CN102800883B - Nitrification microbial fuel cell - Google Patents

Abstract

The invention discloses a nitrifying microorganism fuel cell. It consists of an anode chamber, a cathode chamber and a proton exchange membrane; the anode chamber is equipped with a cubic reactor and a sealing cover, the lower part of the cubic reactor is provided with a water inlet pipe, the upper part is provided with an outlet pipe, and the middle part is provided with an aeration area and a reaction area and the isolation plate, the aeration area and the reaction area are separated by the isolation plate, connected up and down and filled with the electricity generation matrix; the nitrifying bacteria hanging film anode is placed in the electricity generation matrix, and the anode wire fixing tube is arranged on the top sealing cover of the reaction area; the aeration The bottom of the area is provided with a gas distribution pipe; the cathode chamber is provided with a cubic reactor and a sealing cover, the lower part of the cubic reactor is provided with a water inlet pipe, and the upper part is provided with a water outlet pipe. The cubic reactor is immersed in catholyte, and the cathode is placed in the catholyte. A cathode wire fixing tube is arranged on the top sealing cover. The invention uses inorganic ammonia as a raw material, has simple structure, mild operating conditions, small internal resistance, good power generation efficiency, high energy utilization rate, and can simultaneously realize waste water nitrification and biological power generation.

Description

nitrifying microbial fuel cell

technical field

The invention relates to a microbial fuel cell, in particular to a nitrifying microbial fuel cell.

Background technique

In the last century, fossil fuels supported the development of the global economy, but fossil fuels are not renewable and will be exhausted in the next 100 years or a little longer. In energy utilization, the work of "opening up sources of income and reducing expenditure" has been placed in front of people realistically. Microbial fuel cell (MFC) is a device that uses enzymes or microorganisms as a catalyst to directly convert chemical energy into electrical energy. MFC technology has many advantages such as wide source of raw materials, transformation of substrate into electric energy, mild operating conditions, low operating cost, and no harmful gas generation. It is recognized as a green and renewable energy utilization technology with great development prospects.

The biological reaction in which ammonia is oxidized to nitrite or nitrate is usually called biological nitrification, or nitrification for short. Nitrification is a sequential reaction, firstly ammonia is oxidized to nitrite by ammonia oxidizing bacteria, and then nitrite is oxidized to nitrate by nitrite oxidizing bacteria. The nitrification process is a treatment method that uses the action of autotrophic nitrifying bacteria to oxidize ammonia in wastewater to nitrate through engineering measures. The nitrification process was born in the middle of the 20th century. With the deepening of research and popularization of applications, the types of nitrification processes have continued to increase and the treatment efficiency has continued to improve. It has become an important wastewater biological denitrification technology. Ammonia, the substrate for nitrification, is in the highest reduced state, releasing a total of 8 electrons in the process of being oxidized to nitrate as an electron donor. Among them, 2 electrons are used in the synthesis process of hydroxylamine to start the ammonia oxidation reaction, and the rest of the electrons are passed to the terminal oxidase through the respiratory chain of ammonia oxidizing bacteria and nitrous acid oxidizing bacteria, and finally to oxygen; and the oxidation of phosphoric acid is realized during the electron transfer process Chemical, synthesize ATP. It can be seen that ammonia, like organic matter, is an electron donor for biological reactions and an energy source for biological growth; ammonia oxidizing bacteria and nitrous acid oxidizing bacteria as catalysts for nitrification reactions have electron mediators similar to heterotrophic electrogenic microorganisms and the electron transport chain. However, so far, the MFCs that have been seen mainly use organic matter as energy, and there are few MFCs that use inorganic matter as energy. Harsh, poor battery performance, low energy utilization and other defects.

Aiming at the above-mentioned defects of existing microbial fuel cells, the present invention uses ammonia oxidizing bacteria and nitrous acid oxidizing bacteria as electrogenic bacteria to realize electricity generation using inorganic ammonia as fuel; the electricity generating substrate is inorganic ions, and the internal resistance of the battery is low. It is a clean energy production device that does not release the greenhouse effect gas carbon dioxide during the power generation process; the anode chamber is equipped with an internal circulation nitrification reactor, and the double-chamber nitrification microbial fuel cell constructed is simple in structure and mild in operating conditions, and the anode chamber reactor Only part of the area is aerated, which can not only provide the dissolved oxygen needed to start the ammonia oxidation reaction, but also prevent the loss of electrons caused by excessive oxygen concentration; the strong oxidant potassium permanganate is used as the catholyte, the cathode potential is high, and the battery performance is better , higher energy efficiency.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a nitrifying microbial fuel cell.

The nitrifying microbial fuel cell is composed of an anode chamber, a cathode chamber and a proton exchange membrane; the anode chamber and the cathode chamber are provided with a proton exchange membrane and connected by a flange; The flange is connected between the reactor and the sealing cover; the lower part of the cubic reactor is provided with a water inlet pipe, the upper part of the cubic reactor is provided with an outlet pipe, and the middle part of the cubic reactor is provided with an aeration area, a reaction area and an isolation plate. The aeration area and the reaction area are separated by an isolation plate, connected up and down and filled with an electricity-generating substrate; a nitrifying bacteria hanging film anode is placed in the electricity-generating substrate, and an anode wire fixing tube is installed on the top sealing cover of the reaction area; the bottom of the aeration area is equipped with Gas distribution pipe; the cathode chamber is equipped with a cathode chamber cubic reactor and a sealing cover, and the cathode chamber cubic reactor and the sealing cover are connected by a flange; the lower part of the cathode chamber cubic reactor is provided with a water inlet pipe, and the cathode chamber is cubic in reaction The upper part of the device is provided with a water outlet pipe, and the cubic reactor in the cathode chamber is immersed in catholyte; the cathode is placed in the catholyte of the cubic reactor, and the top sealing cover is provided with a cathode wire fixing tube.

The electricity-generating substrate is inorganic wastewater containing ammonium chloride, with a pH value of 8.0-8.5, to which 2.0 g/L KHCO ₃ , 0.35 g/L K ₂ HPO ₄ , 0.35 g/L Na ₂ HPO ₄ and 0.25 mL /L inorganic salt solution; the composition of inorganic salt solution is: CaCl ₂ .2H ₂ O, 7.34 g/L; MgCl ₂ .6H ₂ O, 25.07 g/L; FeCl ₃ .6H ₂ O, 4.8 g/L; MnCl ₂ .4H ₂ O, 1.03 g/L; ZnCl ₂ .2H ₂ O, 0.01 g/L; CuCl ₂ .2H ₂ O, 0.112 g/L; NaMoO ₄ .2H ₂ O, 0.0025 g/L.

The catholyte is a potassium permanganate solution with a pH value of 6.9-7.1, in which 0.2 g/L KMnO ₄ , 0.35 g/L K ₂ HPO ₄ and 0.35 g/L Na ₂ HPO ₄ are added.

The cubic reactor in the anode chamber is the same size as the cubic reactor in the cathode chamber, and the aspect ratio is 2.0:1.0:2.0; the volume of the electricity-generating matrix accounts for 2/3 of the volume of the cubic reactor in the anode chamber ~3/4; the ratio of the aeration zone in the middle of the anode chamber cubic reactor to the cross section of the reaction zone is 1.0:2.0; the top of the isolation plate in the middle of the anode chamber cubic reactor is 1.0 cm lower than the water outlet pipe, The lower end is 1.0 cm higher than the bottom of the cubic reactor in the anode chamber; the catholyte volume accounts for 2/3 to 3/4 of the volume of the cubic reactor in the cathode chamber.

The conductive material of described nitrifying bacteria hanging membrane anode is carbon paper, carbon cloth, carbon felt, graphite felt or graphite plate, and nitrifying bacteria biofilm is attached on the surface, and the lower end of hanging membrane anode is 1～ 2 cm, the ratio of the surface area of the film-hanging anode to the volume of the cubic reactor in the anode chamber is 10~40 m ² : 1 m ³ ; the cathode conductive material is graphite rod, and the ratio of the surface area of the cathode to the volume of the cubic reactor in the cathode chamber 4~10 m ² : 1 m ³ .

Compared with the prior art, the present invention has the following beneficial effects: 1) Using inorganic matter as fuel, ammonia oxidizing bacteria and nitrous acid oxidizing bacteria are used to denitrify waste water and generate electricity biologically, so that waste water pollution control and electricity generation can be realized at the same time. 2) The electricity generation substrate is inorganic ions, the internal resistance of the battery is low, and the greenhouse effect gas carbon dioxide is not released during the electricity generation process. It is a clean energy production device. 3) The anode chamber is equipped with an internal circulation nitrification reactor. The constructed dual-chamber nitrifying microbial fuel cell has a simple structure and mild operating conditions. The anode chamber reactor is only aerated in part of the area, which can provide the solution needed to start the ammonia oxidation reaction. Oxygen can prevent the oxygen concentration from being too high, resulting in the loss of electrons. 4) Potassium permanganate, a strong oxidant, is used as the catholyte, the cathode potential is high, the battery performance is better, and the energy utilization rate is higher.

Description of drawings

Fig. 1 is the structure diagram of nitrifying microbial fuel cell;

Fig. 2 is the A-A sectional view of Fig. 1;

In the figure: anode chamber I, cathode chamber II, proton exchange membrane III; sealing cover 1, anode chamber cubic reactor 2, aeration area 3, reaction area 4, isolation plate 5, water inlet pipe 6, water outlet pipe 7, cloth Trachea 8, membrane-hanging anode 9, cathode 10, flange 11, flange 12, electricity-generating substrate 13, cathode chamber cubic reactor 14, catholyte 15, anode wire fixing tube 16, sealing cover 17, cathode wire fixing tube 18, flange 19, water inlet pipe 20, water outlet pipe 21.

Detailed ways

As shown in Figures 1 and 2, the nitrifying microbial fuel cell is composed of an anode chamber I, a cathode chamber II and a proton exchange membrane III; a proton exchange membrane III is arranged between the anode chamber I and the cathode chamber II and is connected by a flange 12; the anode chamber I is provided with anode chamber cubic reactor 2 and sealing cover 1, is connected by flange 11 between the anode chamber cubic reactor 2 and sealing cover 1; The upper part is provided with a water outlet pipe 7, and the middle part of the cubic reactor is provided with an aeration area 3, a reaction area 4 and an isolation plate 5. The aeration area 3 and the reaction area 4 are separated by an isolation plate 5, connected up and down and filled with an electricity generation substrate 13 Nitrifying bacteria hanging film anode 9 is placed in the electricity-generating substrate 13, and an anode wire fixing pipe 16 is arranged on the sealing cover 1 at the top of the reaction zone; the gas distribution pipe 8 is arranged at the bottom of the aeration region 3; the cathode chamber II is provided with a cathode chamber cubic reaction Device 14 and sealing cover 17, connect by flange 19 between cathode chamber cubic reactor 14 and sealing cover 17; Cathode chamber cubic reactor 14 bottoms are provided with water inlet pipe 20, and cathode chamber cubic reactor 14 tops are provided with Outlet pipe 21, cathodic chamber. Cubic reactor 14 is immersed in catholyte 15; cathode 10 is placed in catholyte 15 of cubic reactor, and cathode wire fixing tube 18 is provided on top sealing cover 17.

The electricity-generating substrate 13 is inorganic waste water containing ammonium chloride, with a pH value of 8.0-8.5, to which 2.0 g/L KHCO ₃ , 0.35 g/L K ₂ HPO ₄ , 0.35 g/L Na ₂ HPO ₄ and 0.25 mL/L inorganic salt solution; the composition of inorganic salt solution is: CaCl ₂ .2H ₂ O, 7.34 g/L; MgCl ₂ .6H ₂ O, 25.07 g/L; FeCl ₃ .6H ₂ O, 4.8 g/L; MnCl _{2.4H 2} O, 1.03 g/L; ZnCl ₂ .2H ₂ O, 0.01 g/L; CuCl ₂ .2H ₂ O, 0.112 g/L; NaMoO ₄ .2H ₂ O, 0.0025 g/L.

The catholyte 15 is a potassium permanganate solution with a pH value of 6.9-7.1, in which 0.2 g/L KMnO ₄ , 0.35 g/L K ₂ HPO ₄ and 0.35 g/L Na ₂ HPO ₄ are added.

The cubic reactor 2 in the anode chamber is the same size as the cubic reactor 14 in the cathode chamber, and the aspect ratio is 2.0:1.0:2.0; the volume of the electricity-generating matrix 13 occupies the volume of the cubic reactor 2 in the anode chamber 2/3 to 3/4 of the anode chamber; the ratio of the aeration zone 3 in the middle of the anode chamber cubic reactor 2 to the cross section of the reaction zone 4 is 1.0:2.0; the separation plate in the middle of the anode chamber cubic reactor 2 5. The upper end is 1.0 cm lower than the outlet pipe (7), and the lower end is 1.0 cm higher than the bottom of the anode chamber cubic reactor (2); the volume of the catholyte 15 accounts for 2/3-3 of the volume of the cathode chamber cubic reactor 14. /4.

The conductive material of described nitrifying bacteria hanging membrane anode 9 is carbon paper, carbon cloth, carbon felt, graphite felt or graphite plate, and the surface is attached with nitrifying bacteria biofilm, and the lower end of hanging membrane anode 9 is distanced from the bottom of anode chamber cube-shaped reactor 2 The ratio of the surface area of the film-hanging anode 9 to the volume of the cubic reactor 2 in the anode chamber is 10 to 40 m ² : 1 m ³ ; the conductive material of the cathode 10 is a graphite rod, and the surface area of the cathode 10 is the same as that of the cathode chamber The volume ratio of the cubic reactor 14 is 4-10 m ² : 1 m ³ .

When the nitrifying microbial fuel cell is connected to the external circuit, aeration starts, and a certain concentration of oxygen is dissolved in the reaction solution in the aeration zone of the cubic reactor in the anode chamber, and the reaction solution is lifted by the air bubbles and overflows the top of the isolation plate to enter the reaction area; the nitrifying bacteria on the anode use the limited dissolved oxygen in the reaction solution to start the ammonia oxidation reaction to generate hydroxylamine, which is further converted into nitrite and nitrate, and the released electrons are transferred to the anode through the respiratory chain, and then pass through the anode wire and external circuit And the cathode wire transfers electrons to the cathode, and at the same time, the protons released by the nitrification reaction pass through the proton membrane to reach the cathode chamber under the action of the electric field force, and the electrons and protons participate in the reduction reaction of potassium permanganate on the surface of the cathode, thus completing nitrification and producing electrical process.

Claims (3)

1. A nitrifying microbial fuel cell is characterized in that: the nitrifying microbial fuel cell is composed of an anode chamber (I), a cathode chamber (II) and a proton exchange membrane (III); the middle of the anode chamber (I) and the cathode chamber (II) A proton exchange membrane (III) is provided and connected by a flange (12); the anode chamber (I) is provided with an anode chamber cubic reactor (2) and a sealing cover (1), and the anode chamber cubic reactor (2) and The sealing covers (1) are connected by flanges (11); the lower part of the anode chamber cubic reactor (2) is provided with a water inlet pipe (6), the upper part of the anode chamber cubic reactor is provided with a water outlet pipe (7), and the anode chamber The middle part of the cubic reactor is equipped with an aeration zone (3), a reaction zone (4) and an isolation plate (5). Inject electricity production matrix (13); place nitrifying bacteria hanging film anode (9) in electricity production matrix (13), and anode wire fixing tube (16) is arranged on the sealing cover (1) at the top of reaction area; aeration area (3) There is an air distribution pipe (8) at the bottom; the cathode chamber (II) is provided with a cathode chamber cubic reactor (14) and a sealing cover (17), and the cathode chamber cubic reactor (14) and the sealing cover (17) pass through The flange (19) is connected; the lower part of the cathode chamber cubic reactor (14) is provided with a water inlet pipe (20), the upper part of the cathode chamber cubic reactor (14) is provided with an outlet pipe (21), and the cathode chamber cubic reactor ( 14) Immersed in catholyte (15); the cathode (10) is placed in the catholyte (15) of the cubic reactor in the cathode chamber, and the cathode wire fixing tube (18) is provided on the top sealing cover (17); The electricity generation substrate (13) is inorganic wastewater containing ammonium chloride, with a pH value of 8.0-8.5, to which 2.0 g/L KHCO ₃ , 0.35 g/L K ₂ HPO ₄ , 0.35 g/L Na ₂ HPO ₄ are added and 0.25 mL/L inorganic salt solution; the composition of inorganic salt solution is: CaCl ₂ ·2H ₂ O, 7.34 g/L; MgCl ₂ ·6H ₂ O, 25.07 g/L; FeCl ₃ ·6H ₂ O, 4.8 g/L ; MnCl ₂ ·4H ₂ O, 1.03 g/L; ZnCl ₂ ·2H ₂ O, 0.01 g/L; CuCl ₂ ·2H ₂ O, 0.112 g/L; NaMoO ₄ ·2H ₂ O, 0.0025 g/L; The catholyte (15) is a potassium permanganate solution with a pH value of 6.9-7.1, in which 0.2 g/L KMnO ₄ , 0.35 g/L K ₂ HPO ₄ and 0.35 g/L Na ₂ HPO ₄ are added. 2. A nitrifying microbial fuel cell according to claim 1, characterized in that: the cubic reactor in the anode chamber (2) and the cubic reactor in the cathode chamber (14) have the same size and the aspect ratio 2.0:1.0:2.0; the volume of the electricity-generating substrate (13) accounts for 2/3 to 3/4 of the volume of the anode chamber cubic reactor (2); the middle part of the anode chamber cubic reactor (2) The cross-sectional ratio of the aeration zone (3) and the reaction zone (4) is 1.0:2.0; the upper end of the isolation plate (5) in the middle of the anode chamber (2) is 1.0 cm lower than the outlet pipe (7), The lower end is 1.0 cm higher than the bottom of the cubic reactor (2) in the anode chamber; the volume of the catholyte (15) accounts for 2/3-3/4 of the volume of the cubic reactor (14) in the cathode chamber. 3. A nitrifying microbial fuel cell according to claim 1, characterized in that: the conductive material of the nitrifying bacteria hanging film anode (9) is carbon paper, carbon cloth, carbon felt, graphite felt or graphite plate, There is a nitrifying bacteria biofilm attached to the surface, the lower end of the nitrifying bacteria film-hanging anode (9) is 1~2 cm away from the bottom of the anode chamber cubic reactor (2), and the surface area of the nitrifying bacteria-hanging film anode (9) is the same as that of the anode chamber cubic reactor (2) The volume ratio is 10~40 m ² : 1 m ³ ; the conductive material of the cathode (10) is graphite rod, and the ratio of the surface area of the cathode (10) to the volume of the cubic reactor (14) in the cathode chamber is 4 ~10 m ² : 1 m ³ .