Application of polyaminoanthraquinone in rapid ammonium removal

Abstract

The invention discloses an application of polyaminoanthraquinone in rapid ammonium removal. The application comprises rapid removal of ammonium ions in water. Ammonium ions in water are removed in a capacitive deionization (CDI) technology on the basis of a polyamino-anthraquinone high-performance organic electrode material, low crystallinity and high controllability of the organic electrode material are utilized, and protonic acid catalysis and interfacial polymerization strategies are combined; the polyamino-anthraquinone nano-particles with rich redox active sites and a pi conjugated structure are successfully prepared, and ammonium ions in a water body are rapidly removed by using rich C = O active sites on a quinone ring structure of the polyamino-anthraquinone and rapid surface redox reaction power. The deamination anthraquinone serving as an electrode material has good cycle stability when used for removing ammonium ions in water, can still keep 84.1% of adsorption capacity after 50 CDI cycles under the external voltage of 1.2 V, can simply realize electrode regeneration without external chemical reagents, and is beneficial to sustainable development and large-scale application.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, in particular to an application of polyaminoanthraquinone in rapid ammonium removal. The polyaminoanthraquinone electrode prepared by combining protonic acid catalysis and interfacial polymerization strategy can rapidly remove ammonium ions from water. Background Art

[0002] With the expansion of agriculture, accelerated industrialization and population growth, the ammonium ion (NH 4+ ) pollution has become a global environmental problem, threatening aquatic ecosystems and human health. It mainly comes from industrial activities (such as metallurgy, chemical industry, fertilizer production and coking), as well as excessive use of fertilizers in agriculture and livestock wastewater discharge. These wastewaters not only cause eutrophication of water bodies, but also produce toxic substances such as nitrite and nitrate. However, ammonia, as an efficient zero-carbon energy carrier, has the characteristics of high volumetric hydrogen density and easy storage and transportation, making it an ideal medium for renewable energy storage. The global annual production is about 180 million tons, making it the second largest commercial chemical. Therefore, the efficient recovery of ammonia in the water environment is of great significance to environmental protection and energy utilization.

[0003] However, traditional carbon-based electrodes lack selectivity for target ions in CDI technology, resulting in a low upper limit for adsorption capacity. Inorganic faradaic electrode materials also suffer from poor conductivity, volume expansion, poor cycling stability, slow ion diffusion kinetics, and the potential introduction of harmful elements such as heavy metals. In contrast, organic electrode materials offer significant advantages in high capacity, adjustability, stability, and low toxicity.

[0004] The electrochemical properties of quinone compounds have been extensively studied, theoretically offering significant specific capacities, even comparable to lithium-ion systems. 1-Aminoanthraquinone, an inexpensive organic raw material containing quinone redox groups, has excellent potential for electrochemical cation adsorption. However, previous studies on aminoanthraquinones have focused on oligomeric materials or large aggregate structures observed under scanning electron microscopy, which hinder the full utilization of the abundant redox-active sites on polyaminoanthraquinones. Summary of the Invention

[0005] To address the shortcomings of the existing technology, the present invention aims to provide a method for rapidly removing ammonium ions from water using a polyaminoanthraquinone electrode prepared by combining protonic acid catalysis and interfacial polymerization. By leveraging the low crystallinity and high controllability of organic materials, combined with protonic acid catalysis and interfacial polymerization, polyaminoanthraquinone nanoparticles with a high number of exposed active sites can be successfully prepared.

[0006] The object of the present invention is achieved through the following technical solutions:

[0007] The invention provides an application of polyaminoanthraquinone in rapid ammonium removal, which comprises the rapid removal of ammonium ions in water.

[0008] In some specific embodiments of the present invention, the polyaminoanthraquinone is used to rapidly remove ammonium ions from water, including using a polyaminoanthraquinone electrode as a cathode for capacitive deionization and an activated carbon electrode as an anode to rapidly remove ammonium ions from water using capacitive deionization. During the deionization process, an operating voltage of 0.8 to 1.2 V is applied to achieve rapid removal of ammonium ions from the water.

[0009] As some specific embodiments of the present invention, the polyaminoanthraquinone electrode uses polyaminoanthraquinone nanoparticles as the main active component.

[0010] In some specific embodiments of the present invention, the polyaminoanthraquinone electrode preparation method includes: thoroughly stirring polyaminoanthraquinone nanoparticles, a conductive agent, and a binder in an organic solvent to form a uniform slurry, coating the slurry on a carbon support, and vacuum drying the slurry. The carbon support includes carbon paper.

[0011] As some specific embodiments of the present invention, the conductive agent includes carbon black, the binder includes polyvinylidene fluoride, and the organic solvent includes N-methylpyrrolidone;

[0012] The mass percentages of the polyaminoanthraquinone nanoparticles, polyvinylidene fluoride, and N-methylpyrrolidone are 75-85wt%: 5-15wt%: 5-15wt%; preferably 80wt%: 10wt%: 10wt%.

[0013] As some specific embodiments of the present invention, the slurry is prepared into electrodes with a length, width and thickness of 2 cm×2 cm×100 μm on a carbon paper with a thickness of 0.1 mm using a four-sided wet film preparation apparatus.

[0014] In some specific embodiments of the present invention, the vacuum drying temperature is 60-70° C. and the time is 10-14 hours, preferably 60° C. and 12 hours.

[0015] As some specific embodiments of the present invention, the polyaminoanthraquinone nanoparticles are prepared by proton acid catalysis combined with interfacial polymerization strategy.

[0016] As some specific embodiments of the present invention, the method for preparing the polyaminoanthraquinone nanoparticles specifically comprises the following steps:

[0017] S1. Add aminoanthraquinone to an organic solvent, add protonic acid dropwise, and stir ultrasonically to mix and dissolve.

[0018] S2. Continue stirring and slowly add the oxidant solution dropwise to form a black solid precipitate;

[0019] S3. Centrifuging, washing, and drying the suspension containing the black solid precipitate to obtain black polyaminoanthraquinone.

[0020] As some specific embodiments of the present invention, in step S1, the aminoanthraquinone (AAQ) includes 1-aminoanthraquinone (ANQ).

[0021] In some specific embodiments of the present invention, in step S1, the organic solvent is selected from at least one of acetonitrile, N,N-dimethylformamide, and dimethyl sulfoxide, preferably acetonitrile.

[0022] In some specific embodiments of the present invention, in step S1, the protonic acid is selected from at least one of perchloric acid, hydrochloric acid, and nitric acid, preferably perchloric acid.

[0023] In some specific embodiments of the present invention, in step S2, the oxidant is selected from at least one of ammonium persulfate, chromium trioxide, and potassium permanganate, preferably ammonium persulfate.

[0024] As some specific embodiments of the present invention, the aminoanthraquinone includes 1-aminoanthraquinone, the protonic acid includes perchloric acid, and the oxidant includes ammonium persulfate;

[0025] The usage ratio of 1-aminoanthraquinone to perchloric acid is 1mmol:0.1-0.2ml;

[0026] The molar ratio of 1-aminoanthraquinone to ammonium persulfate is 1:3-5, preferably 1:4;

[0027] The concentration of the ammonium persulfate solution is 1-2 mol / ml, preferably 1.12 mol / L.

[0028] Excessive use of protonic acid can result in a lack of distinct redox peaks and abnormally distorted curves in CV electrochemical testing of the electrode material. Insufficient or no protonic acid can lead to a low degree of polymerization, making it difficult to form a complete conjugated π system and π-π stacking structure. This results in inefficient electron transfer within the molecule's electron cloud and inactivation of the reversible redox reaction of C=O. Insufficient ammonium persulfate as the oxidant prevents a significant amount of aminoanthraquinone monomer from participating in the polymerization reaction, resulting in a significant amount of residual monomer during the washing process and reduced yield.

[0029] In some specific embodiments, the organic solvent is acetonitrile, the protonic acid is perchloric acid, the oxidant is ammonium persulfate, and the usage ratio of 1-aminoanthraquinone (ANQ), acetonitrile, perchloric acid and ammonium persulfate is 1.4 mmol:40 mL:0.14 mL:5.6 mmol.

[0030] In some specific embodiments of the present invention, in step S2, the stirring speed is 200-400 rpm, the temperature is 0-30°C, and the time is 24-72 hours. Preferably, the stirring speed is 300 rpm, room temperature, and the time is 48 hours. If stirring is not applied during the polymerization process, the obtained polymer product exhibits a large agglomerated structure, and small nanoparticle structures cannot be synthesized.

[0031] As some specific embodiments of the present invention, in step S3, the washing includes: washing with ethanol until the system is no longer brown (when the aminoanthraquinone monomer remaining in the product is dissolved in ethanol, the ethanol will be brown, and when the ethanol is colorless and transparent, it indicates that the monomer has been completely removed), and then washing with deionized water until the pH of the system is neutral.

[0032] In some specific embodiments of the present invention, in step S3, the drying temperature is 60-80°C and the drying time is 12-24 hours, preferably 60°C for 24 hours.

[0033] The present invention provides a method for removing ammonium ions from water using polyaminoanthraquinone (PAQ), a high-performance organic electrode material, in capacitive deionization (CDI) technology. By utilizing the low crystallinity and high controllability of the organic electrode material, combined with proton acid catalysis and interfacial polymerization strategies, polyaminoanthraquinone nanoparticles with abundant redox active sites and a π-conjugated structure were successfully prepared. The abundant C=O active sites on the PAQ quinone ring structure and the rapid surface redox reaction kinetics enable rapid removal of ammonium ions from water. Using the electrode material prepared by the present invention as a cathode and activated carbon as an anode, the system's high electrochemical reaction kinetics allow for rapid removal of ammonium ions from water. The electrode material prepared by the present invention exhibits excellent cyclic stability when removing ammonium ions from water, maintaining 84.1% of its adsorption capacity after 50 CDI cycles at an applied voltage of 1.2 V. Electrode regeneration is easily achieved without the need for external chemical reagents, facilitating sustainable development and large-scale application.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] First, the continuous polymerization of monomers is promoted through the catalytic effect of proton acid. Traditional organic electrode materials usually require high temperature to increase the activation energy required for the reaction, but polyaniline-type polyaminoanthraquinone is more conducive to its polymerization behavior at low temperature. This invention breaks through the idea of ​​high-temperature polymerization and uses proton acid to protonate the -NH2 on the monomer benzene ring to -NH3 + , effectively improving the charge distribution on the monomer structure, so that the polymerization behavior occurs preferentially on -NH3 +and para-C, thereby promoting the continuous polymerization of the monomer. Experimental results show that this acid-assisted catalytic design can significantly improve the yield and electrochemical performance of the polymer, especially in the removal of ammonium ions, surpassing most reported ammonium removal materials.

[0036] Second, leveraging the low crystallinity of organic polymers, a simple interfacial polymerization strategy was proposed to manipulate the structure of polyaminoanthraquinone. During the polymerization process, stirring was used to uniformly disperse the ammonium persulfate solution in the acetonitrile system, resulting in the formation of tiny particles of polyaminoanthraquinone at the interface between the ammonium persulfate solution and acetonitrile.

[0037] Third, the polyaminoanthraquinone nanoparticle electrode of the present invention has a fast removal rate of ammonium ions in water (up to 9.22 mg / g / min), and can still achieve a high adsorption capacity after multiple cycles of regeneration. There is no secondary pollution during the treatment process, and it is safe, environmentally friendly, and has low energy consumption.

[0038] Fourthly, the preparation method of the present invention has simple equipment and easy process, and is suitable for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0040] Figure 1 Schematic diagram of the preparation process of polyaminoanthraquinone in Example 1;

[0041] Figure 2 is an X-ray diffraction pattern of the polyaminoanthraquinone nanoparticles of the present invention;

[0042] Figure 3 This is a graph showing the results of 50 cyclic voltammetry tests of the polyaminoanthraquinone electrode of the present invention using an electrochemical workstation in 1M NH4Cl electrolyte at a scan rate of 5 mV / s;

[0043] Figure 4 The graph shows the CDI ammonium removal capacity and energy consumption of the polyaminoanthraquinone electrode of the present invention in a 10 mM NH4Cl solution at a voltage of 0.8 to 1.2 V.

[0044] Figure 5 This is a diagram showing the stability of the polyaminoanthraquinone during multi-cycle ammonium removal. DETAILED DESCRIPTION

[0045] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several variations and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0046] Example 1

[0047] Polyaminoanthraquinone was prepared by proton acid catalysis combined with interfacial polymerization strategy. Figure 1 As shown:

[0048] (1) Weigh 0.3125 g of 1-aminoanthraquinone (ANQ) (1.4 mmol) and add it to 40 mL of acetonitrile solution. Add 0.14 mL of perchloric acid dropwise and sonicate to dissolve and mix well to obtain solution A.

[0049] (2) Weigh 1.2780 g of ammonium persulfate (5.6 mmol) and add it to 5 mL of deionized water. Ultrasonicate and dissolve to obtain solution B.

[0050] (3) While stirring solution A at 300 r / min, solution B was slowly added dropwise, and then stirring was continued at room temperature until a black solid precipitate appeared;

[0051] (4) The black suspension obtained above was centrifuged, washed with ethanol and deionized water in sequence (washed with ethanol until the system was no longer brown, and washed with deionized water until the pH of the system was neutral), and dried at 60°C for 24 hours to obtain black polyaminoanthraquinone powder.

[0052] Example 2

[0053] The polyaminoanthraquinone prepared in Example 1 was used as an organic electrode to remove ammonium ions in water.

[0054] Using polyaminoanthraquinone nanoparticles as the active material, 80 wt% polyaminoanthraquinone nanoparticles (active component) were thoroughly stirred with 10 wt% carbon black and 10 wt% polyvinylidene fluoride binder in N-methylpyrrolidone solvent to form a uniform slurry. Using a four-sided wet film preparation apparatus, an electrode measuring 2 cm x 2 cm x 100 μm was prepared on 0.1 mm thick carbon paper. The PANQ cathode was vacuum dried at 60°C for 12 hours.

[0055] The activated carbon anode was prepared in the same way. The polyaminoanthraquinone electrode was used as the cathode and the activated carbon electrode as the anode. A working voltage of 0.8 to 1.2 V was applied to achieve rapid removal of ammonium ions in water.

[0056] Effect Example 1

[0057] The crystallinity and electrochemical stability of the polyaminoanthraquinone nanoparticles synthesized in Example 1 were characterized.

[0058] 1. Figure 2 is the X-ray diffraction pattern of the polyaminoanthraquinone nanoparticles of the present invention. Figure 2 As shown in Figure 3, the crystallinity of the ANQ monomer small molecule is very high. After oxidative polymerization to form PANQ, these sharp crystalline peaks transform into broad and short peaks, which is the result of π-π stacking interactions between polymer chains.

[0059] 2. Figure 3 The results of 50 cyclic voltammetry tests of the polyaminoanthraquinone electrode of the present invention were performed using an electrochemical workstation in 1M NH4Cl electrolyte and a scan rate of 5mV / s. Figure 3 As shown in the cyclic voltammetry curve, a pair of redox peaks represents the storage of ammonium ions via the redox enolization reaction of C=O. After 50 cycles, the shape of the curve and the position of the redox peaks remain almost unchanged, indicating that polyaminoanthraquinone has excellent cyclic stability. This is because polyaminoanthraquinone stores cations through its functional groups, avoiding the structural changes that may occur in inorganic faradaic electrodes.

[0060] Effect Example 2

[0061] The ammonium removal capacity, energy consumption and stability of the polyaminoanthraquinone electrode were tested.

[0062] 1. Figure 4 The CDI ammonium removal capacity and energy consumption of the polyaminoanthraquinone electrode of the present invention in 10mM NH4Cl solution at a voltage of 0.8-1.2V are shown. Figure 4 As shown in Figure 3, although energy consumption increases with increasing voltage, its growth rate is significantly lower than the increase in adsorption capacity. Therefore, from the perspective of overall performance and efficiency improvement, moderately increasing voltage within an acceptable energy consumption range can be regarded as an optimization strategy for effectively utilizing polyaminoanthraquinone materials for ammonium removal.

[0063] 2. Figure 5 This is a diagram showing the stability of the polyaminoanthraquinone in multiple cycles of ammonium removal. Figure 5 As shown in Figure 3, after 50 cycles at 1.2 V, the adsorption capacity of polyaminoanthraquinone maintained at 84.1% of the initial value, which fully confirmed its good cycling stability and demonstrated the practical application potential of polyaminoanthraquinone electrodes.

[0064] The above description of the embodiments is intended to facilitate understanding and application of the present invention by those skilled in the relevant art. It will be apparent to those skilled in the art that various modifications may be made to these embodiments and that the general principles described herein may be applied to other embodiments without requiring creative effort. Therefore, the scope of the present invention should not be limited to the above-described embodiments. Any improvements and modifications based on the principles of the present invention, as long as they do not depart from the basic scope of the present invention, shall fall within the scope of protection of the present invention.

Claims

1. An application of polyaminoanthraquinone in rapid ammonium removal, comprising rapidly removing ammonium ions from water.

2. The use according to claim 1, characterized in that The method for applying the polyaminoanthraquinone to quickly remove ammonium ions in water comprises: using a polyaminoanthraquinone electrode as a cathode for capacitive deionization, an activated carbon electrode as an anode, and quickly removing ammonium based on capacitive deionization.

3. The use according to claim 2, characterized in that The polyaminoanthraquinone electrode uses polyaminoanthraquinone nanoparticles as main active components.

4. The use according to claim 3, characterized in that The preparation method of the polyaminoanthraquinone electrode comprises the following steps: stirring polyaminoanthraquinone nanoparticles, a conductive agent and a binder in an organic solvent to form a uniform slurry, coating the slurry on a carbon carrier, and vacuum drying the slurry to obtain the electrode.

5. The use according to claim 4, characterized in that The conductive agent includes carbon black, the binder includes polyvinylidene fluoride, and the organic solvent includes N-methylpyrrolidone; the mass percentages of the polyaminoanthraquinone nanoparticles, polyvinylidene fluoride, and N-methylpyrrolidone are 75-85wt%: 5-15wt%: 5-15wt%; And / or, the vacuum drying temperature is 60-70° C. and the time is 10-14 h.

6. The use according to claim 3, 4 or 5, characterized in that The preparation method of the polyaminoanthraquinone nanoparticles specifically comprises the following steps: S1. Add aminoanthraquinone to an organic solvent, add protonic acid dropwise, and stir ultrasonically to mix and dissolve. S2. Continue stirring and slowly add the oxidant solution dropwise to generate a solid precipitate; S3. Centrifuge, wash and dry the suspension containing the solid precipitate.

7. The use according to claim 6, characterized in that In step S1, the aminoanthraquinone includes 1-aminoanthraquinone; and / or, the organic solvent is selected from at least one of acetonitrile, N,N-dimethylformamide, and dimethyl sulfoxide; And / or, the protonic acid is selected from at least one of perchloric acid, hydrochloric acid, and nitric acid; And / or, in step S2, the oxidant is selected from at least one of ammonium persulfate, chromium trioxide, and potassium permanganate.

8. The use according to claim 7, characterized in that The aminoanthraquinone includes 1-aminoanthraquinone, the protonic acid includes perchloric acid, and the oxidant includes ammonium persulfate; The usage ratio of 1-aminoanthraquinone to perchloric acid is 1mmol:0.1-0.2ml; The molar ratio of 1-aminoanthraquinone to ammonium persulfate is 1:3-5; The concentration of the ammonium persulfate solution is 1-2 mol / ml.

9. The use according to claim 6, characterized in that In step S2, the stirring speed is 200-400 r / min, the temperature is 0-30° C., and the time is 24-72 h.

10. The use according to claim 6, characterized in that In step S3, the washing comprises: washing with ethanol until the system is no longer brown; then washing with deionized water until the pH of the system is neutral; and / or, The drying temperature is 60-80° C. and the drying time is 12-24 hours.

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