Reusable total phosphorus adsorption material and preparation method thereof

Abstract

The invention discloses a reusable total phosphorus adsorption material and a preparation method thereof. The preparation method of the reusable total phosphorus adsorption material comprises the following steps: (1) adding obtained modified shell powder into an electrostatic spinning solution, adding a curing agent, and stirring at room temperature to obtain a uniform spinning solution; and (2) extracting the uniform spinning solution by adopting a disposable syringe, then placing the spinning solution on an injection pump, spinning, taking down the aluminum foil containing the deposition material on the roller after spinning is finished, placing the aluminum foil in a vacuum drying oven, and vacuumizing to obtain the reusable total phosphorus adsorption material after the spinning is finished. The modified shell powder has positive charges on the surface, phosphate ions in water can be effectively adsorbed, and lignocellulose is used as a main substance of an electrostatic spinning solution, so that the prepared material has excellent mechanical property and reusability, and the material can still keep excellent adsorption stability under different pH conditions.

Description

Technical Field

[0001] The invention belongs to the technical field of adsorption materials, and in particular relates to a reusable total phosphorus adsorption material and a preparation method thereof. Background Art

[0002] With the rapid development of industrialization and urbanization, the total phosphorus pollution problem in water bodies has become increasingly serious, which not only seriously affects the sustainable use of water resources, but also aggravates environmental problems such as eutrophication of water bodies. Therefore, the development of efficient and reusable total phosphorus adsorption materials has become a research hotspot in the current field of environmental protection. Such materials need to have high adsorption capacity, fast adsorption kinetics and good regeneration performance to achieve efficient removal of total phosphorus in water bodies and recycling of materials, thereby reducing environmental pressure and promoting sustainable development.

[0003] Patent CN 112221461 B discloses a phosphorus adsorption material and a preparation method thereof. The phosphorus adsorption material is composed of iron oxide and rare earth oxide, wherein the mass percentage of iron oxide is 20-70% and the mass percentage of rare earth oxide is 30-80%. The preparation method adopts the following steps: using a mixed solution of iron salt and rare earth salt as raw material, adding alkaline solution to react, generating a precipitate, aging, washing, separating, drying to constant weight, calcining, crushing and screening to obtain the precipitate. The phosphorus adsorption material prepared by the invention can be applied to phosphorus-containing sewage treatment, river management or lake management, but the reusability of the material and the performance of phosphorus adsorption still have room for improvement. Summary of the invention

[0004] The object of the present invention is to provide a reusable total phosphorus adsorption material and a preparation method thereof, so as to solve the technical problems of the reusability of the adsorption material and the poor phosphorus adsorption effect in the prior art.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a reusable total phosphorus adsorption material, which is prepared from the following ingredients in parts by weight: 3-5 parts of modified shell powder; 20-33 parts of electrospinning solution; 1-2 parts of curing agent; wherein the modified shell powder is obtained by oyster shell powder through high-temperature calcination, sodium carbonate, and L-arginine treatment; the electrospinning solution is prepared with sodium hydroxide, thiourea, urea and wood cellulose as main raw materials.

[0007] Preferably, the method for preparing the modified shell powder comprises the following steps:

[0008] Q1: After collecting the oyster shells, wash off the mud and water plants attached to the surface, dry them naturally, and then crush them. Put the crushed small pieces of oyster shells into an oven to dry, and then put the dried oyster shells into a ball mill for ball milling to obtain shell powder;

[0009] Q2: Place the shell powder in a vacuum tube furnace, calcine at high temperature, and then sieve with a micro-nano grinder to obtain nano shell powder, add the nano shell powder to a sodium carbonate solution, ultrasonically treat until dissolved, and then place the mixture in a Teflon reactor, heat for hydrothermal treatment, filter after treatment, wash the precipitate, and dry to obtain Na-shell powder;

[0010] Q3: Add L-arginine to deionized water and Na-shell powder at the same time, stir and mix evenly, and then vacuum dry to obtain modified shell powder.

[0011] In the above process, the shell powder is first calcined at high temperature to remove the organic matter in the shell powder, and at the same time the calcium carbonate in the shell powder is decomposed into calcium oxide and carbon dioxide to obtain pure calcium oxide. After sodium carbonate is mixed with nano shell powder, it will react with calcium oxide to produce calcium carbonate and sodium hydroxide. L-arginine is a positively charged amino acid. It interacts with the negative charge on the surface of Na-shell powder, including electrostatic interaction, hydrogen bonding and other effects, thereby adsorbing on the surface of Na-shell powder, so that the surface of the modified shell powder has a positive charge.

[0012] Preferably, in Q1, the drying temperature is 90-110° C., the drying time is 2-4 h, the ball milling speed is 400-500 rpm, the ball milling time is 10-15 h, and the ball milling medium is anhydrous ethanol.

[0013] Preferably, in Q2, the high-temperature calcination temperature is 700-800°C, the time is 2-4h, the sieved particle size is 60-80μm, the dosage ratio of nano shell powder to sodium carbonate is (0.2-0.8)g:(28-32)mL, the volume fraction of sodium carbonate solution is 1%vt, the ultrasonic treatment time is 30-50min, the heating temperature is 150-170°C, the treatment time is 22-24h, the drying temperature is 50-70°C, and the drying time is 8-10h.

[0014] Preferably, in Q3, the dosage ratio of L-arginine, deionized water and Na-shell powder is (1-10) g: 100 mL: (1-10) g, the mixing time is 20-30 min, the vacuum drying temperature is 80-100° C., and the vacuum drying time is 20-24 h.

[0015] Preferably, the method for preparing the electrospinning solution comprises the following steps:

[0016] S1: Sodium hydroxide, thiourea, urea and deionized water are mixed, and stirred with a glass rod until the solid agent is completely dissolved to form a transparent solution. After the cellulose is dried, it is placed in the transparent solution and stirred until the cellulose is evenly dispersed in the solution. Then, it is placed in a refrigerator and frozen. After the freezing is completed, it is taken out and magnetically stirred at room temperature until the cellulose is dissolved to form a viscous transparent liquid.

[0017] S2: Pour the viscous transparent liquid into a centrifuge tube, centrifuge at high speed to remove bubbles and separate insoluble matter, and finally obtain a transparent viscous cellulose solution, dissolve the transparent viscous cellulose solution in a mixed solution of N,N-dimethylacetamide and lithium chloride, and stir evenly to obtain an electrospinning solution.

[0018] In the above process, the mixed solution of sodium hydroxide, thiourea, urea and deionized water destroys the hydrogen bonds and ester bonds in the cellulose, dissolving it in the solution in molecular form, thereby making the cellulose molecules evenly dispersed in the mixed solution of N,N-dimethylacetamide and lithium chloride to form a stable electrospinning solution.

[0019] Preferably, in S1, the mass ratio of sodium hydroxide, thiourea, urea and deionized water is (7-9): (5-8): (8-10): (75-80), the mass ratio of lignocellulose and transparent solution is (2-2.5): (40-60), the refrigerator temperature is -18 to -20°C, the freezing time is 30-40 min, the magnetic stirring speed is 1500-2000 rpm, and the stirring time is 10-15 min; in S2, the high-speed speed is 8000-10000 rpm, the centrifugation time is 10-15 min, the dissolution temperature is 70-80°C, and the stirring time is 30-50 min.

[0020] Preferably, the method for preparing the reusable total phosphorus adsorption material comprises the following steps:

[0021] Step (1): adding the obtained modified shell powder to the electrospinning solution to obtain a composite solution, then adding a curing agent, stirring at room temperature, and obtaining a uniform spinning solution;

[0022] Step (2): Use a disposable syringe to extract a uniform spinning solution, and then place it on a syringe pump for spinning. After the spinning is completed, remove the aluminum foil containing the deposition material on the roller and place it in a vacuum drying oven for vacuuming. After the spinning is completed, a reusable total phosphorus adsorption material is obtained.

[0023] Preferably, in the step (1), the stirring time is 9-10 h; in the step (2), during the spinning process, the spinning voltage is controlled to be 20 kV, the receiving distance is 15 cm, the solution injection speed is 3 mL / h, the ambient humidity is maintained at 37-43%, the rotation speed of the drum is set to 50 rpm, and the reciprocating speed is set to 5-8 m / min. In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0024] 1. In the present invention, nano shell powder is first obtained by high-temperature calcination, and then treated with sodium carbonate and L-arginine to obtain modified shell powder with positive charge on the surface; then, a mixed solution of sodium hydroxide, thiourea, urea and deionized water is used to dissolve wood cellulose to obtain an electrospinning solution, and the modified shell powder is added to the electrospinning solution. The adsorption material obtained by this method can not only quickly adsorb total phosphorus in water, but also can be reused and still has excellent adsorption performance under different pH conditions.

[0025] 2. The present invention obtains shell powder from discarded solid waste oyster shells, and obtains modified shell powder through high-temperature calcination, sodium carbonate and L-arginine treatment. The modified shell powder is added to the electrospinning solution to effectively adsorb the total phosphorus in the water. This is because the surface of the modified shell powder carries a positive charge, and the total phosphorus in the water mainly exists in the form of negatively charged phosphate ions. According to the attraction between positive and negative charges, the modified shell powder can attract and adsorb the negatively charged phosphate ions, thereby achieving the purpose of adsorbing the total phosphorus in the water. The hydroxyl group, carboxyl group and other groups on the surface of the modified shell powder can also undergo coordination exchange or ion exchange with the phosphate ions to further adsorb the total phosphorus in the water. The shell powder calcined at high temperature has a porous structure, which increases the surface area of ​​the shell powder, provides more adsorption sites, and enhances the adsorption performance. Using the modified shell powder as one of the main raw materials of the adsorption material can effectively improve the adsorption performance of the adsorption material for the total phosphorus in water.

[0026] 3. In the present invention, sodium hydroxide, thiourea, urea and lignocellulose are used as main raw materials to prepare electrospinning solution. Under the action of electric field force, the molecular chains of lignocellulose are arranged along the axial direction of the fiber during the spinning process to form a highly ordered molecular chain structure, which increases the mechanical strength of the fiber and further improves the mechanical properties of the material. Lignocellulose, as a natural polymer material, has good chemical stability, and its structure will not be destroyed during the adsorption and desorption process, and can be reused many times. Moreover, the surface of the treated lignocellulose carries positive charge and specific functional groups, which have high stability under different pH conditions, are not prone to protonation or deprotonation reactions, and maintain the continuous adsorption capacity for phosphate ions. The multiple adsorption sites provided adsorb phosphate ions, so that the adsorption process has a certain buffering effect on the change of pH. Applying it to the adsorption material can enable the adsorption material to maintain stable adsorption performance under different pH conditions. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Example 1

[0029] This embodiment discloses a method for preparing modified shell powder, comprising the following steps:

[0030] Q1: After collecting the oyster shells, wash off the sludge and water plants attached to the surface, dry them naturally, and then crush them. Put the crushed small pieces of oyster shells into a 110℃ oven to dry for 2 hours, then put the dried oyster shells into a ball mill for ball milling. The ball milling speed is 450rpm, the ball milling time is 12 hours, and the ball milling medium is anhydrous ethanol. Shell powder is obtained after ball milling;

[0031] Q2: The shell powder was placed in a vacuum tube furnace and calcined at 700°C for 3 hours, and then sieved with a micro-nano grinder to obtain nano shell powder with a particle size of 75 μm. 0.5 g of nano shell powder was added to 30 mL of 1% vt sodium carbonate solution, and ultrasonically treated for 50 minutes until dissolved. The mixture was then placed in a Teflon reactor and heated for hydrothermal treatment. After treatment at 170°C for 24 hours, it was filtered, the precipitate was washed, and dried at 70°C for 10 hours to obtain Na-shell powder.

[0032] Q3: Add 5.5 g of L-arginine to 100 mL of deionized water, and add 5.5 g of Na-shell powder at the same time, stir for 30 minutes, mix evenly, and vacuum dry at 80°C for 24 hours to obtain modified shell powder.

[0033] This embodiment discloses a method for preparing an electrospinning solution, comprising the following steps:

[0034] S1: 8g of sodium hydroxide, 6.5g of thiourea, 9g of urea and 78g of deionized water were mixed, and stirred with a glass rod until the solid agent was completely dissolved to form a transparent solution. 2.3g of lignocellulose was dried and placed in 50g of the transparent solution, and stirred until the lignocellulose was evenly dispersed in the solution. Then, it was placed in a -20°C refrigerator and frozen for 30 minutes. After the freezing was completed, it was taken out and magnetically stirred at room temperature at 1800rpm for 13 minutes until the cellulose was dissolved to form a viscous transparent liquid.

[0035] S2: Pour the viscous transparent liquid into a centrifuge tube, centrifuge at 10000 rpm for 15 min to remove bubbles and separate insoluble matter, and finally obtain a transparent viscous cellulose solution. Dissolve the transparent viscous cellulose solution in a mixed solution of N,N-dimethylacetamide and lithium chloride at 80°C, and stir for 50 min to obtain an electrospinning solution.

[0036] This embodiment discloses a reusable total phosphorus adsorption material, which is prepared from the following ingredients in parts by weight: 4 parts of modified shell powder; 26 parts of electrospinning liquid; and 1.5 parts of curing agent.

[0037] This embodiment discloses a method for preparing a reusable total phosphorus adsorption material, comprising the following steps:

[0038] Step (1): adding the obtained modified shell powder to the electrospinning solution to obtain a composite solution, then adding a curing agent, stirring at room temperature for 9 hours, and obtaining a uniform spinning solution;

[0039] Step (2): Use a disposable syringe to extract a uniform spinning solution, and then place it on an injection pump for spinning. During the spinning process, the spinning voltage is controlled to be 20 kV, the receiving distance is 15 cm, the solution injection speed is 3 mL / h, the ambient humidity is maintained at 40%, the roller speed is set to 50 rpm, and the reciprocating speed is set to 6 m / min. After the spinning is completed, the aluminum foil containing the deposited material on the roller is removed and placed in a vacuum drying oven for evacuation. After the spinning is completed, a reusable total phosphorus adsorption material is obtained.

[0040] Example 2

[0041] This embodiment discloses a method for preparing modified shell powder, comprising the following steps:

[0042] Q1: After collecting the oyster shells, wash off the sludge and water plants attached to the surface, dry them naturally, and then crush them. Put the crushed small pieces of oyster shells into a 110℃ oven to dry for 2 hours, then put the dried oyster shells into a ball mill for ball milling. The ball milling speed is 450rpm, the ball milling time is 12 hours, and the ball milling medium is anhydrous ethanol. Shell powder is obtained after ball milling;

[0043] Q2: The shell powder was placed in a vacuum tube furnace and calcined at 700°C for 3 hours, and then sieved with a micro-nano grinder to obtain nano shell powder with a particle size of 75 μm. 0.3 g of nano shell powder was added to 28 mL of 1% vt sodium carbonate solution, and ultrasonically treated for 50 minutes until dissolved. The mixture was then placed in a Teflon reactor and heated for hydrothermal treatment. After treatment at 170°C for 24 hours, it was filtered, the precipitate was washed, and dried at 70°C for 10 hours to obtain Na-shell powder.

[0044] Q3: Add 8g L-arginine to 100mL deionized water and 3g Na-shell powder, stir for 30min, mix well, and dry under vacuum at 80℃ for 24h to obtain modified shell powder.

[0045] This embodiment discloses a method for preparing an electrospinning solution, comprising the following steps:

[0046] S1: 7g of sodium hydroxide, 6g of thiourea, 8g of urea and 75g of deionized water were mixed, and stirred with a glass rod until the solid agent was completely dissolved to form a transparent solution. 2.5g of lignocellulose was dried and placed in 40g of the transparent solution, and stirred until the lignocellulose was evenly dispersed in the solution. Then, it was placed in a -20°C refrigerator and frozen for 30 minutes. After the freezing was completed, it was taken out and magnetically stirred at room temperature at 1800rpm for 13 minutes until the cellulose was dissolved to form a viscous transparent liquid.

[0047] S2: Pour the viscous transparent liquid into a centrifuge tube, centrifuge at 10000 rpm for 15 min to remove bubbles and separate insoluble matter, and finally obtain a transparent viscous cellulose solution. Dissolve the transparent viscous cellulose solution in a mixed solution of N,N-dimethylacetamide and lithium chloride at 80°C, and stir for 50 min to obtain an electrospinning solution.

[0048] This embodiment discloses a reusable total phosphorus adsorption material, which is prepared from the following ingredients in parts by weight: 3 parts of modified shell powder; 20 parts of electrospinning liquid; and 2 parts of curing agent.

[0049] This embodiment discloses a method for preparing a reusable total phosphorus adsorption material, comprising the following steps:

[0050] Step (1): adding the obtained modified shell powder to the electrospinning solution to obtain a composite solution, then adding a curing agent, stirring at room temperature for 9 hours, and obtaining a uniform spinning solution;

[0051] Step (2): Use a disposable syringe to extract a uniform spinning solution, and then place it on an injection pump for spinning. During the spinning process, the spinning voltage is controlled to be 20 kV, the receiving distance is 15 cm, the solution injection speed is 3 mL / h, the ambient humidity is maintained at 40%, the roller speed is set to 50 rpm, and the reciprocating speed is set to 6 m / min. After the spinning is completed, the aluminum foil containing the deposited material on the roller is removed and placed in a vacuum drying oven for evacuation. After the spinning is completed, a reusable total phosphorus adsorption material is obtained.

[0052] Example 3

[0053] This embodiment discloses a method for preparing modified shell powder, comprising the following steps:

[0054] Q1: After collecting the oyster shells, wash off the sludge and water plants attached to the surface, dry them naturally, and then crush them. Put the crushed small pieces of oyster shells into a 110℃ oven to dry for 2 hours, then put the dried oyster shells into a ball mill for ball milling. The ball milling speed is 450rpm, the ball milling time is 12 hours, and the ball milling medium is anhydrous ethanol. Shell powder is obtained after ball milling;

[0055] Q2: The shell powder was placed in a vacuum tube furnace and calcined at 700°C for 3 hours, and then sieved with a micro-nano grinder to obtain nano shell powder with a particle size of 75 μm. 0.7 g of nano shell powder was added to 29 mL of 1% vt sodium carbonate solution, and ultrasonically treated for 50 minutes until dissolved. The mixture was then placed in a Teflon reactor and heated for hydrothermal treatment. After treatment at 170°C for 24 hours, it was filtered, the precipitate was washed, and dried at 70°C for 10 hours to obtain Na-shell powder.

[0056] Q3: Add 3g L-arginine to 100mL deionized water and 8g Na-shell powder at the same time, stir for 30min, mix well, and vacuum dry at 80℃ for 24h to obtain modified shell powder.

[0057] This embodiment discloses a method for preparing an electrospinning solution, comprising the following steps:

[0058] S1: 9g of sodium hydroxide, 7g of thiourea, 10g of urea and 80g of deionized water were mixed, and stirred with a glass rod until the solid agent was completely dissolved to form a transparent solution. 2g of lignocellulose was dried and placed in 45g of the transparent solution, and stirred until the lignocellulose was evenly dispersed in the solution. Then, it was placed in a -20°C refrigerator and frozen for 30 minutes. After the freezing was completed, it was taken out and magnetically stirred at room temperature at 1800rpm for 13 minutes until the cellulose was dissolved to form a viscous transparent liquid.

[0059] S2: Pour the viscous transparent liquid into a centrifuge tube, centrifuge at 10000 rpm for 15 min to remove bubbles and separate insoluble matter, and finally obtain a transparent viscous cellulose solution. Dissolve the transparent viscous cellulose solution in a mixed solution of N,N-dimethylacetamide and lithium chloride at 80°C, and stir for 50 min to obtain an electrospinning solution.

[0060] This embodiment discloses a reusable total phosphorus adsorption material, which is prepared from the following ingredients in parts by weight: 5 parts of modified shell powder; 33 parts of electrospinning liquid; and 1.5 parts of curing agent.

[0061] This embodiment discloses a method for preparing a reusable total phosphorus adsorption material, comprising the following steps:

[0062] Step (1): adding the obtained modified shell powder to the electrospinning solution to obtain a composite solution, then adding a curing agent, stirring at room temperature for 9 hours, and obtaining a uniform spinning solution;

[0063] Step (2): Use a disposable syringe to extract a uniform spinning solution, and then place it on an injection pump for spinning. During the spinning process, the spinning voltage is controlled to be 20 kV, the receiving distance is 15 cm, the solution injection speed is 3 mL / h, the ambient humidity is maintained at 40%, the roller speed is set to 50 rpm, and the reciprocating speed is set to 6 m / min. After the spinning is completed, the aluminum foil containing the deposited material on the roller is removed and placed in a vacuum drying oven for evacuation. After the spinning is completed, a reusable total phosphorus adsorption material is obtained.

[0064] Example 4

[0065] This embodiment discloses a method for preparing modified shell powder, comprising the following steps:

[0066] Q1: After collecting the oyster shells, wash off the sludge and water plants attached to the surface, dry them naturally, and then crush them. Put the crushed small pieces of oyster shells into a 110℃ oven to dry for 2 hours, then put the dried oyster shells into a ball mill for ball milling. The ball milling speed is 450rpm, the ball milling time is 12 hours, and the ball milling medium is anhydrous ethanol. Shell powder is obtained after ball milling;

[0067] Q2: The shell powder was placed in a vacuum tube furnace and calcined at 700°C for 3 hours, and then sieved with a micro-nano grinder to obtain nano shell powder with a particle size of 75 μm. 0.35 g of nano shell powder was added to 31 mL of 1% vt sodium carbonate solution, and ultrasonically treated for 50 minutes until dissolved. The mixture was then placed in a Teflon reactor and heated for hydrothermal treatment. After treatment at 170°C for 24 hours, it was filtered, the precipitate was washed, and dried at 70°C for 10 hours to obtain Na-shell powder.

[0068] Q3: Add 9g L-arginine to 100mL deionized water and 1g Na-shell powder, stir for 30min, mix well, and dry under vacuum at 80℃ for 24h to obtain modified shell powder.

[0069] This embodiment discloses a method for preparing an electrospinning solution, comprising the following steps:

[0070] S1: 7.5 g of sodium hydroxide, 8 g of thiourea, 8.5 g of urea and 79 g of deionized water were mixed, and stirred with a glass rod until the solid agent was completely dissolved to form a transparent solution. 2.1 g of cellulose was dried and placed in 55 g of the transparent solution, and stirred until the cellulose was evenly dispersed in the solution. Then, the mixture was placed in a -20°C refrigerator and frozen for 30 min. After freezing, the mixture was taken out and magnetically stirred at room temperature at 1800 rpm for 13 min until the cellulose was dissolved to form a viscous transparent liquid.

[0071] S2: Pour the viscous transparent liquid into a centrifuge tube, centrifuge at 10000 rpm for 15 min to remove bubbles and separate insoluble matter, and finally obtain a transparent viscous cellulose solution. Dissolve the transparent viscous cellulose solution in a mixed solution of N,N-dimethylacetamide and lithium chloride at 80°C, and stir for 50 min to obtain an electrospinning solution.

[0072] This embodiment discloses a reusable total phosphorus adsorption material, which is prepared from the following ingredients in parts by weight: 3.5 parts of modified shell powder; 30 parts of electrospinning liquid; and 1 part of curing agent.

[0073] This embodiment discloses a method for preparing a reusable total phosphorus adsorption material, comprising the following steps:

[0074] Step (1): adding the obtained modified shell powder to the electrospinning solution to obtain a composite solution, then adding a curing agent, stirring at room temperature for 9 hours, and obtaining a uniform spinning solution;

[0075] Step (2): Use a disposable syringe to extract a uniform spinning solution, and then place it on an injection pump for spinning. During the spinning process, the spinning voltage is controlled to be 20 kV, the receiving distance is 15 cm, the solution injection speed is 3 mL / h, the ambient humidity is maintained at 40%, the roller speed is set to 50 rpm, and the reciprocating speed is set to 6 m / min. After the spinning is completed, the aluminum foil containing the deposited material on the roller is removed and placed in a vacuum drying oven for evacuation. After the spinning is completed, a reusable total phosphorus adsorption material is obtained.

[0076] Example 5

[0077] This embodiment discloses a method for preparing modified shell powder, comprising the following steps:

[0078] Q1: After collecting the oyster shells, wash off the sludge and water plants attached to the surface, dry them naturally, and then crush them. Put the crushed small pieces of oyster shells into a 110℃ oven to dry for 2 hours, then put the dried oyster shells into a ball mill for ball milling. The ball milling speed is 450rpm, the ball milling time is 12 hours, and the ball milling medium is anhydrous ethanol. Shell powder is obtained after ball milling;

[0079] Q2: The shell powder was placed in a vacuum tube furnace and calcined at 700°C for 3 hours, and then sieved with a micro-nano grinder to obtain nano shell powder with a particle size of 75 μm. 0.75 g of the nano shell powder was added to 32 mL of 1% vt sodium carbonate solution, and ultrasonically treated for 50 minutes until dissolved. The mixture was then placed in a Teflon reactor and heated for hydrothermal treatment. After treatment at 170°C for 24 hours, it was filtered, the precipitate was washed, and dried at 70°C for 10 hours to obtain Na-shell powder.

[0080] Q3: Add 1g L-arginine to 100mL deionized water and 9g Na-shell powder at the same time, stir for 30min, mix well, and vacuum dry at 80℃ for 24h to obtain modified shell powder.

[0081] This embodiment discloses a method for preparing an electrospinning solution, comprising the following steps:

[0082] S1: 8.5 g of sodium hydroxide, 7.5 g of thiourea, 9.5 g of urea and 77 g of deionized water were mixed, and stirred with a glass rod until the solid agent was completely dissolved to form a transparent solution. 2.4 g of lignocellulose was dried and placed in 60 g of the transparent solution, and stirred until the lignocellulose was evenly dispersed in the solution. Then, the mixture was placed in a -20°C refrigerator and frozen for 30 min. After freezing, the mixture was taken out and magnetically stirred at room temperature at 1800 rpm for 13 min until the cellulose was dissolved to form a viscous transparent liquid.

[0083] S2: Pour the viscous transparent liquid into a centrifuge tube, centrifuge at 10000 rpm for 15 min to remove bubbles and separate insoluble matter, and finally obtain a transparent viscous cellulose solution. Dissolve the transparent viscous cellulose solution in a mixed solution of N,N-dimethylacetamide and lithium chloride at 80°C, and stir for 50 min to obtain an electrospinning solution.

[0084] This embodiment discloses a reusable total phosphorus adsorption material, which is prepared from the following ingredients in parts by weight: 4.5 parts of modified shell powder; 28 parts of electrospinning solution; and 2 parts of curing agent.

[0085] This embodiment discloses a method for preparing a reusable total phosphorus adsorption material, comprising the following steps:

[0086] Step (1): adding the obtained modified shell powder to the electrospinning solution to obtain a composite solution, then adding a curing agent, stirring at room temperature for 9 hours, and obtaining a uniform spinning solution;

[0087] Step (2): Use a disposable syringe to extract a uniform spinning solution, and then place it on an injection pump for spinning. During the spinning process, the spinning voltage is controlled to be 20 kV, the receiving distance is 15 cm, the solution injection speed is 3 mL / h, the ambient humidity is maintained at 40%, the roller speed is set to 50 rpm, and the reciprocating speed is set to 6 m / min. After the spinning is completed, the aluminum foil containing the deposited material on the roller is removed and placed in a vacuum drying oven for evacuation. After the spinning is completed, a reusable total phosphorus adsorption material is obtained.

[0088] Comparative Example 1

[0089] Compared with Example 1, in the process of preparing the modified shell powder in Comparative Example 1, no L-arginine is added, and other conditions remain unchanged.

[0090] Comparative Example 2

[0091] Compared with Example 1, in Comparative Example 2, during the preparation of the modified shell powder, no sodium carbonate was added, and other conditions remained unchanged.

[0092] Comparative Example 3

[0093] Comparative Example 3 Compared with Example 1, in the process of preparing the electrospinning solution in Comparative Example 3, no lignocellulose was added, and other conditions remained unchanged.

[0094] Comparative Example 4

[0095] Compared with Example 1, in Comparative Example 4, during the preparation of the reusable total phosphorus adsorption material, no modified shell powder was added, and other conditions remained unchanged.

[0096] Experimental example

[0097] The performance of the reusable total phosphorus adsorption materials prepared in Examples 1-5 and Comparative Examples 1-4 was tested.

[0098] 1. Total phosphorus adsorption capacity and material reuse performance test

[0099] The obtained sample was placed in a water environment with an initial total phosphorus concentration of 15 mg / L, a temperature of 25°C, a pH of 7, and a sample dosage of 0.3 g / L. After the sample was placed for 12 hours, the total phosphorus concentration in the water environment was measured, and the reduction rate of the total phosphorus was calculated. After the sample was taken out, the sample was desorbed, dried, and then placed in a water environment with the same initial conditions. The operation was repeated 5 times, the change in total phosphorus content was measured, and the average value of the total phosphorus reduction rate was calculated. The test results are shown in Table 1:

[0100] Table 1

[0101]

[0102] It can be seen from the test results in Table 1 that the reusable total phosphorus adsorption materials prepared by Examples 1-5 of the present invention have excellent total phosphorus adsorption capacity and recyclability. From the comparison of Comparative Example 1, Comparative Example 2 and Examples 1-5, it can be seen that the addition of L-arginine and sodium carbonate will affect the formation of modified shell powder, and then affect the adsorption effect of the adsorption material on total phosphorus; from the comparison of Comparative Example 3 and Examples 1-5, it can be seen that the addition of lignocellulose will affect the reusability of the adsorption material; from the comparison of Comparative Example 4 and Examples 1-5, it can be seen that the addition of modified shell powder can effectively improve the adsorption capacity of the adsorption material for total phosphorus.

[0103] 2. Adsorption capacity test under different pH conditions

[0104] The samples were placed in different water environments, the temperature was 25°C, the initial total phosphorus concentration was 15 mg / L, the sample dosage was 0.3 g / L, and the pH value of the water environment was adjusted with 1 mol / L sodium hydroxide and 1 mol / L hydrochloric acid. After the samples were placed for 12 hours, the total phosphorus concentration in the water environment was measured and the reduction rate of total phosphorus was calculated. The results are shown in Table 2:

[0105] Table 2

[0106]

[0107]

[0108] It can be seen from the test results in Table 2 that the reusable total phosphorus adsorption materials prepared in Examples 1-5 of the present invention still have excellent ability to adsorb total phosphorus under different pH conditions. It can be seen from the comparison between Comparative Example 3 and Examples 1-5 that the addition of lignocellulose can effectively improve the ability of the adsorption material to adsorb total phosphorus under different pH conditions.

[0109] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0110] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A reusable total phosphorus adsorption material, characterized in that: It is prepared from the following ingredients in parts by weight: 3-5 parts of modified shell powder; 20-33 parts of electrospinning solution; 1-2 parts of curing agent; wherein the modified shell powder is obtained by high-temperature calcination of oyster shell powder, and treatment with sodium carbonate and L-arginine; the electrospinning solution is prepared with sodium hydroxide, thiourea, urea and wood cellulose as main raw materials.

2. The reusable total phosphorus adsorption material according to claim 1, characterized in that: The preparation method of the modified shell powder comprises the following steps: Q1: After collecting the oyster shells, wash off the mud and water plants attached to the surface, dry them naturally, and then crush them. Put the crushed small pieces of oyster shells into an oven to dry, and then put the dried oyster shells into a ball mill for ball milling to obtain shell powder; Q2: Place the shell powder in a vacuum tube furnace, calcine at high temperature, and then sieve with a micro-nano grinder to obtain nano shell powder, add the nano shell powder to a sodium carbonate solution, ultrasonically treat until dissolved, and then place the mixture in a Teflon reactor, heat for hydrothermal treatment, filter after treatment, wash the precipitate, and dry to obtain Na-shell powder; Q3: Add L-arginine to deionized water and Na-shell powder at the same time, stir and mix evenly, and then vacuum dry to obtain modified shell powder.

3. The reusable total phosphorus adsorption material according to claim 2, characterized in that: In the Q1, the drying temperature is 90-110° C., the drying time is 2-4 h, the ball milling speed is 400-500 rpm, the ball milling time is 10-15 h, and the ball milling medium is anhydrous ethanol.

4. The reusable total phosphorus adsorption material according to claim 2, characterized in that: In Q2, the high-temperature calcination temperature is 700-800°C, the time is 2-4h, the sieved particle size is 60-80μm, the dosage ratio of nano shell powder to sodium carbonate is (0.2-0.8)g:(28-32)mL, the volume fraction of the sodium carbonate solution is 1%vt, the ultrasonic treatment time is 30-50min, the heating temperature is 150-170°C, the treatment time is 22-24h, the drying temperature is 50-70°C, and the drying time is 8-10h.

5. The reusable total phosphorus adsorption material according to claim 2, characterized in that: In Q3, the dosage ratio of L-arginine, deionized water and Na-shell powder is (1-10) g: 100 mL: (1-10) g, the mixing time is 20-30 min, the vacuum drying temperature is 80-100° C., and the vacuum drying time is 20-24 h.

6. The reusable total phosphorus adsorption material according to claim 1, characterized in that: The method for preparing the electrospinning solution comprises the following steps: S1: Sodium hydroxide, thiourea, urea and deionized water are mixed, and stirred with a glass rod until the solid agent is completely dissolved to form a transparent solution. After the cellulose is dried, it is placed in the transparent solution and stirred until the cellulose is evenly dispersed in the solution. Then, it is placed in a refrigerator and frozen. After the freezing is completed, it is taken out and magnetically stirred at room temperature until the cellulose is dissolved to form a viscous transparent liquid. S2: Pour the viscous transparent liquid into a centrifuge tube, centrifuge at high speed to remove bubbles and separate insoluble matter, and finally obtain a transparent viscous cellulose solution, dissolve the transparent viscous cellulose solution in a mixed solution of N,N-dimethylacetamide and lithium chloride, and stir evenly to obtain an electrospinning solution.

7. The reusable total phosphorus adsorption material according to claim 6, characterized in that: In the S1, the mass ratio of sodium hydroxide, thiourea, urea and deionized water is (7-9): (5-8): (8-10): (75-80), the mass ratio of lignocellulose and transparent solution is (2-2.5): (40-60), the refrigerator temperature is -18 to -20°C, the freezing time is 30-40 min, the magnetic stirring speed is 1500-2000 rpm, and the stirring time is 10-15 min; in the S2, the high-speed speed is 8000-10000 rpm, the centrifugation time is 10-15 min, the dissolution temperature is 70-80°C, and the stirring time is 30-50 min.

8. A method for preparing a reusable total phosphorus adsorption material according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step (1): adding the obtained modified shell powder to the electrospinning solution to obtain a composite solution, then adding a curing agent, stirring at room temperature, and obtaining a uniform spinning solution; Step (2): Use a disposable syringe to extract a uniform spinning solution, and then place it on a syringe pump for spinning. After the spinning is completed, remove the aluminum foil containing the deposition material on the roller and place it in a vacuum drying oven for vacuuming. After the spinning is completed, a reusable total phosphorus adsorption material is obtained.

9. The method for preparing a reusable total phosphorus adsorption material according to claim 8, characterized in that: In the step (1), the stirring time is 9-10 hours; in the step (2), during the spinning process, the spinning voltage is controlled to be 20 kV, the receiving distance is 15 cm, the solution injection speed is 3 mL / h, the ambient humidity is maintained at 37-43%, the roller speed is set to 50 rpm, and the reciprocating speed is set to 5-8 m / min.

Images