Microbial electrochemical device for advanced treatment of organic wastewater and simultaneous energy recovery

Abstract

The present application discloses a microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery, which relates to the field of microbial electrochemistry for wastewater treatment. The device comprises a chemical cathode, a first and a second bioanode, a biocathode, a first and a second diaphragm, a reaction space and an aeration device; two diaphragms separate the reaction space into a first and a second bioanode chamber and a biocathode chamber; the wastewater in the first bioanode chamber is infiltrated into the second bioanode chamber and into the biocathode chamber; the chemical cathode and the first bioanode are in the first bioanode chamber; the second bioanode is in the second bioanode chamber; the biocathode and the aeration device are in the biocathode chamber; the aeration device aerates the biocathode chamber; the chemical cathode and the first bioanode, the second bioanode and the biocathode form two closed loops; and energy is recovered twice through the two closed loops. The present application improves the efficiency of energy conversion and recovery.

Description

Technical Field

[0001] The present application relates to the field of microbial electrochemistry for wastewater treatment, and in particular to a microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery. Background Art

[0002] Water treatment technology based on the principle of microbial electrochemistry provides a means for the simultaneous generation of electricity during wastewater treatment. However, in existing microbial electrochemical water treatment devices, the air cathode microbial electrochemical device usually has a single-chamber configuration, and the interior of the chamber is an anaerobic environment, which is suitable for the degradation of high-concentration organic wastewater, but the effluent of the wastewater treated by it often cannot meet the discharge standards. The biocathode microbial electrochemical device usually has a dual-chamber configuration, with the chambers being an anaerobic environment and an aerobic environment respectively. After the organic wastewater is treated by the device, its effluent can meet the discharge standards. However, when this device is operated in a continuous flow mode (i.e., the wastewater flows through the chamber of the anaerobic environment and the chamber of the aerobic environment successively), since the chamber of the aerobic environment contains aerobic autotrophic bacteria, the chemical oxygen demand (COD) concentration of the device's influent is limited, that is, the influent COD concentration should not be too high. In this process, if the influent COD concentration is low, it will affect the activity of the bioanode microorganisms, thereby affecting the energy conversion efficiency of the water treatment process. During long-term operation, the entire system may even be paralyzed. Therefore, the wastewater treatment capacity of existing organic wastewater treatment devices is limited, and there are problems of low energy conversion efficiency and low energy recovery efficiency. Summary of the invention

[0003] The purpose of the present application is to provide a microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery, which is used to achieve deep degradation of high-concentration organic wastewater, improve energy conversion efficiency, and at the same time achieve higher energy recovery efficiency through graded recovery of electrical energy.

[0004] To achieve the above objectives, this application provides the following solutions:

[0005] The present application provides a microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery, comprising: a chemical cathode electrode, a first bioanode electrode, a second bioanode electrode, a biocathode electrode, a first diaphragm, a second diaphragm, a reaction space and an aeration device;

[0006] The first diaphragm and the second diaphragm divide the reaction space into three working chambers, namely the first bioanode chamber, the second bioanode chamber and the biocathode chamber; the organic wastewater is introduced into the reaction space of the microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery;

[0007] The first diaphragm is used to allow the organic wastewater in the first bioanode chamber to permeate into the second bioanode chamber; the second diaphragm is used to allow the organic wastewater in the second bioanode chamber to permeate into the biocathode chamber;

[0008] The chemical cathode electrode and the first bioanode electrode are both arranged in the first bioanode chamber; the second bioanode electrode is arranged in the second bioanode chamber; the biocathode electrode and the aeration device are both arranged in the biocathode chamber; the aeration device is used to aerate the biocathode chamber;

[0009] A first closed loop is formed between the chemical cathode electrode and the first biological anode electrode; when treating organic wastewater, the first biological anode electrode participates in the biological oxidation reaction of organic matter in the organic wastewater to generate electrons, and the electrons are transferred to the chemical cathode electrode through the first closed loop, and the electrons participate in the oxygen reduction reaction on the chemical cathode electrode to form an electric current for the first energy recovery;

[0010] A second closed loop is formed between the second bioanode electrode and the biocathode electrode; when treating organic wastewater, the second bioanode electrode participates in the biological oxidation reaction of organic matter in the organic wastewater to generate electrons, which are transferred to the biocathode electrode through the second closed loop. The electrons participate in the oxygen reduction reaction on the biocathode electrode to form an electric current for a second energy recovery.

[0011] Optionally, a water inlet and a water outlet are provided on the microbial electrochemical device for deep treatment of organic wastewater and simultaneous energy graded recovery; the water inlet is located above the first bioanode chamber; the water outlet is located above the biocathode chamber; when wastewater treatment is carried out, the organic wastewater enters the first bioanode chamber through the water inlet, then flows through the first diaphragm, the second bioanode chamber, the second diaphragm and the biocathode chamber, and then flows out of the microbial electrochemical device for deep treatment of organic wastewater and simultaneous energy graded recovery through the water outlet.

[0012] Optionally, the microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery further comprises: an electrode fixing plate, an electrode fixing clamping plate, a diaphragm fixing clamping plate and a device housing;

[0013] The interior of the device housing is the reaction space;

[0014] The electrode fixing clamp is used to fix the chemical cathode electrode to one side of the device housing;

[0015] The electrode fixing plate is used to fix the first bioanode electrode, the second bioanode electrode and the biocathode electrode inside the device housing;

[0016] The diaphragm fixing clamp is used to fix the first diaphragm and the second diaphragm inside the device housing.

[0017] Optionally, the thickness of the device housing is greater than or equal to 5 mm.

[0018] Optionally, the microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery further comprises: a first resistor and a second resistor;

[0019] The chemical cathode electrode and the first biological anode electrode are connected via the first resistor to form a first closed loop;

[0020] The second biological anode electrode and the biological cathode electrode are connected via the second resistor to form a second closed loop.

[0021] Optionally, the first membrane and the second membrane both include: a substrate and a biofilm attached to the substrate; the substrate and the biofilm are both water permeable.

[0022] Optionally, the substrate is a porous material; the pore size of the porous material is 1 μm to 2 mm.

[0023] Optionally, the first bioanode chamber is an anaerobic environment; the second bioanode chamber is an anoxic environment; and the biocathode chamber is an aerobic environment.

[0024] Optionally, functional microorganisms for carbon metabolism whose adapted concentration is greater than a set threshold are attached to the first bioanode electrode and the second bioanode electrode.

[0025] Optionally, aerobic autotrophic microorganisms and aerobic heterotrophic microorganisms are attached to the biocathode electrode.

[0026] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0027] The present application provides a microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery. The first diaphragm and the second diaphragm separate the reaction space in the microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery into the first bioanode chamber, the second bioanode chamber and the biocathode chamber, and the organic wastewater in the first bioanode chamber is infiltrated into the second bioanode chamber and the biocathode chamber. The chemical cathode electrode and the first bioanode electrode are both arranged in the first bioanode chamber; the second bioanode electrode is arranged in the second bioanode chamber; the biocathode electrode and the aeration device are both arranged in the biocathode chamber; the aeration device aerates the biocathode chamber. In the wastewater treatment process, the first bioanode chamber and the second bioanode chamber can realize the rapid degradation of COD in the organic wastewater, and the biocathode chamber can realize the deep degradation of residual COD in the organic wastewater. Finally, the entire device realizes the deep degradation of high-concentration organic wastewater, and improves the energy conversion efficiency. In addition, since the device is a coupling of two microbial electrochemical systems (three chambers), by forming a closed loop between the chemical cathode electrode and the first bioanode electrode and between the second bioanode electrode and the biocathode electrode, during the wastewater treatment process, the two closed loops can achieve graded output of electrical energy. Thus, the device can achieve deep treatment of high-concentration organic wastewater while achieving higher energy recovery efficiency through graded recovery of electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 This is a schematic diagram of a microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery in one embodiment of the present application;

[0030] Figure 2 A device optimization diagram of a microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery provided in another embodiment of the present application;

[0031] Figure 3 A list of wastewater treatment effects of a microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery provided in another embodiment of the present application;

[0032] Figure 4 This is a graph showing the output power density of two circuits of a microbial electrochemical device for deep treatment of organic wastewater and synchronous graded energy recovery provided in another embodiment of the present application.

[0033] Figure numerals: chemical cathode electrode-1, first bioanode electrode-2, second bioanode electrode-3, biocathode electrode-4, first diaphragm-5, second diaphragm-6, aeration device-7, first resistor-8, second resistor-9, water inlet-10, water outlet-11, first bioanode chamber-12, second bioanode chamber-13, biocathode chamber-14, device housing-15, electrode fixing plate-16, electrode fixing clamp-17, diaphragm fixing clamp-18. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0035] This application proposes a novel water treatment device that couples an air cathode microbial electrochemical system with a biological cathode microbial electrochemical system. By coupling the characteristics of the air cathode microbial electrochemical system for treating high-concentration organic wastewater with the characteristics of the biological cathode microbial electrochemical system for deep wastewater treatment, deep degradation of high-concentration organic wastewater is achieved in the device. In addition, since the device is a coupling of two microbial electrochemical systems (three chambers), the device can achieve efficient wastewater treatment and graded recovery of electrical energy, and the three chambers can form anaerobic, anoxic, and aerobic environments, similar to the classic anaerobic-anoxic-oxic (AAO) water treatment process, which can achieve efficient nitrogen removal during wastewater carbon removal.

[0036] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0037] In an exemplary embodiment, Figure 1 As shown, a microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery is provided, including: a chemical cathode electrode 1, a first bioanode electrode 2, a second bioanode electrode 3, a biocathode electrode 4, a first diaphragm 5, a second diaphragm 6, a reaction space and an aeration device 7.

[0038] The first diaphragm 5 and the second diaphragm 6 divide the reaction space into three working chambers, namely the first bioanode chamber 12, the second bioanode chamber 13 and the biocathode chamber 14; organic wastewater is introduced into the reaction space of the microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery.

[0039] The first diaphragm 5 is used to allow the organic wastewater in the first bioanode chamber 12 to penetrate into the second bioanode chamber 13 ; the second diaphragm 6 is used to allow the organic wastewater in the second bioanode chamber 13 to penetrate into the biocathode chamber 14 .

[0040] The chemical cathode electrode 1 and the first bioanode electrode 2 are both arranged in the first bioanode chamber 12; the second bioanode electrode 3 is arranged in the second bioanode chamber 13; the biocathode electrode 4 and the aeration device 7 are both arranged in the biocathode chamber 14; the aeration device 7 is used to aerate the biocathode chamber 14.

[0041] The device consists of two closed circuits:

[0042] (a) A first closed loop is formed between the chemical cathode electrode 1 and the first biological anode electrode 2; when treating organic wastewater, the first biological anode electrode 2 participates in the biological oxidation reaction of organic matter in the organic wastewater to generate electrons, which are transferred to the chemical cathode electrode 1 through the first closed loop, and the electrons participate in the oxygen reduction reaction on the chemical cathode electrode 1 to form a current for the first energy recovery. The chemical cathode electrode 1 can be made by rolling, phase conversion, etc., and the first biological anode electrode 2 can be made of materials such as carbon brushes, carbon felt, and carbon cloth, which are characterized by being conductive.

[0043] (b) A second closed loop is formed between the second bioanode electrode 3 and the biocathode electrode 4; when treating organic wastewater, the second bioanode electrode 3 participates in the biological oxidation reaction of organic matter in the organic wastewater to generate electrons, which are transferred to the biocathode electrode 4 through the second closed loop, and the electrons participate in the oxygen reduction reaction on the biocathode electrode 4 to form a current for the second energy recovery. The above two closed loops enable the device to have the characteristics of graded energy recovery. The second bioanode electrode 3 and the biocathode electrode 4 can be made of materials such as carbon brushes, carbon felt, and carbon cloth, which are characterized by being conductive.

[0044] In an exemplary embodiment, Figure 1As shown, the microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery is provided with a water inlet 10 and a water outlet 11; the water inlet 10 is located above the first bioanode chamber 12; the water outlet 11 is located above the biocathode chamber 14; when the wastewater is treated, the organic wastewater enters the first bioanode chamber 12 through the water inlet 10, then flows through the first diaphragm 5, the second bioanode chamber 13, the second diaphragm 6 and the biocathode chamber 14, and then flows out of the microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery through the water outlet 11.

[0045] In an exemplary embodiment, Figure 1 As shown, the microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery also includes: an electrode fixing plate 16 , an electrode fixing clamping plate 17 , a diaphragm fixing clamping plate 18 and a device housing 15 .

[0046] The interior of the device housing 15 is the reaction space.

[0047] The electrode fixing clamp 17 is used to fix the chemical cathode electrode 1 on one side of the device housing 15 .

[0048] The electrode fixing plate 16 is used to fix the first bioanode electrode 2 , the second bioanode electrode 3 and the biocathode electrode 4 inside the device housing 15 .

[0049] The diaphragm fixing clamp 18 is used to fix the first diaphragm 5 and the second diaphragm 6 inside the device housing 15 .

[0050] In an exemplary embodiment, the thickness of the device housing 15 is greater than or equal to 5 mm. In the device, the device housing 15 can be made of cheap polyvinyl chloride (PVC) and the like. To ensure the mechanical strength of the device, the thickness should be no less than 5 mm.

[0051] In an exemplary embodiment, Figure 1 As shown, the microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery also includes: a first resistor 8 and a second resistor 9.

[0052] The chemical cathode electrode 1 and the first biological anode electrode 2 are connected via the first resistor 8 to form a first closed loop.

[0053] The second biological anode electrode 3 and the biological cathode electrode 4 are connected via the second resistor 9 to form a second closed loop.

[0054] In an exemplary embodiment, the first membrane 5 and the second membrane 6 both include: a substrate and a biofilm attached to the substrate; the substrate and the biofilm are both water permeable.

[0055] In an exemplary embodiment, the substrate is a porous material; the pore size of the porous material is 1 μm to 2 mm, and the thickness is not limited. Common ones include filter cloth, filter cotton, carbon felt, microfiltration membrane, etc., and its typical feature is a two-dimensional or three-dimensional porous material. When the device is in operation, the substrate material can be used as a substrate for microorganisms to attach, allowing biofilms to attach thereon. This biofilm will be the core of the first diaphragm 5 and the second diaphragm 6. The community of the substrate and the biofilm attached thereto is characterized by water permeability, allowing water to flow through, and ensuring the internal hydraulic continuity of the device. In particular, the second diaphragm 6 (including the substrate and the biofilm attached thereto) also has the function of preventing dissolved oxygen from directly entering the second bioanode chamber 13 during aeration of the biocathode chamber 14. Considering the water permeability of the second diaphragm 6 and the aeration of the biocathode chamber 14, an internal circulation can be formed between the second bioanode chamber 13 and the biocathode chamber 14, and further the second bioanode chamber 13 forms an anoxic environment, so that the device has the function of denitrification and denitrification. The problem that the air cathode microbial electrochemical device cannot achieve effective wastewater denitrification due to the single anaerobic chamber is solved.

[0056] In an exemplary embodiment, the first bioanode chamber 12 is an anaerobic environment; the second bioanode chamber 13 is an anoxic environment; and the biocathode chamber 14 is an aerobic environment.

[0057] In an exemplary embodiment, functional microorganisms for carbon metabolism whose adapted concentration is greater than a set threshold are attached to the first bioanode electrode 2 and the second bioanode electrode 3 .

[0058] In an exemplary embodiment, aerobic autotrophic microorganisms and aerobic heterotrophic microorganisms are attached to the biocathode electrode 4 .

[0059] In the device, the first bioanode chamber 12 is an anaerobic environment, and the functional microorganisms attached to the first bioanode electrode 2 and the second bioanode electrode 3 are adapted to the metabolism of medium and high concentrations of carbon, and their suitable chemical oxygen demand (COD) concentration (COD concentration of the device inlet) can be relatively high, with a minimum threshold of 150 mg / L. The second bioanode chamber 13 is an anoxic environment, which can meet the metabolic environment needs of the functional microorganisms on the second bioanode electrode 3. The function of this chamber is to further reduce the COD concentration in the wastewater, with a minimum threshold of 150 mg / L. The biocathode chamber 14 is an aerobic environment, and the main function of the microorganisms attached to the biocathode electrode 4 is to catalyze the oxygen reduction reaction, and the microorganism category is aerobic autotrophic microorganisms. In actual operation, some aerobic heterotrophic microorganisms will also be attached to the biocathode electrode 4, which has the function of organic carbon metabolism, so that the biocathode chamber 14 has the function of deeply degrading the residual COD in the wastewater, and the deep treatment function of the wastewater can be realized.

[0060] In this device, the theoretical upper limit of the COD concentration of the wastewater to be treated is not limited, and the pollutant load of each chamber can be adjusted by adjusting the hydraulic retention time to meet the effluent standards. Figure 2 As shown, the working volume ratio of the first bioanode chamber 12, the second bioanode chamber 13, and the biocathode chamber 14 can also be adjusted, and the number of the first bioanode electrode 2, the second bioanode electrode 3, and the biocathode electrode 4 can be changed to further adjust the contribution ratio of different functional electrodes to pollutant removal to meet the effluent standards.

[0061] The embodiments of the present application have the following effects.

[0062] 1) This application is to design a new microbial electrochemical system with a coupled structure. During the wastewater treatment process, two circuit loops can achieve graded output of electrical energy.

[0063] 2) In the wastewater treatment process of the present application, the first bioanode chamber 12 and the second bioanode chamber 13 can achieve rapid degradation of COD in organic wastewater, and the biocathode chamber 14 can achieve deep degradation of residual COD in organic wastewater. Ultimately, the entire device can achieve deep degradation of high-concentration organic wastewater.

[0064] 3) In the wastewater treatment process of the present application, the first diaphragm 5 and the second diaphragm 6 are a community composed of a porous material and a biofilm attached thereto, and are permeable to water, thereby achieving hydraulic continuity within the entire device.

[0065] 4) In the device provided in the present application, since the second diaphragm 6 is water permeable and an aeration device 7 is provided inside the biocathode chamber 14, an internal circulation can be formed between the second bioanode chamber 13 and the biocathode chamber 14, further forming an anaerobic environment in the second bioanode chamber 13, and the biofilm attached to the second bioanode electrode 3 has the function of denitrification, thereby ultimately enabling the device provided in the present application to have the function of denitrification.

[0066] In summary, this application achieves the following effects.

[0067] 1) The advantage of this application is that a microbial electrochemical system with a coupled structure is proposed, which can achieve higher energy recovery efficiency through graded energy recovery during wastewater treatment.

[0068] 2) The advantage of this application is the coupling of different functional chambers, which can simultaneously achieve deep treatment of high-concentration organic wastewater and simultaneously achieve the functions of carbon removal and denitrification of wastewater.

[0069] An example of the application is: Figure 3 As shown in the figure, when the device is used for wastewater treatment, the hydraulic retention time is set to 24 hours, the influent COD concentration is 500 mg / L, the influent ammonia nitrogen concentration is 40 mg / L, the influent total nitrogen concentration is 50 mg / L, and the suspended solid concentration (SS) is 250 mg / L. This device can make the above four indicators meet the Class A standard in the "Pollutant Discharge Standard for Urban Wastewater Treatment Plants" (GB 18918-2002). Figure 4 As shown in the figure, the output powers of the corresponding biological cathode microbial electrochemical circuit and chemical cathode microbial electrochemical circuit are: 0.3W m –2 and 0.15W m –2 The device provided in this application can achieve deep treatment of wastewater, simultaneous carbon removal and denitrification, and at the same time achieve graded recovery of electrical energy.

[0070] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0071] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery, characterized in that: The microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery comprises: a chemical cathode electrode, a first bioanode electrode, a second bioanode electrode, a biocathode electrode, a first diaphragm, a second diaphragm, a reaction space and an aeration device; The first diaphragm and the second diaphragm divide the reaction space into three working chambers, namely the first bioanode chamber, the second bioanode chamber and the biocathode chamber; the organic wastewater is introduced into the reaction space of the microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery; The first diaphragm is used to allow the organic wastewater in the first bioanode chamber to permeate into the second bioanode chamber; the second diaphragm is used to allow the organic wastewater in the second bioanode chamber to permeate into the biocathode chamber; The chemical cathode electrode and the first bioanode electrode are both arranged in the first bioanode chamber; the second bioanode electrode is arranged in the second bioanode chamber; the biocathode electrode and the aeration device are both arranged in the biocathode chamber; the aeration device is used to aerate the biocathode chamber; A first closed loop is formed between the chemical cathode electrode and the first biological anode electrode; when treating organic wastewater, the first biological anode electrode participates in the biological oxidation reaction of organic matter in the organic wastewater to generate electrons, and the electrons are transferred to the chemical cathode electrode through the first closed loop, and the electrons participate in the oxygen reduction reaction on the chemical cathode electrode to form an electric current for the first energy recovery; A second closed loop is formed between the second bioanode electrode and the biocathode electrode; when treating organic wastewater, the second bioanode electrode participates in the biological oxidation reaction of organic matter in the organic wastewater to generate electrons, which are transferred to the biocathode electrode through the second closed loop, and the electrons participate in the oxygen reduction reaction on the biocathode electrode to form an electric current for a second energy recovery; The first bioanode chamber is an anaerobic environment; the second bioanode chamber is an anoxic environment; the biocathode chamber is an aerobic environment; the functional microorganisms attached to the first bioanode electrode and the second bioanode electrode are adapted to the metabolism of medium and high concentrations of carbon; the biocathode electrode is attached with aerobic autotrophic microorganisms and aerobic heterotrophic microorganisms; Taking into account the permeability of the second diaphragm and the aeration effect of the biocathode chamber, an internal circulation is formed between the second bioanode chamber and the biocathode chamber; by adjusting the working volume ratio of the first bioanode chamber, the second bioanode chamber, and the biocathode chamber, and changing the number of the first bioanode electrode, the second bioanode electrode, and the biocathode electrode, the contribution ratio of different functional electrodes to pollutant removal is adjusted.

2. The microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery according to claim 1 is characterized in that: The microbial electrochemical device for deep treatment of organic wastewater and simultaneous energy graded recovery is provided with a water inlet and a water outlet; the water inlet is located above the first bioanode chamber; the water outlet is located above the biocathode chamber; when treating wastewater, the organic wastewater enters the first bioanode chamber through the water inlet, then flows through the first diaphragm, the second bioanode chamber, the second diaphragm and the biocathode chamber, and then flows out of the microbial electrochemical device for deep treatment of organic wastewater and simultaneous energy graded recovery through the water outlet.

3. The microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery according to claim 1 is characterized in that: The microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery also includes: an electrode fixing plate, an electrode fixing clamping plate, a diaphragm fixing clamping plate and a device housing; The interior of the device housing is the reaction space; The electrode fixing clamp is used to fix the chemical cathode electrode to one side of the device housing; The electrode fixing plate is used to fix the first bioanode electrode, the second bioanode electrode and the biocathode electrode inside the device housing; The diaphragm fixing clamp is used to fix the first diaphragm and the second diaphragm inside the device housing.

4. The microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery according to claim 3 is characterized in that: The thickness of the device shell is greater than or equal to 5 mm.

5. The microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery according to claim 1 is characterized in that: The microbial electrochemical device for deep treatment of organic wastewater and synchronous energy classification recovery also includes: a first resistor and a second resistor; The chemical cathode electrode and the first biological anode electrode are connected via the first resistor to form a first closed loop; The second biological anode electrode and the biological cathode electrode are connected via the second resistor to form a second closed loop.

6. The microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery according to claim 1 is characterized in that: The first membrane and the second membrane both include: a substrate and a biofilm attached to the substrate; the substrate and the biofilm both have water permeability.

7. The microbial electrochemical device for deep treatment of organic wastewater and synchronous energy graded recovery according to claim 6 is characterized in that: The substrate is a porous material; the pore size of the porous material is 1 μm to 2 mm.

Images