Preparation method of sewage treatment phosphorus removal filler and application thereof

Abstract

This invention discloses a method for preparing phosphorus removal packing material for wastewater treatment and its application, relating to the field of wastewater treatment technology. The method includes the following steps: preparing a quaternary ammonium salt-lanthanum hybrid organosilane modifier; preparing an activated porous biochar; and grafting the quaternary ammonium salt-lanthanum hybrid organosilane modifier onto the activated porous biochar to obtain the wastewater treatment phosphorus removal packing material. The packing material prepared by this invention has high phosphorus removal efficiency and strong selectivity, and possesses excellent bactericidal and anti-bioclogging capabilities. Its active components are firmly grafted through covalent bonds, exhibiting good stability and allowing for multiple regenerations, effectively avoiding secondary pollution.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a method for preparing phosphorus removal packing material for wastewater treatment and its application. Background Technology

[0002] The large-scale discharge of phosphorus-containing wastewater is a major cause of eutrophication in water bodies, posing a serious threat to the ecological environment and human health. Therefore, efficient and economical phosphorus removal from water bodies is a crucial issue in wastewater treatment. Among numerous phosphorus removal technologies, adsorption has attracted considerable attention due to its advantages such as simple operation, relatively low cost, and no secondary sludge production. Biochar, as a widely available and inexpensive porous material, is often used as a carrier for adsorbents. Modifying biochar by loading specific active functional groups onto its surface to enhance its adsorption capacity and selectivity for phosphates is currently a research hotspot. Existing technologies, besides adsorption, also include chemical precipitation and biological phosphorus removal. Chemical precipitation removes phosphorus by adding metal salt reagents to form precipitates; biological methods utilize the excessive phosphorus uptake by microorganisms to achieve phosphorus removal. These technologies form the foundation of current wastewater phosphorus removal technologies in practical applications.

[0003] Existing phosphorus removal technologies generally have their own limitations, making it difficult to simultaneously meet the multiple requirements of high efficiency, stability, and environmental protection. Firstly, traditional adsorption materials, such as ordinary biochar, have a weak affinity for phosphate, resulting in low adsorption capacity and poor selectivity. Common sulfate ions in water compete with phosphate for adsorption, severely impacting phosphorus removal efficiency. Secondly, during long-term operation in water treatment systems, microorganisms easily proliferate on the surface of the packing material, forming a biofilm, i.e., bioclogging. This not only clogs the reactor and increases hydraulic resistance but also covers the active sites on the material surface, leading to a sharp decline in phosphorus removal performance. Furthermore, to improve adsorption performance, existing technologies often use physical impregnation methods to load active metal components such as lanthanum and zirconium onto a carrier. However, this loading method has weak binding force, and the active components are easily lost under water flow, causing secondary pollution of the water body and making effective regeneration of the packing material difficult, resulting in a short service life and limiting its large-scale application. Chemical precipitation methods produce large amounts of chemical sludge, which is difficult to dispose of; biological methods are sensitive to influent water quality and operating conditions, resulting in unstable effluent quality and failing to meet the requirements for deep phosphorus removal. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing phosphorus removal packing material for wastewater treatment and its application, thereby solving the problems existing in the background art.

[0005] To solve the above-mentioned technical problems, the present invention provides a method for preparing phosphorus removal packing material for wastewater treatment, comprising the following steps:

[0006] Prepare a quaternary ammonium salt-lanthanum hybrid organosilanes modifier;

[0007] Prepare an activated porous biochar;

[0008] A quaternary ammonium salt-lanthanum hybrid organosilicon modifier was grafted onto activated porous biochar to obtain a phosphorus removal packing material for wastewater treatment.

[0009] Preferably, the preparation of quaternary ammonium salt-lanthanum hybrid organosilanes includes:

[0010] Step (a): In anhydrous ethanol solvent, (3-chloropropyl)triethoxysilane and N,N-dimethyl-1,3-propanediamine are refluxed and stirred under nitrogen protection to obtain intermediate A solution containing amination silane coupling agent.

[0011] Step (b): After cooling the solution obtained in step (a), add succinic anhydride and stir to react, so that intermediate A reacts with succinic anhydride to introduce carboxyl groups.

[0012] In step (c), the reaction solution obtained in step (b) is placed in an ice-water bath, and iodomethane is slowly added dropwise. Then, under light-protected conditions, the mixture is continuously stirred to carry out the quaternization reaction to obtain intermediate B.

[0013] In step (d), the solution containing intermediate B is added dropwise to an anhydrous ethanol solution of lanthanum nitrate, and the mixture is stirred to carry out a chelation coordination reaction to obtain a quaternary ammonium salt-lanthanum hybrid organosilicon modifier.

[0014] Preferably, the preparation of activated porous biochar includes:

[0015] Porous biochar was produced by pyrolyzing rice husks under limited oxygen conditions.

[0016] The porous biochar was activated by soaking in an acid solution to clean its pores and increase the number of surface hydroxyl groups. It was then washed until neutral and dried to obtain activated porous biochar.

[0017] Preferably, the grafting steps include:

[0018] The activated porous biochar was placed in a reaction vessel, and an ethanol solution of quaternary ammonium salt-lanthanum hybrid organosilicon modifier was added. Anhydrous ethanol was added to the predetermined solid-liquid ratio, and the mixture was ultrasonically dispersed and then allowed to stand to remove bubbles.

[0019] Deionized water was added to the reactor to initiate the hydrolysis of the silane in the modifier, and the pH of the system was adjusted to acidic using acid.

[0020] The system was heated using a gradient heating method and stirred at a constant temperature at the target temperature to allow the hydrolyzed silanol groups to undergo a dehydration condensation reaction with the hydroxyl groups on the surface of biochar, forming covalent bonds.

[0021] The solid product after the reaction was washed alternately with anhydrous ethanol and deionized water and then dried to obtain the phosphorus removal packing for wastewater treatment.

[0022] Preferably, in step (a), the molar ratio of (3-chloropropyl)triethoxysilane to N,N-dimethyl-1,3-propanediamine is 1:(1.2-1.3), the reaction temperature is 75-85℃, and the reaction time is 20-24 hours; in step (b), the reaction temperature is 25-35℃, and the reaction time is 5-7 hours; in step (c), the reaction temperature is 20-30℃, and the reaction time is 10-14 hours; and in step (d), the reaction temperature is 35-45℃, and the reaction time is 7-9 hours.

[0023] Preferably, in step (b), the molar ratio of the primary amine group in intermediate A to succinic anhydride is 1:(1.0-1.2); in step (c), the molar ratio of the tertiary amine group in intermediate A to iodomethane is 1:(1.4-1.6); and in step (d), the molar ratio of the carboxyl group introduced by succinic anhydride to the lanthanum ion contained in lanthanum nitrate is 1:(1.0-1.2).

[0024] Preferably, the pyrolysis is carried out at 550-650℃ for 1.5-2.5 hours; the acid solution is a hydrochloric acid solution with a concentration of 0.8-1.2 mol / L, and the soaking time is 10-14 hours; the drying is carried out at 100-110℃.

[0025] Preferably, the solid-liquid ratio is 1:(4-6)g / mL; the pH value is adjusted to 4.0-5.0; the gradient heating rate is 1-3℃ / min; the target temperature is 80-90℃; and the constant temperature stirring reaction time is 4-6 hours.

[0026] A wastewater treatment phosphorus removal packing material is also provided, which is prepared by a wastewater treatment phosphorus removal packing material preparation method.

[0027] It also provides an application of a wastewater treatment phosphorus removal packing material in the removal of phosphorus from wastewater or water bodies.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] By constructing active centers with extremely high affinity for phosphate on the surface of the novel packing material, it can efficiently and selectively capture phosphate in water through internal spherical complexation, giving the packing material a phosphorus removal capacity far exceeding that of traditional adsorption materials. Even in complex water quality environments, it can accurately remove target pollutants, significantly improving the efficiency and reliability of deep phosphorus removal.

[0030] By integrating cationic functional groups with broad-spectrum bactericidal efficacy onto the material surface, it possesses excellent antibacterial and anti-fouling capabilities. It can actively destroy the cell structure of bacteria and other microorganisms attached to the surface of the packing material, inhibiting the formation and growth of biofilm from the source. This effectively solves the biological clogging problem that is common in traditional packing materials during long-term operation and ensures the long-term stable operation of the treatment system.

[0031] Through a specific chemical grafting technique, a multifunctional active layer is firmly attached to the surface of the biochar matrix using extremely stable covalent bonds. This robust connection ensures that the active components will not detach or be lost under long-term hydraulic scouring, completely avoiding the risk of secondary pollution to water bodies. At the same time, the packing material has a stable structure and can be efficiently eluted and regenerated by a simple method after adsorption saturation. After multiple cycles of use, its core performance can still be maintained at a high level, demonstrating excellent stability and economic value. Detailed Implementation

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0033] Example 1

[0034] Example 1 discloses a method for preparing phosphorus removal packing material for wastewater treatment. The main chemical raw materials used, such as (3-chloropropyl)triethoxysilane, N,N-dimethyl-1,3-propanediamine, succinic anhydride, lanthanum nitrate, iodomethane, and anhydrous ethanol, are all of analytical grade. Rice husk is agricultural waste. The method first prepares a quaternary ammonium salt-lanthanum hybrid organosilicon modifier. During the preparation process, the molar ratio of (3-chloropropyl)triethoxysilane to N,N-dimethyl-1,3-propanediamine is controlled at 1:1.2, and the mixture is refluxed at 75°C for 20 hours. Then, succinic anhydride (with a molar ratio of 1:1.0 to the primary amine group of the intermediate product) is added, and the mixture is reacted at 25°C for 5 hours. Next, iodomethane (with a molar ratio of 1:1.4 to the tertiary amine group of the intermediate product) is added dropwise, and the mixture is reacted at 20°C in the dark for 10 hours to complete the quaternization. Finally, the obtained product is reacted with lanthanum nitrate (with a molar ratio of 1:1 to the carboxyl group). 0) A chelation reaction was carried out at 35℃ for 7 hours; next, activated porous biochar was prepared by pyrolyzing rice husks at 550℃ under limited oxygen conditions for 1.5 hours, followed by activation by soaking in 0.8mol / L hydrochloric acid solution for 10 hours; finally, a grafting step was carried out, in which the activated porous biochar and the prepared modifier were mixed in an ethanol solution at a solid-liquid ratio of 1:4g / mL, the pH of the system was adjusted to 4.0, and the temperature was increased to 80℃ at a rate of 1℃ / min and kept at a constant temperature for 4 hours; the product obtained by this wastewater treatment phosphorus removal packing preparation method has an effective adsorption capacity for phosphates by its La-quaternary ammonium salt functionalized covalent hybrid biochar phosphorus removal packing. Under the conditions of 25℃ and pH=7, the maximum adsorption capacity reaches 43.5mg-P / g. At the same time, the presence of quaternary ammonium salt groups makes its bactericidal rate against Escherichia coli reach more than 99%, effectively inhibiting the biological clogging phenomenon in the water treatment system.

[0035] Example 2

[0036] Example 2 discloses a method for preparing phosphorus removal packing material for wastewater treatment; all main chemical raw materials used are of analytical grade; the method is characterized in that, in preparing the quaternary ammonium salt-lanthanum hybrid organosilicon modifier, the molar ratio of (3-chloropropyl)triethoxysilane to N,N-dimethyl-1,3-propanediamine is 1:1.2, the reaction temperature is 80℃, and the time is 24 hours; the molar ratio of succinic anhydride to the intermediate primary amine is 1:1.1, the reaction temperature is 30℃, and the time is 6 hours; the molar ratio of iodomethane to the intermediate tertiary amine is 1:1.5, the reaction temperature is 25℃, and the time is 12 hours; the molar ratio of lanthanum nitrate to carboxyl group is 1:1.1, the reaction temperature is 40℃, and the time is 8 hours; in preparing activated porous biochar, the pyrolysis temperature is 600℃, and the time is... 2 hours; acid activation was performed using a 1.0 mol / L hydrochloric acid solution, soaking for 12 hours; in the grafting step, the solid-liquid ratio was 1:5 g / mL, the pH of the system was adjusted to 4.5, the temperature was increased to 85℃ at a rate of 2℃ / min, and the reaction was carried out at a constant temperature for 5 hours; the product obtained by this wastewater treatment phosphorus removal packing preparation method has a balanced comprehensive performance of La-quaternary ammonium salt functionalized covalent hybrid biochar phosphorus removal packing, with a maximum adsorption capacity of 45.8 mg-P / g for phosphate. The lanthanum active centers on its surface efficiently capture phosphate ions through internal spherical complexation. At the same time, the covalently bonded quaternary ammonium salt groups have a bactericidal rate of up to 99.7% against Escherichia coli, demonstrating the ability to cope with microbial pollution in complex wastewater environments and solving the problem of biological clogging.

[0037] Example 3

[0038] Example 3 discloses a method for preparing phosphorus removal packing material for wastewater treatment; all main chemical raw materials used are of analytical grade; the method is characterized in that, in the step of preparing the quaternary ammonium salt-lanthanum hybrid organosilicon modifier, the molar ratios of each raw material are as follows: (3-chloropropyl)triethoxysilane to N,N-dimethyl-1,3-propanediamine is 1:1.3; succinic anhydride to primary amine is 1:1.2; iodomethane to tertiary amine is 1:1.6; lanthanum nitrate to carboxyl group is 1:1.2; the corresponding reaction conditions are: amination reaction is carried out at 85°C for 24 hours; ring-opening reaction is carried out at 35°C for 7 hours; quaternization reaction is carried out at 30°C for 14 hours; chelation reaction is carried out at 45°C for 9 hours; biochar is used. In the preparation of the matrix, the pyrolysis temperature was 650℃ for 2.5 hours; acid activation was performed using 1.2 mol / L hydrochloric acid for 14 hours; in the final grafting step, the solid-liquid ratio was 1:6 g / mL, the pH was adjusted to 5.0, the temperature was increased to 90℃ at a rate of 3℃ / min, and the reaction was carried out at a constant temperature for 6 hours; the product obtained by this wastewater treatment phosphorus removal packing preparation method, its La-quaternary ammonium salt functionalized covalent hybrid biochar phosphorus removal packing, achieved a high-density functional layer at the upper limit of various parameter values, and its maximum adsorption capacity for phosphate reached 45.2 mg-P / g. At the same time, due to the relatively high dosage of each component in the modifier, its bactericidal performance and stability were also reliably guaranteed.

[0039] Example 4

[0040] Example 4 discloses a method for preparing phosphorus removal packing material for wastewater treatment; all main chemical raw materials used are of analytical grade; in this method, the molar ratio of (3-chloropropyl)triethoxysilane to N,N-dimethyl-1,3-propanediamine used to prepare the modifier is 1:1.25, and the reaction is carried out at 78°C for 22 hours; succinic anhydride (molar ratio of 1:1.15 to primary amine) is reacted at 28°C for 6.5 hours; iodomethane (molar ratio of 1:1.45 to tertiary amine) is reacted at 22°C for 11 hours; lanthanum nitrate (molar ratio of 1:1.15 to carboxyl group) is reacted at 42°C for 8.5 hours; when preparing the biochar matrix, the reaction is carried out at 58°C. The material was pyrolyzed at 0℃ for 2.2 hours and then soaked in 0.9mol / L hydrochloric acid for 11 hours. The solid-liquid ratio for the grafting reaction was 1:5.5g / mL, the pH was adjusted to 4.2, and the temperature was increased to 82℃ at a rate of 2.5℃ / min, and the reaction was carried out at a constant temperature for 5.5 hours. The product obtained by this wastewater treatment phosphorus removal packing preparation method has stable performance of La-quaternary ammonium salt functionalized covalent hybrid biochar phosphorus removal packing, with a phosphorus adsorption capacity of 44.6mg-P / g. The bactericidal rate and metal ion dissolution index both met the expected results, proving that the preparation method has good process robustness over a wide parameter range.

[0041] Example 5

[0042] Example 5 discloses a method for preparing phosphorus removal packing material for wastewater treatment; all main chemical raw materials used are of analytical grade; in this method, the molar ratio of (3-chloropropyl)triethoxysilane to N,N-dimethyl-1,3-propanediamine used to prepare the modifier is 1:1.2, and the reaction is carried out at 82°C for 23 hours; succinic anhydride (molar ratio to primary amine 1:1.05) is reacted at 32°C for 5.5 hours; iodomethane (molar ratio to tertiary amine 1:1.55) is reacted at 28°C for 13 hours; lanthanum nitrate (molar ratio to carboxyl group 1:1.05) is reacted at 38°C for 7.5 hours; and the biochar matrix is ​​prepared by pyrolysis at 620°C for 1.8 hours. The substrate was soaked in 1.1 mol / L hydrochloric acid for 13 hours; the solid-liquid ratio of the grafting reaction was 1:4.5 g / mL, the pH was adjusted to 4.8, the temperature was increased to 88℃ at a rate of 1.5℃ / min, and the reaction was carried out at a constant temperature for 4.5 hours; the product obtained by this wastewater treatment phosphorus removal packing preparation method, its La-quaternary ammonium salt functionalized covalent hybrid biochar phosphorus removal packing also showed excellent application performance, with significant phosphorus removal effect and a maximum adsorption capacity of 45.5 mg-P / g. The matrix —O—Si structure formed by covalent bonds ensured the firm adhesion of the functional layer. Under long-term scouring, the packing showed good stability and regeneration performance.

[0043] Comparative Example 1

[0044] This comparative example only prepared activated porous biochar, which was prepared by pyrolyzing rice husks at 600℃ under limited oxygen conditions for 2 hours to obtain porous biochar. It was then activated by soaking in 1mol / L hydrochloric acid solution for 12 hours, washed until neutral, and dried at 105℃. The activated porous biochar was used directly as a phosphorus removal filler. The filler prepared by this method is unmodified activated porous biochar.

[0045] Comparative Example 2

[0046] This comparative example uses a physical impregnation method to prepare the filler. First, activated porous biochar is prepared according to the method of Comparative Example 1. Then, 100g of the biochar is impregnated in 500mL of anhydrous ethanol solution containing 47.6g of lanthanum nitrate hexahydrate. After stirring for 24 hours, it is filtered and dried in an oven at 105°C for 12 hours. This method represents the prior art technique of loading active components by physical impregnation.

[0047] Comparative Example 3

[0048] This comparative example basically follows the preparation method of Example 2, but in the grafting step, the pH of the system is adjusted to 8.0 with sodium hydroxide solution. This pH condition is used to verify the importance of the optimal acid catalytic condition range. The other conditions are exactly the same as in Example 2.

[0049] Effect verification

[0050] The packing materials prepared in Examples 1-5 and Comparative Examples 1-3 were subjected to performance tests, and the test methods were as described in the examples. Four core indicators were mainly examined: maximum adsorption capacity, bactericidal rate against Escherichia coli, long-term stability (characterized by the concentration of lanthanum ions in the leachate after 7 days of soaking), and regeneration performance (characterized by the capacity retention rate after 5 adsorption-desorption cycles). The results are summarized in Table 1 below:

[0051] Table 1 Comparison of packing performance between each embodiment and the comparative example

[0052]

[0053] As can be seen from the data in Table 1, the La-quaternary ammonium salt functionalized covalent hybrid biochar phosphorus removal packings obtained by the wastewater treatment phosphorus removal packing preparation method of the present invention in Examples 1 to 5 exhibit excellent performance in all aspects. Compared with Comparative Example 1 (unmodified biochar), the phosphorus removal capacity of the examples is increased by more than 10 times, and they also achieve highly efficient bactericidal ability that traditional adsorption packings do not possess. Compared with Comparative Example 2 (physical impregnation method), the lanthanum ion dissolution concentration of the examples is extremely low, proving that the covalent grafting effectively avoids the problems of active component loss and secondary pollution, and the regeneration performance is significantly improved. Compared with Comparative Example 3 (incorrect process parameters), all its performance is significantly superior, proving that the acidic pH conditions defined by the present invention are crucial for the occurrence of the grafting reaction, and are the key to ensuring the successful construction of the functional layer and the high performance of the product. In summary, the preparation method and product of the present invention solve the technical problems of low phosphorus removal efficiency, easy bioclogging, and unstable active components in the prior art.

[0054] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications, equivalent changes, and modifications 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 protection scope of the present invention.

Claims

1. A method for preparing a phosphorus removal packing material for wastewater treatment, characterized in that, Includes the following steps: Preparation of quaternary ammonium salt-lanthanum hybrid organosilanes as modifiers; Preparation of activated porous biochar; A quaternary ammonium salt-lanthanum hybrid organosilicon modifier was grafted onto activated porous biochar to obtain a phosphorus removal packing for wastewater treatment. Preparation of quaternary ammonium salt-lanthanum hybrid organosilanes includes: Step (a): In anhydrous ethanol solvent, (3-chloropropyl)triethoxysilane and N,N-dimethyl-1,3-propanediamine are refluxed and stirred under nitrogen protection to obtain intermediate A solution containing amination silane coupling agent. Step (b): After cooling the solution obtained in step (a), add succinic anhydride and stir to react, so that intermediate A reacts with succinic anhydride to introduce carboxyl groups. In step (c), the reaction solution obtained in step (b) is placed in an ice-water bath, and iodomethane is slowly added dropwise. Then, under light-protected conditions, the mixture is continuously stirred to carry out the quaternization reaction to obtain intermediate B. Step (d) involves adding the solution containing intermediate B dropwise to an anhydrous ethanol solution of lanthanum nitrate and continuing stirring to carry out a chelation coordination reaction, thereby obtaining a quaternary ammonium salt-lanthanum hybrid organosilicon modifier. The grafting process includes: The activated porous biochar was placed in a reaction vessel, and an ethanol solution of quaternary ammonium salt-lanthanum hybrid organosilicon modifier was added. Anhydrous ethanol was added to the predetermined solid-liquid ratio, and the mixture was ultrasonically dispersed and then allowed to stand to remove bubbles. Deionized water was added to the reactor to initiate the hydrolysis of the silane in the modifier, and the pH of the system was adjusted to 4.0-5.0 with acid. The system was heated using a gradient heating method and stirred at a constant temperature at the target temperature to allow the hydrolyzed silanol groups to undergo a dehydration condensation reaction with the hydroxyl groups on the surface of biochar, forming covalent bonds. The solid product after the reaction was washed alternately with anhydrous ethanol and deionized water and then dried to obtain the phosphorus removal packing for wastewater treatment. The solid-liquid ratio is 1:(4-6)g / mL; the gradient heating rate is 1-3℃ / min; the target temperature is 80-90℃; and the constant temperature stirring reaction time is 4-6 hours.

2. The method for preparing a phosphorus removal packing material for wastewater treatment according to claim 1, characterized in that, The preparation of activated porous biochar includes: Porous biochar was produced by pyrolyzing rice husks under limited oxygen conditions. The porous biochar was activated by soaking in an acid solution to clean its pores and increase the number of surface hydroxyl groups. It was then washed until neutral and dried to obtain activated porous biochar.

3. The method for preparing a phosphorus removal packing material for wastewater treatment according to claim 2, characterized in that, In step (a), the molar ratio of (3-chloropropyl)triethoxysilane to N,N-dimethyl-1,3-propanediamine is 1:(1.2-1.3), the reaction temperature is 75-85℃, and the reaction time is 20-24 hours; in step (b), the reaction temperature is 25-35℃, and the reaction time is 5-7 hours; in step (c), the reaction time is 10-14 hours; and in step (d), the reaction temperature is 35-45℃, and the reaction time is 7-9 hours.

4. The method for preparing a phosphorus removal packing material for wastewater treatment according to claim 3, characterized in that, In step (c), the molar ratio of the tertiary amine group in intermediate A to iodomethane is 1:(1.4-1.6); in step (d), the molar ratio of the carboxyl group introduced by succinic anhydride to the lanthanum ion contained in lanthanum nitrate is 1:(1.0-1.2).

5. The method for preparing a phosphorus removal packing material for wastewater treatment according to claim 2, characterized in that, The pyrolysis is carried out at 550-650℃ for 1.5-2.5 hours; the acid solution is a hydrochloric acid solution with a concentration of 0.8-1.2 mol / L, and the soaking time is 10-14 hours; the drying is carried out at 100-110℃.

6. A phosphorus removal packing material for wastewater treatment, characterized in that, It is prepared by the method of any one of claims 1-5 for preparing phosphorus removal packing material for wastewater treatment.

7. An application of the wastewater treatment phosphorus removal packing material according to claim 6 in wastewater phosphorus removal.

Images