Microbial fuel cell small-scale test device for wastewater treatment

Abstract

The utility model relates to application of a microbial fuel cell, in particular to a microbial fuel cell small-scale test device for wastewater treatment. Comprising a box body of a single-chamber structure, an anode and a cathode, the anode and the cathode are arranged in the box body, supports which are horizontally distributed at intervals are arranged in an inner cavity of the box body, transmission shafts which are driven by a transmission device to rotate are arranged on the upper portions of the supports in the horizontal direction, and cathode carbon felts are axially arranged on the transmission shafts at intervals. Anode carbon felts are horizontally distributed and longitudinally arranged on the support below the transmission shaft at intervals, the anode carbon felts are in conductive connection with the cathode carbon felts through adjustable resistors and the transmission shaft, and a water inlet, a water outlet and a sludge discharge port are formed in the box body. The device effectively solves the problem that the prior art is difficult to be applied to the field of wastewater treatment, and has the advantages of effectively expanding the equipment scale, being simple in structure, wide in part source, low in cost, wide in application range and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to the application of microbial fuel cell, especially a kind of microbial fuel cell pilot plant for wastewater treatment. BACKGROUND

[0002] Microbial fuel cell (MFC) is a kind of technology using the metabolic activity of microorganism to convert the chemical energy in organic matter into electric energy directly. Its principle is: anaerobic microorganism in anode decomposes organic matter in anode chamber, and generates proton and electron simultaneously, and proton diffuses to cathode. Cell cytochrome c in microorganism or oxidation-reduction medium secreted by itself transmits electron to anode surface, and obtains energy required for growth by ATP form, and the electron on anode surface is transmitted to cathode by wire, and proton through diaphragm (proton exchange membrane) generates water under the condition of oxygen, and a cycle is completed, to obtain electric energy. Organic matter is decomposed into CO2 and H2O in working process, without causing secondary pollution. Compared with existing traditional wastewater treatment technology, microbial fuel cell has the advantages of environmental friendliness, low energy consumption, no secondary pollution and little sludge production, so microbial fuel cell has wide application prospect in wastewater treatment and new energy development field.

[0003] MFC technology can generate electric energy while treating wastewater, realize waste into treasure and save energy, so it is favored by many scholars. As a kind of green renewable technology, microbial fuel cell technology also has problems to be solved, and at present, the research on microbial fuel cell is mostly at laboratory level, and the output power is too small to be enlarged to actual industrial production, and a large amount of research on microbial fuel cell focuses on how to improve power generation performance, such as adding catalyst, optimizing anode and cathode materials, etc., and it is also a problem that researchers need to consider at present to apply to wastewater treatment process. However, expensive catalyst and membrane material, and always unsatisfactory power generation efficiency hinder the progress of microbial fuel cell applied to wastewater treatment field.

[0004] The applicant has not found any domestic patent document similar to the utility model. SUMMARY

[0005] The utility model aims at providing a kind of microbial fuel cell pilot plant for wastewater treatment, by setting multiple groups of microbial fuel cells in the box of single-chamber structure, the cathode carbon felt of each fuel cell is connected in series and then connected in parallel with each anode carbon felt, effectively expand the equipment scale of microbial fuel cell, lay a foundation for microbial fuel cell from laboratory research to industrial application.

[0006] The overall technical concept of the utility model is:

[0007] The utility model provides a microbial fuel cell small test device for wastewater treatment, including reaction chamber and the anode and cathode of setting in reaction chamber, reaction chamber adopts the box body of single chamber structure, is equipped with the support of along horizontal interval distribution in the box body cavity, the upper portion of support is equipped with the transmission shaft that rotates by transmission device along the horizontal direction, transmission shaft is equipped with the carbon felt of cathode along the axial interval arrangement, the carbon felt of anode is equipped with along horizontal distribution and longitudinal interval arrangement on the support below transmission shaft, and the carbon felt of anode is connected with the carbon felt of cathode through adjustable resistance and transmission shaft and conducts electricity, is equipped with the water inlet and water outlet of opening in the top of box body, is equipped with the sludge discharge port of opening in the bottom of box body.

[0008] The applicant needs to explain that the traditional non-biological cathode uses O2 as an electron acceptor, and the oxygen reduction reaction rate is very slow, and a catalyst is needed to accelerate the reaction process. The redox rate of the cathode in the microbial fuel cell is one of the main factors limiting its performance. The utility model adopts a rotating cathode carbon felt as an air cathode, which has a structure similar to a biological rotating disc. A biofilm is formed on the surface of the cathode, and a biological cathode is formed under the action of microorganisms. The cathode microorganisms act as electron acceptors, which can effectively prevent catalyst poisoning and significantly reduce the cost of the microbial fuel cell.

[0009] The specific technical concept of the utility model also includes:

[0010] The transmission device can adopt various existing technical implementation means, which do not deviate from the essence of the utility model. In order to realize the adjustable speed of the transmission shaft and meet the need of relatively accurate transmission ratio, and to better adapt to the working environment, the preferred technical implementation means is that the transmission device adopts a chain wheel and chain transmission pair driven by a variable frequency motor. The applicant needs to explain that, because the small test device of the utility model is applied to wastewater treatment, the support, chain wheel and chain transmission pair located below the wastewater surface meet the functional needs under the premise of meeting the functional needs. Preferably, a rust-resistant material such as stainless steel is used. The transmission device can be connected to an external power source through wires. Since it belongs to the prior art, the applicant will not repeat it here.

[0011] In order to facilitate the installation and maintenance of the variable frequency motor, the preferred technical implementation means is that the variable frequency motor is fixedly arranged on the support.

[0012] In order to facilitate the arrangement and maintenance of the adjustable resistance, the preferred technical implementation means is that the adjustable resistance is arranged in the resistance box fixed on the top of the support.

[0013] In order to facilitate the maintenance and replacement of parts, the preferred technical implementation means is that the top of the box body is provided with a top cover connected to it in a detachable manner.

[0014] The applicant needs to explain that:

[0015] In the description of the utility model, the terms "horizontal", "axial", "longitudinal", "upper", "lower", "top" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of simplifying the description of the utility model, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the utility model.

[0016] The technical progress achieved by the utility model is that:

[0017] 1、The pilot plant in the utility model is not proportionally enlarged from the traditional biofuel cell experimental device, a plurality of microbial fuel cells are arranged in the single-chamber structure box, the cathode carbon felt of each fuel cell is connected in series and then connected in parallel with each anode carbon felt, and expansion can be carried out according to needs, the equipment scale of the microbial fuel cell is effectively enlarged, and a foundation is laid for the industrial application of the microbial fuel cell from laboratory research.

[0018] 2、The utility model avoids using expensive proton exchange membranes (diaphragms) in structure, adopts a more economical single-chamber structure, the sources of parts are extensive and the prices are low, and industrial scale application is facilitated.

[0019] 3、The utility model adopts rotating cathode carbon felt as an air cathode, the structure is similar to a biological rotating disc, a biological membrane is formed on the surface of the cathode, a biological cathode is formed under the action of microorganisms, the cathode microorganisms act as electron acceptors, catalyst poisoning can be effectively avoided, and the cost of the microbial fuel cell is significantly reduced.

[0020] 4、The cathode carbon felt of the utility model is alternately contacted with air and sewage through rotation, after a period of time, a layer of biological membrane and water film will be attached to the cathode carbon felt. When the cathode carbon felt rotates out of the sewage and contacts with air, air is continuously dissolved into the water film to increase the dissolved oxygen. When the cathode carbon felt rotates into the sewage, on the one hand, the electrons and protons reaching the cathode carbon felt react with O2 to generate water; on the other hand, the biological membrane adsorbs the organic pollutants in the water and absorbs the dissolved oxygen in the water film outside the biological membrane to decompose the organic matter. In the working process, the biological membrane is between the sewage and the air, and in addition to the transmission of organic matter and O2, other substances such as CO2 and NH3 are also transmitted, forming a continuous adsorption, oxidation and decomposition and oxygen absorption process, so that the sewage is continuously purified.

[0021] 5、The utility model can be used for repairing various sources of wastewater, such as municipal wastewater, industrial wastewater, agricultural wastewater and aquaculture wastewater. On the one hand, there are abundant organic matters in various types of wastewater, and on the other hand, the distance between the anode and the cathode can be adjusted, different distances produce different resistances, and thus microorganisms suitable for different resistance environments are screened out, and different types of wastewater are treated. BRIEF DESCRIPTION OF DRAWINGS

[0022] The utility model discloses the drawing has:

[0023] Figure 1 It is the overhead structure schematic diagram of the utility model.

[0024] Figure 2 It is Figure 1 A-A view of.

[0025] Figure 3 It is Figure 1 B-B view of.

[0026] Figure 4 It is Figure 1 C-C view of.

[0027] Figure 5 It is electrode connection diagram.

[0028] The reference signs in the drawing are as follows:

[0029] 1, box body;2, water inlet;3, water outlet;4, sludge outlet;5, frequency conversion motor;6, resistance box;7, chain wheel;8, chain;9, transmission shaft;10, cathode carbon felt;11, anode carbon felt;12, adjustable resistance;13, wire, 14, support. Specific implementation

[0030] The utility model is further described below in combination with examples, but should not be understood as the limitation of the utility model, and the protection scope of the utility model is accurate with the content recorded in the claim, and any equivalent technical means replacement according to the specification does not depart from the protection scope of the utility model.

[0031] The overall structure of the embodiment is as shown, and the microbial fuel cell small test device for wastewater treatment includes a reaction chamber, an anode and a cathode arranged in the reaction chamber, the reaction chamber adopts a box body 1 in single-chamber structure, three supports 14 are arranged in the inner cavity of the box body 1 and are distributed horizontally and at intervals, a transmission shaft 9 driven to rotate by a transmission device is arranged on the upper part of the support 14 and extends horizontally, fourteen groups of cathode carbon felt 10 are arranged on the transmission shaft 9 and extend axially and at intervals, five groups of anode carbon felt 11 are arranged on the support 14 below the transmission shaft 9 and extend horizontally and longitudinally and at intervals, the anode carbon felt 11 is electrically connected to the cathode carbon felt 10 through adjustable resistance 12, wire 13 and transmission shaft 9, a water inlet 2 and a water outlet 3 are arranged on the upper part of the box body 1, and a sludge outlet 4 is arranged on the lower part of the box body 1.

[0032] The transmission device adopts a transmission pair composed of a frequency conversion motor 5, a chain wheel 7 and a chain 8. When running, the support 14, the chain wheel 7 and the chain 8 located below the wastewater surface adopt a rust-resistant material, for example, a stainless steel material.

[0033] The variable frequency motor 5 is fixedly arranged on the support 14.

[0034] The adjustable resistance 12 is arranged in the resistance box 6 fixed on the top of the support.

[0035] The box body 1 is provided with a top cover detachably connected therewith.

[0036] The working flow of the embodiment is as follows:

[0037] 1. Pretreatment

[0038] The microbial fuel cell small test device for wastewater treatment in the utility model needs to pretreat the equipment and materials before starting operation. The sludge is filtered through a 200-mesh screen to remove impurities such as particulate matter, and then washed with deionized water for 3 times to remove organic matter therein; the cathode carbon felt 10 and the anode carbon felt 11 need to remove surface impurities and metal ions before use. First, immerse in a 1.0 mol / L hydrochloric acid solution for 24 hours, then immerse in distilled water for 24 hours, then immerse in a 1.0 mol / L sodium hydroxide solution for 24 hours, then immerse in distilled water for 24 hours, and finally immerse in deionized water for standby, and dry in an oven before use.

[0039] 2. Inoculation and domestication

[0040] Before starting the system, the anode biofilm needs to be inoculated and domesticated. The anode carbon felt 11 is completely immersed in the sludge to ensure an oxygen-free environment, and the cathode carbon felt 10 is partially immersed in the overlying water with an immersion rate of 45%, and partially exposed to the air to ensure an oxygen environment. In the initial stage of MFC start-up, easily utilized organic matter such as sodium acetate and glucose is used as substrate, and after each cycle, the organic matter content is gradually reduced and replaced by wastewater until the final conversion to wastewater. Start the microbial fuel cell small test device for wastewater treatment, and the original battery generates current to activate biological activity and promote microbial reproduction and proliferation. The first replacement of wastewater is about 10 days, and then replaced every five days, and the whole domestication period is 5 times of wastewater replacement, and the microbial membrane is basically stable.

[0041] 3. System start-up and monitoring

[0042] Start the system, and the wastewater to be treated flows into through the water inlet, and is discharged through the water outlet 3 after sufficient treatment. The voltage output of the system is measured, and the removal of COD, BOD, TSS, nitrogen and phosphorus is measured.

Claims

1. A microbial fuel cell bench-scale device for wastewater treatment, comprising a reaction chamber, and an anode and a cathode disposed in the reaction chamber, characterized in that The reaction chamber adopts a box (1) with a single chamber structure, a support (14) is arranged in the inner cavity of the box (1) and is distributed horizontally and at intervals, a transmission shaft (9) driven to rotate by a transmission device is arranged on the upper portion of the support (14) and horizontally, a cathode carbon felt (10) is arranged on the transmission shaft (9) and axially at intervals, an anode carbon felt (11) is arranged on the support (14) below the transmission shaft (9) and horizontally and longitudinally at intervals, the anode carbon felt (11) is electrically connected with the cathode carbon felt (10) through an adjustable resistor (12) and the transmission shaft (9), a water inlet (2) and a water outlet (3) are arranged on the upper portion of the box (1), and a sludge discharge port (4) is arranged on the lower portion of the box (1).

2. The microbial fuel cell bench-scale apparatus for wastewater treatment according to claim 1, characterized by The transmission device adopts a chain wheel and chain transmission pair driven by a variable frequency motor (5).

3. The microbial fuel cell bench-scale apparatus for wastewater treatment according to claim 2, characterized by The variable frequency motor (5) is fixedly arranged on the support (14).

4. The microbial fuel cell bench scale unit for wastewater treatment as claimed in claim 1 wherein The adjustable resistor (12) is arranged in a resistor box (6) fixed on the top of the support (14).

5. The microbial fuel cell bench scale device for wastewater treatment according to claim 1, characterized by The top of the box (1) is provided with a top cover connected with the box (1) in a detachable mode.

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