CN110104874A - A kind of continuous flow wetland type microbiological fuel cell reactor sewage-treatment plant - Google Patents

Abstract

The invention relates to a continuous flow wetland type microbial fuel cell reactor sewage treatment device, which comprises a hydrolytic acidification pool (3), an anode chamber (6) and a constructed wetland cathode chamber arranged sequentially from bottom to top, the anode chamber (6) filled with fillers composed of anaerobic granular sludge and granular activated carbon, the filler is provided with an anode electrode (7), and the cathode chamber of the constructed wetland is filled with granular activated carbon, wherein a cathode electrode (10) is provided. The anode electrode (7) and the cathode electrode (10) are connected through a resistor (13); the sewage to be treated enters the anode chamber (6) after passing through the hydrolysis acidification pool (3) from the bottom, and flows out from the top into the artificial The wetland cathode chamber purifies sewage and generates electricity at the same time. Compared with the prior art, the invention has the advantages of simple processing technology, simple use method, suitable for various sewage treatment and the like.

Description

A continuous flow wetland type microbial fuel cell reactor sewage treatment device

technical field

The invention relates to the fields of environmental engineering and water treatment engineering, in particular to a continuous flow wetland type microbial fuel cell reactor sewage treatment device.

Background technique

With the rapid development of economy and society, solving the increasingly serious environmental pollution problem and exploring new energy sources are two fundamental issues for the sustainable development of human society, and they are also two focal issues in the world today. Microbial Fuel Cell (MFC) technology effectively links these two issues together and has attracted widespread attention.

The organic matter in the sewage is decomposed and utilized under the action of the electrogenic bacteria to generate electricity, and the electricity energy is recovered while the sewage treatment is completed. In the anode compartment, organic substrates are decomposed into small molecules such as carbon oxides (such as CO ₂ ) under the catalysis of microorganisms, and electrons and protons are released at the same time. The electrons are transferred to the cathode through the external circuit, and the protons are transferred to the cathode through the proton exchange membrane. The two are combined with the electron acceptor (such as O ₂ ) on the cathode electrode, and a reduction reaction (such as generating water) occurs.

Water pollution is mainly caused by pollutants produced by human activities, mainly including industrial pollution sources, agricultural pollution sources and domestic pollution sources. Constructed wetlands have relatively low investment and operating costs and are easy to maintain. They have good sewage treatment effects and a wide range of applications; they can buffer the impact of hydraulic loads and pollution loads; they have the function of greening the environment. The disadvantage of conventional constructed wetlands is that they occupy a relatively large area, which is about 2-3 times that of traditional sewage treatment processes, and are prone to siltation and blockage.

The present invention is a new exploration of combining artificial wetland water purification and MFC power generation combined with MFC technology on the basis of many years of research on artificial wetlands. To achieve energy utilization while sewage treatment, the system is a set of composite ecological MFC.

Biocathode MFC refers to a microbial fuel cell in which microorganisms are used instead of non-biological catalysts such as Pt to transfer electrons from the cathode to the final electron acceptor. Aerobic biocathodes mainly use oxygen, manganese dioxide and ferric iron as direct electron acceptors. The anaerobic biological cathode type mainly uses nitrate, sulfate, and carbon dioxide as terminal electron acceptors. Virdis et al. used aerobic bio-cathode to simultaneously realize wastewater denitrification and electricity production, and the final denitrification rate reached more than 86.9%. Gao Xiongying et al. used a double-chamber MFC reactor to investigate the electricity production and Cr(VI) removal of chemical cathode and biocathode MFC at different initial Cr(VI) concentrations. The results showed that the electricity generation and Cr(VI) removal performance of the biocathode MFC were better than those of the chemical cathode MFC under various Cr(VI) concentration gradients (20, 28, 32, 36, 40, 44 mg/L). The maximum output voltage is 180.1mV, which is 1.3 times that of the chemical cathode.

The biocathode does not require expensive metal catalysts. The cathode microorganisms can maintain a stable catalytic ability through self-reproduction, which can improve the stability of MFC, and the metabolism of microorganisms in the cathode will produce valuable new products or remove certain pollutants. The potential of chemical cathodes.

The invention aims at the deficiencies of existing microbial fuel cell reactors and processes, and appropriately improves and perfects the MFC configuration and process, adopts the material selection and optimal design of artificial wetland type biological cathodes, and improves the treatment effect.

Contents of the invention

The object of the present invention is to provide a continuous flow wetland microbial fuel cell reactor sewage treatment device which is simple in processing technology and simple in use method and suitable for various sewage treatment in order to overcome the above-mentioned defects in the prior art.

The purpose of the present invention can be achieved through the following technical solutions:

A continuous flow wetland type microbial fuel cell reactor sewage treatment device is characterized in that the device includes a hydrolysis acidification tank, an anode chamber and a constructed wetland cathode chamber arranged in sequence from bottom to top, and the anode chamber is filled with anaerobic particles A filler composed of sludge and granular activated carbon, the filler is provided with an anode electrode, and the cathode chamber of the constructed wetland is filled with granular activated carbon, wherein a cathode electrode is provided, and the anode electrode and the cathode electrode are connected through resistance; the sewage to be treated is collected from The bottom enters the anode chamber after being hydrolyzed and acidified by the hydrolytic acidification tank, and flows out from the top into the constructed wetland cathode chamber after the reaction occurs, purifying sewage and generating electricity at the same time.

Further, the sewage to be treated is input into the hydrolysis acidification tank through the water inlet system, the water inlet system includes a water inlet pump and a water distributor; the water distributor is composed of a water inlet pipe and a perforated plate, wherein the water inlet pipe is connected to the water inlet pump, and the perforated plate is arranged on At the bottom of the hydrolytic acidification tank, the sewage enters the bottom of the perforated plate through the water inlet pump and the water inlet pipe. After the upflow is distributed through the perforated plate, it enters the hydrolytic acidification tank for hydrolysis and acidification, and the macromolecular components in the sewage are decomposed into small molecular components, which is beneficial to the subsequent unit treatment. Improve the substrate utilization efficiency and shorten the MFC start-up period, and the sewage will flow up into the anode chamber after hydrolysis and acidification.

Further, holes with a diameter of 10-15 mm are evenly distributed on the perforated plate, and elastic fillers are contained in the hydrolytic acidification tank.

Further, the lower part of the anode chamber has a packing supporting layer, and the upper part is provided with a three-phase separator, anaerobic granular sludge and granular activated carbon are placed on the packing supporting layer, and the three-phase separator is connected to a water-sealed tank, The water-sealed tank controls the pressure in the air chamber of the three-phase separator, so that the treatment efficiency of the three-phase separator is the highest, and the suspended solids are reduced after the treatment. The reactor does not need to set up a secondary settling tank. The hydraulic retention time of the chamber is 4-6h. After the mixed liquid in the anode chamber is separated from the gas-liquid-solid by the three-phase separator, the anaerobic granular sludge and granular activated carbon fall back to the anode chamber, and the water flow continues to rise into the cathode chamber.

Further, the particle size of the granular activated carbon is 3-6mm, the particle size of the anaerobic granular sludge is 3-6mm, the volume ratio of the two is 1:0.5-2, and the filler supporting layer is perforated stainless steel with a pore size less than 2mm board or HDPE board. The large specific surface area of granular activated carbon is conducive to bacterial attachment and electron transfer.

Further, the cathode chamber of the constructed wetland is filled with activated carbon and supported by a filler supporting layer. There are partitions, plants and water outlets above the cathode chamber of the constructed wetland, and the treated sewage is discharged from the outlet. The activated carbon The particle size is 4-8mm, and the cathode microorganisms can maintain a stable catalytic ability through self-reproduction, which can improve the stability of the MFC, and the microorganisms in the cathode can remove certain pollutants and improve the quality of the effluent.

Further, the cathode chamber of the constructed wetland is also connected with an aeration assembly, the aeration assembly includes an aerator and a perforated disk or a perforated tube connected thereto, the perforated disk or perforated pipe is located in the middle of the cathode chamber of the constructed wetland, when the plant produces When the oxygen is insufficient, use an aerator to aerate through a perforated plate or a perforated tube, and the air-to-water volume ratio is 3-20:1.

Further, the separator separates the wetland soil and plants from the filler in the cathode chamber of the constructed wetland; the selected plants are emergent plants, such as reeds, calamus, cattails or rushes, etc., and the planting density is 10-20 plants/m ^2. The selected separator is water-permeable strip cloth, etc.

Further, the resistance value of the resistor is 500-2000Ω, and the material used for the anode electrode and the cathode electrode is carbon felt.

Furthermore, the COD concentration of the influent sewage to be treated is not higher than 1500mg/L. If the COD concentration of the influent water is higher than 1500mg/L, it is advisable to carry out pretreatment before the device or adopt the effluent circulation, and mix and dilute with the raw water before entering the device. Avoid excessive anaerobic gas production and insufficient dissolved oxygen in wetlands when the concentration is too high;

The volume load rate of the sewage treatment device can reach 0.2-2.0kgCOD/m ³ .d, and the power generation power is 100-600mW/m ² .

Compared with the prior art, the present invention has the following advantages:

(1) The present invention is different from other existing microbial fuel cell sewage treatment devices, especially obviously different from the two-chamber microbial fuel cell reactor with proton exchange membrane, the present invention is without proton exchange membrane, integrated continuous flow Upflow wetland type microbial fuel cell reactor sewage treatment device.

(2) Before entering the microbial fuel cell, it goes through the hydrolytic acidification tank to decompose the macromolecular components in the sewage into small molecular components, which is beneficial to the subsequent unit treatment, can improve the substrate utilization efficiency and shorten the MFC start-up period, which is not available in other MFC devices This class is set.

(3) The hydraulic retention time of the anode reaction chamber is 4-6 hours, which is less than 8-12 hours in the conventional sewage treatment anaerobic reaction tank. The effect of using microbial fuel cell technology to improve the efficiency of the sewage treatment system and reduce the investment cost is more obvious.

(4) The anode chamber adopts a mixture of anaerobic granular sludge and granular activated carbon GAC and other fillers, which can increase the content of electricity-producing microorganisms and improve the efficiency of the anode reaction, which is obviously different from the anode chamber of other microbial fuel cell reactors.

(5) The wetland soil and plants are separated from the GAC filler in the cathode chamber with a separator, which avoids the problem of easy blockage of conventional constructed wetlands. The perforated tube coil/tube aeration is installed at the middle height of the cathode chamber, this design avoids the influence of oxygen on the anode chamber after aeration.

Description of drawings

Fig. 1 is the schematic diagram of continuous flow wetland type biocathode microbial fuel cell reactor sewage treatment device in embodiment 1, as shown in the label among the figure:

Inlet pump 1, water distributor 2, hydrolytic acidification tank 3, packing support layer 4, sampling port 5, anaerobic granular sludge 5, anode chamber 6, anode electrode 7, three-phase separator 8, aerator 9, Cathode electrode 10, separator 11, plant 12, resistor 13, water seal tank 14, water outlet 15.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example 1

As shown in Figure 1, a continuous flow wetland type microbial fuel cell reactor sewage treatment device includes a hydrolytic acidification tank (3), an anode chamber (6) and a constructed wetland cathode chamber arranged in sequence from bottom to top.

The sewage to be treated is input into the hydrolysis acidification tank (3) through the water inlet system, the water inlet system includes the water inlet pump (1) and the water distributor (2); the water distributor (2) is composed of the water inlet pipe and the perforated plate, wherein The water pipe is connected to the water inlet pump (1), the perforated plate is arranged at the bottom of the hydrolytic acidification tank (3), and holes with a diameter of 10mm are evenly distributed on the perforated plate, and the hydrolytic acidification tank (3) contains elastic fillers. Sewage enters the bottom of the perforated plate through the water inlet pump (1) and the water inlet pipe. After the upward flow is distributed through the perforated plate, it enters the hydrolysis acidification tank (3) for hydrolysis and acidification, and the macromolecular components in the sewage are decomposed into small molecular components. After hydrolysis and acidification, the sewage Upflow enters the anode chamber (6).

The anode chamber (6) is filled with fillers composed of anaerobic granular sludge and granular activated carbon, the filler is provided with an anode electrode (7), the lower part of the anode chamber is provided with a filler support layer 4, and the upper part is provided with a three-phase separator 8 , anaerobic granular sludge and granular activated carbon are placed on the packing support layer 4, the three-phase separator 8 is connected to the water-sealed tank 14, and the water-sealed tank 14 controls the pressure in the air chamber of the three-phase separator 8, and the water-sealed water pressure is 25cm , the particle size of granular activated carbon is 3-4mm, the particle size of anaerobic granular sludge is 3-4mm, the volume ratio of the two is 1:2, and the filler support layer 4 is a perforated stainless steel plate with a hole diameter of less than 2mm.

The cathode chamber of the constructed wetland is filled with activated carbon, supported by a filler support layer 4, a cathode electrode (10) is arranged in the activated carbon filler, a partition 11, a plant 12 and a water outlet 15 are arranged above the cathode chamber of the constructed wetland, and the activated carbon The particle size is 4-6mm, and the cathode chamber of the constructed wetland is also connected with an aeration component, which includes an aerator 9 and a perforated disk connected thereto. The perforated disk is located in the middle of the cathode chamber of the constructed wetland. , the aerator 9 is used to aerate through the perforated plate; the partition 11 separates the wetland soil and the plants 12 from the filler in the cathode chamber of the constructed wetland; the selected plants 12 are reeds, and the planting density is 10 plants/m ² , the selected partition The object is a transparent watercolor cloth.

The anode electrode (7) is connected to the cathode electrode (10) through a resistor (13); the resistance value of the resistor 13 of the device is 500Ω, and the material used for the anode electrode 7 and the cathode electrode 10 is carbon felt.

Using the above-mentioned continuous flow wetland type microbial fuel cell reactor sewage treatment device to treat simulated domestic sewage with a COD of 450 mg/L includes the following process steps:

1. The influent COD concentration of the treated sewage is 450mg/L, which is lower than 1500mg/L. It can be directly pumped into the device by the water inlet pump 1, and the water can be evenly distributed through the water inlet pipe and the water distributor 2. The water temperature is room temperature and does not need to be adjusted. After entering the hydrolytic acidification tank 3 for hydrolysis and acidification, the sewage rises and enters the anode chamber 6 for anodic reaction, and the hydraulic retention time of this chamber is 4h;

2. After the anode reaction, the gas-liquid-solid separation is carried out by the three-phase separator 8, and the water flow ascends into the cathode chamber of the constructed wetland. When the oxygen produced by the wetland plants is insufficient, it is necessary to use the aerator 9 to aerate through the perforated plate, and the gas The water ratio is 5:1, under the action of hydraulic shear generated by aeration, water flow and granular activated carbon, etc., the cathode reaction is sufficient;

3. Due to the high amount of biofilm in the reactor, the volumetric loading rate can reach 1.2kgCOD/m ³ .d after stable operation, which is higher than the conventional activated sludge method. The resistance 13 is a load of 500 ohms, and the power generation power is 100-200mW /m ² , the COD of water outlet 15 can be reduced to below 50mg/L.

Example 2

A continuous flow wetland type microbial fuel cell reactor sewage treatment device, the diameter of the uniformly distributed holes on the perforated plate of the water distributor 2 used is 12mm,

Its structure is the same as that of Example 1, the particle diameter of the granular activated carbon filled in the anode chamber is 4-6mm, the particle diameter of the anaerobic granular sludge is 4-6mm, the volume ratio of the two is 1:1, and the filler supporting layer 4 has a pore size smaller than 2mm perforated HDPE board. The water seal tank 14 controls the pressure in the air chamber of the three-phase separator 8, and the water seal water pressure is 35cm.

The particle size of the activated carbon filled in the cathode chamber of the constructed wetland is 6-8 mm. The plant 12 selected in the cathode chamber of the constructed wetland is calamus, and the planting density is 15 plants/m ² .

The resistance value of the resistor 13 is 1000Ω. All the other structures are with embodiment 1.

Using the above-mentioned continuous flow wetland type microbial fuel cell reactor sewage treatment device to treat simulated industrial sewage with a COD of 1200mg/L, the following process steps are included:

1. The influent COD concentration of the treated sewage is 1200mg/L, which is lower than 1500mg/L. It can be directly pumped into the device by the water inlet pump 1, and the water can be evenly distributed through the water inlet pipe and the water distributor 2. The water temperature is room temperature and does not need to be adjusted. Enter the hydrolytic acidification tank 3 for hydrolysis and acidification, and then the sewage rises and enters the anode chamber 6 for anodic reaction. The hydraulic retention time of this chamber is 6h;

2. After the anode reaction, the gas-liquid-solid separation is carried out by the three-phase separator 8, and the water flow ascends into the cathode chamber of the constructed wetland. When the oxygen produced by the wetland plants is insufficient, it is necessary to use the aerator 9 to aerate through the perforated plate, and the gas The water ratio is 15:1, under the action of hydraulic shear generated by aeration, water flow and granular activated carbon, etc., the cathode reaction is sufficient;

3. Due to the high amount of biofilm in the reactor, the volumetric load rate can reach 1.5kgCOD/m ³ .d after stable operation, which is higher than the load of conventional activated sludge method, the power generation power is 150-350mW/m ² , and the water outlet is 15 COD can be reduced to below 500mg/L.

Example 3

A continuous flow wetland type microbial fuel cell reactor sewage treatment device, the diameter of the uniformly distributed holes on the perforated plate of the water distributor 2 used is 15mm. The particle size of the granular activated carbon filled in the anode chamber is 3-6mm, the particle size of the anaerobic granular sludge is 3-6mm, the volume ratio of the two is 2:1, and the water seal tank 14 controls the water seal in the air chamber of the three-phase separator 8 The water pressure is 45cm, the particle size of activated carbon filled in the cathode chamber of the constructed wetland is 5-7mm, and the plants 12 selected in the cathode chamber of the constructed wetland are cattails, and the planting density is 20 plants/m ² . The resistance value of the resistor 13 is 2000Ω.

All the other structures are with embodiment 1.

Using the above-mentioned continuous flow wetland type microbial fuel cell reactor sewage treatment device to treat simulated industrial sewage with a COD of 2500mg/L, the following process steps are included:

1. The influent COD concentration of the treated sewage is higher than 1500mg/L, and the outlet water is circulated, mixed and diluted with raw water at 3:1, and then pumped into the device with the inlet pump 1 for treatment, and evenly distributed through the inlet pipe and water distributor 2 water. The water temperature is room temperature and does not need to be adjusted. Enter the hydrolytic acidification pool 3 for hydrolysis and acidification, and then the sewage rises and enters the anode chamber 6 for anodic reaction. The hydraulic retention time of this chamber is 6h;

2. After the anode reaction, the gas-liquid-solid separation is carried out by the three-phase separator 8, and the water flow ascends into the cathode chamber of the constructed wetland. When the oxygen produced by the wetland plants is insufficient, it is necessary to use the aerator 9 to aerate through the perforated plate, and the gas The water ratio is 20:1, under the action of hydraulic shear generated by aeration, water flow and granular activated carbon, etc., the cathode reaction is sufficient;

3. Due to the high amount of biofilm in the reactor, the volumetric load rate can reach 1.8kgCOD/m ³ .d after stable operation, which is higher than the load of conventional activated sludge method, the power generation power is 250-650mW/m ² , and the water outlet is 15 COD can be reduced to below 500mg/L.

Example 4

A continuous flow wetland type microbial fuel cell reactor sewage treatment device, the diameter of the uniformly distributed holes on the perforated plate of the water distributor 2 used is 10mm. The particle size of the granular activated carbon filled in the anode chamber is 3-5mm, the particle size of the anaerobic granular sludge is 3-5mm, the volume ratio of the two is 1:1.5, and the water seal tank 14 controls the water seal in the air chamber of the three-phase separator 8 The water pressure is 50cm, the particle size of the activated carbon filled in the cathode chamber of the constructed wetland is 4-6mm, the plant 12 selected in the cathode chamber of the constructed wetland is rush grass, and the planting density is 12 plants/m ² . The resistance value of the resistor 13 is 1500Ω.

All the other structures are with embodiment 1.

Using the above-mentioned continuous flow wetland type microbial fuel cell reactor sewage treatment device to treat simulated domestic sewage with a COD of 450 mg/L includes the following process steps:

1. The influent COD concentration of the treated sewage is 450mg/L, which is lower than 1500mg/L. It can be directly pumped into the device by the water inlet pump 1, and the water can be evenly distributed through the water inlet pipe and the water distributor 2. The water temperature is room temperature and does not need to be adjusted. Enter the hydrolytic acidification pool 3 for hydrolysis and acidification, and then the sewage rises and enters the anode chamber 6 for anodic reaction. The hydraulic retention time of this chamber is 5h;

2. After the anode reaction, the gas-liquid-solid separation is carried out by the three-phase separator 8, and the water flow ascends into the cathode chamber of the artificial wetland. When the oxygen produced by the wetland plants is insufficient, it is necessary to use the aerator 9 to aerate the air through the perforated tube. The water ratio is 3:1, under the action of hydraulic shear generated by aeration, water flow and granular activated carbon, etc., the cathode reaction is sufficient;

3. Due to the high amount of biofilm in the reactor, the volumetric load rate can reach 2.0kgCOD/m ³ .d after stable operation, which is higher than the load of conventional activated sludge method. The power generation power is 400-600mW/m ² , and the water outlet is 15°C. COD can be reduced to below 50mg/L.

The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the present invention. Changes, substitutions, modifications, and simplifications made by those of ordinary skill in the art within the essential scope of the present invention are all equivalent transformations. All of them do not deviate from the gist of the present invention, and should also belong to the protection scope of the claims of the present invention.

Claims (10)

1. a continuous flow wetland type microbial fuel cell reactor sewage treatment device is characterized in that the device comprises a hydrolytic acidification tank (3) arranged successively from bottom to top, an anode chamber (6) and a constructed wetland cathode chamber, the The anode chamber (6) is filled with fillers composed of anaerobic granular sludge and granular activated carbon, the filler is provided with an anode electrode (7), and the cathode chamber of the constructed wetland is filled with activated carbon, wherein a cathode electrode (10) is provided. , the anode electrode (7) is connected to the cathode electrode (10) through a resistor (13); the sewage to be treated enters the anode chamber (6) after being hydrolyzed and acidified from the bottom through the hydrolysis acidification pool (3), and flows out from the top after the reaction occurs Enter the cathode chamber of the artificial wetland to purify the sewage and generate electricity at the same time. 2. a kind of continuous flow wetland type microbial fuel cell reactor sewage treatment device according to claim 1 is characterized in that, the sewage to be treated is imported into the hydrolytic acidification tank (3) by the water inlet system, and the water inlet system includes the water inlet pump ( 1) and a water distributor (2); the water distributor (2) is composed of a water inlet pipe and a perforated plate, wherein the water inlet pipe is connected to the water inlet pump (1), and the perforated plate is arranged at the bottom of the hydrolysis acidification tank (3), and the sewage passes through The water inlet pump (1) and the water inlet pipe enter the lower part of the perforated plate. After the upflow is distributed through the perforated plate, it enters the hydrolytic acidification tank (3) for hydrolysis and acidification, and the macromolecular components in the sewage are decomposed into small molecular components. After hydrolysis and acidification, the sewage upflows Enter the anode chamber (6). 3. A continuous flow wetland type microbial fuel cell reactor sewage treatment device according to claim 2, characterized in that, the holes with a diameter of 10-15 mm are uniformly distributed on the perforated plate, and the hydrolytic acidification The pool (3) contains elastic fillers. 4. a kind of continuous flow wetland type microbial fuel cell reactor sewage treatment device according to claim 1, is characterized in that, described anode chamber bottom has filler supporting layer (4), and top is provided with three-phase separator ( 8), the anaerobic granular sludge and granular activated carbon are placed on the packing support layer (4), and the three-phase separator (8) is connected to the water-sealed tank (14), and the water-sealed tank (14) controls the three-phase separation The pressure in the air chamber of the device (8), the water seal water pressure is 25-50cm, the hydraulic retention time of this chamber is 4-6h, and the mixed liquid in the anode chamber is separated from the gas-liquid-solid by the three-phase separator (8), anaerobic The granular sludge and granular activated carbon fall back into the anode chamber (6), and the water flow continues to rise into the cathode chamber. 5. A kind of continuous flow wetland type microbial fuel cell reactor sewage treatment device according to claim 1, is characterized in that, the particle diameter of described granular activated carbon is 3-6mm, and the particle diameter of anaerobic granular sludge is 3mm. -6mm, the volume ratio of the two is 1:0.5-2. 6. A continuous flow wetland type microbial fuel cell reactor sewage treatment device according to claim 1, characterized in that, the cathode chamber of the constructed wetland uses activated carbon as a filler, and is supported by a filler supporting layer (4), A partition (11), a plant (12) and a water outlet (15) are arranged above the cathode chamber of the constructed wetland, and treated sewage is discharged from the water outlet (15), and the particle size of the activated carbon is 4-8mm. 7. A kind of continuous flow wetland type microbial fuel cell reactor sewage treatment device according to claim 6, is characterized in that, described constructed wetland cathode chamber is also connected with aeration assembly, and aeration assembly comprises aerator ( 9) and the perforated plate or perforated tube connected to it, the perforated plate or perforated tube is located in the middle of the cathode chamber of the constructed wetland, when the oxygen produced by the plant (12) is insufficient, the aerator (9) is used to aerate through the perforated plate or perforated tube , The gas-water volume ratio is 3-20:1. 8. according to a kind of continuous flow wetland type microbial fuel cell reactor sewage treatment device described in claim 6, it is characterized in that, described divider (11) wetland soil and plant (12) and constructed wetland cathode chamber The fillers are separated; the selected plants (12) are emergent plants, such as reeds, calamus, cattails or rushes, and the planting density is 10-20 plants/m ² . 9. A kind of continuous flow wetland type microbial fuel cell reactor sewage treatment device according to claim 1, is characterized in that, the resistance value of described resistance (13) is 500-2000Ω, and described cathode electrode (10 ) The material used is carbon felt. 10. A continuous flow wetland type microbial fuel cell reactor sewage treatment device according to claim 1, characterized in that the COD concentration of the influent sewage to be treated is not higher than 1500 mg/L, if the influent COD concentration is higher than 1500 mg /L, it is advisable to carry out pretreatment before the device or take the outlet water circulation, mix and dilute with raw water before entering the device; The volume load rate of the sewage treatment device can reach 0.2-2.0kgCOD/m ³ .d, and the power generation power is 100-600mW/m ² .