A red clay phosphorus adsorbent and a preparation method and application thereof

Abstract

The application discloses a red clay phosphorus adsorbent, which comprises 115-145 parts of red clay particles, 20-30 parts of diatomite, 10-15 parts of glass powder and 3-10 parts of marble powder; and the preparation process comprises the following steps: preparing the red clay particles, weighing the raw materials, crushing, calcining and mixing. The red clay has good adsorption performance on phosphorus, is rich in resources, has a wide distribution range and low cost, and is a natural environment-friendly material. When the red clay is put into sewage, no secondary pollution and other problems are caused, so the red clay has great development potential in the aspect of adsorbing phosphorus.

Description

Technical Field

[0001] This invention relates to the field of phosphorus adsorption materials technology, and more specifically to a red clay phosphorus adsorbent, its preparation method, and its application. Background Technology

[0002] In recent years, eutrophication of water bodies has intensified, becoming a major challenge in water environment management. Phosphorus is a primary cause of eutrophication; therefore, reducing phosphorus emissions is crucial for controlling eutrophication. Currently, wastewater phosphorus removal methods can be categorized into three types: physical, chemical, and biological methods. Physical methods have limitations in practical application due to their poor treatment efficiency, while biological methods are difficult to operate. Currently, chemical phosphorus removal is the most widely used method both domestically and internationally. Adsorption is a commonly used chemical phosphorus removal method, and in recent years, it has received considerable attention due to its cost-effectiveness. The development and research of efficient and inexpensive phosphorus adsorption materials has become a hot topic in adsorption method research.

[0003] As a land resource, red clay is widely distributed in tropical and subtropical regions, but it is fertile, has poor productivity, is not suitable for crop growth, and results in low crop yields. However, red clay has a high clay content and is rich in oxides such as iron and aluminum, especially exhibiting a strong adsorption and fixation capacity for phosphorus. Currently, domestic and international research mainly focuses on the fixation and release of phosphorus in soil by red clay and its influencing factors, while there are few reports on using red clay as an adsorbent material and as an adsorbent for phosphorus in polluted water bodies.

[0004] Therefore, how to prepare red clay into a phosphorus adsorbent and apply it to the adsorption of phosphorus in wastewater is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a red clay phosphorus adsorbent, its preparation method and application. Red clay has good adsorption performance for phosphorus, and is characterized by abundant resources, wide distribution, and low cost. At the same time, red clay is a natural and environmentally friendly material, and its introduction into sewage will not cause secondary pollution or other problems. Therefore, it has great development potential in the adsorption of phosphorus.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A red clay phosphorus adsorbent comprises the following components in the indicated weight ratios:

[0008] 115-145 parts red clay particles, 20-30 parts diatomaceous earth, 10-15 parts glass powder, and 3-10 parts marble powder.

[0009] The technical effects achieved by the above technical solutions are as follows: Red clay has excellent phosphorus adsorption performance and is suitable for adsorbing phosphorus in natural water bodies and wastewater. Moreover, red clay is abundant, widely distributed, and low in cost, making it a natural and environmentally friendly material that will not cause secondary environmental pollution. When marble is calcined, it decomposes and foams, giving diatomaceous earth and glass powder a loose and porous structure, thereby enhancing their phosphorus adsorption capacity.

[0010] As a preferred embodiment of the present invention, the red clay phosphorus adsorbent further includes the following components in parts by weight: 5-10 parts of sodium borate.

[0011] A method for preparing a red clay phosphorus adsorbent includes the following steps:

[0012] Step 1: Preparation of red clay particles: Red clay particles are prepared using natural red clay from the south as raw material;

[0013] Step 2: Weigh the raw materials: Weigh diatomaceous earth, glass powder, marble powder, and sodium borate according to the above weight ratio, and mix the weighed raw materials evenly to obtain a mixture.

[0014] Step 3, crushing and calcining: Dry the mixture obtained in step 2 and crush it to 200-300 mesh. Then, calcine the crushed raw material to obtain the adsorbent formulation.

[0015] Step 4: Mixing: Mix the red clay particles obtained in Step 1 with the adsorption ingredients according to the weight ratio to obtain the phosphorus adsorbent.

[0016] The technical effect achieved by the above technical solution is that by mixing marble, diatomaceous earth, sodium borate and glass powder and calcining them, the CO2 produced after the marble is heated and decomposed causes the glass powder, diatomaceous earth and sodium borate to form a loose and porous structure on their surface, which enhances their adsorption performance for phosphorus and other heavy metals.

[0017] As a preferred technical solution of the present invention, the specific process of preparing red clay particles using red clay as raw material in step one includes:

[0018] (1) Coarse selection of natural red clay, selecting red clay with silt particles and an iron and aluminum oxide content of 35-60%;

[0019] (2) The red clay obtained in step (1) is crushed and purified to separate clay particles with a particle size of 0.1-2μm;

[0020] (3) The clay particles obtained in step (2) are dried and crushed, and the crushed clay particles are passed through a 100-mesh sieve. The sieved clay particles are then placed in a hot reactor and roasted at 200-800℃ for 1-2 hours. After roasting, the clay particles are taken out, cooled and crushed at room temperature to obtain red clay particles.

[0021] The technical effects achieved by the above technical solutions are as follows: highly efficient phosphorus adsorption particles can be obtained from natural red clay through a simple purification and calcination process. The entire preparation process is simple, the production cost is low, and the large-particle soil components generated during the production process can be used for backfilling without generating waste.

[0022] As a preferred technical solution of the present invention, in step (2), a magnetic stirrer is used to purify the red clay; the specific purification process is to mix the red clay and water in a volume ratio of 1:3-5, stir and let it settle by gravity, and screen the clay particles on the upper layer, which is the purified clay.

[0023] As a preferred technical solution of the present invention, in step (3), before roasting, the clay particles are crushed to a fineness of 70-80 mesh.

[0024] As a preferred technical solution of the present invention, in step (3), after calcination, the clay particles are pulverized to a fineness of 200-300 mesh.

[0025] As a preferred embodiment of the present invention, the calcination process of the raw materials in step three is as follows:

[0026] The temperature is increased to 400-500℃ at a heating rate of 10-15℃ / min and held for 20-30 min; then increased to 1000-1100℃ at a heating rate of 10-15℃ / min and held for 10-20 min; then decreased to 800-900℃ at a cooling rate of 20-30℃ / min and finally cooled naturally to room temperature to obtain the adsorbent formulation.

[0027] As a preferred technical solution of the present invention, the crushing is carried out by a crusher in steps two and three.

[0028] Application of a red clay phosphorus adsorbent in the adsorption of phosphorus in wastewater.

[0029] The technical effects achieved by the above technical solutions are as follows: At present, domestic and foreign research mainly focuses on the fixation and release of phosphorus in soil by red clay and its influencing factors. No application of red clay to the adsorption of phosphorus in water has been found. Therefore, the above technical solutions provide a new use for red clay and provide theoretical support for the development of the properties of red clay.

[0030] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a red clay phosphorus adsorbent and its preparation method and application, achieving the following technical effects:

[0031] 1) This invention uses red clay with specific components as raw material, which is abundant and widely distributed, and the cost of the raw material is negligible.

[0032] 2) The adsorbent raw materials in this invention, namely red clay, diatomaceous earth, and marble, are natural and environmentally friendly materials that will not cause secondary pollution or other adverse effects on the environment during the treatment process.

[0033] 3) Highly efficient phosphorus adsorbents can be obtained from natural red clay through simple purification and calcination processes. The entire preparation process is simple, the production cost is low, and the large-particle soil components generated during the production process can be used for backfilling, without generating waste.

[0034] 4) It has a wide range of applications and can be used for phosphorus removal in natural water bodies and aquaculture wastewater. The adsorbent has excellent phosphorus adsorption effect in solution, and the phosphorus concentration in the adsorbent after adsorption is high. It can be used as a raw material for compound fertilizer or phosphorus-rich nutrient soil, and can realize resource reuse. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0036] Figure 1 The attached figure shows the effect of phosphorus adsorption experiments using different adsorbents as phosphorus adsorbents in Example 6;

[0037] Figure 2 The attached figure shows the effect of phosphorus adsorption test using natural red clay (NS), purified red clay (WS) particles and activated carbon in Example 7.

[0038] Figure 3 The attached figure shows the change in phosphorus concentration in the solution during the phosphorus adsorption test when phosphorus adsorbents prepared from natural red clay (NS) and purified red clay (WS) particles were used as raw materials in Example 8.

[0039] Figure 4 The attached figure shows the change in phosphorus adsorption capacity when phosphorus adsorbents prepared from natural red clay (NS) and purified red clay (WS) particles in Example 9 are tested.

[0040] Figure 5 The attached figure shows the relationship between the phosphorus concentration after adsorption and the original pH value of the solution when the phosphorus adsorbent prepared from natural red clay (NS) and purified red clay (WS) particles as raw materials in Example 10 was tested for phosphorus adsorption, with the original phosphorus concentration being 35 mg / L.

[0041] Figure 6The attached figure shows the relationship between the phosphorus concentration after adsorption and the original pH value of the solution when the phosphorus adsorbent prepared from natural red clay (NS) and purified red clay (WS) particles as raw materials was used in Example 10 for phosphorus adsorption test, with the original phosphorus concentration being 50 mg / L. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] In all five embodiments of the present invention, a pulverizer is used for pulverization, and the pulverizer is an MKL-QL airflow pulverizer; the magnetic stirrer is an HS-350C magnetic stirrer.

[0044] Example 1

[0045] A method for preparing a red clay phosphorus adsorbent includes the following steps:

[0046] Step 1: Prepare red clay particles:

[0047] (1) Using natural red clay from the south as raw material, the natural red clay is coarsely selected, and red clay with 35-45% iron and aluminum oxide content is selected.

[0048] (2) The red clay obtained in step (1) is crushed by a pulverizer and purified by a magnetic stirrer to separate clay particles with a particle size of 0.5-2μm. The specific purification process is to mix red clay and water in a volume ratio of 1:3, stir with a magnetic stirrer, and screen the upper layer of clay particles with a particle size of 0.5-2μm.

[0049] (3) The clay particles obtained in step (2) are dried and crushed to a fineness of 70 mesh. The crushed clay particles are then passed through a 100-mesh sieve. The sieved clay particles are then placed in a hot reactor and roasted at 200°C for 1 hour. After roasting, the clay particles are taken out, cooled at room temperature, and crushed to a fineness of 200 mesh to obtain red clay particles.

[0050] Step 2: Weigh the raw materials: Weigh 20 parts diatomaceous earth, 10 parts glass powder, and 3 parts marble powder, and mix the weighed raw materials evenly to obtain a mixture.

[0051] Step 3, pulverization and calcination: Dry and pulverize the mixture obtained in Step 2 to 200 mesh. Calcinate the pulverized raw material. During calcination, first heat the material to 400℃ at a heating rate of 10℃ / min and hold for 20 min; then heat the material to 1000℃ at a heating rate of 10℃ / min and hold for 10 min; then cool the material to 800℃ at a cooling rate of 20℃ / min, and finally allow it to cool naturally to room temperature to obtain the adsorption feedstock.

[0052] Step 4: Mixing: Weigh 115 parts of the red clay particles prepared in Step 1 and mix them with the adsorption ingredients to obtain the red clay phosphorus adsorbent.

[0053] Example 2

[0054] A method for preparing a red clay phosphorus adsorbent includes the following steps:

[0055] Step 1: Prepare red clay particles:

[0056] (1) Using natural red clay from the south as raw material, the natural red clay is coarsely selected, and red clay with silt particles and iron and aluminum oxide content of 46%-50% is selected.

[0057] (2) The red clay obtained in step (1) is crushed by a pulverizer and purified by a magnetic stirrer to separate clay particles with a particle size of 0.1-0.5μm. The specific purification process is to mix red clay and water in a volume ratio of 1:4, stir with a magnetic stirrer, and screen the upper layer of clay particles with a particle size of 0.1-0.5μm.

[0058] (3) The clay particles obtained in step (2) are dried and crushed to a fineness of 80 mesh. The crushed clay particles are then passed through a 100-mesh sieve. The sieved clay particles are then placed in a hot reactor and roasted at 800°C for 2 hours. After roasting, the clay particles are taken out, cooled at room temperature, and crushed to a fineness of 300 mesh to obtain red clay particles.

[0059] Step 2: Weigh the raw materials: Weigh 30 parts diatomaceous earth, 15 parts glass powder, 10 parts marble powder, and 10 parts sodium borate, and mix the weighed raw materials evenly to obtain a mixture.

[0060] Step 3, pulverization and calcination: Dry and pulverize the mixture obtained in Step 2 to 300 mesh. Calcinate the pulverized raw material. During calcination, first heat to 500℃ at a heating rate of 15℃ / min and hold for 30 min; then heat to 1100℃ at a heating rate of 15℃ / min and hold for 20 min; then cool to 900℃ at a cooling rate of 30℃ / min, and finally allow to cool naturally to room temperature to obtain the adsorption feedstock.

[0061] Step 4: Mixing: Weigh 145 parts of the red clay particles prepared in Step 1 and mix them with the adsorption ingredients to obtain the red clay phosphorus adsorbent.

[0062] Example 3

[0063] A method for preparing a red clay phosphorus adsorbent includes the following steps:

[0064] Step 1: Prepare red clay particles:

[0065] (1) Using natural red clay from the south as raw material, the natural red clay is coarsely selected, and red clay with a content of 51-52% of iron and aluminum oxides is selected.

[0066] (2) The red clay obtained in step (1) is crushed by a pulverizer and purified by a magnetic stirrer to separate clay particles with a particle size of 0.5-1μm. The specific purification process is to mix red clay and water in a volume ratio of 1:5, stir with a magnetic stirrer, and screen the upper layer of clay particles with a particle size of 0.5-1μm.

[0067] (3) The clay particles obtained in step (2) are dried and crushed to a fineness of 75 mesh. The crushed clay particles are then passed through a 100-mesh sieve. The sieved clay particles are then placed in a hot reactor and calcined at 400°C for 1.5 hours. After calcination, the clay particles are taken out, cooled at room temperature, and crushed to a fineness of 230 mesh to obtain red clay particles.

[0068] Step 2: Weigh the raw materials: Weigh 25 parts diatomaceous earth, 12 parts glass powder, 6 parts marble powder, and 8 parts sodium borate, and mix the weighed raw materials evenly to obtain a mixture.

[0069] Step 3, pulverization and calcination: Dry and pulverize the mixture obtained in Step 2 to 230 mesh. Calcinate the pulverized raw material. During calcination, first heat to 450℃ at a heating rate of 12℃ / min and hold for 25 min; then heat to 1050℃ at a heating rate of 12℃ / min and hold for 15 min; then cool to 850℃ at a cooling rate of 25℃ / min, and finally allow to cool naturally to room temperature to obtain the adsorption feedstock.

[0070] Step 4: Mixing: Weigh 125 parts of the red clay particles prepared in Step 1 and mix them with the adsorption ingredients to obtain the red clay phosphorus adsorbent.

[0071] Example 4

[0072] A method for preparing a red clay phosphorus adsorbent includes the following steps:

[0073] Step 1: Prepare red clay particles:

[0074] (1) Using natural red clay from the south as raw material, the natural red clay is coarsely selected, and red clay with a content of 53-55% of iron and aluminum oxides is selected.

[0075] (2) The red clay obtained in step (1) is crushed by a pulverizer and purified by a magnetic stirrer to separate clay particles with a particle size of 1.5-2μm. The specific purification process is to mix red clay and water in a volume ratio of 1:4.5, stir with a magnetic stirrer, and screen the upper layer of clay particles with a particle size of 1.5-2μm.

[0076] (3) The clay particles obtained in step (2) are dried and crushed to a fineness of 80 mesh. The crushed clay particles are then passed through a 100-mesh sieve. The sieved clay particles are then placed in a hot reactor and roasted at 500°C for 1.3 hours. After roasting, the clay particles are taken out, cooled at room temperature, and crushed to a fineness of 250 mesh to obtain red clay particles.

[0077] Step 2: Weigh the raw materials: Weigh 27 parts diatomaceous earth, 14 parts glass powder, 9 parts marble powder, and 7 parts sodium borate, and mix the weighed raw materials evenly to obtain a mixture.

[0078] Step 3, pulverization and calcination: Dry and pulverize the mixture obtained in Step 2 to 250 mesh. Calcinate the pulverized raw material. During calcination, first heat the material to 460℃ at a heating rate of 13℃ / min and hold for 27 min; then heat the material to 1070℃ at a heating rate of 13℃ / min and hold for 17 min; then cool the material to 810℃ at a cooling rate of 26℃ / min, and finally allow it to cool naturally to room temperature to obtain the adsorption feedstock.

[0079] Step 4: Mixing: Weigh 135 parts of the red clay particles prepared in Step 1 and mix them with the adsorption ingredients to obtain the red clay phosphorus adsorbent.

[0080] Example 5

[0081] A method for preparing a red clay phosphorus adsorbent includes the following steps:

[0082] Step 1: Prepare red clay particles:

[0083] (1) Using natural red clay from the south as raw material, the natural red clay is coarsely selected, and red clay with gluten particles and iron and aluminum oxide content of 56-60% is selected.

[0084] (2) The red clay obtained in step (1) is crushed by a pulverizer and purified by a magnetic stirrer to separate clay particles with a particle size of 1-2 μm. The specific purification process is to mix red clay and water in a volume ratio of 1:3.5, stir with a magnetic stirrer, and screen the upper layer of clay particles with a particle size of 1-2 μm.

[0085] (3) The clay particles obtained in step (2) are dried and crushed to a fineness of 70 mesh. The crushed clay particles are then passed through a 100-mesh sieve. The sieved clay particles are then placed in a hot reactor and calcined at 600°C for 1.7 hours. After calcination, the clay particles are taken out, cooled at room temperature, and crushed to a fineness of 270 mesh to obtain red clay particles.

[0086] Step 2: Weigh the raw materials: Weigh 28 parts diatomaceous earth, 11 parts glass powder, 8 parts marble powder, and 6 parts sodium borate, and mix the weighed raw materials evenly to obtain a mixture.

[0087] Step 3, pulverization and calcination: Dry and pulverize the mixture obtained in Step 2 to 270 mesh. Calcinate the pulverized raw material. During calcination, first heat the material to 480℃ at a heating rate of 14℃ / min and hold for 22 min; then heat the material to 1080℃ at a heating rate of 11℃ / min and hold for 14 min; then cool the material to 870℃ at a cooling rate of 22℃ / min, and finally allow it to cool naturally to room temperature to obtain the adsorption feedstock.

[0088] Step 4: Mixing: Weigh 140 parts of the red clay particles prepared in Step 1 and mix them with the adsorption ingredients to obtain the red clay phosphorus adsorbent.

[0089] Example 6

[0090] Activated carbon was used as a phosphorus adsorbent in a phosphorus adsorption test as a control group.

[0091] Phosphorus adsorption experiments were conducted using natural red clay that had passed through a 100-mesh sieve directly as a phosphorus adsorbent, which was designated as test group 1.

[0092] The natural red clay was replaced with kaolin and passed through a 100-mesh sieve for phosphorus adsorption test, which was used as test group 2.

[0093] The natural red clay was replaced with attapulgite and passed through a 100-mesh sieve for phosphorus adsorption test, which was used as test group 3.

[0094] The natural red clay was replaced with bentonite and passed through a 100-mesh sieve for phosphorus adsorption test, which was used as test group 4.

[0095] The natural red clay was replaced with zeolite and passed through a 100-mesh sieve for phosphorus adsorption test, which was used as test group 5.

[0096] Four g of each of the six different adsorbents was placed in two 250 mL Erlenmeyer flasks, with 100 mL of phosphorus-containing solutions at concentrations of 35 mg / L and 50 mg / L added to the flasks containing the same adsorbent. The flasks were sealed and placed in a constant-temperature shaker at 25°C and 200 rpm for 2 hours. After the reaction, the mixture was centrifuged at 4000 rpm for 5 minutes in a benchtop centrifuge. The supernatant was filtered through a 0.45 μm microporous membrane, and the residual phosphorus concentration was measured. The experimental results are as follows: Figure 1 As shown, red clay exhibited better phosphorus removal efficiency in solutions with initial concentrations of 35 mg / L and 50 mg / L, significantly higher than kaolin, attapulgite, bentonite, and zeolite. The phosphorus removal efficiencies of red clay in solutions with initial concentrations of 35 mg / L and 50 mg / L were 79.2% and 73.5%, respectively, slightly lower than activated carbon. Activated carbon achieved phosphorus removal efficiencies of 85.3% and 79.6% in solutions with initial concentrations of 35 mg / L and 50 mg / L, respectively.

[0097] Example 7

[0098] Natural red clay (NS) that has passed through a 100-mesh sieve, purified red clay (WS) granules prepared in step one of Example 4, and activated carbon, 4g each, were placed in multiple 250mL conical flasks. 100mL of phosphorus-containing solutions with phosphorus concentrations of 35mg / L and 50mg / L (calculated as P) were added respectively, and phosphorus adsorption tests were conducted, following the same procedure as in Example 6. These were designated as test group 1, test group 2, and control group, respectively. The results are as follows: Figure 2 As shown, the purified red clay (WS) significantly improved the removal rate of phosphorus in solutions with initial phosphorus concentrations of 35 mg / L and 50 mg / L, by 9.1% and 3.5%, respectively, which was comparable to the removal effect of activated carbon.

[0099] Example 8

[0100] Take natural red clay that has passed through a 100-mesh sieve. Without processing it in step one of Example 4, directly mix the natural red clay that has passed through a 100-mesh sieve with other raw materials according to the method in steps three and four in Example 4 and prepare a phosphorus adsorbent for phosphorus adsorption experiment, as test group 1.

[0101] The phosphorus adsorbent prepared in Example 4 was used as a control group in a phosphorus adsorption test.

[0102] The experimental procedure is as follows:

[0103] Take 4g of each phosphorus adsorbent from each group and place it into three 250mL Erlenmeyer flasks. Set up two 250mL Erlenmeyer flasks in each group. Add 100mL of simulated phosphorus-containing wastewater with phosphorus concentrations of 35mg / L and 50mg / L (calculated as P) to each Erlenmeyer flask, respectively. Maintain constant temperature and shake for 5min-24h. Perform the phosphorus adsorption experiment as in Example 6. Results are as follows: Figure 3 As shown; by Figure 3 It was found that, within a reaction time range of 5 min to 2 h, the phosphorus removal rates of experimental group 1 (using natural red clay as raw material) and the control group (using purified red clay particles as raw material) continuously increased with time in solutions with initial concentrations of 35 mg / L and 50 mg / L. Specifically, at 2 h, experimental group 1 achieved phosphorus removal rates of 82.2% and 76.5% for initial concentrations of 35 mg / L and 50 mg / L, respectively, while the control group achieved 91.4% and 82.1%. After 2 h, with increasing shaking time, the removal rates did not increase significantly and tended to reach equilibrium.

[0104] Example 9

[0105] Take natural red clay that has passed through a 100-mesh sieve. Without processing it in step one of Example 4, directly mix the natural red clay that has passed through a 100-mesh sieve with other raw materials according to the method in steps three and four in Example 4 and prepare a phosphorus adsorbent for phosphorus adsorption experiment, as test group 1.

[0106] The phosphorus adsorbent prepared in Example 4 was used as a control group in a phosphorus adsorption test.

[0107] The phosphorus adsorption test procedure was the same as in Example 6. The results are as follows: Figure 4 As shown, the adsorption capacity of phosphorus in experimental group 1 and the control group increased continuously with the increase of the initial phosphorus concentration. When the initial phosphorus concentration reached 450 mg / L, the adsorption capacity of phosphorus in experimental group 1 and the control group reached its maximum value, which was 2.93 mg / g and 3.21 mg / g, respectively. With further increase in the phosphorus concentration in the initial solution, the adsorption capacity no longer increased.

[0108] Example 10

[0109] Take natural red clay that has passed through a 100-mesh sieve. Without processing it in step one of Example 4, directly mix the natural red clay that has passed through a 100-mesh sieve with other raw materials according to the method in steps three and four in Example 4 and prepare a phosphorus adsorbent for phosphorus adsorption experiment, as test group 1.

[0110] The phosphorus adsorbent prepared in Example 4 was used as a control group in a phosphorus adsorption test.

[0111] Take 4g of each phosphorus adsorbent from each group and place it into three 250mL Erlenmeyer flasks. Each group has two 250mL Erlenmeyer flasks. Add 100mL of simulated phosphorus-containing wastewater with phosphorus concentrations of 35mg / L and 50mg / L (calculated as P) to each Erlenmeyer flask, respectively. Adjust the initial pH of the solution to between 3.5 and 10.5 using hydrochloric acid and sodium hydroxide. Conduct phosphorus adsorption tests (refer to Example 6 for the steps and conditions of the adsorption test). Results are as follows... Figures 5-6 As shown, the phosphorus removal rates in both the experimental and control groups for initial phosphorus concentrations of 35 mg / L and 50 mg / L gradually decreased with increasing pH. In experimental group 1 and the control group, with an initial phosphorus concentration of 35 mg / L, the phosphorus removal rates decreased from 91.4% and 94.3% at pH 3.5 to 43.8% and 55.5% at pH 10, respectively. Similarly, in experimental group 1 and the control group, with an initial phosphorus concentration of 50 mg / L, the phosphorus removal rates decreased from 85.0% and 85.8% at pH 3.5 to 35.9% and 47.6% at pH 10, respectively.

[0112] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0113] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A red clay phosphorus sorbent characterized in that, The components include the following parts by weight: The mixture comprises 115-145 parts red clay particles, 20-30 parts diatomaceous earth, 10-15 parts glass powder, and 3-10 parts marble powder; it also includes the following components in parts by weight: 5-10 parts sodium borate. The preparation method of the red clay phosphorus adsorbent includes the following steps: Step 1: Preparation of red clay particles: Red clay particles are prepared using natural red clay from the south as raw material; Step 2: Weigh the raw materials: Weigh the raw materials according to the above weight ratio, and mix the weighed raw materials evenly to obtain a mixture; Step 3, crushing and calcining: Dry the mixture obtained in step 2 and crush it to 200-300 mesh. Then, calcine the crushed raw material to obtain the adsorbent formulation. Step 4: Mixing: Mix the red clay particles obtained in Step 1 with the adsorption materials according to the weight ratio to obtain the phosphorus adsorbent; In step one, the specific process of preparing red clay particles using red clay as raw material includes: (1) Coarse selection of natural red clay, selecting red clay with silt particles and an iron and aluminum oxide content of 35-60%; (2) The red clay obtained in step (1) is crushed and purified to separate clay particles with a particle size of 0.1-2μm; (3) The clay particles obtained in step (2) are dried and crushed, and the crushed clay particles are passed through a 100-mesh sieve. Then the sieved clay particles are placed in a hot reactor and roasted at 200-800℃ for 1-2 hours. After roasting, they are taken out, cooled and crushed at room temperature to obtain red clay particles. In step (2), a magnetic stirrer is used to purify the red clay; In step (3), before roasting, the clay particles are crushed to a fineness of 70-80 mesh; In step (3), after roasting, the clay particles are pulverized to a fineness of 200-300 mesh; The calcination process of the raw materials in step three is as follows: The temperature is increased to 400-500℃ at a heating rate of 10-15℃ / min and held for 20-30 min; then increased to 1000-1100℃ at a heating rate of 10-15℃ / min and held for 10-20 min; then decreased to 800-900℃ at a cooling rate of 20-30℃ / min and finally cooled naturally to room temperature to obtain the adsorbent formulation.

2. The red clay phosphorus sorbent of claim 1, wherein, In steps two and three, the material is pulverized using a pulverizer.

3. The application of the red clay phosphorus adsorbent according to claim 1 in the adsorption of phosphorus in wastewater.

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