Method for accelerating power generation starting of microbial fuel cell

Abstract

The invention discloses a method for accelerating power generation starting of a microbial fuel cell, and relates to the technical field of biology. The method for accelerating power generation starting of the microbial fuel cell comprises the following steps: preparing a mixture of an inoculum, a first electron donor and a buffer solution, and standing to obtain an anode inoculation solution; and preparing the microbial fuel cell by adopting the anode inoculation liquid, and starting the microbial fuel cell. The method has the advantages of simple steps, no need of electrode treatment, low cost, effective acceleration of the power generation starting of the microbial fuel cell, and substantial improvement of the maximum power density, coulombic efficiency and electric activity.

Description

Technical Field

[0001] The invention relates to the field of biotechnology, in particular to a method for accelerating the start-up of power generation of a microbial fuel cell. Background Art

[0002] Microbial fuel cells (MFCs) are a technology that can convert biomass into electricity while reducing pollution. They have been widely studied and applied in new energy, sewage treatment, and water quality testing.

[0003] However, the long startup time has hindered the research of MFCs and its scale-up, standardization and commercial development. The common methods for accelerating the startup of MFCs include: (1) using a potentiostat to stabilize the electrodes of MFCs at a certain potential to promote the stable enrichment of specific electroactive bacterial communities; (2) applying a maximum power point tracking strategy to adjust the external resistance close to the internal resistance in real time to maintain the MFC at maximum power output conditions to promote the enrichment of efficient electricity-producing microorganisms; (3) pre-domesticating or enriching electroactive microorganisms, and inoculating the pre-domesticated or enriched microbial culture or even the existing microbial film into a new device to shorten the time for the electroactive microbial film to form. Although the above methods can effectively accelerate the startup of small microbial fuel cells, there are still problems such as high requirements for professional equipment and complex operations, which make it difficult to implement them in the large-scale production of small microbial fuel cells.

[0004] Therefore, it is necessary to provide a strategy to accelerate the start-up of power generation in microbial fuel cells. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a method for accelerating the start-up of power generation of a microbial fuel cell, which can effectively accelerate the start-up of power generation of a microbial fuel cell.

[0006] A method for accelerating the start-up of power generation of a microbial fuel cell according to a first aspect of the present invention comprises the following steps:

[0007] A mixture of inoculum, a first electron donor and a buffer solution is prepared and placed to obtain an anode inoculum solution; a microbial fuel cell is prepared using the anode inoculum solution and the microbial fuel cell is started.

[0008] The method according to the embodiment of the present invention has at least the following beneficial effects:

[0009] The method of the embodiment has simple steps, does not require electrode processing, is low-cost, can effectively accelerate the start-up of microbial fuel cell power generation, and significantly improves the maximum power density, coulomb efficiency, and electrical activity.

[0010] According to some embodiments of the invention, the inoculum comprises microorganisms capable of electronic storage.

[0011] According to some embodiments of the invention, the microorganism comprises an electrogenic microorganism.

[0012] According to some embodiments of the present invention, the method for preserving the inoculum comprises the following steps: adding a second electron donor to the inoculum every 20 to 40 days. Thus, the potential of the microorganisms in the inoculum to start the MFCs can be maintained. For example, it can be 20 days, 21 days, 22 days, 23 days, 24 days, 25 days, 26 days, 27 days, 28 days, 29 days, 30 days, 31 days, 32 days, 33 days, 34 days, 35 days, 36 days, 37 days, 38 days, 39 days or 40 days.

[0013] According to some embodiments of the present invention, the amount of the first electron donor added is 3 g / time to 10 g / time per liter of inoculum. For example, the amount added can be 3 g / time, 3.5 g / time, 4 g / time, 4.5 g / time, 5 g / time, 5.5 g / time, 6 g / time, 6.5 g / time, 7 g / time, 7.5 g / time, 8 g / time, 8.5 g / time, 9 g / time, 9.5 g / time or 10 g / time per liter of inoculum.

[0014] According to some embodiments of the present invention, the storage temperature of the inoculum is 20°C to 30°C. For example, it can be 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C or 30°C.

[0015] According to some embodiments of the invention, the storage time of the inoculum is more than 2 months.

[0016] According to some embodiments of the present invention, the storage time of the inoculum is 2 to 18 months. For example, it can be 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 13 months, 14 months, 15 months, 16 months, 17 months or 18 months.

[0017] According to some embodiments of the present invention, the inoculant comprises at least one of urine, sludge, lake water, wastewater, sediment, and soil.

[0018] According to some embodiments of the present invention, the source of the sludge includes at least one of electrochemical plant sludge and industrial copper-containing sludge.

[0019] According to some embodiments of the present invention, the first electron donor and the second electron donor each independently include at least one of organic matter and thiosulfate.

[0020] According to some embodiments of the present invention, the organic matter includes at least one of formic acid, lactic acid, butyric acid, sodium formate, sodium acetate, sodium lactate, glucose, sucrose, starch, cysteine, methionine, and ascorbic acid.

[0021] According to some embodiments of the present invention, the thiosulfate includes at least one of sodium thiosulfate and calcium thiosulfate.

[0022] According to some embodiments of the present invention, the dosage ratio of the first electron donor to the inoculum is (0.5 mg to 2 mg): 1 mL. For example, it can be 0.5 mg: 1 mL, 0.6 mg: 1 mL, 0.7 mg: 1 mL, 0.8 mg: 1 mL, 0.9 mg: 1 mL, 1 mg: 1 mL, 1.1 mg: 1 mL, 1.2 mg: 1 mL, 1.3 mg: 1 mL, 1.4 mg: 1 mL, 1.5 mg: 1 mL, 1.6 mg: 1 mL, 1.7 mg: 1 mL, 1.8 mg: 1 mL, 1.9 mg: 1 mL or 2 mg: 1 mL.

[0023] According to some embodiments of the present invention, the volume ratio of the buffer to the inoculum is (0.5 mL to 1.5 mL): 1 mL. For example, it can be 0.5 mL: 1 mL, 0.6 mL: 1 mL, 0.7 mL: 1 mL, 0.8 mL: 1 mL, 0.9 mL: 1 mL, 1 mL: 1 mL, 1.1 mL: 1 mL, 1.2 mL: 1 mL, 1.3 mL: 1 mL, 1.4 mL: 1 mL or 1.5 mL: 1 mL.

[0024] According to some embodiments of the present invention, the buffer is selected from at least one of a phosphate buffer and a bicarbonate buffer.

[0025] According to some embodiments of the present invention, the concentration of the phosphate buffer is 10mM to 100mM, for example, 10mM, 15mM, 20mM, 25mM, 30mM, 35mM, 40mM, 45mM, 50mM, 55mM, 60mM, 65mM, 70mM, 75mM, 80mM, 85mM, 90mM, 95mM or 100mM.

[0026] According to some embodiments of the present invention, the placement time is more than 15 minutes. If the placement time is shorter, the electronic storage may be incomplete and the effect may be poor.

[0027] According to some embodiments of the present invention, the placement time is 15 minutes to 24 hours. For example, it can be 15 minutes, 30 minutes, 45 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours or 24 hours. If the placement time is too long, the working cycle will be extended and it is not conducive to realizing the rapid start-up of the microbial fuel cell.

[0028] According to some embodiments of the present invention, the microbial fuel cell comprises:

[0029] an anode chamber, wherein the anode chamber is provided with an anode and the anode inoculation solution;

[0030] a cathode chamber, the cathode chamber being provided with a cathode and a cathode electrolyte;

[0031] A diaphragm, the diaphragm is used to separate the anode chamber and the cathode chamber;

[0032] An external circuit is used to connect the anode and the cathode.

[0033] According to some embodiments of the present invention, the material of the anode includes at least one of carbon felt, carbon paper, activated carbon, and amorphous carbon fiber.

[0034] According to some embodiments of the present invention, the material of the cathode includes at least one of carbon felt, carbon paper, activated carbon, and amorphous carbon fiber.

[0035] According to some embodiments of the present invention, the diaphragm is a cation exchange membrane or a proton exchange membrane.

[0036] According to some embodiments of the present invention, the external circuit refers to a cathode and an anode being connected to an external resistor via a wire.

[0037] According to some embodiments of the invention, the cathode electrolyte includes a cathode electron acceptor.

[0038] According to some embodiments of the present invention, the cathode electron acceptor includes at least one of potassium ferrocyanide and potassium sulfite.

[0039] According to some embodiments of the present invention, the cathode electrolyte is a buffer solution containing the cathode electron acceptor, and the buffer solution is selected from at least one of a phosphate buffer solution and a bicarbonate buffer solution.

[0040] According to some embodiments of the present invention, the concentration of the cathode electron acceptor in the cathode electrolyte is 20 mM to 80 mM, for example, 20 mM, 25 mM, 30 mM, 35 mM, 40 mM, 45 mM, 50 mM, 55 mM, 60 mM, 65 mM, 70 mM, 75 mM or 80 mM.

[0041] According to some embodiments of the present invention, the microbial fuel cell is operated using a fed-batch method.

[0042] According to some embodiments of the present invention, when the microbial fuel cell is operated, when the output voltage drops suddenly, the electrolytes in the anode chamber and the cathode chamber are replaced with an anolyte and a cathode electrolyte, respectively.

[0043] According to some embodiments of the present invention, the anolyte is a buffer solution containing a third electron donor. The concentration of the second electron donor is 0.5 g / L to 5 g / L. For example, it can be 0.5 g / L, 0.8 g / L, 1 g / L, 1.2 g / L, 1.4 g / L, 1.6 g / L, 1.8 g / L, 2 g / L, 2.2 g / L, 2.4 g / L, 2.6 g / L, 2.8 g / L, 3 g / L, 3.2 g / L, 3.4 g / L, 3.6 g / L, 3.8 g / L, 4 g / L, 4.2 g / L, 4.4 g / L, 4.6 g / L or 5 g / L.

[0044] According to some embodiments of the present invention, the third electron donor includes at least one of organic matter and thiosulfate.

[0045] According to some embodiments of the present invention, the organic matter includes at least one of formic acid, lactic acid, butyric acid, sodium formate, sodium acetate, sodium lactate, glucose, sucrose, starch, cysteine, methionine, and ascorbic acid.

[0046] According to some embodiments of the present invention, the thiosulfate includes at least one of sodium thiosulfate and calcium thiosulfate.

[0047] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0049] Figure 1 The start-up effect of the dual-chamber microbial fuel cell constructed in Example 1 and Comparative Example 1;

[0050] Figure 2The start-up effect of the dual-chamber microbial fuel cell constructed in Examples 2 to 5 and Comparative Example 2;

[0051] Figure 3 The start-up effect of the dual-chamber microbial fuel cell constructed in Examples 6 to 9 and Comparative Example 3;

[0052] Figure 4 This is the start-up effect of the dual-chamber microbial fuel cell constructed in Examples 10 to 13 and Comparative Example 4. DETAILED DESCRIPTION

[0053] The following will be combined with the embodiments to clearly and completely describe the concept of the present invention and the technical effects produced, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0054] In the description of the present invention, if there is a description of first, second, third, etc., it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the sequence of the indicated technical features.

[0055] When a numerical range is disclosed herein, the above range is considered to be continuous and includes the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed herein should be understood to include any and all subranges included therein.

[0056] "And / or" is used to indicate that one or both of the stated situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0057] Unless otherwise specified, "room temperature" in the present invention means (25±5)°C.

[0058] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. If the manufacturers of the reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0059] Conventional MFCs are generally started with fresh or short-term cryopreserved inoculum. The inventors found that the potential of starting MFCs with long-term storage of inoculum under room temperature conditions can be achieved by regularly adding electron donors to the inoculum. By storing the inoculum at room temperature for a long time and regularly adding electron donors, MFCs technology can gain additional flexibility and cost-effectiveness.

[0060] In the conventional MFCs inoculation procedure, the inoculum and electron donor are immediately introduced into the anode chamber once they are mixed into an inoculation solution. The inventors have found that free electroactive microorganisms have the ability to store electrons. In the absence of electron acceptors, free electroactive microorganisms partially oxidize electron donors and store electrons inside the cells until suitable acceptors appear and release them. This can not only significantly improve their efficiency in utilizing electron donors, thereby inhibiting the growth of non-electroactive microorganisms; it can also induce the distribution of extracellular polymer structures in the inoculum, resulting in the transfer of extracellular polysaccharides that can improve the environmental adaptability and adhesion ability of microorganisms from the middle layer to the outer layer. Preliminary electron storage treatment can promote the colonization of electrogenic microorganisms on the anode and the formation of microbial films at the initial start-up of the MFC, and inhibit the contact time between non-electrogenic microorganisms and the anode, thereby achieving rapid start-up of MFCs.

[0061] In the embodiment of the present invention, the length, width and height of the cubic carbon felt electrode are 2*2*1 cm, and are purchased from Zouping Sanjing Carbon Co., Ltd.;

[0062] The cation exchange membrane was purchased from Membranes International, USA, model number CMI-7000;

[0063] The formula of 50 mM phosphate buffer solution (pH=7.4) is 4.34 g / L Na2HPO4, 2.78 g / L KH2PO4, 0.31 g / L NH4Cl, and 0.13 g / L KCl.

[0064] In the embodiment of the present invention, the cathode electrolyte refers to a 50 mM phosphate buffer solution (pH=7.4) containing 50 mM potassium ferrocyanide;

[0065] The anolyte was a 50 mM phosphate buffer solution (pH = 7.4) containing 1 g / L sodium acetate.

[0066] Example 1

[0067] This example provides a method for accelerating the start-up of microbial fuel cell power generation. The inoculum is the feed water sludge of the electrochemical plant (sourced from a certain electrochemical company in Jiangmen City) that has been sealed and stored in a glass bottle with a lid at room temperature for more than one year. During the storage period, 5g of glucose / 1L of sludge is added every 1 month to maintain the potential of the microorganisms in the sludge to start the MFCs. The steps are as follows:

[0068] A dual-chamber microbial fuel cell was used with a cation exchange membrane (working area of ​​7 cm 2 ) is separated into an anode chamber and a cathode chamber, the volumes of which are 10 mL and 10 mL respectively. Both the anode and cathode are cubic carbon felt electrodes, and the electrode spacing is maintained at 2 cm. 10 mL of anode inoculation solution is added to the anode chamber, and 10 mL of cathode electrolyte is added to the cathode chamber. The anode and cathode are connected through a 1000 Ω resistor, and the voltage is recorded every 5 minutes. MFCs are all operated with batch feeding. When the voltage drops significantly, the same volume of anolyte and cathode electrolyte is replaced until a stable and repeatable voltage is obtained.

[0069] Wherein, the preparation method of anode inoculation solution is as follows:

[0070] 5 mL of inoculum was mixed with 50 mM phosphate buffer solution (pH=7.4) containing 1 g / L sodium acetate at a volume ratio of 1:1 and allowed to stand at room temperature for 24 h to obtain the anode inoculum solution.

[0071] Example 2

[0072] This example provides a method for accelerating the start-up of microbial fuel cell power generation. The inoculum is industrial copper-containing sludge (from an electroplating factory in Jiangmen City). The steps are as follows:

[0073] A dual-chamber microbial fuel cell was used with a cation exchange membrane (working area of ​​7 cm 2 ) is separated into an anode chamber and a cathode chamber, the volumes of which are 10 mL and 10 mL respectively. Both the anode and cathode are cubic carbon felt electrodes, and the electrode spacing is maintained at 2 cm. 10 mL of anode inoculum solution is added to the anode chamber, and 10 mL of cathode electrolyte is added to the cathode chamber. The anode and cathode are connected through a 1000 Ω resistor, and the voltage is recorded every 5 minutes. MFCs are all operated with batch feeding. When the voltage drops significantly, a new electrolyte is replaced until a stable and repeatable voltage is obtained.

[0074] Wherein, the preparation method of anode inoculation solution is as follows:

[0075] 5 mL of inoculum was mixed with 50 mM phosphate buffer solution (pH=7.4) containing 1 g / L sodium acetate at a volume ratio of 1:1 and allowed to stand at room temperature for 1 h to obtain the anode inoculum solution.

[0076] Example 3

[0077] This example provides a method for accelerating the start-up of power generation in a microbial fuel cell, which is basically the same as Example 2, except that the method for preparing the anode inoculation solution is different.

[0078] The preparation method of anode inoculation solution is as follows:

[0079] 5 mL of inoculum was mixed with 50 mM phosphate buffer solution (pH=7.4) containing 1 g / L sodium acetate at a volume ratio of 1:1 and allowed to stand at room temperature for 4 h to obtain the anode inoculum solution.

[0080] Example 4

[0081] This example provides a method for accelerating the start-up of power generation in a microbial fuel cell, which is basically the same as Example 2, except that the method for preparing the anode inoculation solution is different.

[0082] The preparation method of anode inoculation solution is as follows:

[0083] 5 mL of inoculum was mixed with 50 mM phosphate buffer solution (pH=7.4) containing 1 g / L sodium acetate at a volume ratio of 1:1 and allowed to stand at room temperature for 16 h to obtain the anode inoculum solution.

[0084] Example 5

[0085] This example provides a method for accelerating the start-up of power generation in a microbial fuel cell, which is basically the same as Example 2, except that the method for preparing the anode inoculation solution is different.

[0086] The preparation method of anode inoculation solution is as follows:

[0087] 5 mL of inoculum was mixed with 50 mM phosphate buffer solution (pH=7.4) containing 1 g / L sodium acetate at a volume ratio of 1:1 and allowed to stand at room temperature for 24 h to obtain the anode inoculum solution.

[0088] Example 6

[0089] This example provides a method for accelerating the start-up of microbial fuel cell power generation. The inoculum is fresh artificial lake water (from an artificial lake at a university in Jiangmen City). The steps are as follows:

[0090] A dual-chamber microbial fuel cell was used with a cation exchange membrane (working area of ​​7 cm 2 ) is separated into an anode chamber and a cathode chamber, the volumes of which are 10 mL and 10 mL respectively. Both the anode and cathode are cubic carbon felt electrodes, and the electrode spacing is maintained at 2 cm. 10 mL of anode inoculation solution is added to the anode chamber, and 10 mL of cathode electrolyte is added to the cathode chamber. The anode and cathode are connected through a 1000 Ω resistor, and the voltage is recorded every 5 minutes. MFCs are all operated with batch feeding. When the voltage drops significantly, the same volume of anolyte and cathode electrolyte is replaced until a stable and repeatable voltage is obtained.

[0091] Wherein, the preparation method of anode inoculation solution is as follows:

[0092] 5 mL of inoculum was mixed with 50 mM phosphate buffer solution (pH=7.4) containing 1 g / L sodium acetate at a volume ratio of 1:1 and allowed to stand at room temperature for 1 h to obtain the anode inoculum solution.

[0093] Example 7

[0094] This example provides a method for accelerating the start-up of power generation in a microbial fuel cell, which is basically the same as Example 6, except that the method for preparing the anode inoculation solution is different.

[0095] The preparation method of anode inoculation solution is as follows:

[0096] 5 mL of inoculum was mixed with 50 mM phosphate buffer solution (pH=7.4) containing 1 g / L sodium acetate at a volume ratio of 1:1 and allowed to stand at room temperature for 4 h to obtain the anode inoculum solution.

[0097] Example 8

[0098] This example provides a method for accelerating the start-up of power generation in a microbial fuel cell, which is basically the same as Example 6, except that the method for preparing the anode inoculation solution is different.

[0099] The preparation method of anode inoculation solution is as follows:

[0100] 5 mL of inoculum was mixed with 50 mM phosphate buffer solution (pH=7.4) containing 1 g / L sodium acetate at a volume ratio of 1:1 and allowed to stand at room temperature for 16 h to obtain the anode inoculum solution.

[0101] Example 9

[0102] This example provides a method for accelerating the start-up of power generation in a microbial fuel cell, which is basically the same as Example 6, except that the method for preparing the anode inoculation solution is different.

[0103] The preparation method of anode inoculation solution is as follows:

[0104] 5 mL of inoculum was mixed with 50 mM phosphate buffer solution (pH=7.4) containing 1 g / L sodium acetate at a volume ratio of 1:1 and allowed to stand at room temperature for 24 h to obtain the anode inoculum solution.

[0105] Example 10

[0106] This example provides a method for accelerating the start-up of microbial fuel cell power generation. The inoculum is anaerobic granular sludge (from a domestic sewage treatment plant in Jiangmen City). The steps are as follows:

[0107] A dual-chamber microbial fuel cell was used with a cation exchange membrane (working area of ​​7 cm 2) is separated into an anode chamber and a cathode chamber, the volumes of which are 10 mL and 10 mL respectively. Both the anode and cathode are cubic carbon felt electrodes, and the electrode spacing is maintained at 2 cm. 10 mL of anode inoculation solution is added to the anode chamber, and 10 mL of cathode electrolyte is added to the cathode chamber. The anode and cathode are connected through a 1000 Ω resistor, and the voltage is recorded every 5 minutes. MFCs are all operated with batch feeding. When the voltage drops significantly, the same volume of anolyte and cathode electrolyte is replaced until a stable and repeatable voltage is obtained.

[0108] Wherein, the preparation method of anode inoculation solution is as follows:

[0109] 5 mL of inoculum was mixed with 50 mM phosphate buffer solution (pH=7.4) containing 1 g / L sodium acetate at a volume ratio of 1:1 and allowed to stand at room temperature for 1 h to obtain the anode inoculum solution.

[0110] Embodiment 11

[0111] This example provides a method for accelerating the start-up of power generation in a microbial fuel cell, which is basically the same as Example 10, except that the method for preparing the anode inoculation solution is different.

[0112] The preparation method of anode inoculation solution is as follows:

[0113] 5 mL of inoculum was mixed with 50 mM phosphate buffer solution (pH=7.4) containing 1 g / L sodium acetate at a volume ratio of 1:1 and allowed to stand at room temperature for 4 h to obtain the anode inoculum solution.

[0114] Example 12

[0115] This example provides a method for accelerating the start-up of power generation in a microbial fuel cell, which is basically the same as Example 10, except that the method for preparing the anode inoculation solution is different.

[0116] The preparation method of anode inoculation solution is as follows:

[0117] 5 mL of inoculum was mixed with 50 mM phosphate buffer solution (pH=7.4) containing 1 g / L sodium acetate at a volume ratio of 1:1 and allowed to stand at room temperature for 16 h to obtain the anode inoculum solution.

[0118] Embodiment 13

[0119] This example provides a method for accelerating the start-up of power generation in a microbial fuel cell, which is basically the same as Example 10, except that the method for preparing the anode inoculation solution is different.

[0120] The preparation method of anode inoculation solution is as follows:

[0121] 5 mL of inoculum was mixed with 50 mM phosphate buffer solution (pH=7.4) containing 1 g / L sodium acetate at a volume ratio of 1:1 and allowed to stand at room temperature for 24 h to obtain the anode inoculum solution.

[0122] Comparative Example 1

[0123] This example provides a method for accelerating the start-up of power generation in a microbial fuel cell, which is basically the same as Example 1, except that the method for preparing the anode inoculation solution is different.

[0124] The preparation method of anode inoculation solution is as follows:

[0125] The anode inoculum was obtained by mixing 5 mL of the inoculum with a 50 mM phosphate buffer solution (pH=7.4) containing 1 g / L sodium acetate at a volume ratio of 1:1.

[0126] Comparative Example 2

[0127] This example provides a method for accelerating the start-up of power generation in a microbial fuel cell, which is basically the same as Example 2, except that the method for preparing the anode inoculation solution is different.

[0128] The preparation method of anode inoculation solution is as follows:

[0129] The anode inoculum was obtained by mixing 5 mL of the inoculum with a 50 mM phosphate buffer solution (pH=7.4) containing 1 g / L sodium acetate at a volume ratio of 1:1.

[0130] Comparative Example 3

[0131] This example provides a method for accelerating the start-up of power generation in a microbial fuel cell, which is basically the same as Example 6, except that the method for preparing the anode inoculation solution is different.

[0132] The preparation method of anode inoculation solution is as follows:

[0133] The anode inoculum was obtained by mixing 5 mL of the inoculum with a 50 mM phosphate buffer solution (pH=7.4) containing 1 g / L sodium acetate at a volume ratio of 1:1.

[0134] Comparative Example 4

[0135] This example provides a method for accelerating the start-up of power generation in a microbial fuel cell, which is basically the same as Example 10, except that the method for preparing the anode inoculation solution is different.

[0136] The preparation method of anode inoculation solution is as follows:

[0137] The anode inoculum was obtained by mixing 5 mL of the inoculum with a 50 mM phosphate buffer solution (pH=7.4) containing 1 g / L sodium acetate at a volume ratio of 1:1.

[0138] Test example

[0139] 1. Start the dual-chamber microbial fuel cell constructed in Example 1 and Comparative Example 1 (3 repetitions in total).

[0140] The startup effect is as follows Figure 1 The three repetitions of Example 1 are respectively recorded as "Implementation 1, Implementation 2, Implementation 3", and the three repetitions of Comparative Example 1 are respectively recorded as "Control 1, Control 2, Control 3".

[0141] All the microbial fuel cells started by the method of Example 1 were successfully started, with a start-up time of 51.6 h to 55.3 h and a maximum power density of (1068.6 ± 5.2) mW / m 2 The coulombic efficiency was (71.8±1.6)%. Only two of the microbial fuel cells started by the method of comparative example 1 were successfully started, and one failed to start normally. The start-up time was 91.8h to 99.7h, which was more than 1.6 times that of example 1. The maximum power density was 680.6mW / m 2 , the Coulombic efficiency is 49.7%.

[0142] This indicates that although leaving the inoculum at room temperature for a long time may result in lower performance, regular addition of electron donor (glucose) can enable the inoculum to be stored at room temperature for more than 1 year and start up the MFCs normally.

[0143] 2. Start the dual-chamber microbial fuel cells constructed in Examples 2 to 5 and Comparative Example 2.

[0144] The startup effect is as follows Figure 2 As shown. The standing time after mixing during the preparation of the anode inoculation solution is defined as the electron storage time. That is, the electron storage time of Example 2 is 1 hour, the electron storage time of Example 3 is 4 hours, the electron storage time of Example 4 is 16 hours, the electron storage time of Example 2 is 24 hours, and the electron storage time of Comparative Example 2 is 0 hours.

[0145] The start-up time of the microbial fuel cells started by the methods of Examples 2 to 5 were 45.36 h, 50.88 h, 57.36 h, and 49.68 h, respectively, while the start-up time of the microbial fuel cell started by the method of Comparative Example 2 was 71.52 h.

[0146] 3. Start the dual-chamber microbial fuel cells constructed in Examples 6 to 9 and Comparative Example 3.

[0147] The startup effect is as follows Figure 3 shown.

[0148] The start-up time of the microbial fuel cells started by the methods of Examples 6 to 9 were 45.84 h, 47.52 h, 52.8 h, and 46.08 h, respectively, while the start-up time of the microbial fuel cell started by the method of Comparative Example 3 was 117.36 h.

[0149] 4. Start the dual-chamber microbial fuel cells constructed in Examples 10 to 13 and Comparative Example 4.

[0150] The startup effect is as follows Figure 4 shown.

[0151] The start-up time of the microbial fuel cells started by the methods of Examples 10 to 13 were 50.16 h, 53.28 h, 56.64 h, and 47.76 h, respectively, while the start-up time of the microbial fuel cell started by the method of Comparative Example 4 was 55.44 h.

[0152] In summary, mixing the inoculum containing mixed bacteria with the electron donor and placing it for a certain period of time before inoculation can effectively shorten the start-up time of MFC and reduce the risk of poor start-up, while also significantly improving the maximum power density, coulombic efficiency and electrical activity. This electron storage method is very effective for inocula that have not been stored at room temperature for a long time (such as fresh lake water) and certain inocula with poor start-up performance after long-term room temperature storage (such as electrochemical plant sludge); it is generally effective for inocula with good start-up performance after long-term room temperature storage (inocula that can start quickly after long-term room temperature storage, such as anaerobic granular sludge).

[0153] The embodiments of the present invention are described in detail above in conjunction with the embodiments, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A method for accelerating the start-up of power generation of a microbial fuel cell, characterized in that: The following steps are involved: A mixture of an inoculum, a first electron donor, and a buffer solution is prepared and allowed to stand to obtain an anode inoculum solution; A microbial fuel cell is prepared by using the anode inoculation solution, and the microbial fuel cell is started.

2. The method according to claim 1, characterized in that The inoculum includes at least one of urine, sludge, lake water, wastewater, sediment, and soil.

3. The method according to claim 1, characterized in that The method for preserving the inoculum comprises the following steps: adding a second electron donor to the inoculum every 20 to 40 days.

4. The method according to claim 1, characterized in that The first electron donor includes at least one of organic matter and thiosulfate.

5. The method according to claim 4, characterized in that The organic matter includes at least one of formic acid, lactic acid, butyric acid, sodium formate, sodium acetate, sodium lactate, glucose, sucrose, starch, cysteine, methionine, and ascorbic acid; And / or, the thiosulfate includes at least one of sodium thiosulfate and calcium thiosulfate.

6. The method according to claim 1, characterized in that The dosage ratio of the first electron donor to the inoculum is 0.5 mg to 2 mg: 1 mL.

7. The method according to claim 1, characterized in that The volume ratio of the buffer solution to the inoculum is 0.5 mL to 1.5 mL: 1 mL.

8. The method according to claim 1, characterized in that: The placement time is more than 15 minutes, preferably 15 minutes to 24 hours.

9. The method according to claim 1, characterized in that: The microbial fuel cell comprises: an anode chamber, wherein the anode chamber is provided with an anode and the anode inoculation solution; a cathode chamber, the cathode chamber being provided with a cathode and a cathode electrolyte; A diaphragm, the diaphragm is used to separate the anode chamber and the cathode chamber; An external circuit is used to connect the anode and the cathode.

10. The method according to claim 9, characterized in that The material of the anode includes at least one of carbon felt, carbon paper, activated carbon, and amorphous carbon fiber; And / or, the material of the cathode includes at least one of carbon felt, carbon paper, activated carbon, and amorphous carbon fiber; And / or, the diaphragm is a cation exchange membrane or a proton exchange membrane; And / or, the cathode electrolyte includes a cathode electron acceptor.

Images