A mine wastewater phosphorus removal treatment system and a phosphorus removal method

Abstract

The present application relates to a kind of mine wastewater phosphorus removal treatment system and phosphorus removal method, belong to water body phosphorus removal technical field.The present application is creatively with nine water ferric nitrate and six water ferric chloride as iron source, glucose as carbon source and reducing agent, urea as alkali source, based on hydrothermal synthesis method, the particle material with four-iron oxide as core and carbon layer as shell is synthesized, then it is further oxidized by using hydrogen peroxide solution, more oxygen-containing groups are constructed, then lanthanum chloride is added for lanthanum doping, metal lanthanum modified material is obtained, finally after surface modification of polydopamine and amino silane coupling agent in turn, a kind of phosphorus removal agent is prepared, when it is used for phosphorus removal of mine wastewater in the phosphorus removal treatment system provided with electromagnet, only simple magnetic attraction treatment is needed, the separation and recovery of phosphorus removal agent can be realized, and at the same time, even in the face of strong acid mine wastewater, metal lanthanum in phosphorus removal agent still dissolves less, and the phosphorus removal effect is very good.

Description

Technical Field

[0001] This invention belongs to the field of water phosphorus removal technology, specifically relating to a phosphorus removal system and method for mine wastewater. Background Technology

[0002] With the large-scale mining of mineral resources, the discharge of mine wastewater is increasing day by day. Among the characteristics of various mine wastewaters, excessive phosphorus content has become a significant and urgent problem to be solved. If mine wastewater is not dephosphorized before discharge, it will undoubtedly have a serious impact on the entire ecological environment. Based on this, many water dephosphorization technologies have been widely applied to the phosphorus removal process of mine wastewater, such as adding adsorbents. However, existing adsorbents still have certain drawbacks that limit their actual application effect. This is because, on the one hand, these adsorbents often have small particle sizes and are easily suspended in water, making it difficult to achieve solid-liquid separation after phosphorus removal and difficult to recover. On the other hand, in order to enhance the phosphorus removal effect, most of these adsorbents are modified with lanthanum. However, due to the complex and variable composition of actual mine wastewater, and the fact that a large part of it is acidic, the application range of lanthanum-modified adsorbents is limited. Lanthanum is very easy to dissolve in acidic environments, which can cause secondary metal pollution, ultimately resulting in more harm than good. Summary of the Invention

[0003] To address the problems existing in the prior art, the present invention aims to provide a phosphorus removal system and method for mine wastewater. This invention creatively uses ferric nitrate nonahydrate and ferric chloride hexahydrate as iron sources, glucose as a carbon source and reducing agent, and urea as an alkali source. Based on a hydrothermal synthesis method, a particulate material with a core of iron(III) oxide and a carbon shell is synthesized. This material is then further oxidized using a hydrogen peroxide aqueous solution to construct more oxygen-containing groups. Lanthanum chloride is then added for lanthanum doping, resulting in a lanthanum-modified material. Finally, after surface modification with polydopamine and aminosilane coupling agents, a phosphorus removal agent is prepared. When used in a phosphorus removal system equipped with an electromagnet to remove phosphorus from mine wastewater, the phosphorus removal agent can be separated and recovered with simple magnetic attraction. Furthermore, even with highly acidic mine wastewater, the lanthanum in the phosphorus removal agent dissolves minimally, resulting in excellent phosphorus removal performance.

[0004] The objective of this invention can be achieved through the following technical solutions:

[0005] A mine wastewater phosphorus removal system includes a reaction tank and a drainage tank. A first inlet is located at the top of the reaction tank; a drain outlet is located on the side of the reaction tank; an electromagnet is located at the bottom of the reaction tank; a stirring device is located inside the reaction tank; a second inlet is located at the top of the drainage tank; the drain outlet and the second inlet are connected by a pipe; and a pipe pump is installed in the pipe.

[0006] A phosphorus removal method based on the aforementioned mine wastewater phosphorus removal treatment system, the phosphorus removal method comprising the following steps:

[0007] (1) The mine wastewater and phosphorus removal agent are added to the reaction tank through the first inlet in sequence, the stirring device is turned on to remove phosphorus, the stirring device is turned off, the electromagnet is turned on to attract the phosphorus, and the pipeline pump is turned on to pump the liquid in the reaction tank into the drainage tank.

[0008] As a preferred technical solution of the present invention, the weight ratio of the mine wastewater and the phosphorus removal agent in step (1) is 100:2-3.

[0009] As a preferred embodiment of the present invention, the phosphorus removal agent in step (1) is prepared by the following steps:

[0010] Step A: Mix deionized water, ferric nitrate nonahydrate, ferric chloride hexahydrate, glucose, and urea in a weight ratio of 30-40:3:1.5-2:2-2.2:6-7 at room temperature for 5-10 minutes. Then, perform a hydrothermal reaction at 180-185℃ for 12-16 hours. Allow the mixture to cool naturally to room temperature, filter, collect the residue, wash it with deionized water, and finally vacuum dry it at 40-60℃ until constant weight to obtain component A.

[0011] Step B: Mix hydrogen peroxide aqueous solution and component A at a weight ratio of 80-100:8-10 at 40-45℃ for 1 hour, filter, collect the filter residue, wash with deionized water, and finally vacuum dry at 40-60℃ until constant weight to obtain component B.

[0012] Step C: Mix deionized water, lanthanum chloride, and component B at a weight ratio of 60:1:0.1-0.2 in an ultrasonic mixer at room temperature for 5-10 minutes. Adjust the pH to 9-10 using sodium hydroxide solution, then continue stirring for 45-60 minutes. Filter the mixture, collect the residue, wash it with deionized water, and finally vacuum dry it at 40-60℃ until constant weight is achieved to obtain component C.

[0013] Step D: Mix component C, dopamine, and buffer solution at a weight ratio of 1:0.2-0.3:50 at room temperature for 15-30 minutes. Then, while stirring, add sodium hydroxide solution dropwise to adjust the pH to 8.5-9. After the addition is complete, continue stirring for 4-5 hours. Filter the mixture, collect the residue, wash it with deionized water, and finally vacuum dry it at 40-60℃ until constant weight to obtain component D.

[0014] Step E: Mix component D, aminosilane coupling agent, anhydrous ethanol and deionized water at a weight ratio of 1:0.08-0.1:80:0.1 at 50-70℃ for 24 hours, filter, collect the filter residue, wash with deionized water, and finally vacuum dry at 40-60℃ until constant weight is achieved, thus completing the preparation.

[0015] Furthermore, the mass fraction of the hydrogen peroxide aqueous solution in step B is 30-40%.

[0016] Furthermore, the power of the ultrasound in step C is 300-500W.

[0017] Furthermore, the sodium hydroxide solution in step C has a mass fraction of 3-5%.

[0018] Further, the buffer solution in step D is a Tris hydrochloric acid buffer with a pH of 7.2.

[0019] Furthermore, the dripping rate in step D is controlled at 1-2 drops / s.

[0020] Furthermore, the sodium hydroxide solution in step D has a mass fraction of 1-3%.

[0021] Further, the aminosilane coupling agent in step E is γ-aminopropyltrimethoxysilane.

[0022] As a preferred technical solution of the present invention, the phosphorus removal in step (1) refers to phosphorus removal at a stirring speed of 150-200 rpm for 3-4 hours at room temperature.

[0023] As a preferred technical solution of the present invention, the working parameters of the electromagnet in step (1) are: a magnetic induction intensity of 150-200mT is generated after being energized; and the magnetic attraction time is 15-30min.

[0024] The beneficial effects of this invention are:

[0025] (1) This invention creatively uses ferric nitrate nonahydrate and ferric chloride hexahydrate as iron sources, glucose as a carbon source and reducing agent, and urea as an alkali source. Based on the hydrothermal synthesis method, a particulate material with a core of iron(III) oxide and a shell of carbon layers is synthesized. Then, it is further oxidized by hydrogen peroxide aqueous solution to construct more oxygen-containing groups. Then, lanthanum chloride is added to dope lanthanum to obtain a lanthanum-modified material. Finally, after surface modification by polydopamine and aminosilane coupling agent, a phosphorus removal agent is prepared. When phosphorus removal is performed on mine wastewater in a phosphorus removal system equipped with an electromagnet, the phosphorus removal agent can be separated and recovered with simple magnetic attraction. At the same time, even when facing highly acidic mine wastewater, the lanthanum in the phosphorus removal agent is still less dissolved, and the phosphorus removal effect is very good.

[0026] (2) This invention creatively uses ferric nitrate nonahydrate and ferric chloride hexahydrate as iron sources, glucose as a carbon source and reducing agent, and urea as an alkali source. Based on hydrothermal synthesis, it synthesizes particulate materials with a core of iron(III) oxide and a shell of carbon layers. On the one hand, iron(III) oxide can be attracted by a magnet, thus endowing the subsequently prepared dephosphorizing agent with the ability to be magnetically separated and recovered. On the other hand, the carbon layer itself has a certain porous structure, which has a good adsorption effect on phosphate groups, thereby achieving the effect of phosphorus removal. At the same time, since the particulate material obtained by hydrothermal synthesis has a high hydroxyl content on its surface, the particulate material can also achieve phosphorus removal to a certain extent through the bonding effect of hydroxyl groups with phosphate groups. Then, it is further oxidized by adding hydrogen peroxide aqueous solution to construct more oxygen-containing groups, which not only enhances the phosphorus removal effect, but also... This provides more sites for subsequent surface modification. Lanthanum doping is then achieved through the coordination of lanthanum with hydroxyl groups. The introduction of lanthanum enables ligand exchange (internal sphere complexation) with phosphate-containing molecules, promoting phosphorus precipitation on its surface. Finally, after surface modification with polydopamine and aminosilane coupling agents, a phosphorus removal agent is prepared. A certain amount of polydopamine is introduced as a protective layer, which enables lanthanum to act as a steric barrier and confinement layer in an acidic environment, reducing the chance of hydrogen ions contacting it. However, this also correspondingly reduces the phosphorus removal effect. Therefore, aminosilane coupling agents are modified by the interaction of hydroxyl and silaneoxy groups. Taking advantage of the property that amino groups are easily protonated in an acidic environment, the surface of the phosphorus removal agent becomes positively charged, which generates electrostatic interaction with the negatively charged phosphate-containing molecules, promoting their combination and enhancing the phosphorus removal effect.

[0027] (3) This invention creatively prepares a phosphorus removal agent that can remove phosphorus through multiple pathways and has an excellent phosphorus removal effect. At the same time, the phosphorus removal agent can be separated and recovered with only simple magnetic adsorption treatment. In addition, the phosphorus removal agent still has less lanthanum leaching in acidic environment, effectively avoiding secondary metal pollution. Detailed Implementation

[0028] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with embodiments, is provided below.

[0029] The mine wastewater used in all embodiments and comparative examples of this invention is from the same batch of mine wastewater. After testing, the pH was 3.11, indicating acidity, and the phosphorus (elemental) content was 1094.5 mg / L (bismuth phosphomolybdenum blue spectrophotometry). It did not contain lanthanum (atomic absorption spectrometry).

[0030] Example 1

[0031] A mine wastewater phosphorus removal system includes a reaction tank and a drainage tank. A first inlet is located at the top of the reaction tank; a drain outlet is located on the side of the reaction tank; an electromagnet is located at the bottom of the reaction tank; a stirring device is located inside the reaction tank; a second inlet is located at the top of the drainage tank; the drain outlet and the second inlet are connected by a pipe; and a pipe pump is installed in the pipe.

[0032] A phosphorus removal method based on the aforementioned mine wastewater phosphorus removal treatment system, the phosphorus removal method comprising the following steps:

[0033] (1) The mine wastewater and phosphorus removal agent are added to the reaction tank through the first inlet in sequence, the stirring device is turned on to remove phosphorus, the stirring device is turned off, the electromagnet is turned on to attract the phosphorus, and the pipeline pump is turned on to pump the liquid in the reaction tank into the drainage tank.

[0034] The weight ratio of the mine wastewater and the phosphorus removal agent in step (1) is 100:2.

[0035] The phosphorus removal agent described in step (1) is prepared through the following steps:

[0036] Step A: Mix deionized water, ferric nitrate nonahydrate, ferric chloride hexahydrate, glucose, and urea in a weight ratio of 30:3:1.5:2:6 at room temperature for 5 minutes, then hydrothermally react at 180°C for 12 hours. After naturally cooling to room temperature, filter the mixture, collect the residue, wash it with deionized water, and finally vacuum dry it at 40°C until constant weight to obtain component A.

[0037] Step B: The hydrogen peroxide aqueous solution and component A are stirred at 40°C for 1 hour at a weight ratio of 80:8. The mixture is then filtered, the filter residue is washed with deionized water, and finally dried under vacuum at 40°C until constant weight is obtained to obtain component B.

[0038] Step C: Mix deionized water, lanthanum chloride and component B in a weight ratio of 60:1:0.1 under ultrasonic stirring at room temperature for 5 min. Adjust the pH to 9 using sodium hydroxide solution, then continue stirring for 45 min. Filter the mixture, collect the filter residue, wash it with deionized water, and finally vacuum dry it at 40°C until constant weight to obtain component C.

[0039] Step D: Mix component C, dopamine, and buffer solution at a weight ratio of 1:0.2:50 at room temperature for 15 minutes. Then, while stirring, add sodium hydroxide solution dropwise to adjust the pH to 8.5. After the addition is complete, continue stirring for 4 hours. Filter the mixture, collect the filter residue, wash it with deionized water, and finally vacuum dry it at 40°C until constant weight is obtained to obtain component D.

[0040] Step E: Mix component D, aminosilane coupling agent, anhydrous ethanol and deionized water at a weight ratio of 1:0.08:80:0.1 at 50°C for 24 hours, filter, collect the filter residue, wash with deionized water, and finally vacuum dry at 40°C until constant weight is achieved, thus completing the preparation.

[0041] The hydrogen peroxide aqueous solution in step B has a mass fraction of 30%.

[0042] The power of the ultrasound in step C is 300W.

[0043] The sodium hydroxide solution in step C has a mass fraction of 3%.

[0044] The buffer solution in step D is a Tris hydrochloric acid buffer with a pH of 7.2.

[0045] The dripping rate in step D is controlled at 1 drop / s.

[0046] The sodium hydroxide solution in step D has a mass fraction of 1%.

[0047] The aminosilane coupling agent in step E is γ-aminopropyltrimethoxysilane.

[0048] The phosphorus removal mentioned in step (1) refers to removing phosphorus for 3 hours at a stirring speed of 150 rpm at room temperature.

[0049] The operating parameters of the electromagnet in step (1) are: a magnetic induction intensity of 150mT is generated after energization; and the magnetic attraction time is 15min.

[0050] Example 2

[0051] A mine wastewater phosphorus removal system includes a reaction tank and a drainage tank. A first inlet is located at the top of the reaction tank; a drain outlet is located on the side of the reaction tank; an electromagnet is located at the bottom of the reaction tank; a stirring device is located inside the reaction tank; a second inlet is located at the top of the drainage tank; the drain outlet and the second inlet are connected by a pipe; and a pipe pump is installed in the pipe.

[0052] A phosphorus removal method based on the aforementioned mine wastewater phosphorus removal treatment system, the phosphorus removal method comprising the following steps:

[0053] (1) The mine wastewater and phosphorus removal agent are added to the reaction tank through the first inlet in sequence, the stirring device is turned on to remove phosphorus, the stirring device is turned off, the electromagnet is turned on to attract the phosphorus, and the pipeline pump is turned on to pump the liquid in the reaction tank into the drainage tank.

[0054] The weight ratio of the mine wastewater and the phosphorus removal agent in step (1) is 100:3.

[0055] The phosphorus removal agent described in step (1) is prepared through the following steps:

[0056] Step A: Deionized water, ferric nitrate nonahydrate, ferric chloride hexahydrate, glucose, and urea were mixed at a weight ratio of 40:3:2:2.2:7 and stirred at room temperature for 10 minutes. Then, the mixture was hydrothermally reacted at 185°C for 16 hours. After naturally cooling to room temperature, the mixture was filtered, and the residue was washed with deionized water. Finally, it was vacuum dried at 60°C until constant weight was obtained to obtain component A.

[0057] Step B: The hydrogen peroxide aqueous solution and component A are stirred at 45°C for 1 hour at a weight ratio of 100:10. The mixture is then filtered, the filter residue is washed with deionized water, and finally dried under vacuum at 60°C until constant weight is obtained to obtain component B.

[0058] Step C: Mix deionized water, lanthanum chloride and component B in a weight ratio of 60:1:0.2 under ultrasonic stirring at room temperature for 10 min, adjust the pH to 10 using sodium hydroxide solution, continue stirring for 60 min, filter, collect the filter residue, wash with deionized water, and finally vacuum dry at 60℃ until constant weight to obtain component C;

[0059] Step D: Mix component C, dopamine, and buffer solution at a weight ratio of 1:0.3:50 at room temperature for 30 minutes. Then, while stirring, add sodium hydroxide solution dropwise to adjust the pH to 9. After the addition is complete, continue stirring for 5 hours. Filter the mixture, collect the filter residue, wash it with deionized water, and finally vacuum dry it at 60°C until constant weight is obtained to obtain component D.

[0060] Step E: Mix component D, aminosilane coupling agent, anhydrous ethanol and deionized water at a weight ratio of 1:0.1:80:0.1 at 70°C for 24 hours, filter, collect the filter residue, wash with deionized water, and finally vacuum dry at 60°C until constant weight is achieved, thus completing the preparation.

[0061] The hydrogen peroxide aqueous solution in step B has a mass fraction of 40%.

[0062] The power of the ultrasound in step C is 500W.

[0063] The sodium hydroxide solution in step C has a mass fraction of 5%.

[0064] The buffer solution in step D is a Tris hydrochloric acid buffer with a pH of 7.2.

[0065] The dropping rate in step D is controlled at 2 drops / s.

[0066] The sodium hydroxide solution in step D has a mass fraction of 3%.

[0067] The aminosilane coupling agent in step E is γ-aminopropyltrimethoxysilane.

[0068] The phosphorus removal mentioned in step (1) refers to removing phosphorus at a stirring speed of 200 rpm for 4 hours at room temperature.

[0069] The operating parameters of the electromagnet in step (1) are: a magnetic induction intensity of 200mT is generated after energization; the magnetic attraction time is 30min.

[0070] Example 3

[0071] A mine wastewater phosphorus removal system includes a reaction tank and a drainage tank. A first inlet is located at the top of the reaction tank; a drain outlet is located on the side of the reaction tank; an electromagnet is located at the bottom of the reaction tank; a stirring device is located inside the reaction tank; a second inlet is located at the top of the drainage tank; the drain outlet and the second inlet are connected by a pipe; and a pipe pump is installed in the pipe.

[0072] A phosphorus removal method based on the aforementioned mine wastewater phosphorus removal treatment system, the phosphorus removal method comprising the following steps:

[0073] (1) The mine wastewater and phosphorus removal agent are added to the reaction tank through the first inlet in sequence, the stirring device is turned on to remove phosphorus, the stirring device is turned off, the electromagnet is turned on to attract the phosphorus, and the pipeline pump is turned on to pump the liquid in the reaction tank into the drainage tank.

[0074] The weight ratio of the mine wastewater and the phosphorus removal agent in step (1) is 100:2.8.

[0075] The phosphorus removal agent described in step (1) is prepared through the following steps:

[0076] Step A: Deionized water, ferric nitrate nonahydrate, ferric chloride hexahydrate, glucose, and urea were mixed at a weight ratio of 35:3:1.8:2.1:6.5 and stirred for 8 minutes at room temperature. The mixture was then hydrothermally reacted at 183°C for 14 hours. After naturally cooling to room temperature, the mixture was filtered, and the residue was washed with deionized water. Finally, it was vacuum dried at 50°C until constant weight was obtained to obtain component A.

[0077] Step B: The hydrogen peroxide aqueous solution and component A are stirred at 43°C for 1 hour at a weight ratio of 90:9, filtered, the filter residue is washed with deionized water, and finally dried under vacuum at 50°C until constant weight is obtained to obtain component B.

[0078] Step C: Mix deionized water, lanthanum chloride, and component B in a weight ratio of 60:1:0.15 under ultrasonic stirring at room temperature for 8 minutes. Adjust the pH to 9.5 using sodium hydroxide solution, and continue stirring for 50 minutes. Filter the mixture, collect the filter residue, wash it with deionized water, and finally vacuum dry it at 50°C until constant weight is obtained to obtain component C.

[0079] Step D: Mix component C, dopamine, and buffer solution at a weight ratio of 1:0.25:50 at room temperature for 20 minutes. Then, while stirring, add sodium hydroxide solution dropwise to adjust the pH to 8.8. After the addition is complete, continue stirring for 4.5 hours. Filter the mixture, collect the filter residue, wash it with deionized water, and finally vacuum dry it at 50°C until constant weight is obtained to obtain component D.

[0080] Step E: Mix component D, aminosilane coupling agent, anhydrous ethanol and deionized water at a weight ratio of 1:0.09:80:0.1 at 60°C for 24 hours, filter, collect the filter residue, wash with deionized water, and finally vacuum dry at 50°C until constant weight is achieved, thus completing the preparation.

[0081] The hydrogen peroxide aqueous solution in step B has a mass fraction of 35%.

[0082] The power of the ultrasound in step C is 400W.

[0083] The sodium hydroxide solution in step C has a mass fraction of 4%.

[0084] The buffer solution in step D is a Tris hydrochloric acid buffer with a pH of 7.2.

[0085] The dripping rate in step D is controlled at 1.5 drops / s.

[0086] The sodium hydroxide solution in step D has a mass fraction of 2%.

[0087] The aminosilane coupling agent in step E is γ-aminopropyltrimethoxysilane.

[0088] The phosphorus removal mentioned in step (1) refers to removing phosphorus for 3.5 hours at a stirring speed of 180 rpm at room temperature.

[0089] The operating parameters of the electromagnet in step (1) are: a magnetic induction intensity of 190mT is generated after energization; the magnetic attraction time is 20min.

[0090] Comparative Example 1

[0091] Based on Example 3, the aminosilane coupling agent was replaced with an equal weight of deionized water, while all other aspects remained unchanged.

[0092] Comparative Example 2

[0093] Based on Example 3, dopamine was replaced with an equal weight of buffer solution, while everything else remained the same.

[0094] Comparative Example 3

[0095] Based on Example 3, the hydrogen peroxide aqueous solution was replaced with an equal weight of deionized water, while all other aspects remained unchanged.

[0096] Comparative Example 4

[0097] Based on Example 3, the weight ratio of component C, dopamine and buffer solution was changed from 1:0.25:50 to 1:0.4:50, while all other parts remained unchanged.

[0098] Test Example 1

[0099] Phosphorus removal efficiency test:

[0100] Water samples were taken from the drainage tanks of Example 3 and Comparative Examples 1-4, and the phosphorus content was determined by bismuth phosphomolybdenum blue spectrophotometry to calculate the phosphorus removal rate.

[0101] Table 1. Results of phosphorus removal efficiency test

[0102] Phosphorus removal rate / % Example 3 99.7 Comparative Example 1 80.5 Comparative Example 2 86.6 Comparative Example 3 92.0 Comparative Example 4 96.2

[0103] Test Example 2

[0104] Lanthanum dissolution test:

[0105] Water samples were taken from the drainage tanks of Examples 3 and Comparative Examples 1-4, and the lanthanum content was determined by atomic absorption spectrometry. If the concentration of lanthanum was greater than 1 mg / L, it was considered that leaching had occurred.

[0106] Table 2. Lanthanum dissolution test results

[0107] Is the concentration of lanthanum greater than 1 mg / L? Example 3 no Comparative Example 1 no Comparative Example 2 yes Comparative Example 3 no Comparative Example 4 no

[0108] As can be seen from the comparison of Test Examples 1-2, Example 3 and Comparative Examples 1-4, the phosphorus removal agent prepared by the present invention has excellent phosphorus removal effect, and even in acidic environment, the leaching of lanthanum is still relatively small.

[0109] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A phosphorus removal method for a mine wastewater phosphorus removal treatment system, characterized in that: The phosphorus removal method includes the following steps: (1) Add mine wastewater and phosphorus removal agent into the reaction tank through the first inlet in sequence, turn on the stirring device to remove phosphorus, turn off the stirring device, turn on the electromagnet to magnetically attract, and turn on the pipeline pump to pump the liquid in the reaction tank into the drainage tank. The phosphorus removal agent described in step (1) is prepared through the following steps: Step A: Mix deionized water, ferric nitrate nonahydrate, ferric chloride hexahydrate, glucose, and urea in a weight ratio of 30-40:3:1.5-2:2-2.2:6-7 at room temperature for 5-10 minutes. Then, perform a hydrothermal reaction at 180-185℃ for 12-16 hours. Allow the mixture to cool naturally to room temperature, filter, collect the residue, wash it with deionized water, and finally vacuum dry it at 40-60℃ until constant weight to obtain component A. Step B: Mix hydrogen peroxide aqueous solution and component A at a weight ratio of 80-100:8-10 at 40-45℃ for 1 hour, filter, collect the filter residue, wash with deionized water, and finally vacuum dry at 40-60℃ until constant weight to obtain component B. Step C: Mix deionized water, lanthanum chloride, and component B at a weight ratio of 60:1:0.1-0.2 in an ultrasonic mixer at room temperature for 5-10 minutes. Adjust the pH to 9-10 using sodium hydroxide solution, then continue stirring for 45-60 minutes. Filter the mixture, collect the residue, wash it with deionized water, and finally vacuum dry it at 40-60℃ until constant weight is achieved to obtain component C. Step D: Mix component C, dopamine, and buffer solution at a weight ratio of 1:0.2-0.3:50 at room temperature for 15-30 minutes. Then, while stirring, add sodium hydroxide solution dropwise to adjust the pH to 8.5-9. After the addition is complete, continue stirring for 4-5 hours. Filter the mixture, collect the residue, wash it with deionized water, and finally vacuum dry it at 40-60℃ until constant weight to obtain component D. Step E: Mix component D, aminosilane coupling agent, anhydrous ethanol and deionized water at a weight ratio of 1:0.08-0.1:80:0.1 at 50-70℃ for 24 hours, filter, collect the filter residue, wash with deionized water, and finally vacuum dry at 40-60℃ until constant weight is achieved, thus completing the preparation.

2. The phosphorus removal method of the mine wastewater phosphorus removal treatment system according to claim 1, characterized in that: In step (1), the weight ratio of the mine wastewater to the phosphorus removal agent is 100:2-3.

3. The phosphorus removal method of the mine wastewater phosphorus removal treatment system according to claim 1, characterized in that: The sodium hydroxide solution in step C has a mass fraction of 3-5%.

4. The phosphorus removal method of the mine wastewater phosphorus removal treatment system according to claim 1, characterized in that: The buffer solution in step D is a Tris hydrochloric acid buffer with a pH of 7.

2.

5. The phosphorus removal method of the mine wastewater phosphorus removal treatment system according to claim 1, characterized in that: The sodium hydroxide solution in step D has a mass fraction of 1-3%.

6. The phosphorus removal method of the mine wastewater phosphorus removal treatment system according to claim 1, characterized in that: The aminosilane coupling agent in step E is γ-aminopropyltrimethoxysilane.

7. The phosphorus removal method of the mine wastewater phosphorus removal treatment system according to claim 1, characterized in that: The phosphorus removal mentioned in step (1) refers to removing phosphorus at a stirring speed of 150-200 rpm for 3-4 hours at room temperature.

8. The phosphorus removal method of the mine wastewater phosphorus removal treatment system according to claim 1, characterized in that: The operating parameters of the electromagnet in step (1) are: a magnetic induction intensity of 150-200mT is generated after energization; the magnetic attraction time is 15-30min.