CN203871429U - Simultaneous phosphorus and nitrogen removal double-chamber microbiological fuel cell - Google Patents

Abstract

The utility model discloses a synchronous denitrification and dephosphorization dual-chamber microbial fuel cell, which comprises a reaction system and a data acquisition and monitoring system. The reaction system includes an anode reaction system and a cathode reaction system, wherein the anode reaction system includes an anode microorganism, an anode electrode, an anode chamber, a sampling port, a sample inlet and an electrolyte. The cathode reaction system includes cathode microorganisms, cathode electrode, cathode chamber, water inlet pipe, water outlet pipe, constant flow pump hose, blower pump, brown buffer bottle, aeration head, constant flow pump and electrolyte. The anode electrode and the cathode electrode are respectively attached to both sides of the proton exchange membrane. The data acquisition and monitoring system includes conductive filaments, loads, leads, data collectors and computers. The utility model operates intermittently, the device has simple structure, small internal resistance, high efficiency and stable performance, has the effects of both productivity and water treatment, and opens up a new method for microbial fuel cell denitrification and phosphorus removal.

Description

A Simultaneous Nitrogen and Phosphorus Removal Dual-chamber Microbial Fuel Cell

technical field

The utility model belongs to the technical field of biological fuel cells, in particular to a dual-chamber microbial fuel cell for synchronous denitrification and phosphorus removal.

Background technique

Eutrophication, also known as water bloom, refers to the phenomenon of water pollution caused by excessive plant nutrients such as nitrogen and phosphorus in lakes, rivers, reservoirs and other water bodies. Due to the enrichment of nitrogen and phosphorus nutrients in the water body, the rapid reproduction of algae and other plankton is caused, the dissolved oxygen content of the water body is reduced, and the pollution phenomenon of the decline or even extinction of algae, plankton, plants, aquatic organisms and fish is caused. The prevention and control of eutrophication is the most complicated and difficult problem in water pollution treatment. The usual secondary biochemical treatment method can only remove 30-50% of nitrogen and phosphorus.

Microbial Fuel Cells (MFC for short) is a device that uses microorganisms to convert chemical energy into electrical energy. The use of microbial fuel cells not only directly degrades organic matter in water or sludge, but also converts electrons generated during the metabolism of organic matter into electric current to obtain electrical energy. Under the double pressure of environmental pollution and energy crisis, because microbial fuel cells can treat wastewater and generate electricity at the same time, the research and development of MFC technology has attracted the attention of governments and large companies, and is considered to be a clean and efficient power generation technology in the 21st century. . Microbial power generation using wastewater as fuel is a new renewable energy utilization method, which has many advantages such as normal temperature power generation, clean and efficient, and recyclable utilization.

The basic electricity generation principle of MFC is (1) biological oxidation of substrate (i.e. fuel): organic matter is oxidized under the action of microorganisms in the anode chamber to produce electrons, protons and metabolites; (2) anode reduction: electrons generated by oxidation of organic matter are converted from Microbial cells are delivered to the anode surface to reduce the electrode; (3) External circuit electron transport: electrons reach the cathode via the external circuit; (4) Proton migration: Protons generated by the oxidation of organic matter migrate from the anode chamber to the cathode chamber and reach the cathode surface; ( 5) Cathode reaction: The oxidized substance in the cathode chamber, that is, the electron acceptor, undergoes a reduction reaction with the protons and electrons transferred from the anode on the surface of the cathode, and the oxidized substance is reduced. The production, transfer and consumption of electrons form current and complete the process of electricity production.

Using microbial fuel cell technology to treat nitrogen and phosphorus polluted wastewater can not only remove nitrogen and phosphorus in wastewater with high efficiency, but also generate electricity.

Utility model content

The purpose of the utility model is to overcome the deficiencies of the prior art and provide a dual-chamber microbial fuel cell for synchronous denitrification and dephosphorization. The specific technical scheme is as follows.

A dual-chamber microbial fuel cell for synchronous denitrification and phosphorus removal includes a reaction system and a data acquisition monitoring system; the reaction system includes an anode reaction system and a cathode reaction system, wherein the anode reaction system includes an anode microorganism, an anode electrode, an anode chamber, a sampling Inlet, sample inlet and electrolyte; the cathode reaction system includes cathode microorganisms, cathode electrode, cathode chamber, water inlet pipe, water outlet pipe, constant flow pump hose, air pump, brown buffer bottle, aeration head, constant flow pump and electrolysis liquid; the electrolyte in the cathode reaction system passes through the water outlet pipe, the first constant flow pump hose, the brown buffer bottle, the second constant flow pump hose, and the water inlet pipe in sequence, forming an internal circulation under the action of the constant flow pump; the blower pump passes through The third constant flow pump hose is connected to the aeration head in the brown buffer bottle, the anode chamber and the cathode chamber are separated by a proton exchange membrane, and the anode electrode and the cathode electrode are respectively attached to both sides of the proton exchange membrane; the data acquisition and monitoring system Including conductive wire, load, wire, data collector and computer, the anode electrode and the cathode electrode are connected with conductive wire, and the conductive wire is connected to the load through the wire to form a closed loop; both ends of the load are also connected to the input end of the data collector through the wire Connection, the output end of the data collector is connected with the input end of the computer.

Further, the structure and size of the anode chamber and the cathode chamber are exactly the same, and the sampling port and the sampling port are located on the top of the anode chamber.

Further, the constant flow pump acts on the hose of the second constant flow pump.

Further, the water outlet pipe is connected to the water outlet on the top of the cathode chamber; the water inlet pipe passes through the water inlet on the top of the cathode chamber and extends into the bottom of the cathode chamber.

Further, except for the sampling and sampling process in the anode chamber, the sampling port and the sampling port on the top of the anode chamber are always closed to ensure that the anode chamber is an anaerobic environment; the air blower is always open so that the cathode reaction system Always in an aerobic state, the amount of aeration in the brown buffer bottle is regulated by the flow control button of the blower pump.

Further, the dissolved oxygen in the anode chamber is 0.05-0.1 mg/L, and the dissolved oxygen in the electrolyte in the brown buffer bottle is 2.0-3.5 mg/L.

Further, the electrolyte solution is organic wastewater containing nitrogen and phosphorus, and the initial pH is 7.0-7.5.

Further, when the output voltage of the microbial fuel cell is less than 50 mV, the electrolyte in the brown buffer bottle is discharged outside the reaction system; the electrolyte in the anode chamber is returned to the brown buffer bottle, and then the anode chamber is filled with fresh untreated The nitrogen and phosphorus-containing organic wastewater is treated in such a cycle that the entire time period from the addition of nitrogen and phosphorus-containing organic wastewater to the reaction system to the discharge of the reaction system is regarded as a reaction cycle.

Further, the height of the anode chamber and the cathode chamber is greater than the width in the horizontal direction.

Further, the anode electrode and the cathode electrode have the same area, are carbon cloth, carbon paper, carbon felt, graphite felt or graphite plate, the two materials are the same or different, and the ratio of the electrode area to the volume of the reaction chamber is 1 cm ² : 0.1~ 10 cm ³ .

Further, the microorganisms are activated sludge microorganisms inoculated from sewage treatment plants with the function of denitrification and phosphorus removal.

Further, the electrolyte is nitrogen and phosphorus-containing organic wastewater, and the initial pH is 7.0-7.5.

Further, the anode chamber and the cathode chamber are filled with electrolyte solution. When the initial start-up, the inoculum solution is the anaerobic and aerobic sludge supernatant of the secondary sedimentation tank of the sewage treatment plant with a volume ratio of 1:1, and the inoculum solution The volume to reaction chamber volume ratio is 1:3. The entire period from the time when the nitrogen- and phosphorus-containing organic wastewater is added to the reaction system to when it is discharged from the reaction system is regarded as a reaction cycle. When the output voltage is less than 50 mV, the electrolyte in the brown buffer bottle is discharged out of the reaction system, all the electrolyte in the anode chamber is returned to the brown buffer bottle, and fresh untreated nitrogenous and phosphorus-containing organic wastewater (artificially distribution water or actual wastewater).

Further, the anode chamber is a strictly anaerobic environment, and the dissolved oxygen in the anolyte is 0.05-0.1 mg/L. The blower pump connected to the brown buffer bottle is always on, and the flow control button of the blower pump is used to control the amount of aeration, thereby controlling the dissolved oxygen in the catholyte, and the dissolved oxygen in the cathode chamber is controlled within the range of 2.0~3.5 mg/L.

Further, the data collector is Keithley 2007 data collector.

Compared with the prior art, the utility model has the following beneficial effects:

(1) The utility model can realize simultaneous denitrification and phosphorus removal and electricity generation without adding ferricyanide, permanganate and other chemical substances with high oxidation activity;

(2) All the effluent from the anode chamber is returned to the cathode chamber, which can effectively alleviate the pH problem of the cathode and anode, and can further improve the removal rate of organic matter;

(3) The use of buffer bottle aeration can reduce the diffusion of oxygen from the cathode chamber to the anode chamber, which improves the electricity production efficiency and the electricity production stability of the entire reactor;

(4) Through the flow control of the blower pump, different denitrification and phosphorus removal and power generation effects can be obtained, and the reactor can be operated flexibly;

(5) The cathode circulation system strengthens the material flow inside the reaction chamber and accelerates the rate of electricity generation;

(6) The anode electrode and the cathode electrode are closely attached to both sides of the proton exchange membrane, and the distance between the two electrodes is very small, which greatly reduces the internal resistance of the battery;

(7) Cathode aeration achieves the multiple effects of providing electron acceptors, nitrifying bacteria for ammonia nitrogen nitrification, denitrifying phosphorus accumulating bacteria for denitrification, and phosphorus accumulating bacteria for aerobic phosphorus uptake, reducing energy consumption.

(8) Nitrogenous and phosphorus-containing organic wastewater is successively treated by the anode reaction system and the cathode reaction system, which can decompose the organic substances in the nitrogenous and phosphorus-containing organic wastewater more thoroughly.

Description of drawings

Figure 1 is a schematic diagram of the structure of a simultaneous nitrogen and phosphorus removal dual-chamber microbial fuel cell.

Figure 2 is the relationship between the battery power density and the battery voltage and current density when the liquid dissolved oxygen in the cathode chamber is about 3.5 mg/L in the embodiment.

Fig. 3 is a graph showing the relationship between the battery power density and the battery voltage and current density when the liquid dissolved oxygen in the cathode chamber is about 2.5 mg/L in the embodiment.

Detailed ways

The implementation of the utility model is described in detail below through specific examples, but the implementation of the utility model is not limited thereto.

As shown in Figure 1, a dual-chamber microbial fuel cell for simultaneous denitrification and phosphorus removal includes an anode reaction system and a cathode reaction system, wherein the anode reaction system includes an anode microorganism 1, an anode electrode 2, an anode chamber 3, a sampling port 5, and a sampling port 6 and electrolyte; the cathode reaction system includes cathode microorganism 21, cathode electrode 20, cathode chamber 19, water inlet pipe 16, water outlet pipe 17, constant flow pump hose, air pump 11, brown buffer bottle 14, aeration head 15, constant Flow pump 12 and electrolyte; In the cathode reaction system, the electrolyte passes through the water outlet pipe 17, the first constant-current pump flexible pipe, the brown buffer bottle 14, the second constant-current pump flexible pipe, and the water inlet pipe 16 successively. The internal circulation is formed under the action; the blower pump 11 is connected with the aeration head 15 in the brown buffer bottle 14 through the third constant flow pump hose, the anode chamber 3 and the cathode chamber 19 are separated by the proton exchange membrane 18, the anode electrode 2 and the cathode The electrodes 20 are respectively attached to both sides of the proton exchange membrane 15; the data acquisition and monitoring system includes a conductive wire 4, a load 7, a wire 8, a data collector 9 and a computer 10, and the anode electrode 2 and the cathode electrode 20 are connected with the conductive wire 4 , the conductive wire 4 is connected to the load 7 through a wire to form a closed loop; both ends of the load 7 are also connected to the input end of the data collector 9 through a wire, and the output end of the data collector 9 is connected to the input end of the computer 10. In this example, the anode electrode 2 is carbon paper, the cathode electrode 20 is carbon cloth coated with 0.5 mg/cm ² platinum carbon, and the catalytic layer faces the proton exchange membrane 18 .

The external 1000 ohm resistance of the battery operates intermittently at room temperature, and whenever the battery voltage is lower than 50 mV, the electrolyte in the brown buffer bottle 14 is discharged to the outside of the reaction system, and the electrolyte in the anode chamber 3 is returned to the brown buffer bottle 14 to Fresh untreated nitrogen and phosphorus-containing organic wastewater is added to the anode chamber 3 .

Artificial simulated wastewater formula: NTA 1.5 g/L, MgSO ₄ 3 g/L, MnSO ₄ H ₂ O 0.5 g/L, NaCl 1 g/L, FeSO ₄ 7H ₂ O 0.1 g/L, CaCl 2H ₂ O 0.1 g/L, CoCl 6H ₂ O 0.1 g/L, ZnCl 0.13 g/L, CuSO ₄ 5H ₂ O 0.01 g/L, AlK(SO ₄ ) ₂ 12H ₂ O 0.01 g/L, H ₃ BO ₃ 0.01 g/L, NaMoO ₄ 0.025 g/L, NiCl 6H ₂ O 0.024 g/L, Na ₂ WO ₄ 2H ₂ O 0.025 g/L, NaHCO ₃ 5.96 g/L, NaC ₂ H ₃ O ₂ 1.00 g/L, KH ₂ PO ₄ 0.54 g/L, NH ₄ Cl 0.21 g/L, vitamin H 2 mg/L, vitamin B 2 mg/L, vitamin B ₆ 10 mg/L, riboflavin 5 mg/L L, thiamine 5 mg/L, niacin 5 mg/L, pantothenic acid 5 mg/L, B ₁₂ 0.1 mg/L, p-aminobenzoic acid 5 mg/L, lipoic acid 5 mg/L.

The simultaneous denitrification and phosphorus removal dual-chamber microbial fuel cell starts as follows:

Add 80 ml of artificial simulated organic wastewater containing nitrogen and phosphorus into a clean beaker, and then add 40 ml of inoculum solution (the inoculum solution is the anaerobic and aerobic sludge in the secondary sedimentation tank of the sewage treatment plant with a volume ratio of 1:1 Supernatant), mix well, fill the anode chamber 3 with the mixture of simulated waste water and inoculum solution (about 28 ml), and add about 92 ml of the remaining mixture into the brown buffer bottle 14. Seal the sampling port 6 and the sampling port 5 at the top of the anode chamber 3, and turn on the constant flow pump 12 and the blowing pump 11. Two days later, drain the electrolyte in the brown buffer bottle 14 out of the reaction system, open the sampling port 5 on the top of the anode chamber 3, and return all the electrolyte in the anode chamber 3 to the brown buffer bottle 14. This cycle runs like this. The entire period from the time when the nitrogen- and phosphorus-containing organic wastewater is added to the reaction system to when it is discharged from the reaction system is regarded as a reaction cycle. When the output voltage of the microbial fuel cell is stable for more than three operating cycles, the start-up process is completed.

The working process of simultaneous denitrification and phosphorus removal dual-chamber microbial fuel cell is as follows:

The simulated waste water is added to the anode chamber 3, and after 72 hours of operation, the battery output voltage is less than 50 mV, the electrolyte in the brown buffer bottle 14 is discharged, all the electrolyte in the anode chamber 3 is returned to the brown buffer bottle 14, and the anode chamber 3 is added For fresh untreated simulated wastewater, after 72 h, the previous round of operation was repeated.

FIG. 2 shows the relationship between the battery power density and the battery voltage and current density when the dissolved oxygen in the electrolyte in the cathode chamber 19 is about 3.5 mg/L in the embodiment. The maximum output power of the battery is 531 mW/m ² when the current density is 1777 mA/m ² . Under this condition, nitrogen has almost no removal effect, and phosphorus removal rate is over 95%.

Fig. 3 shows the relationship between the battery power density and the battery voltage and current density when the dissolved oxygen in the electrolyte solution of the cathode chamber 19 is about 2.5 mg/L in the embodiment. The battery reaches a maximum output power of 429 mW/m ² at a current density of 1427 mA/m ² . Under these conditions, the removal rates of nitrogen and phosphorus were above 90%.

From the above experimental data, it can be seen that the power generation performance and the denitrification and phosphorus removal effects of wastewater are very different when the dual-chamber microbial fuel cell is operated with different dissolved oxygen in the electrolyte of the cathode chamber 19 .

Finally, it should be noted that the above examples are only some specific implementation examples of the present invention. Apparently, the utility model is not limited to the above implementation examples, and many variations are possible. All deformations that a person skilled in the art can derive or associate directly from the content disclosed in the utility model shall be considered as the protection scope of the utility model.

Claims (6)

1. A dual-chamber microbial fuel cell for synchronous denitrification and phosphorus removal, comprising a reaction system and a data acquisition monitoring system, characterized in that: the reaction system includes an anode reaction system and a cathode reaction system, wherein the anode reaction system includes an anode microorganism (1 ), anode electrode (2), anode chamber (3), sampling port (5), sample inlet (6) and electrolyte; the cathode reaction system includes cathode microorganism (21), cathode electrode (20), cathode chamber (19 ), water inlet pipe (16), water outlet pipe (17), constant flow pump hose, blower pump (11), brown buffer bottle (14), aeration head (15), constant flow pump (12) and electrolyte; In the cathode reaction system, the electrolyte sequentially passes through the water outlet pipe (17), the first constant flow pump hose, the brown buffer bottle (14), the second constant flow pump hose, the water inlet pipe (16), and in the constant flow pump (12) The internal circulation is formed under the action of the pump; the blower pump (11) is connected with the aeration head (15) in the brown buffer bottle (14) through the hose of the third constant flow pump, and the anode chamber (3) and the cathode chamber (19) are controlled by proton The exchange membrane (18) is separated, and the anode electrode (2) and the cathode electrode (20) are respectively attached to both sides of the proton exchange membrane (15); the data acquisition and monitoring system includes a conductive wire (4), a load (7), a wire (8), the data collector (9) and the computer (10), the anode electrode (2) and the cathode electrode (20) are connected with a conductive wire (4), and the conductive wire (4) is connected to the load (7) through a wire A closed loop is formed; both ends of the load (7) are also connected to the input end of the data collector (9) through wires, and the output end of the data collector (9) is connected to the input end of the computer (10). 2. A dual-chamber microbial fuel cell for synchronous denitrification and phosphorus removal according to claim 1, characterized in that the structure and size of the anode chamber (3) and the cathode chamber (19) are exactly the same, and the sampling port (5), The injection port (6) is located at the top of the anode chamber (3). 3. A dual-chamber microbial fuel cell for synchronous denitrification and phosphorus removal according to claim 1, characterized in that the constant flow pump (12) acts on the hose of the second constant flow pump. 4. A dual-chamber microbial fuel cell for synchronous denitrification and phosphorus removal according to claim 1, characterized in that the water outlet pipe (17) is connected to the water outlet on the top of the cathode chamber (19); the water inlet pipe (16) passes through the cathode The water inlet on the top of the chamber (19) extends into the bottom of the cathode chamber (19). 5. A dual-chamber microbial fuel cell for synchronous denitrification and phosphorus removal according to claim 1, characterized in that the height of the anode chamber and the cathode chamber is greater than the width in the horizontal direction. 6. A dual-chamber microbial fuel cell for synchronous denitrification and phosphorus removal according to any one of claims 1 to 5, characterized in that the anode electrode (2) and the cathode electrode (20) have the same area, both of which are carbon cloth, carbon Paper, carbon felt, graphite felt or graphite plate, the two materials are the same or different, the ratio of the electrode area to the volume of the reaction chamber is 1 cm ² : 0.1~10 cm ³ .