CN210764607U - Coil spring type microbial fuel cell for synchronous nitrogen and phosphorus removal based on zero-valent iron - Google Patents

Abstract

The utility model discloses a coil spring type synchronous denitrification and phosphorus removal microbial fuel cell based on zero-valent iron. A cathode electrode and an anode reactor are both in coil spring shape; a cathode biofilm is arranged on the surface of the cathode electrode; the cathode electrode and The upper end of the anode reactor is connected with the sealing plate; the anode electrode of zero-valent iron is arranged in the anode reactor, the proton exchange membrane is arranged on the outer wall of the anode reactor; the anode water inlet pipe is arranged at the upper end of the anode reactor, and the lower end of the anode reactor is arranged with a proton exchange membrane. There are anode product discharge pipe and anode water outlet pipe, anode water inlet pipe, anode water outlet pipe and anode product discharge pipe all extend to the outside of the casing; the lower end of the casing is provided with a cathode water inlet pipe, and the upper part of the casing is provided with a cathode water outlet pipe; the cathode electrode and the anode The electrodes are all connected with external wires, and the external wires extend to the outside of the casing. The utility model can solve the problem of denitrification and dephosphorization of sewage with insufficient carbon sources in my country, realize the recovery of nitrogen and phosphorus resources in wastewater, and has the advantages of economy, environmental protection, resource reuse and the like.

Description

A microbial fuel cell based on zero-valent iron for synchronous denitrification and phosphorus removal by coil spring

technical field

The utility model belongs to the technical field of microbial fuel cells, in particular to a microbial fuel cell based on zero-valent iron for synchronous denitrification and phosphorus removal by coil spring.

Background technique

The amount of nitrogen, phosphorus and other nutrients discharged into the natural water body exceeds the water body's receiving capacity, which will make the receiving water body eutrophic, and the aquatic organisms in the water body, especially algae and some aquatic plants, will overgrow and reproduce, and the water body ecosystem will be destroyed. , causing the water body to lose its proper function. Water eutrophication is a prominent global environmental problem. The increasingly serious water eutrophication has brought huge negative impacts on human life, production and the entire ecosystem. According to the 2018 China Environmental Status Bulletin, eutrophication is still a serious pollution problem in my country's water environment. Among the 107 lakes (reservoirs) monitored for nutrient status, 66 were in mesotrophic state, accounting for 61.7%; 25 were in mild eutrophic state, accounting for 23.4%; and 6 were in moderate eutrophic state, accounting for 5.6%. The monitoring results of 453 direct sea pollution sources with a daily discharge of more than 100 cubic meters of sewage in my country show that the total sewage discharge is about 8,664.24 million tons, 6,217 tons of ammonia nitrogen, 50,873 tons of total nitrogen, and 1,280 tons of total phosphorus. The situation of nitrogen and phosphorus pollution in water bodies in my country is severe.

The construction of sewage treatment plants is an effective way to reduce the discharge of sewage in my country, reduce the environmental load of water bodies, and improve the quantity and quality of water for human production and living. Wastewater biological treatment technology is the mainstream technology of modern urban sewage treatment. The organic matter concentration of wastewater after biological treatment basically reached the standard, but the nitrogen and phosphorus concentration still exceeded the standard. For this kind of wastewater with low C:N:P ratio, the traditional denitrification process can no longer meet the discharge standard, because the traditional denitrification technology process requires organic matter as an electron donor. Similarly, the traditional biological phosphorus removal process usually requires organic matter to provide energy materials in the process of biological phosphorus uptake. Insufficient carbon source has become the bottleneck factor for biological nitrogen and phosphorus removal in urban sewage.

In recent years, iron and iron salts have been widely used in sewage treatment processes, including zero-valent iron, divalent iron salts, and trivalent iron salts. The ferrous autotrophic denitrification technology has been successfully implemented in a small laboratory device. This technology uses divalent iron salts to replace organic matter as electron donors for denitrification, but the consumption of iron salts is huge.

Utility model content

The purpose of this utility model is to solve the problem of denitrification and dephosphorization of sewage with low C:N:P ratio in my country, by changing the reaction configuration of the microbial fuel cell (MFC) to improve the power generation and decontamination capabilities, and to provide a zero-valent iron-based Coil-spring synchronous denitrification and phosphorus removal of microbial fuel cells.

The technical scheme adopted by the utility model is as follows:

A zero-valent iron-based coil spring type synchronous denitrification and phosphorus removal microbial fuel cell, comprising an outer shell and a sealing plate arranged in the outer shell, a cathode electrode, an anode reactor and a cathode biofilm, and the cathode electrode and the anode reactor are arranged next to each other , both the cathode electrode and the anode reactor are in the shape of a coil spring; the cathode biofilm is arranged on the surface of the cathode electrode; the sealing plate is arranged on the upper part of the inner cavity of the shell, and the cathode electrode and the anode reactor are located at the lower part of the sealing plate; the cathode electrode and the anode react The upper end of the reactor is connected with the sealing plate, and the upper end of the anode reactor is sealed with the sealing plate; the inner cavity of the anode reactor is the anode reaction zone, and an anode electrode is arranged in the anode reactor. The anode electrode is made of zero-valent iron, and the anode reaction A proton exchange membrane is arranged on the outer wall of the reactor, and the proton exchange membrane is used for material exchange between the anode reaction zone and the cathode reaction zone; the anode water inlet pipe is arranged at the upper end of the anode reactor, and the anode product discharge pipe and the anode water outlet pipe are arranged at the lower end of the anode reactor. The anode water inlet pipe, the anode water outlet pipe and the anode product discharge pipe all extend to the outside of the casing; the lower end of the casing is provided with a cathode water inlet pipe, and the upper part of the casing is provided with a cathode water outlet pipe; both the cathode electrode and the anode electrode are connected with external wires, and the external wires extend to the outside of the housing.

The lower end of the anode reactor is in a spiral downward spiral structure, the anode water outlet pipe is arranged at the lower end of the edge of the anode spiral structure, and the anode product discharge pipe is arranged at the lower end of the center of the spiral structure.

The lower part of the shell is provided with a cathode biofilm shedding hopper, the cathode biofilm shedding hopper is funnel-shaped, and the cathode biofilm shedding hopper is provided with a cathode biofilm shedding outlet.

When the lower end of the anode reactor is in a spiral downward spiral structure, the lower end of the anode reactor extends into the cathode biofilm shedding hopper, and the anode product discharge pipe extends from the cathode biofilm shedding outlet.

The upper end of the anode electrode extends to the sealing plate, the lower end of the anode electrode extends to the bottom of the anode reactor, and the shape of the anode electrode is the same as the shape of the coil spring of the anode reactor.

The upper and lower ends of the anode reactor have no end faces, the upper end of the anode reactor is sealed with the sealing plate, the anode electrode is suspended and fixed on the sealing plate, and the upper end of the anode electrode is connected with the external wire; the lower end of the anode reactor is sealed by the anode silica gel sealing strip .

A number of longitudinal openings are spaced apart on the outer wall of the anode reactor, and the proton exchange membrane is arranged at the longitudinal openings.

The cathode electrode is wrapped on the outside of the anode reactor and is close to the outer wall of the anode reactor, and cathode biofilms are arranged on both sides of the cathode electrode.

The anode reactor is filled with a power-generating substrate containing phosphate, the inner cavity of the shell is filled with a power-consuming substrate containing nitrate, and DNRA bacteria are attached to the surface of the cathode biofilm.

The material of the shell and the sealing plate is PVC, and the material of the outer wall of the anode reactor is plexiglass.

The utility model has the following beneficial effects:

In the microbial fuel cell of the utility model, inexpensive and easily available zero-valent iron is used to replace the organic matter as the electron donor for biological denitrification of wastewater in the prior art, so the cost is saved; the anode electrode adopts zero-valent iron, and the anode electrode and the cathode electrode After being connected, the electric current can be generated through electron transfer to realize the resource recovery of electric energy; the cathode electrode and the anode reactor are arranged next to each other, and both the cathode electrode and the anode reactor are in the shape of a coil spring, so the area of the opposite electrode is greatly increased, and the The mass transfer area enhances the decontamination capability of the fuel cell while achieving higher volumetric energy density. The anode product discharge pipe and the anode water outlet pipe are arranged at the lower end of the anode reactor, so the anode reactor can discharge the liquid and solid in it separately, which is convenient for separate recovery and utilization. The generated waste is separated. The lower end of the casing is provided with a cathode water inlet pipe, and the upper part of the casing is provided with a cathode water outlet pipe, so the microbial fuel cell of the present invention can adopt an ascending mass transfer mode, which has better mass transfer effect than the traditional mass transfer mode.

Further, the lower end of the anode reactor is in a spiral downward spiral structure, the anode water outlet pipe is arranged at the lower end of the edge of the anode spiral structure, and the anode product discharge pipe is arranged at the lower end of the center of the spiral structure. This structure enables the solid-liquid separation of the substances produced inside the anode reactor. Since the lower end of the anode reactor has a spiral structure of descending spiral, after the heavier solid material is generated, the solid material descends to the bottom along the spiral structure and can pass through the spiral structure. The anode product discharge pipe is discharged, and the lighter liquid material is discharged through the anode water outlet pipe at a higher position, thereby directly realizing solid-liquid separation inside the oxygen reactor.

Further, the lower part of the casing is provided with a cathode biofilm shedding hopper, and the cathode biofilm shedding hopper is funnel-shaped, so the solid material produced by the cathode can be gathered in the cathode biofilm shedding hopper, and the gravity of the solid material and the gravity of the upper liquid material can be utilized. The solid matter produced by the action of gravity is easier to discharge through the cathode biofilm shedding outlet.

Further, when the lower end of the anode reactor is in a spiral structure with a downward spiral, the lower end of the anode reactor extends into the cathode biofilm shedding hopper, so the effective reaction area of the anode electrode and the cathode electrode can be further increased, and the microorganisms of the present invention can be increased. The volumetric energy density of the fuel cell enhances the decontamination ability of the fuel cell; the anode product discharge pipe extends from the cathode biofilm shedding outlet, which first enables the anode product discharge pipe to go straight up and down to avoid turning, which is conducive to the discharge of solid substances produced by the anode Secondly, it can also prevent the solid matter produced by the cathode from depositing on the anode product discharge pipe and the connection between the anode product discharge pipe and the shell or the cathode biofilm shedding hopper, resulting in incomplete sewage discharge.

Further, the upper end of the anode electrode extends to the sealing plate, and the lower end of the anode electrode extends to the bottom of the anode reactor, and the shape of the anode electrode is the same as that of the anode reactor. The relative electrode area is increased, the mass transfer area is increased, a higher volume energy density can be obtained, the decontamination ability of the fuel cell can be enhanced, and the refueling period can be increased.

Further, DNRA bacteria are attached to the surface of the cathode biofilm, and the DNRA bacteria can directly convert nitrate nitrogen into ammonia nitrogen, so there is no accumulation of nitrite nitrogen in the microbial fuel cell of the present invention.

Description of drawings

Fig. 1 is the front sectional view of the microbial fuel cell of the utility model based on the coil spring type synchronous denitrification and dephosphorization of zero-valent iron;

FIG. 2 is an A-A sectional view of FIG. 1 .

3 is a partial view of the outer wall of the anode reactor of the microbial fuel cell based on the zero-valent iron coil spring type synchronous denitrification and phosphorus removal of the present invention.

FIG. 4 is an enlarged schematic view of part B in FIG. 1 .

FIG. 5 is an enlarged schematic view of part C in FIG. 1 .

In the figure, 1-electrical signal acquisition system, 2-external load, 3-anode water inlet pipe, 4-external wire, 5-shell, 6-cathode water outlet, 7-cathode external wire port, 8-sealing plate, 9-cathode Electrode, 10-Anode electrode, 11-Anode reactor outer wall, 12-Cathode biofilm, 13-Anode silica gel sealing strip, 14-Cathode water inlet pipe, 15-Anode water outlet pipe, 16-Water stop valve, 17-Anode product discharge Tube, 18-Anode external wire port, 19-Anode reaction zone, 20-Cathode reaction zone, 21-Cathode biofilm shedding bucket, 22-Cathode biofilm shedding outlet, 23-Proton exchange membrane, 24-Plexiglas, 24 -1- Opening.

Detailed ways

The present utility model will be further described below with reference to the specific drawings and specific embodiments.

1 and 2, the present utility model is based on the coil spring type synchronous denitrification and phosphorus removal microbial fuel cell of zero-valent iron, comprising an outer casing 5 and a sealing plate 8, a cathode electrode 9, an anode reactor and a sealing plate 8 arranged in the outer casing 5. The cathode biofilm 12, the cathode electrode 9 and the anode reactor are arranged next to each other, and both the cathode electrode 9 and the anode reactor are in the shape of a coil spring; the cathode biofilm 12 is arranged on the surface of the cathode electrode 9; the sealing plate 8 is arranged on the inner cavity of the casing 5 The upper part, the cathode electrode 9 and the anode reactor are located in the lower part of the sealing plate 8; the upper end of the cathode electrode 9 and the anode reactor are all connected with the sealing plate 8, and the upper end of the anode reactor is sealed with the sealing plate 8; The cavity is an anode reaction zone 19, an anode electrode 10 is arranged in the anode reactor, the anode electrode 10 is made of zero-valent iron, a proton exchange membrane 23 is arranged on the outer wall 11 of the anode reactor, and the proton exchange membrane 23 is used for the anode reaction zone 19 and the cathode The reaction zone 20 carries out material exchange; the upper end of the anode reactor is provided with an anode water inlet pipe 3, the lower end of the anode reactor is provided with an anode product discharge pipe 17 and an anode water outlet pipe 15, an anode water inlet pipe 3, an anode water outlet pipe 15 and an anode product discharge pipe 17 Both extend to the outside of the outer casing 5; the lower end of the outer casing 5 is provided with a cathode water inlet pipe 14, and the upper part of the outer casing 5 is provided with a cathode water outlet pipe 6; external.

As a preferred embodiment of the present utility model, referring to FIG. 1 , the lower end of the anode reactor is in a spiral downward spiral structure, the anode water outlet pipe 15 is arranged at the lower end of the edge of the anode spiral structure, and the anode product discharge pipe 17 is arranged at the lower end of the center of the spiral structure.

As a preferred embodiment of the present utility model, referring to FIG. 1 , the lower part of the casing 5 is provided with a cathode biofilm shedding hopper 21 , the cathode biofilm shedding hopper 21 is funnel-shaped, and the cathode biofilm shedding hopper 21 is provided with a cathode biofilm shedding outlet 22 .

As a preferred embodiment of the present invention, referring to FIG. 1 , when the lower end of the anode reactor is in a spiral structure with a downward spiral, the lower end of the anode reactor extends into the cathode biofilm shedding hopper 21, and the anode product discharge pipe 17 falls off from the cathode biofilm. The discharge port 22 protrudes.

As a preferred embodiment of the present invention, referring to FIGS. 1 , 2 and 5 , the upper end of the anode electrode 10 extends to the sealing plate 8 , the lower end of the anode electrode 10 extends to the bottom of the anode reactor, and the shape of the anode electrode 10 is the same as the The anode reactor has the same coil spring shape.

As a preferred embodiment of the present utility model, referring to Fig. 1, Fig. 4 and Fig. 5, the upper and lower ends of the anode reactor have no end faces, the upper end of the anode reactor is sealed with the sealing plate 8, and the anode electrode 10 is suspended and fixed on the sealing plate 8. The upper end of the anode electrode 10 is connected to the external wire 4 ; the lower end of the anode reactor is sealed by the anode silica gel sealing strip 13 .

As a preferred embodiment of the present invention, referring to FIG. 5 , a plurality of longitudinal openings 24-1 are spaced apart on the outer wall 11 of the anode reactor, and the proton exchange membrane 23 is disposed at the longitudinal openings.

1, 2, 4 and 5, the cathode electrode 9 is wrapped on the outside of the anode reactor and is adjacent to the outer wall 11 of the anode reactor, and both sides of the cathode electrode 9 are provided with cathode biofilms 12.

As a preferred embodiment of the present invention, the anode reactor is filled with a phosphate-containing electricity-generating substrate, the inner cavity of the shell 5 is filled with a nitrate-containing electricity-consuming substrate, and DNRA bacteria are attached to the surface of the cathode biofilm 12 .

As a preferred embodiment of the present invention, the material of the casing 5 and the sealing plate 8 is PVC, and the material of the outer wall 11 of the anode reactor is plexiglass.

Referring to Fig. 1 and Fig. 2, the working method of the microbial fuel cell of the present utility model based on the coil spring type synchronous denitrification and dephosphorization of zero-valent iron, comprises the following process:

The anode reactor adopts the sequence batch operation, and the wastewater containing phosphate enters the anode reaction zone 19 from the anode water inlet pipe 3 to form the anode electrolyte; The valence iron ion reacts with the phosphate ion of the anode electrolyte to form a cyanite precipitation; the cyanite is discharged from the anode product discharge port 17 through the precipitation; the treated phosphorus-free waste water is discharged from the anode water outlet pipe 15;

The sequence batch operation is adopted, and the wastewater containing nitrate is taken from the cathode water inlet pipe 14 to enter the cathode reaction zone 20 of the inner cavity of the casing 5 by means of an ascending mass transfer to form a cathode electrolyte;

When the cathode electrode 9 and the anode electrode 10 are connected to form a loop, the microorganisms on the cathode biofilm 12 use the electrons lost from the anode electrode 10 to convert the nitrate in the cathode electrolyte into ammonia nitrogen, and the produced ammonia nitrogen-containing wastewater is discharged from the cathode. The water pipe 6 is discharged;

The anolyte and catholyte maintain charge balance through the proton exchange membrane 23 of the outer wall 11 of the anode reactor.

It can be seen from the above that the working method of the microbial fuel cell of the present invention is simple to operate, and while the phosphorus is removed in the anode reactor, ferrous iron and phosphorus form cyanite, and the removal and recovery of phosphorus are realized simultaneously. The ascending mass transfer method has better mass transfer effect than the traditional mass transfer method.

Example

As shown in FIG. 1 and FIG. 2 , the coil spring type synchronous denitrification and phosphorus removal microbial fuel cell based on zero-valent iron in this embodiment includes an outer casing 5 and a sealing plate 8 arranged in the outer casing 5 , a cathode electrode 9 and an anode reactor. and the cathode biofilm 12, the cathode electrode 9 and the anode reactor are arranged next to each other, the cathode electrode 9 and the anode reactor are both in the shape of a coil spring; the cathode biofilm 12 is arranged on the surface of the cathode electrode 9; the sealing plate 8 is arranged in the inner cavity of the casing 5 The upper part, the cathode electrode 9 and the anode reactor are located at the bottom of the sealing plate 8; the upper end of the cathode electrode 9 and the anode reactor are all connected with the sealing plate 8, and the upper end of the anode reactor is sealed with the sealing plate 8; The inner cavity is an anode reaction zone 19, an anode electrode 10 is arranged in the anode reactor, the anode electrode 10 is made of zero-valent iron, a proton exchange membrane 23 is arranged on the outer wall 11 of the anode reactor, and the proton exchange membrane 23 is used for the anode reaction zone 19 and the anode. The cathode reaction zone 20 carries out material exchange; the anode reactor upper end is provided with the anode water inlet pipe 3, the anode reactor lower end is provided with the anode product discharge pipe 17 and the anode water outlet pipe 15, and the anode product discharge pipe 17 and the anode water outlet pipe 15 are all installed with The water stop valve 16, the anode water inlet pipe 3, the anode water outlet pipe 15 and the anode product discharge pipe 17 all extend to the outside of the casing 5; the lower end of the casing 5 is provided with a cathode water inlet pipe 14, and the upper part of the casing 5 is provided with a cathode water outlet pipe 6; The electrode 9 and the anode electrode 10 are both connected with an external lead 4, which extends to the outside of the casing 5, and the sealing plate 8 is provided with a cathode external lead port 7 and an anode external lead port 18 for the external lead 4 to pass through. The lower part of the casing 5 is provided with a cathode biofilm shedding hopper 21 , the cathode biofilm shedding hopper 21 is funnel-shaped, and the cathode biofilm shedding hopper 21 is provided with a cathode biofilm shedding outlet 22 . The lower end of the anode reactor is in a spiral downward spiral structure, the anode water outlet pipe 15 is arranged at the lower end of the edge of the anode spiral structure, and the anode product discharge pipe 17 is arranged at the lower end of the center of the spiral structure. The lower end of the anode reactor extends into the cathode biofilm shedding hopper 21, and the anode product discharge pipe 17 extends from the cathode biofilm shedding outlet 22. The upper end of the anode electrode 10 extends to the sealing plate 8 , the lower end of the anode electrode 10 extends to the bottom of the anode reactor, and the shape of the anode electrode 10 is the same as that of the anode reactor. The upper and lower ends of the anode reactor have no end faces, the upper end of the anode reactor is sealed with the sealing plate 8, the anode electrode 10 is suspended and fixed on the sealing plate 8, and the upper end of the anode electrode 10 is connected with the external wire 4; The anode silicone sealing strip 13 is sealed. The material of the outer wall 11 of the anode reactor is plexiglass, the outer wall 11 of the anode reactor is provided with a plurality of longitudinal openings 24-1 at intervals, and the proton exchange membrane 23 is arranged at the longitudinal openings. The cathode electrode 9 is wrapped on the outside of the anode reactor and is adjacent to the outer wall 11 of the anode reactor, and cathode biofilms 12 are provided on both sides of the cathode electrode 9 . The anode reactor is filled with a power-generating substrate containing phosphate, the inner cavity of the shell 5 is filled with a power-consuming substrate containing nitrate, and the surface of the cathode biofilm 12 is attached with DNRA bacteria (Dissimilatory Nitrate Reduction to ammonium bacteria). Ammonium)). The material of the casing 5 and the sealing plate 8 is PVC. Among them, the inner cavity of the anode reactor is the anode reaction zone 19; in the inner cavity of the shell, the area outside the anode reactor is used as the cathode reaction zone 20, and the cathode water inlet pipe 14 is arranged at the lower end of the cathode reaction zone 20. mass transfer. The external lead 4 connected to the anode electrode 10 extends into the cathode reaction zone 20 through the anode external lead interface 18 and is connected to the cathode electrode 9, and the anode water inlet pipe 3 is arranged above the center of the coil spring structure. The external lead 4 connected to the cathode electrode 9 extends into the anode reaction zone 19 through the cathode external lead interface 7 and is connected to the anode electrode 10 . The cathode electrode 9 is suspended and fixed to the sealing plate 8 . The casing 5 is a sealed casing.

When testing the biofuel cell, as shown in FIG. 1 , a load 2 is provided on the external lead 4, and the two ends of the load are connected in parallel to the electrical signal acquisition system 1, and the anode chamber substrate and the cathode chamber substrate pass through the outer wall 11 of the anode reactor. The proton exchange membrane performs material exchange.

Specifically, the dimensions and proportions of the above components may be set according to actual conditions. In the solution of this embodiment, the ratio of the minimum inner diameter to the maximum outer diameter of the coiled spring-like structure formed by the anode reaction zone 19 and the cathode electrode 9 is 1:48, the number of turns of the coiled spring-shaped structure is 3, and the coiled spring-shaped structure The height to diameter ratio of the structure is 25:6. The distance from the anode water inlet pipe 3 to the top of the anode reaction zone 19 is 1/10 of the height of the anode reaction zone 19 . The anode electrode 10 is a pure iron sheet with a thickness of 2 mm, and the height of the anode electrode 10 is consistent with the height of the anode reaction zone 19 . The height to length ratio of the anode electrode 10 is 1:9, and the ratio of its surface area to the total volume of the anode reaction zone 19 is 1 cm ² : 50 cm ³ . The bottom of the anode reaction zone 19 spirally descends from the edge to the center, forming a slope, which facilitates the collection of anode products. An anode product discharge pipe 17 is provided at the bottom of the anode reaction zone 19 .

The height-diameter ratio of the casing 5 is 14:5, the distance from the cathode water outlet pipe 6 to the top of the casing 5 is 1/8 of the total height of the casing 5, and the headspace ratio is 12.5%. The cathode electrode 9 is made of carbon felt with a thickness of 2 mm, and the height of the cathode electrode 9 extends downward from the sealing plate to the cathode biofilm shedding bucket 21 . The height to length ratio of the cathode electrode 9 is 1:9, and the ratio of its surface area to the total volume of the cathode part is 1 cm ² : 50 cm ³ . The included angle between the biofilm shedding collection bucket 21 and the horizontal direction is 30°, and the ratio of the inner diameter of the cathode biofilm shedding discharge outlet 22 to the inner diameter of the biofilm shedding collection bucket is 1:64.

As shown in FIG. 3 , the outer wall 11 of the anode reactor is formed by the interphase between the proton exchange membrane 23 and the organic glass 24 , and the ratio of the area of the proton exchange membrane to the surface area of the outer wall 11 of the anode reactor is 1cm ² : 1.5cm ² . The anode silica gel sealing strip 13 at the bottom end of the anode reaction zone is wrapped with plexiglass and connected to the anode water outlet pipe 15 . The anode electrolyte (containing phosphate) and the cathode electrolyte (containing nitrate) are separated by the proton exchange membrane 23 of the outer wall 11 of the anode reactor. The ratio of the area of the proton exchange membrane 23 to the surface area of the anode electrode 10 is 1 cm ² : 1.5 cm ² . After tests, the above dimensions and ratios can well accomplish the test purpose of the present invention.

The working process of the microbial fuel cell in this embodiment is as follows: the anode part adopts the sequence batch operation, and the simulated wastewater containing phosphate enters the anode reaction zone 19 from the anode water inlet pipe 3 to form an anode electrolyte; The valence iron ion enters the anode reaction zone 19, and the soluble divalent iron ion reacts with the phosphate ion of the anode electrolyte to form a cyanite precipitation; the cyanite is discharged from the anode product discharge port 17 after precipitation; the phosphorus-free wastewater after treatment It is discharged from the anode water outlet pipe 15. The electrons lost by the anode electrode 10 are transmitted to the cathode electrode 9 through the external wire 4 , and the electrical signals generated in the process are detected by the electrical signal acquisition system 1 . The cathode part adopts the sequence batch operation, and the simulated wastewater containing nitrate enters the cathode reaction zone 20 by means of ascending mass transfer from the cathode water inlet pipe 14 to form the cathode electrolyte; Part of the electrons dissimilate and reduce the nitrate in the power-consuming matrix, convert the nitrate in the cathode electrolyte into ammonia nitrogen, and the produced ammonia nitrogen-containing wastewater is discharged from the cathode water outlet pipe 6, and can be processed in the next step; as the reaction proceeds, The outer layer of the cathode biofilm 12 is gradually aged and peeled off, and the peeled biofilm is collected by the peeled biofilm collection bucket 21 and then discharged from the peeled biofilm discharge port 22 . The anolyte and catholyte maintain the charge balance of the anode part and the cathode part through the proton exchange membrane of the outer wall 11 of the anode reactor.

It can be seen from the above that the advantages of the present utility model are 1) the use of cheap and easily available zero-valent iron instead of organic matter as an electron donor for biological denitrification of wastewater, which saves costs; Iron and phosphorus form cyanite, and at the same time, phosphorus can be removed and recovered. The collected cyanite can be used to process decorations or make drawing dyes; 3) The DNRA bacteria in the cathode part can directly convert nitrate to ammonia nitrogen without nitrous Nitrogen accumulation; 4) Zero-valent iron is used for anode electrode, carbon felt is used for cathode electrode, electric current is generated through electron transfer between electrodes, and electric energy is recycled; 5) The cathode part adopts ascending mass transfer method, which is different from traditional mass transfer Compared with other methods, the mass transfer effect is better; 6) The coil spring configuration greatly increases the relative electrode area, improves the mass transfer area, and enhances the decontamination ability of the fuel cell while obtaining a higher volumetric energy density. .

Claims (10)

1. a kind of microbial fuel cell based on the coil spring type synchronous denitrification and dephosphorization of zero-valent iron, is characterized in that, comprises shell (5) and the sealing plate (8), the cathode electrode (9) that are arranged in the shell (5) ), an anode reactor and a cathode biofilm (12), the cathode electrode (9) and the anode reactor are arranged next to each other, and both the cathode electrode (9) and the anode reactor are in the shape of a coil spring; the cathode biofilm (12) is arranged on the cathode electrode (9) surface; the sealing plate (8) is arranged on the upper part of the inner cavity of the casing (5), and the cathode electrode (9) and the anode reactor are located at the lower part of the sealing plate (8); The upper ends are all connected with the sealing plate (8), and the upper end of the anode reactor is sealed with the sealing plate (8); the inner cavity of the anode reactor is an anode reaction zone (19), and an anode electrode (10) is arranged in the anode reactor , the anode electrode (10) adopts zero-valent iron, the outer wall (11) of the anode reactor is provided with a proton exchange membrane (23), and the proton exchange membrane (23) is used for the anode reaction zone (19) and the cathode reaction zone (20). Material exchange; an anode water inlet pipe (3) is arranged at the upper end of the anode reactor, an anode product discharge pipe (17) and an anode water outlet pipe (15) are arranged at the lower end of the anode reactor, an anode water inlet pipe (3), and an anode water outlet pipe (15) and the anode product discharge pipe (17) both extend to the outside of the casing (5); the lower end of the casing (5) is provided with a cathode water inlet pipe (14), and the upper part of the casing (5) is provided with a cathode water outlet pipe (6); the cathode electrode ( 9) and the anode electrode (10) are both connected with an external wire (4), and the external wire (4) extends to the outside of the casing (5). 2. a kind of microbial fuel cell based on the coil spring type synchronous denitrification and dephosphorization of zero-valent iron according to claim 1, is characterized in that, the lower end of the anode reactor is in the spiral structure of spiral descending, and the anode water outlet pipe (15) It is arranged at the lower end of the edge of the anode spiral structure, and the anode product discharge pipe (17) is arranged at the lower end of the center of the spiral structure. 3. a kind of microbial fuel cell based on the coil spring type synchronous denitrification and dephosphorization of zero-valent iron according to claim 1 and 2, is characterized in that, the lower part of shell (5) is provided with cathode biofilm shedding bucket (21) The cathode biofilm shedding hopper (21) is funnel-shaped, and the cathode biofilm shedding hopper (21) is provided with a cathode biofilm shedding discharge port (22). 4. a kind of microbial fuel cell based on the coil spring type synchronous denitrification and dephosphorization of zero-valent iron according to claim 3, is characterized in that, when the lower end of the anode reactor is in the spiral structure of spiral descending, the lower end of the anode reactor Extending into the cathode biofilm shedding hopper (21), the anode product discharge pipe (17) extends from the cathode biofilm shedding discharge port (22). 5. a kind of microbial fuel cell based on zero-valent iron coil spring type synchronous denitrification and phosphorus removal according to claim 1, is characterized in that, the upper end of the anode electrode (10) extends to the sealing plate (8), the anode electrode The lower end of (10) extends to the bottom of the anode reactor, and the shape of the anode electrode (10) is a coil spring shape which is the same as the shape of the anode reactor. 6. a kind of microbial fuel cell based on the coil spring type synchronous denitrification and dephosphorization of zero-valent iron according to claim 1, is characterized in that, the upper and lower ends of the anode reactor have no end faces, and the upper end of the anode reactor and The sealing plate (8) is sealed and connected, the anode electrode (10) is suspended and fixed on the sealing plate (8), the upper end of the anode electrode (10) is connected with the external wire (4); the lower end of the anode reactor is connected with the anode silica gel sealing strip (13) seal. 7. a kind of microbial fuel cell based on the coil spring type synchronous denitrification and dephosphorization of zero-valent iron according to claim 1, is characterized in that, the anode reactor outer wall (11) is spaced apart with a number of longitudinal openings, and the proton The exchange membrane (23) is arranged at the longitudinal opening. 8. a kind of microbial fuel cell based on the coil spring type synchronous denitrification and phosphorus removal of zero-valent iron according to claim 1, is characterized in that, the cathode electrode (9) is wrapped on the outside of the anode reactor and is close to the outer wall of the anode reactor (11), cathode biofilms (12) are provided on both sides of the cathode electrode (9). 9. a kind of microbial fuel cell based on zero-valent iron coil spring type synchronous denitrification and phosphorus removal according to claim 1, it is characterized in that, in the anode reactor, fill the electricity-generating substrate containing phosphate in the anode reactor, the shell (5) The inner cavity is filled with a power-consuming substrate containing nitrate, and DNRA bacteria are attached to the surface of the cathode biofilm (12). 10. a kind of microbial fuel cell based on zero-valent iron coil spring type synchronous denitrification and dephosphorization according to claim 1, is characterized in that, the material of shell (5) and sealing plate (8) is PVC, anode reaction The material of the outer wall (11) of the device is plexiglass.

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