Sediment fuel cell anode with high strength and high microbial adhesion rate and preparation method thereof

Abstract

The invention belongs to the technical field of sediment fuel cells, and particularly discloses a high-strength and high-microbial adhesion rate sediment fuel cell anode and a preparation method thereof. The preparation method comprises the following steps: mixing carbon black, carbon nanotubes and stearic acid to obtain mixed carbon powder; then mixing and granulating with high-density polyethylene, a coupling agent and graphene nanoplatelets to obtain composite granules, and processing the composite granules to obtain thick strips with holes; then sequentially carrying out pretreatment and bacterial liquid inoculation to obtain a microorganism attachment thick strip; and carrying out ultrasonic welding on the microorganism adhesion thick strips to form a geocell structure, so as to obtain the high-strength and high-microorganism adhesion rate sediment fuel cell anode. The obtained anode of the sediment fuel cell has excellent strength and microbial adhesion rate, shows good biocompatibility, and promotes the practical application of the sediment fuel cell.

Description

Technical Field

[0001] This invention relates to the field of sediment fuel cell technology, and in particular to a high-strength sediment fuel cell anode with high microbial adhesion rate and its preparation method. Background Technology

[0002] Sediment fuel cells, as a novel energy recovery and environmental remediation technology, can generate electricity by utilizing the redox gradient at the interface between organic matter in sediments and bottom mud and water. At the same time, they can promote the degradation of pollutants in sediments, and have broad application prospects in ecological restoration and sustainable energy development.

[0003] The anode is one of the core components of a sediment fuel cell, and its performance directly affects the cell's output power and stability. An ideal anode not only needs good conductivity and chemical stability, but also mechanical strength for easy installation and biocompatibility to promote the attachment and growth of electroactive microorganisms. Currently, in existing sediment fuel cell anode devices, carbon-based electrode materials such as carbon cloth and carbon felt, although able to achieve start-up and function in laboratory pilot tests, are difficult to install and apply in the field due to their softness and inability to be pressed into the sediment, and also have poor stability in flowing water environments. While metallic materials have good conductivity and high mechanical properties, making them easy to press into the sediment, their small specific surface area makes them difficult for electroactive microorganisms to attach to and they are prone to corrosion.

[0004] Therefore, how to provide a deposited fuel cell anode that combines high mechanical strength and high microbial adhesion rate to promote the practical application of deposited fuel cells is an urgent problem to be solved in this field. Summary of the Invention

[0005] In view of this, the present invention provides a sediment fuel cell anode that combines high mechanical strength and high microbial adhesion rate, in order to solve the problems of existing sediment fuel cell carbon-based anode devices that cannot be pressed into the bottom mud and have poor stability, as well as the problems of metal-based anode devices that are difficult for electroactive microorganisms to adhere to and are prone to corrosion.

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

[0007] A method for preparing a high-strength, high-microbial-adhesion-rate deposited fuel cell anode includes the following steps:

[0008] 1) Mix carbon black, carbon nanotubes and stearic acid to obtain mixed carbon powder;

[0009] 2) Mix the mixed carbon powder, high-density polyethylene, coupling agent and graphene micro flakes, extrude and granulate to obtain composite granules, and process the composite granules to obtain thick strips with pores.

[0010] 3) The thick strip with holes is pretreated and then immersed in the environmental engineering bacteria solution for inoculation to obtain the microbial attached thick strip;

[0011] 4) The thick strips of microbial attachment are ultrasonically welded into a geocell structure to obtain a high-strength sediment fuel cell anode with high microbial attachment rate.

[0012] Preferably, the mass ratio of carbon black, carbon nanotubes and stearic acid in step 1) is 80-85:15-17:0.5-1.

[0013] Preferably, the mixing temperature in step 1) is 80-100°C and the mixing time is 10-15 min.

[0014] Preferably, the mass ratio of the mixed toner, high-density polyethylene, coupling agent and graphene microsheets in step 2) is 15-30: 70-85: 0.5-1: 0.5-1.

[0015] Preferably, the mixing temperature in step 2) is 80-100°C, the mixing speed is 1000-1500 rpm, and the mixing time is 10-15 min.

[0016] Preferably, the extrusion granulation temperature in step 2) is 160-180℃, the rotation speed is 400-600rpm, the feeding rate is 30-50kg / h, and the mixing time is 5-8min;

[0017] The particle size of the composite granules is 5-8 mm.

[0018] Preferably, the processing temperature in step 2) is 135-145°C, the processing pressure is 10-30 MPa, the holding time is 10-20 min, and the pressure is released 1-2 times from the start of holding the pressure to within 2 min.

[0019] The thickness of the perforated strip is 1-2 mm, and the width is 50-200 mm.

[0020] Preferably, the pretreatment in step 3) includes sequential acetone soaking, buffer washing, and water washing;

[0021] The acetone soaking time is 2 to 4 hours.

[0022] Preferably, the temperature for inoculating the bacterial solution in step 3) is 30°C, the time is 72 hours, and the inoculation is carried out under stirring conditions with a stirring rate of 150-200 rpm.

[0023] The environmental engineered bacteria in the bacterial solution include one or more of the following: Bacillus, Yeast, Actinomycetes, Lactobacillus, photosynthetic bacteria, and Shewanella.

[0024] Another objective of this invention is to provide a high-strength, high-microbial-adhesion-rate deposit fuel cell anode prepared by the above-described preparation method.

[0025] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The thick strip prepared by this invention is a conductive polyethylene sheet. Using immobilization technology, environmental engineering bacteria with high pollutant degradation ability or power generation performance are loaded onto the anode surface, and finally a sediment fuel cell anode structure with both high mechanical strength and high microbial adhesion rate is prepared. This structure is then applied to the anode of a sediment microbial fuel cell.

[0027] 2. High-density polyethylene as the matrix in the composite granules provides good mechanical support, while carbon black, carbon nanotubes, and graphene microsheets synergistically enhance conductivity. Coupling agents improve the interfacial compatibility of each component, solving the problem of traditional materials struggling to balance strength and conductivity. The thick strip design with pores increases the specific surface area, facilitating microbial attachment, while ensuring permeability, which is conducive to substrate transport and the discharge of metabolic products. The geocell structure formed by ultrasonic welding further enhances the overall mechanical strength, allowing it to be directly pressed into the bottom sediment and remain stable in a water flow environment. At the same time, the cell structure can fix the microbial community, improving the stability of power generation and the efficiency of pollutant degradation. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the thick strip with holes obtained by the present invention;

[0030] Figure 2 This is a schematic diagram of the geocell structure obtained by the present invention;

[0031] Figure 3 This is a SEM image of the anode material prepared in Example 1 of the present invention. Figure 3 In the image, 'a' represents a 3k magnified view of a thick band without attached environmental engineered bacteria. Figure 3 In the image, b represents a 3k magnified view of the thick band of engineered bacteria in the attached environment. Figure 3 In the image, 'c' represents a 9k magnified view of the thick band of engineered bacteria in the attached environment.

[0032] Figure 4This is a SEM image of the anode material prepared in Example 2 of the present invention. Figure 4 In the image, 'a' represents a 3k magnified view of a thick band without attached environmental engineered bacteria. Figure 4 In the image, b represents a 3k magnified view of the thick band of engineered bacteria in the attached environment. Figure 4 In the image, 'c' represents a 9k magnified view of the thick band of engineered bacteria in the attached environment.

[0033] Figure 5 This is a SEM image of the anode material prepared in Example 3 of the present invention. Figure 5 In the image, 'a' represents a 3k magnified view of a thick band without attached environmental engineered bacteria. Figure 5 In the image, b represents a 3k magnified view of the thick band of engineered bacteria in the attached environment. Figure 5 In the image, 'c' represents a 9k magnified view of the thick band of engineered bacteria in the attached environment.

[0034] Figure 6 This is a polarization power curve of the SMFC system corresponding to Embodiment 1 of the present invention;

[0035] Figure 7 The graphs show the TP degradation effect of the SMFC system corresponding to Example 1 and Comparative Example 1 of this invention.

[0036] Figure 8 This is the polarization power curve of the SMFC system corresponding to Embodiment 2 of the present invention;

[0037] Figure 9 The graphs show the TP degradation effect of the SMFC system corresponding to Example 2 and Comparative Example 2 of this invention.

[0038] Figure 10 This is the polarization power curve of the SMFC system corresponding to Embodiment 3 of the present invention;

[0039] Figure 11 The graphs show the TP degradation effect of the SMFC system corresponding to Example 3 and Comparative Example 3 of this invention.

[0040] Figure 12 The results are from the tensile property test of Example 1 of the present invention. Detailed Implementation

[0041] This invention provides a method for preparing a high-strength, high-microbial-adhesion-rate deposited fuel cell anode, comprising the following steps:

[0042] 1) Mix carbon black, carbon nanotubes and stearic acid to obtain mixed carbon powder;

[0043] 2) Mix the mixed carbon powder, high-density polyethylene, coupling agent and graphene micro flakes, extrude and granulate to obtain composite granules, and process the composite granules to obtain thick strips with pores.

[0044] 3) The thick strip with holes is pretreated and then immersed in the environmental engineering bacteria solution for inoculation to obtain the microbial attached thick strip;

[0045] 4) The thick strips of microbial attachment are ultrasonically welded into a geocell structure to obtain a high-strength sediment fuel cell anode with high microbial attachment rate.

[0046] In this invention, the mass ratio of carbon black, carbon nanotubes and stearic acid in step 1) is 80-85:15-17:0.5-1, preferably 82-84:15.5-16.5:0.6-0.9, and more preferably 83.5:16:0.8.

[0047] In this invention, the particle size of carbon black is preferably 5-20 μm, 6 μm, 8 μm, 10 μm, 12 μm, 14 μm, 15 μm, 16 μm, or 18 μm; the diameter of carbon nanotubes is preferably 2-7 nm, specifically 3 nm, 4 nm, 5 nm, or 6 nm; and the length is preferably 0.1-100 μm, specifically 0.5 μm, 1 μm, 2 μm, 5 μm, 10 μm, 20 μm, 40 μm, 50 μm, 60 μm, or 80 μm.

[0048] In this invention, the mixing temperature in step 1) is 80-100°C, specifically 82°C, 84°C, 85°C, 86°C, 88°C, 90°C, 92°C, 94°C, 95°C, 96°C, or 98°C; the mixing time is 10-15 min, specifically 10 min, 11 min, 12 min, 13 min, 14 min, or 15 min.

[0049] In this invention, the mass ratio of the mixed toner, high-density polyethylene, coupling agent and graphene microsheets in step 2) is 15-30:70-85:0.5-1:0.5-1, preferably 18-25:75-80:0.6-0.9:0.6-0.9, and more preferably 20:78:0.8:0.8.

[0050] In this invention, the coupling agent in step 2) is preferably a compound of isopropyl triisostearate titanate.

[0051] In this invention, the mixing temperature in step 2) is 80-100℃, specifically 82℃, 85℃, 88℃, 90℃, 92℃, 95℃, or 98℃; the mixing speed is 1000-1500 rpm, specifically 1100 rpm, 1200 rpm, 1300 rpm, or 1400 rpm; and the mixing time is 10-15 min, specifically 11 min, 12 min, 13 min, or 14 min.

[0052] In this invention, the extrusion granulation temperature in step 2) is 160–180°C, specifically 162°C, 165°C, 168°C, 170°C, 172°C, 175°C, or 178°C; the rotation speed is 400–600 rpm, specifically 420 rpm, 450 rpm, 480 rpm, 500 rpm, 520 rpm, 550 rpm, or 580 rpm; the feeding rate is 30–50 kg / h, specifically 32 kg / h, 34 kg / h, 35 kg / h, 36 kg / h, 38 kg / h, 40 kg / h, 42 kg / h, 45 kg / h, 46 kg / h, or 48 kg / h; and the mixing time is 5–8 min, specifically 5 min, 5.5 min, 6 min, 6.5 min, 7 min, 7.5 min, or 8 min.

[0053] In this invention, the particle size of the composite granules is 5-8 mm, specifically 5.5 mm, 6 mm, 6.5 mm, 7 mm, or 7.5 mm.

[0054] In this invention, the processing temperature in step 2) is 135–145°C, specifically 136°C, 138°C, 140°C, 142°C, or 144°C; the processing pressure is 10–30 MPa, specifically 12 MPa, 15 MPa, 18 MPa, 20 MPa, 22 MPa, 25 MPa, or 28 MPa; the holding time is 10–20 min, specifically 12 min, 14 min, 15 min, 16 min, or 18 min; and the pressure is released 1–2 times from the start of the holding time until 2 min. The purpose of releasing the pressure is to remove small molecules that volatilize during melting (such as PE degradation products and residual moisture) and to prevent the formation of pores.

[0055] In this invention, the thickness of the perforated strip is 1-2 mm, specifically 1.2 mm, 1.4 mm, 1.5 mm, 1.6 mm, or 1.8 mm; and the width is 100-200 mm, specifically 100 mm, 120 mm, 150 mm, 160 mm, 180 mm, or 200 mm.

[0056] In this invention, a schematic diagram of the thick strip with holes is shown below. Figure 1 As shown, the pores on the thick strip ensure water permeability and also facilitate the attachment of microorganisms.

[0057] In this invention, the pretreatment in step 3) includes sequential acetone soaking, buffer washing, and water washing.

[0058] In this invention, the acetone soaking operation uses an acetone aqueous solution, and the volume ratio of acetone to deionized water is preferably 0.8-1.2:0.8-1.2, more preferably 0.9-1.1:0.9-1.1, and even more preferably 1:1.

[0059] In this invention, the acetone soaking time is 2 to 4 hours, specifically 2.2 hours, 2.5 hours, 2.8 hours, 3 hours, 3.2 hours, 3.5 hours, and 3.8 hours.

[0060] In this invention, pretreatment can remove organic matter from the surface of thick strips, thereby improving the adhesion rate of microorganisms and biocompatibility.

[0061] In this invention, the temperature for bacterial inoculation in step 3) is 30°C and the time is 72 hours. The bacterial inoculation is carried out under stirring conditions, and the stirring speed is 150-200 rpm, specifically 160 rpm, 170 rpm, 180 rpm, or 190 rpm.

[0062] In this invention, the environmental engineered bacteria in the bacterial solution include one or more of the genera Bacillus, Yeast, Actinomycetes, Lactobacillus, photosynthetic bacteria, and Shewanella.

[0063] In this invention, when preparing the environmental engineered bacteria solution, the mass-to-volume ratio of the environmental engineered bacteria to the culture medium is preferably 10-50 g: 20 L, more preferably 20-40 g: 20 L, and even more preferably 30 g: 20 L.

[0064] In this invention, the dimensions (length × width) of the geocell structure described in step 4) can specifically be 210×245, 224×260, 290×340, 385×430, 420×490, or 448×520; the height (mm) of the geocell structure can specifically be 50, 75, 100, 120, 150, or 200; the number of longitudinal cells is preferably 3 to 45, specifically 5, 10, 15, 20, 25, 30, 35, or 40; the number of strips is preferably 6 to 90, specifically 10, 20, 30, 40, 50, 60, 70, or 80; and the weld spacing (mm) is preferably 330 to 712, specifically 330, 356, 445, 600, 660, or 712.

[0065] In this invention, the schematic diagram of the geocell structure is as follows: Figure 2 As shown.

[0066] The present invention also provides a high-strength, high-microbial-attachment-rate deposit fuel cell anode prepared by the above preparation method.

[0067] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0068] Example 1

[0069] Prepare carbon black with a particle size of 5-20 μm and carbon nanotubes with a diameter of 2-6 nm and a length of 5-20 μm; mix carbon black, carbon nanotubes and stearic acid in a mass ratio of 83.5:15.5:1 in a high-speed mixer at 80°C for 10 min, and dry in a vacuum oven at 150°C for 6 h to obtain mixed carbon powder.

[0070] The obtained mixed toner was combined with a compound of high-density polyethylene, isopropyl triisostearate titanate (HY-130 from Hangzhou Jessica Chemical Co., Ltd.), and graphene microsheets (W5 from Xiamen Lvshe Biotechnology Co., Ltd.) at a mass ratio of 28:70:1:1. The mixing temperature was 100℃, the speed was 1500 rpm, and the mixing time was 10 min. Then, the mixed material was fed into a twin-screw extruder for melt mixing at a temperature of 180℃, a speed of 500 rpm, a feed rate of 40 kg / h, and a mixing time of 6 min. Composite granules with a particle size of 5 mm were obtained.

[0071] The composite granules were uniformly filled into a mirror-finished stainless steel mold. The inner wall of the mold was sprayed with a conductive release agent and lightly compacted. The mold was heated to 140℃ and held for 8 minutes, then pressurized to 20MPa and held for 15 minutes. The pressure was released once every 2 minutes after the start of the holding period. After that, the pressure was kept constant and the mold was rapidly cooled to below 60℃ by water cooling at a rate of 8℃ / min. The mold was demolded, the flash was removed, and the surface was polished with 400-grit sandpaper. The material was then prepared into a 2mm thick strip with a width of 150mm. Two sets of holes were set vertically along the strip, with each set of holes arranged in 3 rows and 8 columns. The diameter of each hole was 5mm and the spacing between holes was 5mm. The vertical spacing between each set of holes was 30mm, and the distance from the edge was 30mm to avoid stress concentration at the edge. A repeating unit structure of "two sets of holes" was set every 80mm along the horizontal direction of the strip. The hole design can maximize the specific surface area and water permeability while ensuring the mechanical strength of the thick strip, creating favorable conditions for microbial attachment. The schematic diagram of the thick strip is as follows: Figure 1 As shown.

[0072] The obtained thick strips were completely immersed in acetone solution (acetone:deionized water = 1:1, v / v) and placed in a constant temperature shaking incubator with the following parameters: temperature 25℃, rotation speed 150 rpm, soaking for 3 hours. The thick strips were then removed from the acetone solution and quickly transferred to a beaker containing PBS buffer (pH 7.4). The material was ensured to be completely submerged. The beaker was then placed in a constant temperature shaking incubator with the following parameters: temperature 25℃, rotation speed 150 rpm, soaking for 12 hours. The strips were then removed from the PBS solution and rinsed three times with a thin stream of deionized water using a wash bottle, each time for 5 minutes. The strips were then transferred to a deionized water container and incubated at 4℃ for 24 hours, with the deionized water changed every 8 hours. These steps altered the surface properties of the thick strips, enhancing microbial adhesion and improving the biocompatibility of the material.

[0073] The thick strip was then immersed in sterile LB medium and inoculated with pre-cultured environmental engineered bacteria. The biofilm culture conditions were: 150 rpm and 30°C in a constant temperature water bath for 72 hours, with LB medium added once during the process to the original volume to ensure that the environmental engineered bacteria could successfully attach and form a stable biofilm on the anode surface.

[0074] LB medium: 10 g / L tryptone, 5 g / L yeast extract, 10 g / L NaCl; autoclave at 121°C for 20 minutes, then cool to room temperature.

[0075] The environmental engineering bacteria included Bacillus, yeast, actinomycetes, lactic acid bacteria, and photosynthetic bacteria. These environmental engineering bacteria were derived from a sediment conditioner produced by Jiangxi Diversion Water Ecological Environment Engineering Co., Ltd. 50g of this sample was weighed, ground into powder, and added to 20L of LB medium.

[0076] Thick strips of microbial-attached material are ultrasonically needle-welded to create geocells, resulting in high-strength, high-microbial-attachment-rate sediment fuel cell anodes. A schematic diagram is shown below. Figure 2 As shown, the unfolded dimensions of the geocell are 4m*2m.

[0077] Example 2

[0078] The only difference between this embodiment and Example 1 is that the environmental engineered bacteria is Shewanella (the mass-to-volume ratio of Shewanella to LB medium is 10g:20L).

[0079] Example 3

[0080] The only difference between this embodiment and Embodiment 1 is that Shewanella is added to the environmental engineered bacteria (the environmental engineered bacteria (including Bacillus, Yeast, Actinomycetes, Lactobacillus, photosynthetic bacteria, and Shewanella) are added to LB medium at a mass-to-volume ratio of 50g:20L, and the Shewanella is added to LB medium at a mass-to-volume ratio of 10g:20L).

[0081] SEM images of the anode materials prepared in Examples 1-3 are shown below. Figures 3-5 As shown, where Figures 3-5 The 'a' in the diagram corresponds to the 3k magnified images of the thick strips of unattached environmental engineered bacteria in Examples 1-3. Figures 3-5 In the diagram, 'b' corresponds to the 3k magnified image of the thick strips of engineered bacteria in the attachment environment of Examples 1-3. Figures 3-5 The 'c' in the diagram corresponds sequentially to the 9k magnified images of the thick bands of engineered bacteria in the attachment environment of Examples 1-3. Figures 3-5 It can be seen that after adopting the microbial immobilization technology, microorganisms can adhere well to the anode surface.

[0082] Example 4

[0083] Prepare carbon black with a particle size of 10-20 μm and carbon nanotubes with a diameter of 2-6 nm and a length of 30-50 μm; mix carbon black, carbon nanotubes and stearic acid in a mass ratio of 80:15:0.8 in a high-speed mixer at 100°C for 10 min, and dry in a vacuum oven at 150°C for 6 h to obtain mixed carbon powder.

[0084] The obtained mixed carbon powder was combined with a compound of high-density polyethylene, isopropyl triisostearate titanate (HY-130 from Hangzhou Jessica Chemical Co., Ltd.), and graphene microsheets (W5 from Xiamen Lvshe Biotechnology Co., Ltd.) at a mass ratio of 25:75:0.5:0.8. The mixing temperature was 80℃, the speed was 1200 rpm, and the time was 15 min. Then, the mixed material was fed into a twin-screw extruder for melt mixing at a temperature of 170℃, a speed of 600 rpm, a feed rate of 50 kg / h, and a mixing time of 6 min. Composite granules with a particle size of 8 mm were obtained.

[0085] The composite granules were uniformly filled into a mirror-finished stainless steel mold. The inner wall of the mold was sprayed with a conductive release agent and lightly compacted. The mold was heated to 140℃ and held for 8 minutes, then pressurized to 20MPa and held for 20 minutes. The pressure was released once every 2 minutes after the start of the holding period. After that, the pressure was kept constant and the mold was rapidly cooled to below 60℃ by water cooling at a rate of 8℃ / min. The mold was demolded, the flash was removed, and the surface was polished with 400-grit sandpaper. The material was then prepared into a 2mm thick strip with a width of 150mm. Two sets of holes were set vertically along the strip, with each set of holes arranged in 3 rows and 8 columns. The diameter of each hole was 5mm and the spacing between holes was 5mm. The vertical spacing between each set of holes was 30mm, and the distance from the edge was 30mm to avoid stress concentration at the edge. A repeating unit structure of "two sets of holes" was set every 80mm along the horizontal direction of the strip. The hole design can maximize the specific surface area and water permeability while ensuring the mechanical strength of the thick strip, creating favorable conditions for microbial attachment.

[0086] The obtained thick strips were completely immersed in acetone solution (acetone:deionized water = 1:1, v / v) and placed in a constant temperature shaking incubator with the following parameters: temperature 25℃, rotation speed 150 rpm, soaking for 3 hours. The thick strips were then removed from the acetone solution and quickly transferred to a beaker containing PBS buffer (pH 7.4). The material was ensured to be completely submerged. The beaker was then placed in a constant temperature shaking incubator with the following parameters: temperature 25℃, rotation speed 150 rpm, soaking for 12 hours. The strips were then removed from the PBS solution and rinsed three times with a thin stream of deionized water using a wash bottle, each time for 5 minutes. The strips were then transferred to a deionized water container and incubated at 4℃ for 24 hours, with the deionized water changed every 8 hours. These steps altered the surface properties of the thick strips, enhancing microbial adhesion and improving the biocompatibility of the material.

[0087] Then, the thick strip was immersed in sterile LB medium and inoculated with pre-cultured environmental engineering bacteria solution (inoculation method is the same as in Example 1). The unfolded size of the geocell is 4m*2m.

[0088] Example 5

[0089] Prepare carbon black with a particle size of 5-20 μm and carbon nanotubes with a diameter of 2-6 nm and a length of 10-40 μm; heat and mix carbon black, carbon nanotubes and stearic acid in a high-speed mixer at 85:17:1 by mass for 15 min at 80 °C, and dry in a vacuum oven at 150 °C for 6 h to obtain mixed carbon powder.

[0090] The obtained mixed carbon powder was combined with a compound of high-density polyethylene, isopropyl triisostearate titanate (HY-130 from Hangzhou Jessica Chemical Co., Ltd.), and graphene microsheets (W5 from Xiamen Lvshe Biotechnology Co., Ltd.) at a mass ratio of 18:85:0.8:0.8. The mixing temperature was 100℃, the speed was 1000rpm, and the time was 10min. Then, the mixed material was fed into a twin-screw extruder for melt mixing at a temperature of 160℃, a speed of 400rpm, a feed rate of 30kg / h, and a mixing time of 8min. Composite granules with a particle size of 6mm were obtained.

[0091] The composite granules were uniformly filled into a mirror-finished stainless steel mold. The inner wall of the mold was sprayed with a conductive release agent and lightly compacted. The mold was heated to 140℃ and held for 8 minutes, then pressurized to 30MPa and held for 15 minutes. The pressure was released once every 2 minutes after the start of the holding period. After that, the pressure was kept constant and the mold was rapidly cooled to below 60℃ by water cooling at a rate of 8℃ / min. The mold was demolded, the flash was removed, and the surface was polished with 400-grit sandpaper. The material was then prepared into a 2mm thick strip with a width of 150mm. Two sets of holes were set vertically along the strip, with each set of holes arranged in 3 rows and 8 columns. The diameter of each hole was 5mm and the spacing between holes was 5mm. The vertical spacing between each set of holes was 30mm, and the distance from the edge was 30mm to avoid stress concentration at the edge. A repeating unit structure of "two sets of holes" was set every 80mm along the horizontal direction of the strip. The hole design can maximize the specific surface area and water permeability while ensuring the mechanical strength of the thick strip, creating favorable conditions for microbial attachment.

[0092] The obtained thick strips were completely immersed in acetone solution (acetone:deionized water = 1:1, v / v) and placed in a constant temperature shaking incubator with the following parameters: temperature 25℃, rotation speed 150 rpm, soaking for 3 hours. The thick strips were then removed from the acetone solution and quickly transferred to a beaker containing PBS buffer (pH 7.4). The material was ensured to be completely submerged. The beaker was then placed in a constant temperature shaking incubator with the following parameters: temperature 25℃, rotation speed 150 rpm, soaking for 12 hours. The strips were then removed from the PBS solution and rinsed three times with a thin stream of deionized water using a wash bottle, each time for 5 minutes. The strips were then transferred to a deionized water container and incubated at 4℃ for 24 hours, with the deionized water changed every 8 hours. These steps altered the surface properties of the thick strips, enhancing microbial adhesion and improving the biocompatibility of the material.

[0093] Then, the thick strip was immersed in sterile LB medium and inoculated with pre-cultured environmental engineering bacteria solution (inoculation method is the same as in Example 1). The unfolded size of the geocell is 4m*2m.

[0094] Experimental Example 1

[0095] The anode materials prepared in Examples 1-3 were cut to appropriate sizes, and then the anode materials were buried in the bottom mud to assemble into an SMFC system. The dimensions of each anode after unfolding were 4m*2m, and the anode top was buried in the bottom mud to a depth of 5cm. Insulating posts were nailed into the cells at the four vertices of the anode. Each cathode (graphite felt, purchased from Dongguan Tianwang Graphite Products Co., Ltd., 3mm) measures 1m*1m. To ensure full contact with air, it is floated on the water surface by a special float and fixed to a column with ropes, keeping its position directly above the center of the anode. A wire is led out from both the cathode and anode to the shore, connected to an external resistor, and the real-time voltage is monitored and recorded. This forms an SMFC system. (The SMFC systems corresponding to Examples 1-3 are repeated, but not connected (the anode and cathode do not form an electrical connection), and are referred to as Comparative Examples 1-3 respectively). In the SMFC system, 60mM lactic acid is added to the surface of the anode material as a substrate for the microbial inoculant to start the process. The output voltage of the SMFC device is recorded every four minutes using a paperless recorder. The external resistance is gradually reduced from 9999Ω to 19Ω to change the external resistance, and the output voltage of the SMFC at the corresponding resistance is recorded. The corresponding current is then calculated according to Ohm's law to obtain the curve. The treated water was tested using the "Determination of Total Phosphorus in Water - Ammonium Molybdate Spectrophotometric Method" (GB 11893-1989), and the results are as follows:

[0096] The electrochemical performance of the SMFC device was characterized by steady-state discharge method. The polarization power curve of Example 1 is shown in the figure below. Figure 6 As shown, the TP degradation effects of Example 1 and Comparative Example 1 are as follows: Figure 7 As shown. (Through) Figure 6 It can be seen that after the experimental setup stabilized, the polarization power was measured using the transformer method, and the maximum power density was found to be 402.28 mW / m². 2 Based on the slope, its inner group is calculated to be 3.8 Ω·m. 2 ;pass Figure 7 It can be seen that the total phosphorus degradation effect of Example 1, at 67.36%, is far better than that of Comparative Example 1, increasing by 187%. The polarization power curve of Example 2 is shown below. Figure 8 As shown, the TP degradation effects of Example 2 and Comparative Example 2 are as follows: Figure 9 As shown. (Through) Figure 8 It can be seen that the maximum power density is 550.02 mW / m 2 Based on the slope, its inner group is calculated to be 1.9 Ω·m. 2 ;pass Figure 9 It can be seen that the total phosphorus degradation effect of Example 2 (84.72%) is far better than that of Comparative Example 1, increasing by 156.6%. The polarization power curve of Example 3 is shown below. Figure 10 As shown, the TP degradation effects of Example 2 and Comparative Example 2 are as follows: Figure 11 As shown. (Through) Figure 10 It can be seen that the maximum power density is 570.42 mW / m 2 Based on the slope, its inner group is calculated to be 2.2 Ω·m. 2 ;pass Figure 11 It can be seen that the total phosphorus degradation effect of Example 2, at 68.77%, is much better than that of Comparative Example 1, increasing by 118.9%.

[0097] Experiment Example 2

[0098] The final product sample prepared in Example 1 was subjected to tensile testing using a universal testing machine. The stress-strain relationship was recorded, and the matrix rigidity, fracture resistance, and toughness were analyzed to determine whether they met engineering requirements. The tensile performance test results are as follows: Figure 12 As shown, through Figure 12 It can be seen that the elastic modulus of the battery anode material is 302.59 MPa, the yield strength is 2.19 MPa, the ultimate strength is 7.23 MPa, and the elongation is 30.94%, which can meet the engineering requirements.

[0099] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0100] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a high-strength, high-microbial-adhesion-rate deposited fuel cell anode, characterized in that, Includes the following steps: 1) Mix carbon black, carbon nanotubes and stearic acid to obtain mixed carbon powder; 2) Mix the mixed carbon powder, high-density polyethylene, coupling agent and graphene micro flakes, extrude and granulate to obtain composite granules, and process the composite granules to obtain thick strips with pores. 3) The thick strip with holes is pretreated and then immersed in the environmental engineering bacteria solution for inoculation to obtain the microbial attached thick strip; 4) The thick strips of microbial attachment are ultrasonically welded into a geocell structure to obtain a high-strength sediment fuel cell anode with high microbial attachment rate.

2. The method for preparing a high-strength, high-microbial-adhesion-rate deposited fuel cell anode according to claim 1, characterized in that, The mass ratio of carbon black, carbon nanotubes and stearic acid in step 1) is 80-85:15-17:0.5-1.

3. The method for preparing a high-strength, high-microbial-adhesion-rate deposited fuel cell anode according to claim 2, characterized in that, The mixing temperature in step 1) is 80-100℃, and the mixing time is 10-15 min.

4. A method for preparing a high-strength, high-microbial-adhesion-rate deposited fuel cell anode according to any one of claims 1 to 3, characterized in that, The mass ratio of the mixed toner, high-density polyethylene, coupling agent and graphene microsheets in step 2) is 15-30: 70-85: 0.5-1: 0.5-1.

5. The method for preparing a high-strength, high-microbial-adhesion-rate deposited fuel cell anode according to claim 4, characterized in that, The mixing temperature in step 2) is 80-100℃, the mixing speed is 1000-1500 rpm, and the mixing time is 10-15 min.

6. The method for preparing a high-strength, high-microbial-adhesion-rate deposited fuel cell anode according to claim 5, characterized in that, The extrusion granulation temperature in step 2) is 160-180℃, the rotation speed is 400-600rpm, the feeding rate is 30-50kg / h, and the mixing time is 5-8min; The particle size of the composite granules is 5-8 mm.

7. A method for preparing a high-strength, high-microbial-adhesion-rate deposited fuel cell anode according to claim 5 or 6, characterized in that, The processing temperature in step 2) is 135-145℃, the processing pressure is 10-30MPa, the holding time is 10-20min, and the pressure is released 1-2 times from the start of holding the pressure to within 2min. The thickness of the perforated strip is 1-2 mm, and the width is 50-200 mm.

8. The method for preparing a high-strength, high-microbial-adhesion-rate deposited fuel cell anode according to claim 7, characterized in that, The pretreatment described in step 3) includes sequential acetone soaking, buffer washing, and water washing; The acetone soaking time is 2 to 4 hours.

9. The method for preparing a high-strength, high-microbial-adhesion-rate deposited fuel cell anode according to claim 8, characterized in that, The temperature for inoculating the bacterial solution in step 3) is 30℃, the time is 72h, and the inoculation is carried out under stirring conditions at a stirring rate of 150-200 rpm. The environmental engineered bacteria in the bacterial solution include one or more of the following: Bacillus, Yeast, Actinomycetes, Lactobacillus, photosynthetic bacteria, and Shewanella.

10. A high-strength, high-microbial-adhesion-rate deposit fuel cell anode prepared by the preparation method according to any one of claims 1 to 9.

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