A comprehensive sewage treatment process

Abstract

The present invention relates to the field of environmental purification technology, and in particular to a comprehensive sewage treatment process, which includes: domestic sewage treatment process, mixed acidification process, thermal hydrolysis process, fermentation process, precipitation process, composite anaerobic ammonium oxidation process, mixed discharge process, deep purification process, drying process, storage process. This application combines the technical idea of ​​"waste treatment with waste" to establish a correlation between domestic sewage and sludge treatment processes and acid mine wastewater treatment processes. At the same time, two types of nitrate-type anaerobic ammonium oxidation reactions mediated by organic matter and ferrous iron and sulfate-type anaerobic ammonium oxidation reactions are established to achieve linkage and coordinated governance, optimize acid mine wastewater treatment and domestic sewage and sludge treatment process flow, and remove heavy metals and phosphorus in the pre-process of the composite anaerobic ammonium oxidation process and adjust the wastewater pH to weak alkalinity to improve the acid mine wastewater treatment effect.

Description

Technical Field

[0001] The invention relates to the technical field of environmental purification, and in particular to a comprehensive sewage treatment process. Background Art

[0002] The development of mineral resources has provided strong support for economic and social development, but mining activities have also caused ecological and environmental problems to a certain extent. Mining and tailings accumulation will produce a large amount of acidic mine wastewater. These acidic mine wastewaters are extremely acidic and rich in ferrous ions, sulfate ions and many heavy metal ions. They are one of the most serious pollution problems facing the water and soil environment around mining areas.

[0003] At present, water neutralization is widely used in the treatment of acid mine drainage in my country. However, the discharge volume of acid mine drainage is large, the composition is complex, and its generation is continuous. Therefore, there are still bottleneck problems such as insufficient treatment depth, easy secondary pollution to the environment, and high long-term operation costs. At the same time, the treatment of urban domestic sewage and sludge also has the disadvantages of insufficient treatment depth and high cost. In the existing technology, it is difficult to establish a connection between the two and develop economical and efficient comprehensive treatment technologies for acid mine drainage, urban domestic sewage, and sludge, making it difficult to achieve coordinated and coordinated treatment. Summary of the invention

[0004] In view of this, an object of the present invention is to provide a comprehensive sewage treatment process.

[0005] In a first aspect, an embodiment of the present invention provides a comprehensive sewage treatment process, comprising:

[0006] Domestic sewage treatment process: Domestic sewage passes through the anaerobic tank, anoxic tank, aerobic tank, secondary sedimentation tank and high-efficiency sedimentation tank in sequence; the tail water of the aerobic tank is also transported to the anaerobic ammonium oxidation reactor for denitrification treatment;

[0007] Mixed acidification process: The excess sludge and acid mine wastewater from the secondary sedimentation tank are transported to the mixed acidification tank and the pH range is controlled to 1-2 for acidification treatment;

[0008] Thermal hydrolysis process: When the phosphorus release rate in the mixed acidification tank reaches 90%-92%, the sludge is dehydrated to a moisture content of 80%-85% and then transported to the thermal hydrolyzer for thermal hydrolysis treatment;

[0009] Fermentation process: The sludge in the thermal hydrolyzer is diluted and cooled to a moisture content range of 90%-95% and a temperature range of 50℃-55℃, and then transported to the fermentation tank, where the pH range is controlled to be 10-11 and the reaction temperature range is 20℃-30℃ for anaerobic fermentation treatment;

[0010] Sedimentation process: send the tail liquid of the mixed acidification tank and the tail liquid of the thermal hydrolyzer to the sedimentation tank for sedimentation treatment to obtain sediment and tail water;

[0011] Composite anaerobic ammonium oxidation process: The tail water from the aerobic pool, the fermentation liquid from the fermentation tank and the tail water from the sedimentation tank are respectively transported to the anaerobic ammonium oxidation reactor for organic-mediated nitrate-type anaerobic ammonium oxidation reaction, ferrous-mediated nitrate-type anaerobic ammonium oxidation reaction and sulfate-type anaerobic ammonium oxidation reaction. After separation in the cyclone, the precipitate is transported to the dryer for drying and storage;

[0012] The fermentation liquid is also returned to the anaerobic tank in the domestic sewage treatment process to provide the domestic sewage treatment process with organic matter required for purifying the domestic sewage.

[0013] In combination with the first aspect, it also includes:

[0014] Alkali solution and / or sodium sulfide are added to the sedimentation tank in batches. When the amount of precipitate does not increase, alkali solution is added to further increase the pH value, and the final pH value range is 6-10 to obtain sedimentation tail water.

[0015] In combination with the first aspect, it also includes:

[0016] Mixed discharge process: When the tail water produced by the sedimentation tank reaches a pH range of 8.5-10, the tail water produced by the sedimentation tank is mixed with the purified effluent from the terminal output of the domestic sewage treatment process and then discharged.

[0017] In combination with the first aspect, it also includes:

[0018] Deep purification process: When the tail water produced by the sedimentation tank reaches a pH range of 6-8, the tail water produced by the sedimentation tank is transported to the high-efficiency sedimentation tank of the domestic sewage treatment process as a flocculant to achieve deep purification.

[0019] In combination with the first aspect, it also includes:

[0020] Drying process, the sediment produced in the sedimentation tank and the sediment produced in the anaerobic ammonium oxidation reactor are transported to the dryer for drying.

[0021] In combination with the first aspect, it also includes:

[0022] Storage process: transport the dried sediment to the storage room for sealed and dry storage.

[0023] In combination with the first aspect, it includes a PLC, a sodium sulfide tank and an alkali liquid tank. The sodium sulfide tank is controlled by the PLC to add sodium sulfide to the sedimentation tank in batches, and the alkali liquid tank is controlled to add alkali liquid to the sedimentation tank in batches until the pH range in the sedimentation tank is 6-10 and the amount of precipitate does not increase.

[0024] In combination with the first aspect, the sludge retention time of the fermentation tank is in the range of 3-9 days; the volume of the sludge transported to the fermentation tank is the same as the volume of the previous sludge fermentation product discharged from the fermentation tank.

[0025] Combined with the first aspect, the pH range of the composite anaerobic ammonium oxidation process is 7.27-7.32, the reaction temperature range is 30℃-37℃, -300mV <ORP<-150mV。

[0026] Combined with the first aspect, the sludge after thermal hydrolysis is also dehydrated to a moisture content of 40%-60% by a plate and frame dehydration system and then sent to surrounding farmland.

[0027] The embodiments of the present invention bring the following beneficial effects: the comprehensive sewage treatment process provided by the present application, combined with the technical idea of ​​"treating waste with waste", establishes a link between the domestic sewage and sludge treatment process and the acid mine wastewater treatment process, and at the same time, constructs a "composite" anaerobic ammonia oxidation process, and establishes a link between the organic-mediated nitrate-type anaerobic ammonia oxidation reaction, the ferrous-mediated nitrate-type anaerobic ammonia oxidation reaction and the sulfate-type anaerobic ammonia oxidation reaction, so as to achieve coordinated and synergistic governance, optimize the process flow of acid mine wastewater treatment and domestic sewage and sludge treatment, and, in the pre-process of the composite anaerobic ammonia oxidation process, remove heavy metals and phosphorus and adjust the pH of the wastewater to weak alkalinity, thereby overcoming the problem that traditional microbial treatment technology has poor treatment effect on acid mine wastewater.

[0028] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description, claims and drawings.

[0029] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 A schematic diagram of a comprehensive sewage treatment process provided by an embodiment of the present invention;

[0032] Figure 2 A structural diagram of the integrated sewage treatment process provided by an embodiment of the present invention;

[0033] Figure 3 A schematic diagram of a comprehensive sewage treatment process including a mixed discharge process provided by an embodiment of the present invention;

[0034] Figure 4 A schematic diagram of a comprehensive sewage treatment process including a deep purification process provided by an embodiment of the present invention;

[0035] Figure 5 A schematic diagram of a comprehensive sewage treatment process including a drying process and a storage process provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are 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 those skilled in the art without creative work are within the scope of protection of the present invention.

[0037] In order to facilitate the understanding of this embodiment, the technical terms designed in this application are briefly introduced below.

[0038] Acid mine drainage is a type of low pH, high ferrous (Fe2) sulfide minerals in coal mines or various non-ferrous metal mines that are exposed to air and groundwater or surface water through a series of chemical and biological oxidation processes. 2+ ) and sulfate (SO4 2- ) is a type of difficult-to-treat wastewater that contains a variety of heavy metal ions, which has the characteristics of wide pollution area, long pollution duration and serious harm.

[0039] After introducing the technical terms involved in this application, the application scenarios and design concepts of the embodiments of this application are briefly introduced.

[0040] At present, the treatment methods of acid mine drainage can be divided into two methods: physical and chemical treatment and microbial treatment. The physical and chemical methods mainly include ion exchange, membrane separation, adsorption, neutralization and precipitation, etc., which have problems such as lengthy process, high economic cost, poor treatment efficiency, and secondary pollution. The passive treatment method based on microorganisms is limited by factors such as slow growth of microorganisms, poor tolerance to metal ions, and single target pollutants, resulting in poor treatment effects. At the same time, in the process of domestic sewage treatment, additional organic matter, flocculants, etc. are required to optimize the treatment effect, and a large amount of residual sludge still needs to be treated, and the required cost accounts for a very high proportion of the overall operating cost of the water plant. The existing technology fails to establish a connection between the two, and the cost of treating acid mine drainage and domestic sewage and sludge separately is high, and the treatment effect is poor.

[0041] Based on this, an embodiment of the present application provides a comprehensive sewage treatment process, in which the residual sludge produced by the domestic sewage treatment process is acidified by acid mine wastewater, and is returned to the domestic sewage treatment process after thermal hydrolysis and fermentation treatment to provide organic matter, and the waste liquid generated in the above treatment process is returned to the domestic sewage treatment process after sedimentation treatment to enhance the flocculation sedimentation effect. At the same time, the nitrate tail water produced by the above fermentation liquid, sedimentation tail water and domestic sewage treatment process can be reused to replenish groundwater after deep treatment by a composite anaerobic ammonia oxidation process, thereby realizing the resource reuse of waste and optimizing the process flow of acid mine wastewater, domestic sewage and sludge treatment.

[0042] Example 1

[0043] The present application provides a comprehensive sewage treatment process, combining Figure 1 As shown, it includes: domestic sewage treatment process, mixed acidification process, thermal hydrolysis process, fermentation process, sedimentation process and composite anaerobic ammonia oxidation process.

[0044] Domestic sewage treatment process: Domestic sewage passes through anaerobic tank, anoxic tank, aerobic tank, secondary sedimentation tank and high-efficiency sedimentation tank (combined Figure 2 The tail water of the aerobic pool is also transported to the anaerobic ammonium oxidation reactor for denitrification.

[0045] Domestic sewage is collected through sewage pipes and preliminarily screened and pretreated, such as removing large suspended solids, grease and other impurities. The pretreated domestic sewage is pumped into the anaerobic tank, which mainly uses organic matter for anaerobic phosphorus release and denitrification. The effluent from the anaerobic tank enters the anoxic tank to continue denitrification. The effluent from the anoxic tank enters the aerobic tank to oxidize the ammonia nitrogen in the domestic sewage into nitrate nitrogen and aerobic phosphorus absorption. Finally, it enters the secondary sedimentation tank or high-efficiency sedimentation tank for mud-water separation, so that the mixed liquid is clarified and the residual sludge is concentrated. In the existing technology, a large amount of residual sludge separated from the secondary sedimentation tank needs to be processed again, and the cost of residual sludge treatment is high, which has reached 50% - 60% of the overall operating cost of the water plant.

[0046] Mixed acidification process: The residual sludge in the secondary sedimentation tank and the acid mine wastewater are transported to the mixed acidification tank, and the pH range is controlled to 1-2 for acidification treatment.

[0047] In this application, the excess sludge and acid mine wastewater are mixed, and the excess sludge is acidified by the acid mine wastewater to utilize the abandoned acid mine wastewater. After many experiments, it was found that the phosphorus in the excess sludge began to be released when the pH range was 3-4, and when the pH = 2, the phosphorus release rate can reach 90%. Therefore, controlling the pH range at 1-2 can quickly release the phosphorus in the excess sludge.

[0048] Thermal hydrolysis process: When the phosphorus release rate in the mixed acidification tank reaches 90%-92%, the sludge is dehydrated to a moisture content of 80%-85% and then transported to the thermal hydrolyzer for thermal hydrolysis treatment.

[0049] Among them, the reaction temperature of thermal hydrolysis is 150℃-170℃, the pressure is 0.5-0.8MPa, and the reaction time is 30min. By heating and pressurizing, the sludge treated by the mixed acidification process can further release organic phosphorus, improve the volume utilization rate of the sludge anaerobic fermentation tank and the degradation rate of organic matter in anaerobic fermentation. At the same time, through high temperature and high pressure pretreatment, pathogens can be completely killed and the sanitary properties of the sludge can be improved.

[0050] Fermentation process: The sludge in the thermal hydrolyzer is diluted and cooled to a moisture content range of 90%-95% and a temperature range of 50℃-55℃, and then transported to the fermentation tank. The pH range is controlled to be 10-11 and the reaction temperature is within the range of 20℃-30℃ for anaerobic fermentation treatment.

[0051] The fermentation residence time SRT of thermal hydrolysis sludge in the fermentation tank is controlled at 3-9 days. According to SRT, the sludge fermentation product is discharged in each cycle and the same volume of thermal hydrolysis sludge is introduced for the next cycle of sludge fermentation. The content of heavy metals, iron, phosphorus and other substances in the sludge treated by thermal hydrolysis process is low, so the fermentation liquid is mainly composed of ammonia nitrogen and organic matter. The sludge fermentation liquid or the supernatant after centrifugation is transported to the anaerobic tank in the domestic sewage treatment process to provide the organic matter required for purifying domestic sewage; it can also be transported to the anaerobic ammonium oxidation reactor in the composite anaerobic ammonium oxidation process to achieve the simultaneous removal of ammonia nitrogen, nitrate nitrogen and organic matter.

[0052] Sedimentation process: send the tail liquid of the mixed acidification tank and the tail liquid of the thermal hydrolyzer to the sedimentation tank for sedimentation treatment to obtain sediment and tail water.

[0053] In the precipitation process, sodium sulfide and lye are quantitatively and steadily added to the sedimentation tank to batch-precipitate and remove heavy metals, phosphorus, and ferrous ions from the tail liquid of the mixed acidification tank and the tail liquid of the hydrolysator, and to adjust the pH of the wastewater to weakly alkaline to improve its biodegradability.

[0054] Composite anammox process: The tail water of the aerobic tank, the fermentation broth of the fermentation tank, and the tail water of the sedimentation tank are respectively transported to the anammox reactor for nitrate-type anammox reaction mediated by organic matter, nitrate-type anammox reaction mediated by ferrous ions, and sulfate-type anammox reaction. After separation by a cyclone, the precipitate is transported to a dryer for drying treatment and storage.

[0055] In this embodiment, the pH range of the composite anammox process is 7.27 - 7.32, the reaction temperature range is 30°C - 37°C, and -300 mV < ORP < -150 mV, where ORP is the oxidation-reduction potential.

[0056] Combined with the first aspect, it also includes: adding lye and / or sodium sulfide to the sedimentation tank in batches. When the precipitation amount of the precipitate does not increase, adding lye to further increase the pH value, and the final pH value range is 6 - 10 to obtain the precipitation tail water.

[0057] Specifically, first add sodium sulfide to the sedimentation tank until the precipitation amount of the precipitate does not increase, and discharge the precipitate; add lye to the sedimentation tank until the pH value is 3, then add sodium sulfide again until the precipitation amount of the precipitate does not increase, and discharge the precipitate; add lye to the sedimentation tank until the pH value is 5 - 5.5, then add sodium sulfide again until the precipitation amount of the precipitate does not increase, and discharge the precipitate. At this point, heavy metals are basically precipitated and separated in the form of sulfides;

[0058] Add lye to the sedimentation tank until the pH value is 6 - 8 and the precipitation amount of the precipitate does not increase, and discharge the precipitate. At this point, FeP is basically precipitated, and the recovery rate can reach 95%.

[0059] Add lye to the sedimentation tank until the pH value is 8.5 - 10 and the precipitation of the precipitate does not increase, and discharge the precipitate. At this point, ferrous hydroxide is basically precipitated.

[0060] Obviously, combined with the first aspect and the working process of the sedimentation tank, it also includes: a mixed discharge process (as Figure 3 shown). When the tail water generated by the sedimentation tank reaches a pH range of 8.5 - 10, the tail water generated by the sedimentation tank is mixed with the purified effluent output from the terminal of the domestic sewage treatment process and then discharged.

[0061] Obviously, combined with the first aspect and the working process of the sedimentation tank, it also includes: a deep purification process (as Figure 4When the tail water from the sedimentation tank reaches a pH range of 6-8, the tail water from the sedimentation tank is transported to the high-efficiency sedimentation tank of the domestic sewage treatment process as a flocculant to achieve deep purification.

[0062] In combination with the first aspect, it also includes: a drying process (such as Figure 5 The sediment produced in the sedimentation tank and the sediment produced in the anaerobic ammonium oxidation reactor are transported to the dryer for drying.

[0063] In combination with the first aspect, the method further includes: a storage process, in which the precipitate after drying is transported to a storage room for sealed and dry storage.

[0064] In combination with the first aspect, it also includes a PLC, a sodium sulfide tank and an alkali liquid tank. The PLC controls the sodium sulfide tank to add sodium sulfide to the sedimentation tank in batches, and controls the alkali liquid tank to add alkali liquid to the sedimentation tank in batches until the pH range in the sedimentation tank is 6-10 and the amount of precipitate does not increase.

[0065] In combination with the first aspect, the sludge retention time of the fermentation tank is in the range of 3-9 days; the volume of the sludge transported to the fermentation tank is the same as the volume of the previous sludge fermentation product discharged from the fermentation tank.

[0066] Combined with the first aspect, the sludge after thermal hydrolysis is also dehydrated to a moisture content of 40%-60% by a plate and frame dehydration system and then sent to surrounding farmland.

[0067] In this embodiment, the mixed acidification tank, the thermal hydrolyzer and the fermentation tank are solidly connected, the secondary sedimentation tank and the mixed acidification tank, the thermal hydrolyzer and the farmland are solidly connected, the residual sludge in the secondary sedimentation tank is transported to the mixed acidification tank for acidification treatment, the acidified sludge is transported to the thermal hydrolyzer for thermal hydrolysis, the thermally hydrolyzed sludge is transported to the fermentation tank for fermentation, and the sludge produced by the thermal hydrolyzer that meets the discharge standards can be discharged to the farmland when needed by agriculture. In addition, the sedimentation tank, the anaerobic ammonium oxidation reactor and the storage room are also solidly connected to the dryer respectively, and the dryer dries the sediment generated by the sedimentation tank and the anaerobic ammonium oxidation reactor and stores it in the storage room.

[0068] In this embodiment, the mixed acidification tank is also connected to the liquid of the acidic mine wastewater source, the mixed acidification tank, the thermal hydrolyzer, the alkali liquid tank and the sodium sulfide tank are respectively connected to the liquid of the sedimentation tank; the sedimentation tank, the fermentation tank and the aerobic tank are respectively connected to the liquid of the anaerobic ammonia oxidation reactor; the sedimentation tank is also connected to the liquid of the high-efficiency sedimentation tank.

[0069] In actual application, water quality meters are installed in the mixed acidification tank, sedimentation tank and anaerobic ammonium oxidation reactor to detect water quality parameters. The water quality parameters corresponding to the mixed acidification tank include total phosphorus concentration and pH value; the water quality parameters corresponding to the sedimentation tank include pH value, ammonia nitrogen and nitrate concentration; the water quality parameters corresponding to the anaerobic ammonium oxidation reactor include pH value, ORP value, temperature value and ammonia nitrogen, nitrite nitrogen, nitrate nitrogen and sulfate concentration.

[0070] A temperature controller is also installed in the thermal hydrolyzer and the fermentation tank to adjust the temperature in the thermal hydrolyzer and the fermentation tank to reach a suitable reaction temperature.

[0071] A pressure controller is also installed in the thermal hydrolyzer to adjust the pressure in the thermal hydrolyzer to reach a suitable reaction pressure.

[0072] An acid-base regulating device is also provided in the fermentation tank to adjust the pH value in the fermentation tank to be within a suitable pH value range.

[0073] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system and device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0074] In addition, in the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0075] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0076] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0077] Finally, it should be noted that the above embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above embodiments, those skilled in the art should understand that any person skilled in the art can still modify the technical solutions recorded in the above embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A comprehensive sewage treatment process, characterized in that: include: Domestic sewage treatment process: Domestic sewage passes through anaerobic tank, anoxic tank, aerobic tank, secondary sedimentation tank and high-efficiency sedimentation tank in sequence; The tail water of the aerobic pool is also transported to the anaerobic ammonium oxidation reactor for denitrification treatment; Mixed acidification process: the excess sludge and acid mine wastewater in the secondary sedimentation tank are transported to the mixed acidification tank, and the pH range is controlled to be 1-2 for acidification treatment; Thermal hydrolysis process: When the phosphorus release rate in the mixed acidification tank reaches 90%-92%, the sludge is dehydrated to a moisture content of 80%-85% and then transported to a thermal hydrolyzer for thermal hydrolysis treatment; Fermentation process: The sludge in the thermal hydrolyzer is diluted and cooled to a moisture content range of 90%-95% and a temperature range of 50°C-55°C, and then transported to a fermentation tank, and the pH range is controlled to be 10-11, and the reaction temperature range is 20°C-30°C for anaerobic fermentation treatment; Sedimentation process: sending the tail liquid of the mixed acidification tank and the tail liquid of the thermal hydrolyzer to a sedimentation tank for sedimentation treatment to obtain sediment and tail water; Composite anaerobic ammonium oxidation process: the tail water of the aerobic pool, the fermentation liquid of the fermentation tank and the tail water of the sedimentation tank are respectively transported to the anaerobic ammonium oxidation reactor for organic-mediated nitrate-type anaerobic ammonium oxidation reaction, ferrous-mediated nitrate-type anaerobic ammonium oxidation reaction and sulfate-type anaerobic ammonium oxidation reaction. After separation by the cyclone, the precipitate is transported to the dryer for drying and storage; The fermentation liquid is also returned to the anaerobic tank in the domestic sewage treatment process to provide the domestic sewage treatment process with organic matter required for purifying the domestic sewage; The comprehensive sewage treatment process also includes: adding alkali solution and sodium sulfide to the sedimentation tank in batches, and when the amount of precipitate precipitation does not increase, adding alkali solution to further increase the pH value, and the final pH value range is 6-10, to obtain sedimentation tail water; wherein, when the tail water produced by the sedimentation tank reaches a pH range of 8.5-10, the tail water produced by the sedimentation tank is mixed with the purified effluent output from the terminal of the domestic sewage treatment process and then discharged; when the tail water produced by the sedimentation tank reaches a pH range of 6-8, the tail water produced by the sedimentation tank is transported to the high-efficiency sedimentation tank of the domestic sewage treatment process as a flocculant to achieve deep purification.

2. The comprehensive sewage treatment process according to claim 1, characterized in that: Also includes: A drying process is to transport the sediment produced in the sedimentation tank and the sediment produced in the anaerobic ammonium oxidation reactor to a dryer for drying.

3. The comprehensive sewage treatment process according to claim 2, characterized in that: Also includes: Storage process: transport the dried sediment to the storage room for sealed and dry storage.

4. The comprehensive sewage treatment process according to claim 3, characterized in that: The method comprises a PLC, a sodium sulfide tank and an alkali liquid tank. The PLC controls the sodium sulfide tank to add sodium sulfide to the sedimentation tank in batches, and controls the alkali liquid tank to add alkali liquid to the sedimentation tank in batches until the pH range in the sedimentation tank is 6-10 and the amount of precipitate does not increase.

5. The comprehensive sewage treatment process according to claim 1, characterized in that: The sludge retention time of the fermentation tank is in the range of 3-9 days; the volume of the sludge transported to the fermentation tank is the same as the volume of the previous sludge fermentation product discharged from the fermentation tank.

6. The comprehensive sewage treatment process according to claim 1, characterized in that: The pH range of the composite anaerobic ammonium oxidation process is 7.27-7.32, the reaction temperature range is 30°C-37°C, -300mV <ORP<-150mV。 7. The comprehensive sewage treatment process according to claim 1, characterized in that: The sludge after thermal hydrolysis is further dehydrated to a moisture content of 40%-60% by a plate and frame dehydration system and then sent to surrounding farmland.

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