Nano cobalt functionalized acrylic fiber and preparation method and application thereof

Abstract

The application belongs to the technical field of wastewater treatment, and relates to a nano cobalt functionalized acrylic fiber as well as a preparation method and application thereof. A F; 2) preparing the nano cobalt functionalized acrylic fiber PAN A F-Co by a step-by-step method. A The nano cobalt functionalized acrylic fiber PAN A F-Co prepared by the application has the advantages of simple preparation, high stability, good recycling, environmental friendliness, and efficient degradation of organic phosphorus.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, and relates to a functionalized acrylic fiber, its preparation method and application, and particularly to a nano-cobalt functionalized acrylic fiber, its preparation method and application. Background Technology

[0002] Phosphorus is an indispensable element on Earth. It not only exists in the cells of living organisms, maintaining bone growth, but also participates in almost all physiological and chemical reactions. With the rapid development of industry and agriculture, China's phosphorus emissions have increased dramatically, leading to high phosphorus levels in water bodies. Phosphorus is a major factor contributing to eutrophication. When the phosphorus concentration in water exceeds 0.3 mg / L, it easily causes the proliferation of algae and aquatic plants, reducing the oxygen content in the water and even threatening human safety. On the other hand, phosphorus is also a non-renewable resource in nature. Unlike petrochemical resources, no other substance in the world can replace phosphorus in industrial and agricultural production. The use of chemical fertilizers has increased the global population, but it also means that our food security now depends on chemical fertilizers. However, phosphate rock reserves, the source of phosphate fertilizers, are decreasing. Although estimates of reserves vary, the peak production of rock phosphate fertilizers may occur no earlier than around 2030, after which phosphate fertilizer production will decline significantly due to poor phosphate rock quality and the technological cost limitations of extracting phosphorus from phosphate rock. Currently, wastewater treatment in China's environmental protection sector mainly relies on dephosphorization, and there is still a serious deficiency in phosphorus recovery and utilization. Therefore, removing and recycling phosphorus from water is key to mitigating the environmental phosphorus crisis.

[0003] Currently, phosphorus recovery from wastewater mainly focuses on inorganic phosphorus, while research on organophosphorus recovery is relatively limited. Many studies indicate that organophosphorus compounds (OPs) are also a significant component of phosphorus in water, accounting for approximately 10-65% of total phosphorus. Currently, the most widely used pesticides belong to the organophosphorus class, accounting for 38% of total pesticide use globally. OPs are commonly detected in water bodies due to direct or indirect discharges of agricultural and industrial wastewater, contributing to eutrophication. Several organophosphorus compounds are fat-soluble, allowing them to easily penetrate the skin and potentially enter meat and dairy products. Grains, vegetables, and fruits can also be contaminated with organophosphorus compounds. Therefore, the removal and recovery of organophosphorus from water is urgently needed. However, direct recovery of organophosphorus from wastewater is challenging, necessitating further research into how to effectively degrade organophosphorus in polluted water and recover the resulting inorganic phosphorus. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a nano-cobalt functionalized acrylic fiber, its preparation method, and its application. The nano-cobalt functionalized acrylic fiber PAN prepared by this invention... AF-Co has advantages such as simple preparation, high stability, good recyclability, environmental friendliness, and efficient degradation of organophosphorus compounds.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A method for preparing nano-cobalt functionalized acrylic fiber, characterized by comprising the following steps:

[0007] 1) Synthesis of functionalized acrylic fiber PAN modified with amine ligands A F;

[0008] 2) Preparation of nano-cobalt functionalized acrylic fiber PAN using a stepwise method A F-Co, which includes:

[0009] 2.1) Weigh a certain amount of functionalized acrylic fiber PAN A F is added to a Co(NO3)2·6H2O solution and stirred to react.

[0010] 2.2) After the reaction has been going on for a certain period of time, the reactants are removed and placed in a NaBH4 solution for stirring and reaction.

[0011] 2.3) After the reaction has proceeded for a certain period of time, the reactants are removed and repeatedly washed with deionized water until the pH value is neutral. The washed reactants are then vacuum dried to obtain nano-cobalt functionalized acrylic fiber PAN. A F-Co.

[0012] Preferably, in step 2.1), the concentration of the Co(NO3)2·6H2O solution is 0.15 mol / L-0.25 mol / L, and the functionalized acrylic fiber PAN... A The ratio of F to the Co(NO3)2·6H2O solution is 100 mg: 50 mL.

[0013] Preferably, in step 2.1), the stirring reaction time is 60 min.

[0014] Preferably, in step 2.2), the concentration of the NaBH4 solution is 0.1 mol / L, and the amount of NaBH4 solution used is the same as the amount of Co(NO3)2·6H2O solution used in step 2.1).

[0015] Preferably, the stirring reaction time in step 2.2) is 30 min and the vacuum drying temperature in step 2.3) is 60°C.

[0016] Preferably, step 1) specifically includes:

[0017] 1.1) Weigh a certain amount of ethylenediamine and deionized water and put them into the reaction vessel, and put in a certain amount of acrylic fiber to completely submerge it;

[0018] 1.2) Tightly close the lid of the reactor and place it in an oven at 110 ℃-125 ℃ for 100 min;

[0019] 1.3) After the reaction is complete, allow it to cool naturally. After the reaction vessel has cooled, remove the reactants and wash them repeatedly with hot water at 60-70 ℃ until the pH value is neutral.

[0020] 1.4) The reactants were vacuum dried and cleaned at 60 °C to obtain yellow functionalized acrylic fiber PAN. A F.

[0021] Preferably, in step 1.1), the ratio of ethylenediamine, deionized water and acrylic fiber is 20 mL: 40 mL: (1000-2000) mg.

[0022] In addition, the present invention provides a nano-cobalt functionalized acrylic fiber, characterized in that it is prepared by the above-described preparation method.

[0023] Furthermore, the present invention also provides a method for degrading organic phosphorus in wastewater using the above-mentioned nano-cobalt functionalized acrylic fiber, characterized in that the nano-cobalt functionalized acrylic fiber is used to degrade the organic phosphorus in the wastewater.

[0024] Preferably, the pH value of the wastewater is adjusted to 3-9, and the concentration of PMS in the wastewater is 0.8 mM.

[0025] Compared with the prior art, the nano-cobalt functionalized acrylic fiber, its preparation method and application of the present invention have one or more of the following beneficial technical effects:

[0026] 1. The nano-cobalt functionalized acrylonitrile fiber prepared by this invention is simple to prepare, has high stability, is easy to recycle, and is environmentally friendly.

[0027] 2. The nano-cobalt functionalized acrylonitrile fiber prepared by this invention can achieve efficient degradation and recycling of organophosphorus compounds.

[0028] 3. The nano-cobalt functionalized acrylic fiber prepared by this invention can be recycled and has high reusability.

[0029] 4. The nano-cobalt functionalized acrylic fiber prepared by this invention has strong pH adaptability. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the preparation process of the nano-cobalt functionalized acrylic fiber of the present invention.

[0031] Figure 2 Functionalized acrylic fibers PAN with different weight gains are shown. A PAN prepared by F A The effect of F-Co on the degradation of PPOA.

[0032] Figure 3 PAN prepared with different concentrations of Co(NO3)3·6H2O is shown. A The effect of F-Co on the degradation of PPOA.

[0033] Figure 4 The degradation effects of PPOA under different systems are shown.

[0034] Figure 5 The effect of different PMS concentrations on the degradation of PPOA is shown.

[0035] Figure 6 The effect of different initial solution pH on the degradation efficiency of PPOA is shown.

[0036] Figure 7 Different PANs are shown A The effect of F-Co dosage on PPOA degradation.

[0037] Figure 8 The effect of coexisting anions on the degradation of PPOA is shown. Detailed Implementation

[0038] The present invention will be further described below with reference to the accompanying drawings and embodiments. The content of the embodiments is not intended to limit the scope of protection of the present invention.

[0039] Advanced oxidation processes (AOPs) based on highly reactive free radicals have been widely used to eliminate and fully mineralize recalcitrant organic pollutants. Among the various AOPs, peroxymonosulfate (PMS) stands as a promising alternative to hydrogen peroxide (H₂O₂) due to its ability to simultaneously generate hydroxyl (OH) and sulfate (SO₄) groups. - SO42- has attracted widespread attention due to its high radical activity and enhanced stability over a wide pH range. However, SO42- decomposes only from peroxydisulfate (PS) or peroxymonosulfate (PMS). ·- The rate of activation is very limited. Among these agents, transition metals, particularly Co ions, have long been considered as the catalysts for the activation of PMS in the production of SO4. - One of the best results. Compared with homogeneous catalysts, heterogeneous catalysts based on metal ions can effectively overcome the difficulties of reuse and do not require additional chemicals and energy.

[0040] Catalyst-activated oxidants are considered an acceptable method for environmental remediation due to their freedom of external energy input and ease of operation during the reaction process. Therefore, various PDS / PMS activation catalysts have been designed and prepared. Besides commonly used iron-based catalysts, Cu, Co, Mn, Ag, and Ni metal catalysts have also been proven effective in PDS / PMS activation. Currently, significant progress has been made in the research of cobalt-based catalysts activating PMS to degrade organic matter in water, but many problems remain to be solved. For example, silica gel, carbon materials, MOFs, and other materials supported on cobalt nanoparticles have achieved good research progress in degrading organic pollutants. However, these materials generally suffer from low immobilization efficiency, difficult recovery, complex preparation, and high cost, limiting their application. Appropriate support selection is a prerequisite for improving catalytic activity and stability. Therefore, developing new support materials, constructing supported cobalt nanoparticle catalysts with specific recognition of PS and OP, and exploring their efficiency and mechanism in activating PMS to promote degradation are of significant research importance and practical value.

[0041] Among all catalyst supports, textile fibers have attracted much attention due to their high stability, large specific surface area, ease of recycling, chemical modification, and ease of interface control. Acrylic fiber is a very mature synthetic fiber, widely used in textiles, construction, and daily life. Furthermore, acrylic fibers are rich in functional groups, which can be easily cross-linked and transformed into other functional groups. However, there are few reports on the degradation and recycling of OP using functionalized polyacrylonitrile fibers loaded with cobalt nanoparticles. Therefore, using polyacrylonitrile fibers as a support to load cobalt nanoparticles to activate PMS for OP degradation is theoretically feasible and of great significance.

[0042] Therefore, in this invention, firstly, amine ligand-modified functionalized acrylic fibers are synthesized; then, nano-cobalt functionalized acrylic fibers (PAN) are prepared using a stepwise method. A F-Co was used to activate persulfate to degrade phenylphosphonic acid (PPOA). PPOA is a typical organophosphorus compound used as an important pharmaceutical and material intermediate in the production of pesticides and smoldering agents, and therefore was selected as a model contaminant in this invention.

[0043] I. Preparation of Nanocobalt Functionalized Acrylic Fibers

[0044] In this invention, such as Figure 1 As shown, in the preparation of nano-cobalt functionalized acrylic fibers, firstly, amine ligand-modified functionalized acrylic fibers are synthesized; then, nano-cobalt functionalized acrylic fibers PAN are prepared using a stepwise method. A F-Co. Details are as follows:

[0045] 1. Synthesis of functionalized acrylic fiber PANAF modified with amine ligands.

[0046] Measure 20 mL, 20 mL, 15 mL, 10 mL, and 10 mL of ethylenediamine, and 40 mL, 40 mL, 35 mL, 20 mL, and 20 mL of deionized water, respectively, and place them into a 100 mL reaction vessel. Add 1000 mg, 2000 mg, 2000 mg, 400 mg, and 400 mg of acrylic fiber, respectively, ensuring complete immersion. Then, tighten the lid of the reaction vessel and place it in an oven at 120°C, 125°C, 110°C, and 115°C for 100 min, 100 min, 100 min, 270 min, and 270 min, respectively. After the reaction vessel cools, remove it and repeatedly wash it with hot water (60-70°C) until neutral. Then, vacuum dry it overnight at 60°C to obtain yellow functionalized acrylic fiber PAN with weight gains of 2.5%, 5%, 7.5%, 10%, and 12.5%, respectively. A F.

[0047] 2. Nanocobalt functionalized acrylic fiber PAN A Synthesis of F-Co.

[0048] Weigh out 100 mg of dried functionalized acrylic fiber PAN A F was added to 50 mL of Co(NO3)2·6H2O solution (concentrations of 0.05 mol / L, 0.10 mol / L, 0.15 mol / L, 0.20 mol / L, and 0.25 mol / L, respectively) and stirred for 60 min. After washing and drying with tweezers, it was then added to 50 mL of 0.1 mol / L solution. -1 The fiber was reacted in NaBH4 solution for 30 min. After being removed and washed several times with deionized water, it was then freeze-dried and stored.

[0049] II. Optimization of Preparation Conditions for Cobalt Nanofunctional Acrylic Fibers

[0050] The degradation effect of PANAF-Co nano-cobalt functionalized acrylic fibers prepared under different synthesis conditions on PPOA was determined to obtain the optimal preparation conditions.

[0051] 1. Functionalized acrylic fibers (PAN) with different weight gains A PAN prepared by F A The effect of F-Co on the degradation of PPOA.

[0052] The functionalized acrylic fiber PAN with different weight gain was measured. A PAN prepared by F A The effect of F-Co on the degradation of PPOA was shown in the following results. Figure 2 As shown.

[0053] Depend on Figure 2It can be seen that functionalized acrylic fiber PAN A When the F weight gain is 2.5%–5%, the prepared PAN A F-Co exhibits the best degradation ability for PPOA. Therefore, it makes functionalized acrylic fiber PAN... A The optimal preparation conditions for functionalized acrylic fiber PAN are a weight gain of 2.5%–5%. A F preparation conditions.

[0054] 2. PAN prepared with different concentrations of Co(NO3)3·6H2O A The effect of F-Co on the degradation of PPOA.

[0055] PAN prepared with different concentrations of Co(NO3)3·6H2O was determined. A The effect of F-Co on the degradation of PPOA was shown in the following results. Figure 3 As stated above.

[0056] Depend on Figure 3 It can be seen that as the concentration of Co(NO3)3·6H2O increases, the prepared PAN... A The degradation ability of F-Co on PPOA gradually increases. Therefore, it is preferable to have a Co(NO3)3·6H2O concentration of 0.15-0.25 mol / L. -1 Considering economic benefits, 0.15 mol L is the preferred option. -1 .

[0057] III. PAN A Study on the degradation performance of F-Co on PPOA in water

[0058] To investigate the degradation effect of PPOA under different conditions and optimize and improve the degradation performance of PPOA, this invention studied the effects of different systems, different PMS concentrations, different pH values, different fiber amounts, and coexisting ions on the degradation effect of PPOA, and all experiments were repeated in 3 groups.

[0059] All degradation experiments were conducted in 20 mL glass vials at 25 °C. 5 mg PL was obtained through dilution. -1 PPOA and 0.8 mmol L -1A 20 mL initial solution of PMS was prepared. After adding 10 mg of fiber catalyst, the degradation reaction was initiated. To monitor the reaction process, 1 mL of aqueous sample was collected periodically. This aqueous sample was quenched with 0.5 mL of methanol and immediately filtered through a 0.22 µm syringe filter. The filtrate was analyzed for PPOA content using high-performance liquid chromatography (HPLC). The remaining 1 mL was analyzed using a spectrophotometer at 700 nm to determine the phosphate content via a colorimetric reaction. The degradation rate of PPOA in the solution during the reaction was calculated using the following formula.

[0060]

[0061] Wherein, C0, C1, and D (%) represent the initial concentration of PPOA, the concentration of PPOA at a given time, and the degradation rate of PPOA, respectively.

[0062] 1. Degradation effect of PPOA under different systems.

[0063] Use PANF, (5%) PAN A F and (5%) PAN A F-Co, PMS, PMS / PANF, PMS / (5%) PAN A F, PMS / (5%) PAN A F-Co degradation experiments were conducted, and the results are as follows: Figure 4 As shown.

[0064] Depend on Figure 4 It can be seen that within 60 minutes, PMS / (5%) PAN A The F-Co system achieved a degradation rate of 98.94% for PPOA. This fully demonstrates the effectiveness of PAN degradation. A F-Co exhibits excellent catalytic performance.

[0065] 2. Effect of PMS concentration on the degradation effect of PPOA.

[0066] PMS has a significant impact on the degradation of PPOA, and the degradation behavior at different PMS concentrations is as follows: Figure 5 As shown.

[0067] Depend on Figure 5 It can be seen that the degradation effect of PPOA increases with the increase of PMS concentration. When the PMS concentration is increased to 0.8 mM, no organophosphates can be detected in the solution, and the same is true when the PMS concentration is 1 mM. This indicates that the PMS concentration of 0.8 mM is optimal.

[0068] 3. Effect of initial solution pH on the degradation effect of PPOA.

[0069] PPOA degradation may be related to solution pH. The effect of initial pH values ​​from 3 to 11 on the degradation efficiency of PPOA was investigated, and the results are as follows: Figure 6 As stated above.

[0070] Depend on Figure 6 It can be seen that PPOA can be almost completely degraded within 60 minutes as the pH increases from 3 to 9. As the pH value further increases (> 9), the degradation efficiency of PPOA decreases.

[0071] 4. Different PAN A The effect of F-Co dosage on the degradation effect of PPOA.

[0072] PPOA degradation is related to fiber content. The effect of fiber content on PPOA degradation efficiency was investigated, and the results are as follows: Figure 7 As shown.

[0073] Depend on Figure 7 It can be seen that when the fiber dosage is 0mg, the degradation rate of PPOA is only about 10%. With the increase of fiber dosage, when it is greater than or equal to 10mg, more than 90% of PPOA can be removed within 60 minutes.

[0074] 5. The effect of coexisting anions on the degradation effect of PPOA.

[0075] 10 mmol L -1 CO3 2- and SO4 2- NO3 - Cl - and HCO3 - To represent the reaction system, the results are as follows: Figure 8 As shown.

[0076] Depend on Figure 8 It can be known that CO3 2- and Cl - It significantly inhibited the degradation efficiency of PPOA, reducing both by nearly 90%. When HCO3- is present in the reaction solution... - At that time, the PPOA degradation efficiency decreased from 97.19% to 47.07%. SO4 2- and NO3 - The impact on the PMS / 5% PANAF-Co system is minimal. Overall, the PMS / 5% PANAF-Co system... A The F-Co system can still effectively activate PMS to degrade PPOA even in an anion-rich environment.

[0077] The above embodiments of the present invention are merely examples for clearly illustrating the present invention and are not intended to limit the implementation of the present invention. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is impossible to exhaustively list all possible implementations here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A method for preparing nano-cobalt functionalized acrylic fiber, characterized in that, Includes the following steps: 1) Synthesis of functionalized acrylic fiber PAN modified with amine ligands A F, specifically includes: 1.1) Weigh a certain amount of ethylenediamine and deionized water and put them into a reaction vessel, and add a certain amount of acrylic fiber to completely submerge it; 1.2) Tightly cover the reaction vessel and place it in an oven at 110℃-125℃ for 100 min; 1.3) After the reaction is completed, allow it to cool naturally. After the reaction vessel has cooled, remove the reactants and wash them repeatedly with hot water at 60-70℃ until the pH value is neutral; 1.4) Vacuum dry the washed reactants at 60 °C to obtain yellow functionalized acrylic fiber PAN. A F; 2) Preparation of cobalt-functionalized acrylic fiber PAN using a stepwise method A F-Co, which includes: 2.1) Weigh a certain amount of functionalized acrylic fiber PAN A F is added to a Co(NO3)2·6H2O solution for stirring and reaction; wherein the concentration of the Co(NO3)2·6H2O solution is 0.15 mol / L-0.25 mol / L, and the functionalized acrylic fiber PAN is... A The ratio of F to the Co(NO3)2·6H2O solution was 100 mg: 50 mL, and the stirring time was 60 min; 2.2) After a certain reaction time, the reactant was removed and placed in NaBH4 solution for stirring reaction, wherein the concentration of NaBH4 solution was 0.1 mol / L, and the amount of NaBH4 solution used was the same as the amount of Co(NO3)2·6H2O solution used in step 2.1), and the stirring time was 30 min; 2.3) After a certain reaction time, the reactant was removed and repeatedly washed with deionized water until the pH value was neutral, and the washed reactant was vacuum dried to obtain nano-cobalt functionalized acrylic fiber PAN. A F-Co was vacuum dried at a temperature of 60°C.

2. The method for preparing nano-cobalt functionalized acrylic fibers according to claim 1, characterized in that, In step 1.1), the ratio of ethylenediamine, deionized water and acrylic fiber is 20 mL: 40 mL: (1000-2000) mg.

3. A nano-cobalt functionalized acrylic fiber, characterized in that, It is prepared by the preparation method described in any one of claims 1-2.

4. A method for degrading organophosphorus compounds in wastewater using the nano-cobalt functionalized acrylic fiber described in claim 3, characterized in that, The cobalt-functionalized acrylic fiber nanofiber is used to degrade organic phosphorus in the wastewater.

5. The method according to claim 4, characterized in that, The pH of the wastewater is adjusted to 3-9, and the concentration of PMS in the wastewater is 0.8 mM.

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