Internal circulation sludge electrolysis system and application thereof in self-heating microaerobic stabilization of sludge

Abstract

The invention discloses an internal circulation sludge electrolysis system and application of the internal circulation sludge electrolysis system in sludge self-heating microaerobic stabilization, and belongs to the technical field of excess sludge treatment of urban sewage factories, the internal circulation sludge electrolysis system comprises an electrolytic tank and a digestion tank which are connected in series; wherein a sludge discharge port of the electrolytic tank comprises reticular zero-valent iron, and the area of the reticular zero-valent iron is 1 / 3 of the area of the electrolytic tank. The invention also provides an application of the internal circulation sludge electrolysis system in sludge self-heating microaerobic stabilization. According to the invention, the self-heating micro-aerobic digestion stabilization rate of the sludge can be obviously improved, and the volume of a digestion device for treating unit mass of dry sludge is reduced by more than half, so that the capital construction facility construction cost and the occupied area of a city with land shortage are reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of excess sludge treatment in urban sewage plants, and in particular relates to an internal circulation sludge electrolysis system and application thereof in sludge self-heating micro-aerobic stabilization. Background Art

[0002] Sludge is an important byproduct in the biological treatment of sewage. With the acceleration of urbanization and the development of industrialization in my country, the amount of sludge generated by sewage treatment plants has increased year by year. It is estimated that by 2025, the amount of sludge with a water content of 80% in my country will exceed 90 million tons, and the pressure of treatment and disposal is huge. In addition, sludge contains a large amount of organic matter, pathogenic microorganisms, heavy metals and other harmful substances. If it is not effectively treated and disposed of, it will pose a serious threat to the environment and human health. Stabilization treatment is an important means of sludge reduction and harmlessness, and it is also an important link in sludge treatment and disposal. Commonly used sludge stabilization technologies can be divided into: chemical stabilization method (such as lime stabilization method and chlorine oxidation method), physical stabilization method (such as heat treatment method) and biological stabilization method (such as anaerobic digestion, aerobic digestion and high temperature composting). Among them, biological stabilization method is widely used due to its low operating cost, safety and reliability. However, the existing biological stabilization technology has problems such as low stabilization efficiency, long treatment time and large equipment footprint.

[0003] At present, the application of electrochemical technology and microaerobic technology in sludge treatment has gradually attracted attention. For example, patent CN201410203930.7 discloses a method for improving the biological stabilization rate of sewage plant sludge. By applying a DC voltage of 0.3-1.5V in the aerobic digestion system, the time required for sludge stabilization is 10 to 15 days. However, although these enhanced technologies can enhance the sludge stabilization process to a certain extent, it is still difficult to meet the requirements for sludge treatment and disposal in large cities with limited land.

[0004] Therefore, how to provide a coupling process based on a side-flow internal circulation electrolysis system and self-heating micro-aerobic digestion to further improve the sludge stabilization rate is a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0005] In order to solve the technical problems existing in the prior art such as high ammonia nitrogen concentration, slow stabilization rate, long cycle, weak microbial metabolic activity, etc. in the process of sludge self-heating high-temperature aerobic stabilization, the present invention proposes an internal circulation sludge electrolysis system and its application in sludge self-heating micro-aerobic stabilization, so as to improve the sludge biological stabilization rate and significantly shorten the sludge stabilization cycle, so as to provide technical support for small and medium-sized sewage treatment plants with limited land and using biological methods to stabilize sludge.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] An internal circulation sludge electrolysis system comprises an electrolytic cell and a digestion tank connected in series;

[0008] Wherein, the mud discharge port of the electrolytic cell includes a mesh of zero-valent iron, and the area of ​​the mesh of zero-valent iron is 1 / 3 of the area of ​​the electrolytic cell.

[0009] The term "electrolytic cell area" in the present invention refers to the area of ​​a surface parallel to the electrolytic plate in a rectangular parallelepiped electrolytic cell. As shown in the figure, 1 refers to the height×width of the electrolytic cell.

[0010] Preferably, the ratio of the effective volume of the electrolytic cell to that of the digestion tank is 1:5 to 1:10.

[0011] Beneficial effects: The biological stabilization process of sludge is actually a process in which the chemoheterotrophic microorganisms in the sludge use the biodegradable organic matter in the sludge as a carbon source and continuously carry out metabolic degradation. Among them, the protein in the sludge organic matter is continuously degraded to generate macromolecular amino acid compounds, which are then hydrolyzed to generate free ammonia. Studies have shown that the ammonia nitrogen concentration in the system of 500-800 mg / L will have an inhibitory effect on the metabolic activity of microorganisms, thereby affecting the biological stabilization process of the sludge. The internal circulation electrolysis system proposed in the present invention, on the one hand, can directly convert the ammonia nitrogen compounds produced in the self-heating microaerobic process of the sludge into nitrogen gas under the action of electrochemistry and release, thereby reducing the free ammonia concentration in the sludge digestion system and relieving its inhibitory effect on microorganisms; on the other hand, the active oxygen species or active chlorine species produced in the electrolysis process are used to break the sludge cells, release the contents therein, increase the concentration of biodegradable substrates in the system, increase the metabolic activity of microorganisms, and accelerate the sludge stabilization process. In addition, the mesh zero-valent iron structure arranged near the sludge discharge port in the internal circulation electrolysis system can utilize the strong reducing property of zero-valent iron to eliminate the active oxygen species or active chlorine species in the sludge discharged from the electrolysis system, reduce their harmful effects on the sludge microorganisms in the self-heating microaerobic digestion system, maintain their metabolic activity, and further provide a stabilization effect for the sludge in the side-flow internal circulation electrolysis and self-heating microaerobic coupling system.

[0012] Preferably, the electrolytic cell further comprises an electrolytic plate, and the electrolytic plate comprises a cathode electrode and an anode electrode;

[0013] Wherein, the electrolytic plate is suspended and fixed in the electrolytic cell;

[0014] The distance between the cathode electrode and the anode electrode is 0.5-1.5 cm.

[0015] Beneficial effects: The choice of the distance between the plates is very important, which is related to the electrolysis treatment effect and the energy consumption of the system operation. In actual use, different groups should be set according to the size of the electrolytic cell (one group represents the positive and negative electrodes with a plate distance of 0.5-1.5 cm). If the electrode spacing is too close, it may cause a short circuit, making it impossible for the current to pass through the electrolyte effectively, thereby reducing the current efficiency. On the contrary, if the distance is too far, it may increase the resistance, resulting in energy loss, and also reduce the current efficiency. In addition, the distance between the anode and the cathode will also affect the mass transfer rate and the electrode reaction rate during the electrolysis process, thereby affecting the current. The present invention selects 0.5-1.5cm as a more appropriate range during the sludge electrolysis process.

[0016] Preferably, the cathode electrode is a titanium electrode;

[0017] The anode electrode is a titanium-plated ruthenium-iridium electrode.

[0018] Beneficial effects: The titanium-plated ruthenium-iridium electrode as the anode has strong corrosion resistance and excellent chemical stability. It can be used for a long time in a harsh chemical environment without being corroded. It has high catalytic activity, promotes the electrochemical reaction, and improves the current efficiency and reaction rate. It has a relatively long service life, which can reduce the frequency of electrode replacement and the cost of use. It has good conductivity, ensuring that the current can be transmitted stably and efficiently.

[0019] Preferably, the electrolytic plate is suspended and fixed in the electrolytic cell, and the area of ​​the electrolytic plate is 1 / 2-2 / 3 of the electrolytic cell.

[0020] More preferably, a stirring device may be added to the bottom of the electrolytic cell, which is more conducive to the uniformity of the electrolysis system.

[0021] The invention discloses an application of an internal circulation sludge electrolysis system in sludge self-heating micro-aerobic stabilization.

[0022] A sludge self-heating micro-aerobic stabilization method, using the above-mentioned internal circulation sludge electrolysis system, specifically includes the following steps:

[0023] The sludge is placed in a self-heating micro-aerobic digester for stabilization, and then placed in an electrolytic cell including the internal circulation sludge electrolysis system, and the sludge is electrolyzed by a stabilized power supply, and the stabilization and electrolysis are internally circulated until the sludge is stabilized.

[0024] Preferably, the sludge is sludge discharged from a primary sedimentation tank and a secondary sedimentation tank of a sludge treatment, and has a solid content of 3-5%.

[0025] Beneficial effects: When the solid content of the sludge stabilized by self-heating micro-aerobic sludge is low, one is that the sludge treatment efficiency is low, the second is that the heat generated by the reaction is insufficient, resulting in the inability to achieve the self-heating function of the system; third, if the solid content is high, although the treatment rate is improved, the sludge viscosity increases, and the mass transfer and heat transfer effects of the system decrease. At that time, the biochemical reaction is not complete, ammonia nitrogen and organic acids accumulate, inhibiting the activity of related microorganisms, resulting in low system reaction efficiency.

[0026] Preferably, the voltage of the electrolysis is 6-8V, and the electrolysis time is 30-60min.

[0027] Beneficial effects: Within the voltage range of 6-8V, the electrolysis process can usually be carried out in a relatively efficient manner, neither too high to increase energy consumption nor too low to slow down the electrolysis reaction rate. It helps to control energy consumption costs and make the electrolysis process more economically feasible. Compared with higher voltages, the electrolysis voltage of 6-8V is usually safer during operation, reducing potential risks such as electric shock. Importantly, this voltage range can effectively destroy the sludge floc structure, the incomplete structure of some microbial cells, promote the release of soluble organic matter, provide a reaction matrix for subsequent self-heating microaerobic stabilization, and increase the reaction rate. If the voltage is too low, it will not destroy the flocs and microbial cells. If the voltage is too high, the microorganisms will be destroyed too much, and the subsequent microbial metabolic activity will be inhibited, which is not conducive to the reaction. Therefore, 6-8V is a more suitable range.

[0028] Preferably, during the stabilization process, the stabilization temperature is 55° C., the sludge stirring speed is 150-250 rpm, and the aeration intensity is 100-300 ml air / L sludge·min.

[0029] Beneficial effects: The activity of microorganisms will be enhanced at 55°C, thereby accelerating the decomposition process of organic matter, and can promote faster reproduction and metabolism of microorganisms, thereby improving the efficiency of digestion. In addition, the high temperature environment helps to kill or inhibit the growth of harmful microorganisms and pathogens, reducing the risk of pollution during the digestion process. This is especially important for the treatment of organic waste containing pathogens or harmful microorganisms. During the autothermal high-temperature aerobic digestion process, the community structure of microorganisms will gradually stabilize, forming a dominant bacterial community that adapts to the high temperature environment. This helps to improve the stability and impact resistance of the digestive system. Therefore, if the temperature is low, the reaction rate decreases, resulting in a decrease in the stabilization level. If the temperature is too high, the protein in the microbial cell body will denature, affecting metabolism and microbial activity.

[0030] Preferably, the internal circulation time is 6-8 days.

[0031] Beneficial effects: The method provided by the present invention can significantly improve the metabolism of microorganisms by reducing the concentration of ammonia nitrogen in the self-heating microaerobic digestion system, reducing its inhibitory effect on the metabolic activity of microorganisms, and eliminating the harmful effects of oxygen-active or chlorine-active substances on microorganisms in the self-heating microaerobic system through the reduction of zero-valent iron, thereby promoting the biological stabilization of sludge. Compared with the self-heating microaerobic digestion system alone and the system without the mesh zero-valent iron structure, the sludge stabilization time of the electrolysis system (with mesh zero-valent iron) and the self-heating microaerobic digestion process coupling system was reduced from 16 days and 12 days to 6-8 days, respectively.

[0032] Compared with the prior art, the present invention has the following advantages and technical effects:

[0033] The present invention places the sludge discharged from the primary sedimentation tank and the secondary sedimentation tank and having a solid content of 3-5% after being concentrated into the sludge self-heating micro-aerobic digestion device, and places it into the electrolysis system in an internal circulation manner using a sludge pump, and then enters the self-heating micro-aerobic digestion device, and repeats the cycle until the sludge reaches the stabilization effect specified in the "Pollutant Discharge Standard for Urban Sewage Treatment Plants" (GB18918-2002), and the required time is only 6-8 days, thereby achieving the promotion of the stabilization speed of the sludge self-heating micro-aerobic digestion. The present invention can significantly improve the stabilization rate of the sludge self-heating micro-aerobic digestion, so that the volume of the digestion device for processing unit mass of dry sludge is reduced by more than half, thereby reducing the infrastructure construction cost and floor area in cities with limited land use. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0035] Figure 1 This is a process flow chart of the internal circulation sludge electrolysis system in the present invention. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] Unless otherwise specified, the "stabilization" in the embodiments of the present invention is in compliance with the provisions of the Pollutant Discharge Standard for Urban Wastewater Treatment Plants (GB18918-2002).

[0039] Example 1

[0040] An internal circulation sludge electrolysis system, such as Figure 1 As shown, it includes an electrolytic cell and a digestion tank connected in series;

[0041] The mud outlet of the electrolytic cell is connected to the mud inlet of the digestion tank through a mud inlet pipe; the bottom of the digestion tank is connected to the mud inlet of the electrolytic cell through a reflux pipe;

[0042] Both the inlet pipe and the return pipe include sludge pumps;

[0043] A meshed zero-valent iron is provided at the sludge outlet of the electrolytic cell.

[0044] The digester also includes an exhaust port, a sludge outlet, and an aerator;

[0045] Among them, the exhaust port is located at the top of the digester, and the mud discharge port is connected to the aerator installed at the bottom of the digester.

[0046] The electrolytic cell is provided with an electrolytic plate, which includes a cathode electrode and an anode electrode;

[0047] The electrolytic plates are suspended and fixed in the electrolytic cell.

[0048] The cathode electrode is a titanium electrode;

[0049] The anode electrode is a titanium-plated ruthenium-iridium electrode.

[0050] The electrolytic plates are suspended and fixed in the electrolytic cell.

[0051] Comparative Example 1

[0052] An internal circulation electrolytic cell (without meshed zero-valent iron) comprises an electrolytic cell and a digestion tank connected in series;

[0053] The mud outlet of the electrolytic cell is connected to the mud inlet of the digestion tank through a mud inlet pipe; the bottom of the digestion tank is connected to the mud inlet of the electrolytic cell through a reflux pipe;

[0054] Both the inlet pipe and the return pipe include sludge pumps;

[0055] The digester also includes an exhaust port, a sludge outlet, and an aerator;

[0056] The exhaust port is located at the top of the digester, and the mud discharge port is connected to the aerator installed at the bottom of the digester.

[0057] The electrolytic cell is provided with an electrolytic plate and a cathode electrode and an anode electrode installed on the electrolytic plate;

[0058] The electrolytic plates are suspended and fixed in the electrolytic cell.

[0059] The cathode electrode is a titanium electrode;

[0060] The anode electrode is a titanium-plated ruthenium-iridium electrode.

[0061] The electrolytic plates are suspended and fixed in the electrolytic cell.

[0062] Example 2

[0063] A sludge self-heating micro-aerobic stabilization method, using the internal circulation sludge electrolysis system in Example 1, comprises the following steps:

[0064] (1) The residual sludge discharged from the primary and secondary sedimentation tanks of a sewage treatment plant in Shanghai was concentrated to a solid content of 5%, and then placed in a self-heating micro-aerobic digester for stabilization. The digestion temperature was 55°C, the sludge stirring speed was 250 rpm, and the aeration intensity was 300 ml air / L·min.

[0065] (2) The sludge that has been digested for a period of time is discharged into the sludge electrolysis system with cathode and anode electrodes by using a sludge pump, and the sludge is electrolyzed by using a voltage-stabilized power supply. The cathode and anode electrodes of the electrolysis are titanium electrode and titanium-plated ruthenium-iridium electrode respectively. The electrolysis voltage is 8V, and the electrolysis plate is suspended and fixed in the electrolysis cell, with an area of ​​2 / 3 of the entire electrolysis cell. The distance between the electrolysis electrodes is 1.5cm, and the electrolysis time is 45min. A mesh zero-valent iron structure is provided near the sludge discharge port of the electrolysis cell, and the mesh zero-valent iron area is 1 / 3 of the electrolysis cell; the ratio of the effective volume of the electrolysis system to the effective volume of the digestion tank is 1:7.5.

[0066] (3) The sludge in the electrolytic cell is discharged into the self-heating micro-aerobic digestion tank through the sludge pump for stabilization; the sludge in the self-heating micro-aerobic digestion system is then pumped into the electrolytic cell by the sludge pump for electrolysis; after multiple cycles, the sludge is stabilized.

[0067] Comparative Example 2

[0068] A sludge self-heating micro-aerobic stabilization method uses the internal circulation sludge electrolysis system in comparative example 1, and other process steps and parameters are the same as those in example 2.

[0069] Technical effect:

[0070] Compared with a separate self-heating micro-aerobic digestion system (i.e., using only a digestion tank), the time it takes for the sludge to reach stabilization in the internal circulation electrolysis cell (equipped with a meshed zero-valent iron) and the self-heating micro-aerobic process coupling system of Example 1 is reduced from 16 days to 6 days. Compared with the electrolysis system without a meshed zero-valent iron structure (i.e., Comparative Example 1) and the self-heating aerobic digestion coupling process, the time it takes for the sludge to reach stabilization is reduced from 12 days to 6 days.

[0071] Example 3

[0072] A sludge self-heating micro-aerobic stabilization method, using the internal circulation sludge electrolysis system in Example 1, comprises the following steps:

[0073] (1) The residual sludge discharged from the primary and secondary sedimentation tanks of a sewage treatment plant in Shanghai was concentrated to a solid content of 3%. It was then placed in a self-heating micro-aerobic digester for stabilization. The digestion temperature was 55°C, the sludge stirring speed was 150 rpm, and the aeration intensity was 100 ml air / L·min sludge.

[0074] (2) The sludge that has been digested for a period of time is discharged into the sludge electrolysis system with cathode and anode electrodes by using a sludge pump, and the sludge is electrolyzed by using a voltage-stabilized power supply. The cathode and anode electrodes of the electrolysis are titanium electrode and titanium-plated ruthenium-iridium electrode respectively. The electrolysis voltage is 6V, and the electrolysis plate is suspended and fixed in the electrolysis cell, with an area of ​​1 / 2 of the entire electrolysis cell. The distance between the electrolysis electrodes is 0.5cm, and the electrolysis time is 30min. A mesh zero-valent iron structure is provided near the sludge discharge port of the electrolysis cell, and the mesh zero-valent iron area is 1 / 3 of the electrolysis cell; the ratio of the effective volume of the electrolysis system to the effective volume of the digestion tank is 1:5.

[0075] (3) The sludge in the electrolytic cell is discharged into the self-heating micro-aerobic digestion tank through the sludge pump for stabilization; the sludge in the self-heating micro-aerobic digestion system is then pumped into the electrolytic cell by the sludge pump for electrolysis; after multiple cycles, the sludge is stabilized.

[0076] Comparative Example 3

[0077] A sludge self-heating micro-aerobic stabilization method uses the internal circulation sludge electrolysis system in comparative example 1, and other process steps and parameters are the same as those in example 3.

[0078] Compared with a separate self-heating micro-aerobic digestion system (i.e., using only a digestion tank), the time it takes for the sludge to reach stabilization in the internal circulation electrolytic cell (equipped with a meshed zero-valent iron) and the self-heating micro-aerobic process coupling system is reduced from 16 days to 8 days. Compared with the electrolytic system without a meshed zero-valent iron structure (i.e., Comparative Example 3) and the self-heating aerobic digestion coupling process, the time it takes for the sludge to reach stabilization is reduced from 12 days to 8 days.

[0079] Example 4

[0080] A sludge self-heating micro-aerobic stabilization method, using the internal circulation sludge electrolysis system in Example 1, comprises the following steps:

[0081] (1) The residual sludge discharged from the primary and secondary sedimentation tanks of a sewage treatment plant in Shanghai was concentrated to a solid content of 4%. It was then placed in a self-heating micro-aerobic digester for stabilization. The digestion temperature was 55°C, the sludge stirring speed was 200 rpm, and the aeration intensity was 200 ml air / L◆min sludge.

[0082] (2) The sludge that has been digested for a period of time is discharged into the sludge electrolysis system with cathode and anode electrodes by using a sludge pump, and the sludge is electrolyzed by using a voltage-stabilized power supply, wherein the cathode and anode electrodes of the electrolysis are titanium electrodes and titanium-plated ruthenium-iridium electrodes, respectively, the electrolysis voltage is 7V, the electrolysis plate is suspended and fixed in the electrolysis cell, the area is 7 / 12 of the entire electrolysis cell, the distance between the electrolysis electrodes is 1.0cm, and the electrolysis time is 60min. In addition, a meshed zero-valent iron structure is provided near the sludge discharge port of the electrolysis cell, and the meshed zero-valent iron area is 1 / 3 of the electrolysis cell; the ratio of the effective volume of the electrolysis system to the effective volume of the digestion tank is 1:10.

[0083] (3) The sludge in the electrolytic cell is discharged into the self-heating micro-aerobic digestion tank through the sludge pump for stabilization; the sludge in the self-heating micro-aerobic digestion system is then pumped into the electrolytic cell by the sludge pump for electrolysis; after multiple cycles, the sludge is stabilized.

[0084] Comparative Example 4

[0085] A sludge self-heating micro-aerobic stabilization method uses the internal circulation sludge electrolysis system in comparative example 1, and other process steps and parameters are the same as those in example 4.

[0086] Compared with a separate self-heating micro-aerobic digestion system (i.e., using only a digestion tank), the time it takes for the sludge to reach stabilization in the internal circulation electrolytic cell (equipped with a meshed zero-valent iron) and the self-heating micro-aerobic process coupling system is reduced from 16 days to 7 days. Compared with the electrolytic system without a meshed zero-valent iron structure (i.e., Comparative Example 4) and the self-heating aerobic digestion coupling process, the time it takes for the sludge to reach stabilization is reduced from 12 days to 7 days.

[0087] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. An internal circulation sludge electrolysis system, characterized in that: It includes an electrolytic cell and a digestion tank connected in series; Wherein, the mud discharge port of the electrolytic cell includes a mesh of zero-valent iron, and the area of ​​the mesh of zero-valent iron is 1 / 3 of the area of ​​the electrolytic cell.

2. The internal circulation sludge electrolysis system according to claim 1, characterized in that: The electrolytic cell is also provided with an electrolytic plate, and the electrolytic plate comprises a cathode electrode and an anode electrode; Wherein, the electrolytic plate is suspended and fixed in the electrolytic cell; The distance between the cathode electrode and the anode electrode is 0.5-1.5 cm.

3. The internal circulation sludge electrolysis system according to claim 1, characterized in that: The cathode electrode is a titanium electrode; the anode electrode is a titanium-plated ruthenium-iridium electrode.

4. The internal circulation sludge electrolysis system according to claim 1, characterized in that: The electrolytic plate is suspended and fixed in the electrolytic cell, and the area of ​​the electrolytic plate is 1 / 2-2 / 3 of the electrolytic cell.

5. Application of an internal circulation sludge electrolysis system as described in any one of claims 1 to 4 in sludge self-heating micro-aerobic stabilization.

6. A sludge self-heating micro-aerobic stabilization method, characterized in that: The internal circulation sludge electrolysis system according to any one of claims 1 to 4 specifically comprises the following steps: The sludge is placed in a self-heating micro-aerobic digester for stabilization, and then placed in an electrolytic cell including the internal circulation sludge electrolysis system, and the sludge is electrolyzed by a stabilized power supply, and the stabilization and electrolysis are internally circulated until the sludge is stabilized.

7. A sludge self-heating micro-aerobic stabilization method according to claim 6, characterized in that: The sludge is the sludge discharged from the primary sedimentation tank and the secondary sedimentation tank of the sludge treatment, and the solid content is 3-5%.

8. The method for sludge self-heating micro-aerobic stabilization according to claim 6, characterized in that: The voltage of the electrolysis is 6-8V, and the electrolysis time is 30-60min.

9. The method for sludge self-heating micro-aerobic stabilization according to claim 6, characterized in that: During the stabilization process, the stabilization temperature is 55° C., the sludge stirring speed is 150-250 rpm, and the aeration intensity is 100-300 ml air / L sludge·min.

10. The method for sludge self-heating micro-aerobic stabilization according to claim 6, characterized in that: The internal circulation time is 6-8 days.

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