A metal-loaded sodium alginate carbon aerogel-based granular bioelectrode, a preparation method and application thereof

Abstract

The application provides a granular bioelectrode based on metal-loaded sodium alginate carbon aerogel and a preparation method and application thereof, and belongs to the technical field of granular electrode preparation.The granular bioelectrode is prepared from raw materials including metal-loaded sodium alginate carbon aerogel, garden soil and starch, and the mass ratio of the three is (6-8):(1-3):1.The granular bioelectrode is prepared by using metal-loaded sodium alginate carbon aerogel as a substrate, and the substrate is functionally modified by starch and garden soil, so that the electrochemical performance and stability of the granular bioelectrode are improved; and the granular bioelectrode can be used in various bioelectrochemical systems and has a wide application prospect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of particle electrode preparation, and particularly relates to a particle biological electrode based on metal-loaded sodium alginate carbon aerogel and a preparation method and application thereof. BACKGROUND

[0002] Phenolic wastewater is widely sourced from the production processes of coal processing, petroleum chemical industry, pharmaceutical industry, wood processing, plastic and rubber production, paint manufacturing, papermaking and food processing. Due to the high toxicity of phenol, phenol has potential carcinogenic, teratogenic and mutagenic properties, and is one of the harmful wastewaters that need to be solved in current water pollution control in China. Effective treatment of phenolic wastewater is of great significance for saving water resources, protecting the environment, improving people's living standards and realizing sustainable economic development.

[0003] Three-dimensional electro-catalytic biological aerated filter provides an effective way for the deep degradation of phenolic pollutants in wastewater, and the core is the selection of particle biological electrode. Using widely available and low-cost sodium alginate carbon aerogel as raw material to prepare particle biological electrode is an economical and sustainable method. SUMMARY

[0004] To solve the above technical problems, the present application provides a particle biological electrode based on metal-loaded sodium alginate carbon aerogel and a preparation method and application thereof.

[0005] To achieve the above purpose, the present application provides the following technical solutions:

[0006] One of the technical solutions of the present application is:

[0007] A particle biological electrode based on metal-loaded sodium alginate carbon aerogel, the raw materials of which include metal-loaded sodium alginate carbon aerogel, garden soil and starch; the mass ratio of the three is (6-8) :(1-3) :1.

[0008] Beneficial effects: The present application uses metal-loaded sodium alginate carbon aerogel as the main material, selects garden soil as the binder, and selects soluble starch as the pore-forming agent, and finally prepares the particle biological electrode based on metal-loaded sodium alginate carbon aerogel. The particle biological electrode has high electro-catalytic activity, high specific surface area and good electrical conductivity, and can be applied to the treatment of phenolic wastewater in three-dimensional electro-catalytic biological filter. The particle electrode surface has a typical hierarchical pore structure, has good adsorption capacity for phenolic substances, and has environmental safety performance. The preparation raw materials are widely available and low in cost, and have great potential for promotion.

[0009] Preferably, the mass ratio of the metal-loaded sodium alginate carbon aerogel, garden soil and starch is 8:1:1 or 7:2:1 or 6:3:1.

[0010] Preferably, the preparation process of the metal-loaded sodium alginate carbon aerogel is as follows:

[0011] Mix the metal salt solution with the sodium alginate solution under stirring to obtain a hydrogel;

[0012] Freeze and vacuum freeze dry the hydrogel in sequence to obtain an aerogel;

[0013] Carbonize the aerogel under a nitrogen atmosphere to obtain the metal-loaded sodium alginate carbon aerogel.

[0014] Preferably, the metal ions in the metal salt solution include one or more of Co 2+ , Cu 2+ , Zn 2+ , Al 3+ , or Fe 3+ .

[0015] Preferably, the concentration of the sodium alginate solution is 1wt%.

[0016] Preferably, the conditions of the vacuum freeze drying are as follows: the temperature is-40℃, and the pressure is 10Pa.

[0017] Preferably, the conditions in the carbonization process are as follows: carbonization at 500-700℃ for 4h.

[0018] The second technical solution of the present application is as follows:

[0019] The preparation method of the granular bioelectrode based on the metal-loaded sodium alginate carbon aerogel includes the following steps:

[0020] Mix the metal-loaded sodium alginate carbon aerogel, garden soil, and starch, spray water to shake into spherical particles, calcine, cool, and obtain the granular bioelectrode based on the metal-loaded sodium alginate carbon aerogel.

[0021] Preferably, the conditions in the calcination process are as follows: calcination at 1200℃ for 6h.

[0022] The third technical solution of the present application is as follows:

[0023] The application of the above-mentioned granular bioelectrode based on the metal-loaded sodium alginate carbon aerogel in the treatment of phenol-containing wastewater.

[0024] Compared with the prior art, the present application has the following advantages and technical effects:

[0025] The preparation process of the granular bioelectrode based on the metal loaded sodium alginate carbon aerogel is simple, and the cost is low; the carbon aerogel obtained in the preparation process has good biocompatibility and conductivity as a substrate; the electrochemical performance and stability of the granular bioelectrode are improved through functional modification of the starch and garden soil; and the granular bioelectrode can be used in various bioelectrochemical systems, and has wide application prospects. BRIEF DESCRIPTION OF DRAWINGS

[0026] The accompanying drawings, which form a part of the present application, are used to provide further understanding of the present application, and the illustrative embodiments of the present application and their description serve the purpose of explaining the present application. The drawings do not constitute an inappropriate limitation on the present application. In the drawings:

[0027] Figure 1 A preparation flow chart of the granular bioelectrode based on the metal loaded sodium alginate carbon aerogel of the present application;

[0028] Figure 2 A removal effect diagram of the granular bioelectrode based on the metal loaded sodium alginate carbon aerogel prepared in Example 1-3 of the present application for removing phenol;

[0029] Figure 3 SEM diagrams (20, 5, 2, 1 nm, respectively) of the granular bioelectrode based on the metal loaded sodium alginate carbon aerogel prepared in Example 1 of the present application. DETAILED DESCRIPTION

[0030] Now, various exemplary embodiments of the present application will be described in detail, which should not be considered as a limitation on the present application, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present application.

[0031] It should be understood that the terms described in the present application are only for describing the specific embodiments, and are not used to limit the present application. In addition, for the numerical range in the present application, it should be understood that each intermediate value between the upper limit and the lower limit of the range is also specifically disclosed. Each smaller range between any stated value or intermediate value in the stated range and any other stated value or intermediate value in the stated range is also included in the present application. The upper limit and the lower limit of these smaller ranges can be independently included or excluded from the range.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application pertains. Although preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials in connection with which the documents are concerned. In the event of any conflict between the content of this specification and the documents incorporated by reference, the content of this specification shall prevail.

[0033] Many modifications and variations of the present application described herein will be apparent to those skilled in the art from the foregoing description. Such modifications and variations are intended to come within the scope of the present application. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. The specification and examples are illustrative only.

[0034] As used herein, the terms "comprises", "comprising", "includes", "including", "has", "having", "contains", "containing", or variations thereof, are intended to be open-ended terms that mean inclusion, but not limited to, the listed material or step.

[0035] The present application provides a preparation method of a granular bioelectrode based on metal-loaded sodium alginate carbon aerogel, comprising the following steps:

[0036] Step one: first, add the sodium alginate solution to the prepared metal salt solution through a separatory funnel and continuously stir for 12 h to obtain a metal ion chelated hydrogel; wash the hydrogel with deionized water for 10 times, then place it in a freeze dryer, freeze for 24 h, and then vacuum freeze dry to obtain an aerogel;

[0037] Step two: place the obtained aerogel in a tube furnace and carbonize it under 100% N2 atmosphere for 4 h to obtain a metal oxide-loaded carbon aerogel (M-CA);

[0038] Step three: dry the obtained loaded carbon aerogel and garden soil in an oven at 100°C for 4 h, sieve, mix the carbon aerogel, garden soil and starch uniformly at a mass ratio of 8:1:1, shake into spherical particles after spraying water, and calcine for 6 hours, and then naturally cool to room temperature.

[0039] In some preferred embodiments, the concentration of the sodium alginate solution in step one is 1 wt%.

[0040] In some preferred embodiments, the metal salt solution in step one comprises one or more of Co 2+ , Cu 2+ , Zn 2+ , Al 3+ or Fe 3+ .

[0041] In some preferred embodiments, the vacuum freeze drying conditions in step one are -40°C and 10 Pa.

[0042] In some preferred embodiments, the carbonization temperature in step two is 500-700°C.

[0043] In some preferred embodiments, the sieving in step three is sieving through a 200 mesh sieve.

[0044] In some preferred embodiments, the size of the spherical particles in step three is 5-8 mm.

[0045] In some preferred embodiments, the calcination temperature in step three is 1200℃.

[0046] In some preferred embodiments, the garden soil in step three is any loess in the garden of North China, which is passed through a 200-mesh sieve.

[0047] In some preferred embodiments, the starch in step three is purchased from the National Pharmaceutical Group.

[0048] In addition, the application also provides the use of the above-mentioned granular bioelectrode based on metal-loaded sodium alginate carbon aerogel in treating phenol-containing wastewater.

[0049] The specific implementation method is to place the prepared granular bioelectrode in a three-dimensional electrocatalytic biological filter to treat the phenol-containing wastewater.

[0050] In some preferred embodiments, the phenol-containing wastewater is laboratory-simulated phenol-containing wastewater.

[0051] In some preferred embodiments, a ruthenium-iridium titanium mesh is selected as the anode and cathode electrode plates.

[0052] The raw materials used in the embodiments of the application are all obtained by market purchase.

[0053] The technical solutions of the application are further described below through examples.

[0054] Example 1

[0055] As shown in the following: Figure 1 A preparation method of a granular bioelectrode based on metal-loaded sodium alginate carbon aerogel, comprising the following steps:

[0056] 1000 mL of a 1wt% sodium alginate solution is added to 1000 mL of copper nitrate (concentration of 10M) through a separatory funnel and continuously stirred for 12h to obtain a metal ion chelated hydrogel;

[0057] The obtained hydrogel is washed with deionized water for 10 times and then placed in a freeze dryer for 24h freezing, and then vacuum freeze-dried under the conditions of-40℃ and 10Pa to obtain an aerogel;

[0058] The obtained aerogel is placed in a tube furnace and carbonized under the conditions of 100% N2 atmosphere and 600℃ for 4h to obtain a metal oxide-loaded carbon aerogel (M-CA);

[0059] The obtained loaded carbon aerogel and garden soil are dried in a 100℃ oven for 4h, and sieved using a 200-mesh laboratory standard sieve;

[0060] Metal oxide-supported carbon aerogel, garden soil, and starch were mixed evenly in a mass ratio of 8:1:1. After spraying with water, the mixture was shaken into 6mm spherical particles and calcined in a muffle furnace at 1200℃ for 6 hours, then allowed to cool naturally to room temperature.

[0061] Example 2

[0062] The difference from Example 1 is that the metal oxide-supported carbon aerogel, garden soil and starch are mixed evenly in a ratio of 7:2:1, while other conditions are the same as in Example 1.

[0063] Example 3

[0064] The difference from Example 1 is that the metal oxide-supported carbon aerogel, garden soil and starch are mixed evenly in a ratio of 6:3:1, while other conditions are the same as in Example 1.

[0065] Example 4

[0066] The difference from Example 1 is that the metal in the metal oxide-supported carbon aerogel is Fe. 3+ Other conditions are the same as in Example 1.

[0067] The characterization parameters of the particulate bioelectrodes based on metal-supported sodium alginate carbon aerogels prepared in Examples 1-4 are shown in Table 1 below.

[0068] Table 1

[0069] Sample Specific surface area (m 2· g -1 )]]> Total pore volume (cm 3· g -1 )]]> Average pore size (nm) Example 1 162.4 0.108 2.74 Example 2 145.6 0.092 2.58 Example 3 128.8 0.088 2.42 Example 4 178.8 0.164 2.98

[0070] Effect verification

[0071] Using the metal-supported sodium alginate carbon aerogel-based particulate bioelectrode prepared in Examples 1-3, simulated phenol-containing wastewater (initial concentration of phenol-containing wastewater was 10 mg / L) was prepared with phenol solution. A three-dimensional electrocatalytic pilot-scale reactor was prepared, and ruthenium-iridium-titanium plated mesh was selected as the anode and cathode electrodes. A constant current density (current density 2.5 mA / cm²) was used. 2 The efficiency of the reactor in degrading phenol was tested under the following conditions.

[0072] Figure 2 The images show the phenol removal performance of the particulate bioelectrodes based on metal-supported sodium alginate carbon aerogel prepared in Examples 1-3 of this invention. Figure 2 As can be seen, the removal rate of phenol by the three three-dimensional electrocatalytic pilot reactors increased with the increase of electrolysis time (0-30 min), and the final removal rate of phenol was higher than 85%. In particular, the removal rate of phenol by the reactor using the metal-supported sodium alginate carbon aerogel particle bioelectrode prepared in Example 1 as the bioelectrode was higher than 95%.

[0073] The above merely provides the preferred embodiment of the present application, and the protection scope of the present application is not limited thereto. Any modification or replacement within the technical scope disclosed by the present application can be easily conceived by those skilled in the art, and should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A granular bioelectrode based on metal-loaded sodium alginate carbon aerogel, characterized by, The raw materials include metal-loaded sodium alginate carbon aerogel, garden soil and starch; the mass ratio of the three is (6-8):(1-3):1; The preparation method of the granular bioelectrode based on the metal-loaded sodium alginate carbon aerogel comprises the following steps: The metal-loaded sodium alginate carbon aerogel, the garden soil and the starch are mixed, water is sprayed and shaken into spherical particles, calcination is performed, and cooling is performed to obtain the granular bioelectrode based on the metal-loaded sodium alginate carbon aerogel; The preparation process of the metal-loaded sodium alginate carbon aerogel is as follows: The metal salt solution and the sodium alginate solution are mixed and stirred to obtain a hydrogel; The hydrogel is sequentially subjected to freezing and vacuum freeze-drying to obtain an aerogel; The aerogel is subjected to carbonization in a nitrogen atmosphere to obtain the metal-loaded sodium alginate carbon aerogel; The metal ions in the metal salt solution include one or more of Co 2+ , Cu 2+ , Zn 2+ , Al 3+ , or Fe 3+ .

2. A metal supported sodium alginate carbon aerogel based particulate bi-electrode according to claim 1, wherein, The mass ratio of the metal-loaded sodium alginate carbon aerogel, the garden soil and the starch is 8:1:1 or 7:2:1 or 6:3:

1.

3. A metal supported sodium alginate carbon aerogel based particulate bi-electrode according to claim 1, wherein, The concentration of the sodium alginate solution is 1wt%.

4. A metal supported sodium alginate carbon aerogel based particulate bi-electrode according to claim 1, wherein, The conditions of the vacuum freeze-drying are as follows: the temperature is -40℃, and the pressure is 10Pa.

5. A metal supported sodium alginate carbon aerogel based particulate bi-electrode according to claim 1, wherein, The conditions in the carbonization process are as follows: carbonization at 500-700℃ for 4h.

6. A method for the preparation of a metal supported sodium alginate carbon aerogel based particulate bi-electrode according to any one of claims 1 to 5, characterized in that, The preparation method comprises the following steps: The metal-loaded sodium alginate carbon aerogel, the garden soil and the starch are mixed, water is sprayed and shaken into spherical particles, calcination is performed, and cooling is performed to obtain the granular bioelectrode based on the metal-loaded sodium alginate carbon aerogel.

7. A method of preparing a metal supported sodium alginate carbon aerogel based particulate bi-electrode as claimed in claim 6, wherein, The conditions in the calcination process are as follows: calcination at a temperature of 1200℃ for 6h.

8. Use of a granular bioelectrode based on a metal-loaded sodium alginate carbon aerogel in the treatment of phenol-containing wastewater according to any one of claims 1-5.

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