agglomeration, and lanthanum resources are scarce and the cost is relatively high. In the prior art, lanthanum-loaded materials are usually prepared by modifying activated carbon, clay or zeolite with lanthanum. However, the specific surface area of the carrier is insufficient, resulting in low utilization rate of active sites and poor regeneration performance. The phosphorus remover of lanthanum composite iron double metal oxide usually requires high-temperature (≥800 °C) calcination to form a crystal phase structure, with high energy consumption. Summary of the Invention

[0004] In order to overcome the above technical problems, the present invention provides a lanthanum-modified phosphorus remover and a preparation method thereof. The lanthanum-modified phosphorus remover prepared by the present invention has a large phosphorus removal capacity and a high capacity retention rate after multiple phosphorus removals.

[0005] The present invention solves the above technical problems through the following technical solutions.

[0006] A lanthanum-modified phosphorus remover, comprising the following parts by mass of preparation raw materials: 40-60 parts of lanthanum-loaded zeolite, 20-45 parts of porous aluminosilicate microspheres, 2-3 parts of sodium carboxymethylcellulose, and 3-5 parts of ferrous sulfate;

[0007] Preferably, the lanthanum-modified phosphorus remover comprises the following parts by mass of preparation raw materials: 40-50 parts of lanthanum-loaded zeolite, 20-35 parts of porous aluminosilicate microspheres, 2-3 parts of sodium carboxymethylcellulose, and 3-5 parts of ferrous sulfate;

[0008] The preparation method of the porous aluminosilicate microspheres comprises the following steps: sodium silicate and aluminum sulfate are co-precipitated in water to obtain a gel, and the gel is spray granulated and then sintered and activated to obtain the porous aluminosilicate microspheres;

[0009] The preparation method of the lanthanum-loaded zeolite comprises the following steps: the clinoptilolite powder is acid-activated and then subjected to an ion exchange reaction with a lanthanum nitrate solution, and then calcined. Among them, after the clinoptilolite is acid-activated, its aluminum-oxygen tetrahedron framework fixes La 3+ through ion exchange to form a stable La-O-Si bond, avoiding lanthanum loss.

[0010] Further, the coprecipitation is carried out at a pH of 10.1 - 10.7 and a temperature of 55 - 65°C for 5 - 8 h.

[0011] Further, the particle size of the product discharged from the spray granulation is D50 of 100 - 150 μm.

[0012] Further, the sintering activation is carried out by roasting at 580 - 610°C for 0.5 - 2 h.

[0013] In some preferred embodiments, the porous aluminosilicate microspheres comprise the following raw materials in parts by mass: 30 - 60 parts of sodium silicate, 20 - 30 parts of aluminum sulfate, 3 - 7 parts of polyethylene glycol, and 20 - 35 parts of water; preferably, the porous aluminosilicate microspheres comprise the following raw materials in parts by mass: 40 - 50 parts of sodium silicate, 20 - 35 parts of aluminum sulfate, 4 - 6 parts of polyethylene glycol, and 20 - 30 parts of water.

[0014] In the present invention, the polyethylene glycol includes PEG400:PEG2000, and the mass ratio of PEG400:PEG2000 is 10:3 - 5. In the present invention, the rich pores of the porous aluminosilicate microspheres improve the dispersion degree of the active components and avoid the 3+ agglomeration and inactivation of La. During the preparation by the coprecipitation method, two types of pore-forming agents, PEG400 and PEG2000, are added, so that the porous aluminosilicate microspheres have a pore structure with different pore diameters.

[0015] In the present invention, the modulus of the sodium silicate is 1.5 - 3.5, preferably 3.0 - 3.5.

[0016] In the present invention, the specific surface area of the porous aluminosilicate microspheres is 300 - 350 m 2 / g, preferably 300 - 330 m 2 / g.

[0017] In the present invention, the material ratio of the clinoptilolite powder to the lanthanum nitrate solution is 0.1 - 0.2 g / L.

[0018] In the present invention, the concentration of the lanthanum nitrate solution is 0.3 - 0.8 mol / L, preferably 0.5 - 0.7 mol / L.

[0019] In the present invention, the pH needs to be controlled during the ion exchange reaction, and dilute nitric acid is used to control the pH of the ion exchange reaction at 4.5 - 5.0.

[0020] In the present invention, the time of the ion exchange reaction is 5 - 12 h.

[0021] In the present invention, the acid activation is to stir clinoptilolite powder in 2.5 - 3.5 mol / L HCl solution at 55 - 65 °C for 2 - 3 h and then wash it to neutrality.

[0022] In the present invention, the calcination is carried out at 400 - 450 °C for 1.5 - 3.5 h.

[0023] In the present invention, the lanthanum loading amount of the lanthanum - loaded zeolite is 8 - 10 wt%;

[0024] In the present invention, the specific surface area of the lanthanum - loaded zeolite ≥ 200 m 2 / g, preferably 200 - 220 m 2 / g.

[0025] In the present invention, the phosphorus removal capacity of the lanthanum - modified phosphorus - removing agent ≥ 40 mg P / g, preferably 43 - 50 mg P / g.

[0026] In the present invention, the lanthanum - modified phosphorus - removing agent is used in the range of pH 5 - 9.

[0027] In the present invention, the lanthanum - modified phosphorus - removing agent is regenerated by soaking in 1 mol / L NaOH and reused, and the phosphorus removal capacity retention rate after 5 regeneration times ≥ 80%.

[0028] The present invention also discloses a preparation method of a lanthanum - modified phosphorus - removing agent, comprising the following steps: wet - kneading and granulating lanthanum - loaded zeolite, porous aluminosilicate microspheres and sodium carboxymethylcellulose, drying, and then impregnating in ferrous sulfate solution and curing. The ferric ions generated by the oxidation of ferrous ions can form ferric phosphate precipitation with phosphate radicals, jointly constructing a dual - effect phosphorus - removing system with lanthanum phosphate precipitation.

[0029] The concentration of the ferrous sulfate solution is 0.1 - 0.2 mol / L;

[0030] The impregnation time is 20 - 40 min;

[0031] The curing temperature is 140 - 160 °C and the time is 2 - 3 h.

[0032] On the basis of conforming to the common knowledge in the art, the above - mentioned preferred conditions can be combined arbitrarily to obtain various preferred examples of the present invention.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] 1. The lanthanum - loaded zeolite of the present invention provides a high density of lanthanum ions to fix phosphates. The removal of phosphorus is not a simple adsorption, but experiences: diffusion - surface coordination - LaPO4 crystal nucleus formation - crystal grain growth; the porous aluminosilicate microspheres of the present invention contain different - level pore diameters and can provide a loading space for lanthanum.

[0035] 2. The lanthanum-modified phosphorus removal agent of the present invention has regeneration performance. First, the La-O-Si bonds formed on the surface of lanthanum ions and clinoptilolite are not easily lost; moreover, the silanol groups (Si-OH) on the surface of the porous aluminosilicate microspheres form Si-O-La covalent bonds, which is conducive to maintaining structural stability during the regeneration cycle.

[0036] 3. The lanthanum-modified phosphorus removal agent prepared by the present invention has a high phosphorus adsorption capacity, ≥40mg P / g in some preferred embodiments; and the capacity retention rate is ≥80% after being used five times, and the capacity retention rate is 82-88% in some preferred embodiments. This solution can remove phosphorus efficiently, stably and at low cost, and is expected to be applied to the advanced phosphorus removal in sewage treatment plants, with market application potential. Detailed implementation manners

[0037] For the convenience of understanding the present invention, the following will describe the present invention more comprehensively and meticulously in combination with preferred embodiments, but the protection scope of the present invention is not limited to the following specific embodiments.

[0038] Unless otherwise defined, all professional terms used hereinafter have the same meaning as commonly understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the protection scope of the present invention.

[0039] The "range" disclosed in the present invention is defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a specific range. The range defined in this way can include or not include the end values, and can be combined arbitrarily, that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, ranges of 60-110 and 80-120 are also contemplated. In addition, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4 and 5 are listed, then the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present invention, unless otherwise stated, the numerical range "a-b" represents the abbreviated representation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been fully listed herein, and "0-5" is only the abbreviated representation of these numerical combinations. In addition, when it is stated that a certain parameter is an integer ≥2, it is equivalent to disclosing that the parameter is, for example, the integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0040] If there is no special instruction, all implementation manners and optional implementation manners of the present invention can be combined with each other to form a new technical solution.

[0041] Unless otherwise specified, all technical features and optional technical features of the present invention can be combined with each other to form new technical solutions.

[0042] Unless otherwise specified, all steps of the present invention can be carried out sequentially or randomly, and preferably sequentially. For example, the method includes steps (a) and (b), which means that the method can include steps (a) and (b) carried out sequentially, or can also include steps (b) and (a) carried out sequentially. For example, it is mentioned that the method may further include step (c), which means that step (c) can be added to the method in any order. For example, the method can include steps (a), (b) and (c), or can also include steps (a), (c) and (b), or can also include steps (c), (a) and (b), etc.

[0043] Unless otherwise specified, the "including" and "comprising" mentioned in the present invention mean open-ended, and can also be closed-ended. For example, the "including" and "comprising" can mean that other components not listed can also be included or comprised, or can only include or comprise the listed components.

[0044] Unless otherwise specified, in the present invention, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) while B is true (or exists); or both A and B are true (or exist).

[0045] The raw material information used in the following examples is as follows:

[0046] Clinoptilolite was purchased from Shijiazhuang Huabang Mineral Products Co., Ltd., with a particle size of 200 mesh;

[0047] Including but not limited to the above raw material manufacturers.

[0048] Example 1

[0049] 1. The lanthanum-modified phosphorus removal agent of this example is composed of the following parts by mass of preparation raw materials: 50 parts of lanthanum-loaded zeolite, 30 parts of porous aluminosilicate microspheres, 3 parts of sodium carboxymethylcellulose, and 5 parts of ferrous sulfate.

[0050] (1) Porous aluminosilicate microspheres

[0051] The porous aluminosilicate microspheres are composed of the following parts by mass of preparation raw materials: 45 parts of sodium silicate, 30 parts of aluminum sulfate, 5 parts of polyethylene glycol, and 25 parts of water;

[0052] The mass ratio of PEG400:PEG2000 in polyethylene glycol is 10:5;

[0053] According to the above formula, sodium silicate (modulus 3.2, modulus n = SiO2 / Na2O) and aluminum sulfate are co-precipitated in water. The co-precipitation pH is controlled at 10.2, and the reaction is carried out at 50 °C for 8 h to obtain a gel; the gel is spray granulated, and the particle size of the discharged material is D50 = 120 μm, and then sintered and activated by roasting at 610 °C for 0.5 h to obtain porous aluminosilicate microspheres. The specific surface area of the porous aluminosilicate microspheres is 320 m 2 / g.

[0054] (2) Lanthanum-loaded zeolite

[0055] Clinoptilolite powder is stirred in 3.0 mol / L HCl solution at 55 °C for 2.5 h, then washed to neutrality to complete acid activation, and dried; the acid-activated clinoptilolite powder is subjected to an ion exchange reaction in 0.5 mol / L lanthanum nitrate solution. The ratio of the feed liquid of clinoptilolite powder to lanthanum nitrate solution is 0.2 g / L. Dilute nitric acid is used to adjust the pH during the ion exchange reaction, and the pH of the ion exchange reaction is controlled at 4.5; the time of the ion exchange reaction is 10 h, filtered and dried, and sintered at 420 °C for 2 h to obtain lanthanum-loaded zeolite; the lanthanum loading amount of the lanthanum-loaded zeolite is 9.1 wt% (measured by the mass difference method), and the specific surface area of the lanthanum-loaded zeolite is 215 m 2 / g.

[0056] 2. The preparation method of the lanthanum-modified phosphorus remover in this example is as follows:

[0057] The lanthanum-loaded zeolite, porous aluminosilicate microspheres and sodium carboxymethyl cellulose (prepared into a 5 wt% CMC solution) are wet kneaded and granulated. Granulation is carried out by twin-screw extrusion granulation, the screw speed is 40 rpm, the die head aperture is 2.5 mm, dried, and then impregnated in ferrous sulfate solution (0.15 mol / L) for 35 min, and finally cured at 150 °C for 2 h to obtain the lanthanum-modified phosphorus remover.

[0058] Example 2

[0059] The difference between this example and Example 1 is:

[0060] Preparation method of porous aluminosilicate microspheres: Sodium silicate and aluminum sulfate are co-precipitated in water. The co-precipitation pH is controlled at 10.6, and the reaction is carried out at 60 °C for 5 h to obtain a gel; the gel is spray granulated, and the particle size of the discharged material is D50 = 100 μm, and then sintered and activated by roasting at 600 °C for 1 h to obtain porous aluminosilicate microspheres. The specific surface area of the porous aluminosilicate microspheres is 307 m 2 / g.

[0061] Other raw materials, steps and parameters are the same as those in Example 1.

[0062] Example 3

[0063] The difference between this embodiment and Embodiment 1 is as follows:

[0064] The porous aluminosilicate microspheres are composed of the following raw materials in parts by mass: 60 parts of sodium silicate, 20 parts of aluminum sulfate, 5 parts of polyethylene glycol, and 27 parts of water; the modulus of sodium silicate is 2.5;

[0065] The specific surface area of the porous aluminosilicate microspheres is 304 m 2 / g;

[0066] Other raw materials, steps, and parameters are the same as those in Embodiment 1.

[0067] Embodiment 4

[0068] The difference between this embodiment and Embodiment 1 is as follows:

[0069] The mass ratio of PEG400:PEG2000 in polyethylene glycol is 10:8;

[0070] The specific surface area of the porous aluminosilicate microspheres is 297 m 2 / g;

[0071] Other raw materials, steps, and parameters are the same as those in Embodiment 1.

[0072] Embodiment 5

[0073] The difference between this embodiment and Embodiment 1 is as follows:

[0074] In this embodiment, the clinoptilolite is not acid-activated, and the clinoptilolite and lanthanum nitrate solution are directly subjected to an ion exchange reaction. Other raw materials, steps, and parameters are the same as those in Embodiment 1; the lanthanum loading amount of the obtained lanthanum-loaded zeolite is 4.8 wt%, and the specific surface area of the lanthanum-loaded zeolite is 173 m 2 / g.

[0075] The clinoptilolite in this embodiment is not acid-activated, and the lanthanum loading amount in the prepared lanthanum-loaded zeolite is relatively small. Therefore, compared with other embodiments, the initial phosphorus removal capacity of the lanthanum-modified phosphorus remover in this embodiment is relatively poor.

[0076] Embodiment 6

[0077] The difference between this embodiment and Embodiment 1 is as follows:

[0078] ​The clinoptilolite powder was acid-activated by stirring in 2.5 mol / L HCl solution at 65 °C for 2 h, followed by washing until neutral and drying. The acid-activated clinoptilolite powder was subjected to an ion exchange reaction in 0.7 mol / L lanthanum nitrate solution. The ratio of the clinoptilolite powder to the lanthanum nitrate solution was 0.1 g / L. The pH of the ion exchange reaction was adjusted with dilute nitric acid to 5.0, and the reaction time was 8 h. After filtration and drying, the sample was sintered at 450 °C for 2.5 h to obtain lanthanum-loaded zeolite. The lanthanum loading of the lanthanum-loaded zeolite was 8.4 wt%, and the specific surface area of the lanthanum-loaded zeolite was 203 m 2 / g.

[0079] All other raw materials, steps, and parameters were the same as in Example 1.

[0080] Comparative Example 1

[0081] The difference between this comparative example and Example 1 is that:

[0082] The lanthanum-modified phosphorus remover in this comparative example was composed of the following raw materials by mass: 70 parts of lanthanum-loaded zeolite, 3 parts of sodium carboxymethylcellulose, and 5 parts of ferrous sulfate.

[0083] All other raw materials, steps, and parameters were the same as in Example 1.

[0084] Comparative Example 2

[0085] The difference between this comparative example and Example 1 is that:

[0086] The lanthanum-modified phosphorus remover in this comparative example was composed of the following raw materials by mass: 38 parts of lanthanum-loaded zeolite, 50 parts of porous aluminosilicate microspheres, 2 parts of sodium carboxymethylcellulose, and 4 parts of ferrous sulfate.

[0087] All other raw materials, steps, and parameters were the same as in Example 1.

[0088] Effect Example

[0089] The lanthanum-modified phosphorus removers prepared in the above examples and comparative examples were tested for phosphorus removal capacity, and the test results are shown in Table 1.

[0090] Initial phosphorus removal capacity test (adsorption test): By simulating the adsorption reaction between the phosphorus-containing wastewater (pH = 7, TP = 5 mg / L) and the lanthanum-modified phosphorus remover, the maximum adsorption amount (mg) of phosphorus (P) per unit mass of the phosphorus remover (g) was measured, and the static saturation adsorption capacity was calculated.

[0091] The phosphorus content test method was referred to GB / T 11893 and tested at a temperature of 23 ± 2 °C.

[0092] Regeneration test: After the lanthanum-modified phosphorus remover undergoes the adsorption test-regeneration process 5 times repeatedly, calculate the phosphorus removal capacity of the lanthanum-modified phosphorus remover for the 6th time; calculate the capacity retention rate after 5 uses, and the capacity retention rate = the 6th phosphorus removal capacity / the initial phosphorus removal capacity.

[0093] The regeneration method is to soak the lanthanum-modified phosphorus remover after phosphorus removal in a 1 mol / L sodium hydroxide solution according to a liquid-solid ratio of 1:10, oscillate at 25 °C for 2 h, and wash with deionized water until the pH = 7-8 to achieve regeneration.

[0094]

[0095] Application example

[0096] Add 700 mg of the lanthanum-modified phosphorus remover (prepared from the above-mentioned examples and comparative examples respectively) to 10 L of phosphorus-containing sewage (initial pH is 6.2, TP is 106.3 mg / L), and calculate the total phosphorus removal rate after oscillating at 23 °C for 1 h. The results are shown in Table 2.

[0097]

[0098] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be obtained through market purchase or can be prepared by existing methods. The specific embodiments described above have further elaborated on the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A lanthanum-modified phosphorus removal agent, characterized in that, It includes the following raw materials in parts by mass: 40 - 60 parts of lanthanum - loaded zeolite, 20 - 45 parts of porous aluminosilicate microspheres, 2 - 3 parts of sodium carboxymethylcellulose, and 3 - 5 parts of ferrous sulfate; The preparation method of the porous aluminosilicate microspheres includes the following steps: Sodium silicate and aluminum sulfate are co - precipitated in water to obtain a gel; The gel is spray - granulated and then sintered and activated to obtain the porous aluminosilicate microspheres; The preparation method of the lanthanum - loaded zeolite includes the following steps: The clinoptilolite powder is acid - activated and then undergoes an ion - exchange reaction with a lanthanum nitrate solution, and then is calcined.

2. The lanthanum-modified phosphorus removal agent according to claim 1, wherein Meet at least one of the following conditions ① - ③: ① The co - precipitation is carried out at a pH of 10.1 - 10.7 and a temperature of 55 - 65 °C for 5 - 8 h; ② The particle size of the discharged material of the spray - granulation is D50 of 100 - 150 μm; ③ The sintering and activation is carried out by calcining at 580 - 610 °C for 0.5 - 2 h.

3. The lanthanum-modified phosphorus removal agent according to claim 1, wherein, The porous aluminosilicate microspheres include the following raw materials in parts by mass: 30 - 60 parts of sodium silicate, 20 - 30 parts of aluminum sulfate, 3 - 7 parts of polyethylene glycol, and 20 - 35 parts of water.

4. The lanthanum-modified phosphorus removal agent according to claim 3, characterized in that, Meet at least one of the following conditions ① - ③: ① The polyethylene glycol includes PEG400 and PEG2000, and the mass ratio of PEG400:PEG2000 is 10:3 - 5; ② The modulus of the sodium silicate is 1.5 - 3.5; ③ The specific surface area of the porous aluminosilicate microspheres is 300 - 350 m 2 / g.

5. The lanthanum-modified phosphorus removal agent according to claim 1, wherein Meet at least one of the following conditions ① - ④: ① The material - liquid ratio of the clinoptilolite powder and the lanthanum nitrate solution is 0.1 - 0.2 g / L; ② The concentration of the lanthanum nitrate solution is 0.3 - 0.8 mol / L; ③ During the ion - exchange reaction, the pH is controlled, and dilute nitric acid is used to control the pH of the ion - exchange reaction to be 4.5 - 5.0; ④ The time of the ion - exchange reaction is 5 - 12 h.

6. The lanthanum-modified phosphorus removal agent according to claim 1, wherein Meet at least one of the following conditions ① - ②: ① The acid - activation is to stir the clinoptilolite powder in a 2.5 - 3.5 mol / L HCl solution at 55 - 65 °C for 2 - 3 h and then wash it to neutral; ② The calcination is carried out at 400 - 450 °C for 1.5 - 3.5 h.

7. The lanthanum-modified phosphorus removal agent according to claim 6, wherein Meet at least one of the following conditions ① - ②: ① The lanthanum loading amount of the lanthanum - loaded zeolite is 8 - 10 wt%; ② The specific surface area of the lanthanum-loaded zeolite ≥ 200 m 2 / g.

8. The lanthanum-modified phosphorus removal agent according to claim 1, wherein, The phosphorus - removal capacity of the lanthanum - modified phosphorus - removing agent ≥ 40 mg P / g.

9. The preparation method of the lanthanum-modified phosphorus-removing agent according to any one of claims 1 to 8, characterized in that, It includes the following steps: The lanthanum - loaded zeolite, porous aluminosilicate microspheres and sodium carboxymethylcellulose are wet - kneaded and granulated, dried, and then impregnated in a ferrous sulfate solution and cured.

10. The preparation method of the lanthanum-modified phosphorus removal agent according to claim 9, characterized in that, Meet at least one of the following conditions ① - ③: ① The concentration of the ferrous sulfate solution is 0.1 - 0.2 mol / L; ② The impregnation time is 20 - 40 min; ③ The curing temperature is 140 - 160 °C and the time is 2 - 3 h.

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