Mobile microbial electrochemical module system for performance recovery of anaerobic digestion tanks

Abstract

The present invention relates to a mobile microbial electrochemical module system for restoring the performance of an anaerobic digester, and more specifically, to a mobile microbial electrochemical module system for restoring the performance of an anaerobic digester characterized by installing a mobile module body outside the anaerobic digester, decomposing polymeric substances in the digestion liquid circulating between the anaerobic digester and the mobile module body with electroactive microorganisms using voltage applied from the main unit to produce carbon dioxide and bicarbonate ions, and reducing the carbon dioxide and bicarbonate ions through electrochemical methane reduction to produce methane.

Description

Technology Field

[0001] The present invention relates to a mobile microbial electrochemical module system for restoring the performance of an anaerobic digester, and more specifically, to a system that improves methane production by decomposing high-molecular substances in the circulating digestate through a mobile microbial electrochemical module separately provided outside the anaerobic digester, and enables the restoration of the treatment performance of the anaerobic digester by responding quickly to problems that occur in the anaerobic digester.

[0002] In particular, the invention relates to a mobile microbial electrochemical module system capable of high-efficiency anaerobic digestion by activating electron transfer of methanogenic bacteria, wherein an oxidation electrode and a reduction electrode provided in the mobile microbial electrochemical module are assembled by being wound in a spiral manner with a certain spacing between them. Background Technology

[0003] Generally, high-concentration organic waste (sewage sludge, food waste, livestock manure, alcohol wastewater, landfill leachate, etc.) is decomposed through an anaerobic digestion process and can produce biogas (methane, etc.).

[0004] This anaerobic digestion process is largely composed of a hydrolysis process that decomposes high-molecular-weight organic substances into high-molecular-weight organic substances, an acid fermentation process that causes an acid-generating reaction to occur in an acid fermentation tank equipped with a stirrer to convert high-molecular-weight substances into organic acids, and a methane fermentation process that removes acid fermentation microorganisms dominant in the acid fermentation tank in a solid-liquid separation tank and digests organic substances containing acetic acid and alcohol introduced in an anaerobic digestion tank connected to the solid-liquid separation tank to produce biogas.

[0005] Here, various variables such as the concentration and load of organic acids and acid-fermenting microorganisms, pH in the reactor, concentration of VFAs (volatile fatty acids), and ammonia concentration affect the amount and content of biogas produced. In particular, since methane-producing bacteria have a slow growth rate and are sensitive to environmental changes, various problems arise during actual operation due to these factors.

[0006] The above problems included the difficulty of taking 2 to 9 months or more from the start of operation until methane production stabilized, the difficulty of smooth biogas production due to changes in the load and characteristics of the incoming substrate, and the problem of inhibiting the activity of methane-producing bacteria due to sensitivity to changes in pH, VFAs, temperature, toxic substances, etc.

[0007] Therefore, various methods have been proposed to overcome the aforementioned problems and maximize methane production. For example, in the hydrolysis process, pretreatment methods such as high temperature, high pressure, and ultrasound are used, while in the acid fermentation process, high-temperature acid fermentation and two-phase separation methods are applied.

[0008] In addition, various technologies such as microbial attachment media, addition of trace elements, improved stirring efficiency, and upward-flow anaerobic digestion have been introduced in the methane fermentation process, but these methods have not been established as clear solutions due to their respective limitations.

[0009] Recently, bio-electrochemical systems (BES), such as microbial fuel cells (MFCs) and microbial electrolytic cells (MECs), are attracting attention as sustainable new and renewable energy production technologies.

[0010] When such technology is applied to an anaerobic digester, not only is rapid decomposition of high-concentration organic waste possible, but VFAs, toxic substances, non-biodegradable substances, and even ammonia can also be decomposed through electrochemical reactions, and the amount of methane gas produced can be maximized through the electrochemical methane reduction of hydrogen and carbon dioxide.

[0011] Although the above BES can contribute to stable operation by maximizing methane production in anaerobic digesters and solving problems such as VFAs accumulation or pH reduction, most BES systems to date have been operated in small reactors on a lap-scale, and there have been no cases of their efficiency being proven through actual field application.

[0012] Furthermore, in order to apply it to existing anaerobic digesters, there was a major drawback in that it required destroying anaerobic conditions and installing a cell for electrochemical reaction within the reactor. Consequently, the inflow of organic waste, which varied according to the design standards and time periods of the existing anaerobic digesters, not only inhibited biogas production in the anaerobic digesters but also caused significant time and economic losses incurred in restoring the efficiency of the anaerobic digesters.

[0013] Therefore, in order to solve the problems of existing anaerobic digesters, a method to efficiently and economically apply BES must be sought, and there was a need for the development of technology that could rapidly restore biogas production efficiency by operating the anaerobic digester intermittently when problems occurred. Prior art literature

[0014] Republic of Korea Registered Patent Publication No. 10-0481699 'Electric field reaction device for water treatment' The problem to be solved

[0015] In order to solve the above problems, the present invention improves biogas production by decomposing polymeric substances in the circulating digestate through a mobile microbial electrochemical module separately provided outside the anaerobic digester, and enables rapid response to the occurrence of problems in the anaerobic digester to restore treatment performance.

[0016] In particular, the purpose is to provide a mobile microbial electrochemical module system for restoring the performance of an anaerobic digester capable of high-efficiency anaerobic digestion by activating electron transfer of methanogenic bacteria, wherein the oxidation electrode and reduction electrode provided in the mobile microbial electrochemical module are assembled by being wound in a spiral manner with a certain spacing between them.

[0017] In addition, the present invention aims to provide a mobile microbial electrochemical module system for restoring the performance of an anaerobic digester by installing a BES (microbial electrochemical system) in a side stream manner and monitoring problems occurring in the anaerobic digester (accumulation of VFAs (volatile fatty acids), decrease in pH, decrease in methane production and content, decrease in organic matter removal efficiency, etc.) in real time, thereby enabling the immediate recovery of the anaerobic digester's efficiency through intermittent side stream circulation. means of solving the problem

[0018] To achieve the above objectives, the mobile microbial electrochemical module system for restoring the performance of an anaerobic digester according to the present invention comprises:

[0019] A movable module (40) is installed outside the anaerobic digester (10), and the polymeric substances of the digestion liquid circulating between the anaerobic digester (10) and the movable module (40) are decomposed by electroactive microorganisms using voltage applied from the main unit (30) to produce carbon dioxide and bicarbonate ions, and the carbon dioxide and bicarbonate ions are reduced through electrochemical methane reduction to produce methane.

[0020] Additionally, the above-mentioned movable module body (40) comprises: a module body (50) disposed outside the anaerobic digester (10) and having an inlet (51) and an outlet (52) formed at both ends of a cylindrical structure; an electrode module (60) installed within the module body (50) to electrochemically react the flow rate circulated by the supplied voltage; a circulation line (55) in which the inlet (51) and the outlet (52) of the module body (50) are respectively connected to a supply line (16) and a drainage line (17) connected to the anaerobic digester (10) via a valve (V), thereby allowing the digestion liquid to circulate along the anaerobic digester (10) and the module body (50); a power supply unit (43) that supplies power to the electrode module (60); and a circulation pump (45) that circulates the digestion liquid of the anaerobic digester (10) and the module body (50). It may be configured to include a sensor unit (47) for monitoring the state of the digester liquid of the anaerobic digester (10) and the module body (50); and a main unit (30) for controlling the operation of the electrode module (60) and the movement of the digester liquid based on the data from the sensor unit (47).

[0021] Additionally, the electrode module (60) is configured to include an oxidation electrode section (61) in which electroactive microorganisms are attached and grown on the surface of the oxidation electrode to produce protons and carbon dioxide; a reduction electrode section (63) in which the protons and carbon dioxide are reduced to produce methane; and a spacer (62) installed between the oxidation electrode section (61) and the reduction electrode section (63), so that the electrode module (60) is wound in a spiral winding manner to form the oxidation electrode section (61) and the reduction electrode section (63) alternately, and can be assembled and configured inside the module body (50).

[0022] Additionally, the electrode module (60) may be configured such that a mixing hole is formed horizontally through one surface of the reduction electrode part (63) facing the oxidation electrode part (61), and an electrode plate fitting (65) having a ring shape is assembled in the mixing hole, so that the oxidation electrode part (61) and the reduction electrode part (63) are maintained at a certain distance from each other, and methane produced by reduction between the oxidation electrode part (61) and the reduction electrode part (63) by electrochemical reaction is moved through the electrode plate fitting (65) to the other side between the oxidation electrode part (61) and the reduction electrode part (63).

[0023] In addition, the electrode module (60) may have a gas movement groove (64) formed on one or both sides of an oxidation electrode part (61) and a reduction electrode part (63) arranged at regular intervals by a spacer (62), in which a shape among a rhombus, a square, and a hexagon is continuously repeated.

[0024] Additionally, the power supply unit (43) may be configured to apply a voltage of 0.2 to 0.9 V to the oxidation electrode unit (61) and the reduction electrode unit (63), such that the oxidation electrode unit (61) has a potential of -0.4 to -0.1 V and the reduction electrode unit (63) has a potential of 0.1 to 0.5 V.

[0025] Additionally, the sensor unit (47) may be configured to install a sensor in the anaerobic digester (10) that measures pH (hydrogen ion) concentration, VFAs (volatile fatty acid) concentration, and methane generation amount, and to transmit the measured sensor signal to the main unit (30) via wired or wireless means so that the movable module (40) operates in response to the processing signal of the calculation unit (32).

[0026] delete

[0027] Additionally, the main unit (30) may be configured to include: a storage unit (31) that receives a measurement value from a sensor unit (47) provided in an anaerobic digester (10); a calculation unit (32) that compares the measurement value of the storage unit (31) with a set value; a control unit (33) that operates a movable module (40) when the comparison value of the calculation unit (32) deviates from an allowable range; a display unit (34) that outputs the measurement value, set value, and comparison value to a display; and a communication unit (35) included in the control unit (33) that displays a buzzer or light signal when the comparison value deviates from an allowable range and transmits it to a designated contact network connected via a wired or wireless network. Effects of the invention

[0028] With the above-described solution, the present invention has the effect of improving biogas production by decomposing polymeric substances in the digestate circulated through a mobile microbial electrochemical module separately provided outside the anaerobic digester, and rapidly responding to the occurrence of problems in the anaerobic digester to restore treatment performance.

[0029] In particular, the oxidation electrode and reduction electrode provided in the mobile microbial electrochemical module are assembled by being wound in a spiral shape with a certain spacing between them, thereby activating electron transfer of methanogenic bacteria to enable high-efficiency anaerobic digestion, which has the effect of improving economic efficiency by increasing the removal efficiency of organic matter and VFAs and the amount of methane produced.

[0030] In addition, by installing a BES (microbial electrochemical system) in a side stream manner and monitoring in real time the problems occurring in the anaerobic digester (accumulation of VFAs (volatile fatty acids), decrease in pH, decrease in methane production and content, decrease in organic matter removal efficiency, etc.), it is possible to immediately restore the efficiency of the anaerobic digester through intermittent side stream circulation, which has excellent applicability to existing facilities and allows for the convenient improvement of treatment efficiency by connecting and installing multiple units as needed.

[0031] In addition, it is not operated during normal operation of the anaerobic digester, but operates intermittently in response to emergency situations regarding anaerobic digestion, such as a decrease in pH due to VFA accumulation, and changes in major factors such as COD and methane production, thereby promoting stable operation of the anaerobic digester.

[0032] Meanwhile, the effects described above are merely illustrative, and effects predicted or expected from the detailed configuration of the present invention from the perspective of a person skilled in the art may also be added to the effects unique to the present invention. Brief explanation of the drawing

[0033] FIG. 1 is an overall schematic diagram of a mobile microbial electrochemical module system for restoring the performance of an anaerobic digester according to the present invention. FIG. 2 is an enlarged perspective view of a key part of a movable module according to the present invention. FIG. 3 is a plan cross-sectional view of a movable module according to the present invention. FIG. 4 is a front enlarged view of the electrode portion according to the present invention. FIG. 5 is a block diagram illustrating the configuration of the main part according to the present invention. Specific details for implementing the invention

[0034] Examples of a mobile microbial electrochemical module system for restoring the performance of an anaerobic digester according to the present invention can be applied in various ways, and below, the most preferred embodiment will be described with reference to the attached drawings.

[0035] First, as shown in FIGS. 1 to 3, the microbial electrochemical module system described in the present invention is configured such that a movable module body (40) is installed outside the anaerobic digester (10), and the polymeric substances of the digestion liquid circulating between the anaerobic digester (10) and the movable module body (40) are decomposed by electroactive microorganisms using voltage applied from the main unit (30) to produce carbon dioxide and bicarbonate ions, and the carbon dioxide and bicarbonate ions are reduced through electrochemical methane reduction to produce methane.

[0036] Here, the movable module (40) is installed outside the existing installed anaerobic digester (10) and is operated to restore the performance of the anaerobic digester (10), and the anaerobic digester may include a reaction tank in which organic waste and anaerobic sludge are stored.

[0037] The above organic waste and anaerobic sludge oxidize the accumulated VFAs through biological or electrochemical reactions within the mobile module (40) or convert hydrogen ions, which cause a decrease in pH, into methane along with carbon dioxide.

[0038] The above existing anaerobic digester (10) is equipped with a stirrer for stirring organic waste and a motor for rotating the stirrer.

[0039] The movable module body (40) has an electrode module (60) inserted into a module body (50) that electrochemically reacts the treated water, which is largely placed outside the anaerobic digester (10), and the module body (50) is connected to the anaerobic digester (10) by a circulation line (55) so that the digested liquid is circulated.

[0040] The above circulation line (55) is configured such that the inlet (51) and outlet (52) of the above module body (50) are respectively connected to the supply line (16) and drainage line (17) connected to the anaerobic digester (10) through a valve (V), thereby allowing the digested liquid to circulate along the anaerobic digester (10) and the module body (50). The above valve (V) is configured to be openable and closed according to the application of the main part (30), and the configuration of such a valve can be applied in various ways according to the requirements of a person skilled in the art, so it is not limited to a specific one.

[0041] Additionally, the module body (50) has a cylindrical structure, and the inlet (51) and outlet (52) provided at both ends are connected to the supply line (16) and drainage line (17) connected to the anaerobic digester (10) respectively by a circulation line (55) including a valve (V), so that the module body (50) can be easily installed in the existing anaerobic digester (10), and a plurality of module bodies (50) can be connected using the circulation line (55) according to the processing capacity of the anaerobic digester (10), so that it can be used even when the fluctuation range of the inflow of treated water is high.

[0042] And, the electrode module (60) is installed within the cylindrical module body (50) to cause an electrochemical reaction in the digestion liquid circulated by the voltage applied from the main part (30), thereby oxidizing VFAs accumulated in organic waste and anaerobic sludge contained in the digestion liquid, or reducing hydrogen ions, which are the cause of pH reduction, into methane together with carbon dioxide.

[0043] Additionally, the electrode module (60) is configured to receive power to the oxidation electrode unit (61) and the reduction electrode unit (63) through the power supply unit (43) in accordance with the application of the main unit (30), and the main unit (30) is configured to control the operation of the electrode module (60) and the movement of the digestion liquid based on data measured by the sensor unit (47) which monitors the digestion liquid status of the anaerobic digester (10) and the module body (50).

[0044] In addition, the sensor unit (47) is configured such that sensors for measuring pH (hydrogen ion) concentration, VFAs (volatile fatty acid) concentration, and methane generation amount are installed in the anaerobic digester (10), drainage line (17), and methane discharge pipe, and the measured sensor signals are transmitted to the main unit (30) via a wired or wireless network so that the movable module (40) is operated by the processing signal of the computation unit (32).

[0045] The main unit (30) is configured to include a storage unit (31) that receives a measurement value from a sensor unit (47) provided in an anaerobic digester (10) as shown in FIG. 5 and stores it in a database, a calculation unit (32) that compares the measurement value of the storage unit (31) with a setting value stored in the database, a control unit (33) that operates a movable module (40) when the comparison value obtained by comparing the measurement value and the setting value in the calculation unit (32) is outside the allowable range and stops the operation of the movable module (40) when it is within the allowable range, a display unit (34) that outputs the measurement value, setting value, and comparison value to a display so that a worker can recognize them, and a communication unit (35) included in the control unit (33) that displays a buzzer or light signal when the comparison value is outside the allowable range so that a worker can recognize an emergency situation and transmits the situation to a designated contact network connected via a wired or wireless network.

[0046] In addition, the present invention includes automating the process so that the digestion liquid of the anaerobic digester (10) is supplied to the mobile module (40) through the control unit (33) included in the main unit (30), and power from the power supply unit (43) is supplied to the electrode module (60) housed inside the mobile module (40) to oxidize the accumulated VFAs through electrochemical reactions of organic waste and anaerobic sludge contained in the digestion liquid, or reduce hydrogen ions, which are the cause of pH reduction, into methane together with carbon dioxide, and then circulate and discharge it back to the anaerobic digester (10).

[0047] That is, when the measurement value of the sensor unit (47) of the main unit (30) deviates from the allowable range, the power supply unit (43) automatically supplies voltage to the electrode module (60) of the movable module body (40) through the control unit (33) to carry out the methane reduction operation. As an example, the power supply unit (43) applies a voltage of 0.2 to 0.9 V to the oxidation electrode unit (61) and the reduction electrode unit (63).

[0048] At this time, the potential applied to the oxidation electrode (61) is configured to be -0.4 to -0.1 V, and the potential applied to the reduction electrode (63) is configured to be 0.1 to 0.5 V, thereby ensuring safety of the treatment efficiency, and at the same time, organic waste is oxidized by the oxidation electrode (61) to generate electrons and hydrogen ions, and the electrons move to the reduction electrode (63).

[0049] More specifically, on the surface of the oxidation electrode (61), organic acids, etc., which are products of the acid-generating reaction, are electrochemically decomposed to produce cations such as hydrogen ions, electrons, and carbon dioxide, and on the surface of the reduction electrode (63), the generated cations such as hydrogen ions, electrons, and carbon dioxide are converted into methane.

[0050] And, the electrode module (60) comprises an oxidation electrode part (61) in which electroactive microorganisms are attached and grown on the surface of the oxidation electrode to produce protons and carbon dioxide, a reduction electrode part (63) in which the protons and carbon dioxide are reduced to produce methane, and a spacer (62) installed between the oxidation electrode part (61) and the reduction electrode part (63).

[0051] Additionally, the electrode module (60) is wound in a spiral wound manner as shown in FIG. 3, and the oxidation electrode part (61) and reduction electrode part (63) are maintained at a constant distance from each other by a spacer (62) and are formed to alternately repeat, so that they are more easily assembled inside the module body (50).

[0052] That is, the electrode module (60) has a flexible oxidation electrode part (61) and a reduction electrode part (63) fixed to both sides of a spacer (62) and spaced apart by a certain distance. When rotated in one direction with one end as a reference axis and the other end as a rotation axis, the electrode module (60) is wound in a spiral shape like a whirlwind, and is inserted in a sequence such as an oxidation electrode part connected to a positive electrode, a reduction electrode part connected to a negative electrode, an oxidation electrode part, and a reduction electrode part, so that an electrochemical reaction occurs over a wider area in the treated water moving along the module body (50).

[0053] In addition, the oxidation electrode part (61) of the electrode module (60) is provided with a positive electrode connection part (61a) that is electrically connected to a positive electrode on one side, and the reduction electrode part (63) is provided with a negative electrode connection part (63a) that is electrically connected to a negative electrode on one side, so that voltage supply from the power supply part (43) is made easier.

[0054] At this time, as an embodiment of the present invention, a mixing hole penetrating in the horizontal direction is formed on one side of the reduction electrode part (63) facing the oxidation electrode part (61), and an electrode plate fitting (65) having a ring shape is assembled in the mixing hole so that the oxidation electrode part (61) and the reduction electrode part (63) are maintained at a certain distance, and methane produced by reduction between the oxidation electrode part (61) and the reduction electrode part (63) by electrochemical reaction moves through the electrode plate fitting (65) to the other side between the oxidation electrode part (61) and the reduction electrode part (63), and the treated water moves mixed, thereby improving the oxidation of VFAs and the methane reduction efficiency of hydrogen ions and carbon dioxide.

[0055] In addition, the present invention includes forming a gas crushing projection protruding outwardly from the upper part of the mixing hole of the oxidation electrode part (61) and the reduction electrode part (63), thereby further improving the reduction efficiency by catching carbon dioxide and methane gas moving up and down in the treated water on the gas crushing projection and destroying the bubbles.

[0056] In addition, the electrode module (60) has a gas passage groove (64) formed on one or both sides of an oxidation electrode part (61) and a reduction electrode part (63) that are arranged facing each other at a certain distance by a spacer (62), with a shape of a rhombus, square, or hexagon being continuously repeated as shown in FIG. 4, so that the production capacity of methane gas can be improved by increasing the electrochemical reaction area.

[0057] In addition, the oxidation electrode part (61) and the reduction electrode part (63) of the electrode module (60) are manufactured using a metal containing an electrically conductive material and are coated to increase corrosion resistance and chemical resistance so as to prevent damage to the electrode module even if the treated water is ionized. Since the composition of the metal applied to the electrode module and the plating material can be varied according to the requirements of those skilled in the art, they are not limited to a specific material.

[0058] Additionally, the spacer (62) and the electrode plate fitting (65) can be manufactured using Teflon, a material with excellent chemical resistance, heat resistance, and hydrophobicity, but it is also possible to use a material that can insulate between the oxidation electrode part (61) and the reduction electrode part (63), such as silicone or synthetic resin.

[0059] The mobile microbial electrochemical module system for restoring the performance of an anaerobic digester according to the present invention has been described above. It will be understood by those skilled in the art to which the present invention pertains that the technical configuration of the present invention can be implemented in other specific forms without altering the technical concept or essential features of the present invention.

[0060] Therefore, the embodiments described above should be understood as exemplary in all respects and not limiting. Explanation of the symbols

[0061] 10: Anaerobic digester 16: Feed line 17 : Drainage line 30 : Main part 40 : Mobile modular unit 45 : Circulation pump 47 : Sensor unit 50 : Module body 55 : Circulation line 60 : Electrode module 61: Oxidation electrode 62: Spacer 63: Reduction electrode section 64: Gas transfer groove

Claims

Claim 1 A mobile microbial electrochemical module system for restoring the performance of an anaerobic digester, wherein a mobile module is installed outside the anaerobic digester, and electroactive microorganisms decompose high-molecular substances in the digestion liquid circulating between the anaerobic digester and the mobile module using a voltage applied from a main unit to produce carbon dioxide and bicarbonate ions, and produce methane through electrochemical methane reduction, wherein the mobile module comprises: a module body disposed outside the anaerobic digester and having an inlet and an outlet formed at both ends of a cylindrical structure; and an electrode module installed within the module body to electrochemically react the flow rate circulating by the supplied voltage. A circulation line in which the inlet and outlet of the module body are respectively connected to a supply line and a drainage line connected to an anaerobic digester via valves, thereby allowing the digestion liquid to circulate along the anaerobic digester and the module body; a power supply unit that supplies power to the electrode module; a circulation pump that circulates the digestion liquid in the anaerobic digester and the module body; and a sensor unit that monitors the state of the digestion liquid in the anaerobic digester and the module body. A mobile microbial electrochemical module system for restoring the performance of an anaerobic digester, comprising a main unit that controls the operation of the electrode module and the movement of the digestion liquid based on data from the sensor unit, wherein the electrode module comprises: an oxidation electrode unit in which electroactive microorganisms are attached and grown on the surface of the oxidation electrode to produce protons and carbon dioxide; a reduction electrode unit in which the protons and carbon dioxide are reduced to produce methane; and a spacer installed between the oxidation electrode unit and the reduction electrode unit, wherein the electrode module is wound in a spiral winding manner to form the oxidation electrode unit and the reduction electrode unit alternately, and is assembled and configured inside the module body, and further wherein the electrode module is characterized by having gas movement grooves formed repeatedly in a shape among a rhombus, a square, and a hexagon on one or both sides of the oxidation electrode unit and the reduction electrode unit. Claim 2 delete Claim 3 delete Claim 4 A mobile microbial electrochemical module system for restoring the performance of an anaerobic digester, characterized in that, in claim 1, the electrode module forms a mixing hole penetrating horizontally on one surface of an oxidation electrode and a reduction electrode, and an electrode plate fitting having a ring shape is assembled in the mixing hole so that methane produced by reduction between the oxidation electrode and the reduction electrode by an electrochemical reaction is moved through the electrode plate fitting to the other side between the oxidation electrode and the reduction electrode while maintaining a certain distance between the oxidation electrode and the reduction electrode. Claim 5 delete Claim 6 A mobile microbial electrochemical module system for restoring the performance of an anaerobic digester, characterized in that, in claim 1, the power supply unit applies a voltage of 0.2 to 0.9 V to an oxidation electrode and a reduction electrode, wherein the oxidation electrode has a potential of -0.4 to -0.1 V and the reduction electrode has a potential of 0.1 to 0.5 V. Claim 7 A mobile microbial electrochemical module system for restoring the performance of an anaerobic digester, characterized in that, in claim 1, the sensor unit installs a sensor that measures pH, VFAs (volatile fatty acids) concentration, and methane generation amount in the anaerobic digester, transmits the measured sensor signal to the main unit via wired or wireless means, and is configured so that the mobile module operates in response to the processing signal of the computation unit. Claim 8 delete Claim 9 A mobile microbial electrochemical module system for restoring the performance of an anaerobic digester, characterized in that, in claim 1, the main unit comprises: a storage unit that receives a measurement value from a sensor unit equipped in an anaerobic digester; a calculation unit that compares the measurement value from the storage unit with a set value; a control unit that operates a mobile module when the comparison value from the calculation unit deviates from an allowable range; a display unit that outputs the measurement value, set value, and comparison value to a display; and a communication unit included in the control unit that displays a buzzer or light-emitting signal and transmits it to a designated contact network connected via a wired or wireless network when the comparison value deviates from an allowable range.

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